Here is Earl Geddes explaining subwoofers https://mehlau.net/audio/multisub_geddes/ Smoothing the bass frequency response in a room with multiple subs is a simple matter of overlapping nodes. He thinks that three subs is optimal the 4th adding little to the solution. He also wants the subs as far apart as possible. He would cross over somewhere below 80 Hz where he thinks bass becomes non directional. So his approach is radically different than mine. I cross over higher but still below the Schroeder frequency and create a line source. Funny thing is that he greatly favors directional speakers over omni directional speakers because they reduce room interactions in a way superior to room treatments. He does not say that in this paper but relates this strongly in other papers. My array does exactly this. Again, I have a sophisticated room correction system which is to some extent cheating. If I bypass it my speakers sound like crap because of the rising response of the transformers I am using. I can not separate the subs from the satellites in this regard. It is either all on or all off. This paper was written for lay people so he does not use terms like minimal phase system. He may well use terms such as this in more scientific papers aimed at people who understand what he is talking about. I got as far as the Fourier wave equations and gave up. So Tim, According to Earl Geddes I am wrong. You want to keep your subs as far apart as possible and throw the fourth one away. It is just taking up space. Or, you could try making a line array using all 4 subs and see what happens. Couldn’t hurt to try:) Mike |
Ok Tim, first of all this is not my method. It a rule of acoustics and speaker design. I started applying it to subwoofers because I was having difficulty matching subwoofers to my Line source ESLs. So I created a horizontal line source subwoofer array which has the added benefits of being very efficient and greatly reducing reflected sound in the room because of the way a Line Source radiates.
Now I have no experience doing Swarm systems around point source satellites. But I find it an interesting concept as I too have great performance using four subwoofers. Your numbers are about right. So, if you are crossing at 40 Hz you would want 14 or less feet from one sub to the next. Theoretically the drivers are now acting as one acoustically and are phase coherent. But, then you have to add the room into the equation which I think is Duke's message and I would like to understand what he is trying to describe better. With subs at various distances from walls and each other you have a very random pattern of reflections at different times (phase) and with dimensions in and around the wavelengths of the frequencies you are producing certain frequencies are going to resonate longer. Simplifying the situation, what Duke is saying is that placing subs randomly throughout the room creates a situation that smooths out the frequency response throughout the room. I am trying to understand how that happens.
I would not say that the line array is better bass in all situations. It is better in my situation because I cross over much higher and I have line source satellites. If I put my subs around the room it would really screw up the image. In your case crossing over at 40 Hz you can not tell where the bass is coming from. The question I have Tim is if you arrange your subs so that any gap is not longer than 14 feet can you detect any difference in the bass. 40 Hz is way down there. What you might try is playing a 30 Hz test tone. Many test records have test tones. You can even download them digitally. Play the tone and some music with deep bass before and after you rearrange things. It may not make any difference at all. |
Tim, I just read your full post. I will comment on it when I have a chance.
Mike |
Thanks Tim, Subs oriented in a line array are going to project more power because the volume drops off slower as you move away from the speaker than a point source. I can up with this approach because it is the best way to integrate subs with line source loudspeakers. I also cross over to my subs at 125 Hz which may be why Duke and I have somewhat opposing views.
Duke I need you to define what you mean by a minimum phase system.
Yes, I understand if the decay is slower at a certain frequency that frequency will be emphasized. Your ears register everything immediately just like any good microphone. It is your brain that takes time to register just about anything. I think you missed my point about impact. It is the visceral component that adds excitement to the music and why live performances can be so exciting. You not only hear sound but at lower frequencies you feel it. When you confuse phase like that the impact goes missing. When said individual reconfigured his system he described it as having more impact without my prompting him. The result I would have expected.
I have to admit I also cheat because I am using very elaborate room control. Anyway there is more but my wife is pressing me to go out for a bike ride. Time to go out and assault the motoring public. Back later:)
Mike |
Hello Mike,
I usually crossover my four Swarm subs at 40 Hz for music and HT but sometimes as high as 50 Hz. According to your method of 1/2 the length of the crossover frequency, this would mean my subs should be no more than 14 feet apart at 40 Hz and no more than 11 feet at 50 Hz.
My room is 23'x16'x8' with my main speakers (with bass extension rated at 35 Hz +/- 3db) along the 16' wall and run full-range. Two of my subs are along this 16' front wall with each about 2' away from the nearest corner and about 6' apart from each other. The other two subs are located, one each, along the left and right 23' walls and each about 3' away from the corners along the rear 16' wall. This results in my rear subs being about 16'apart from each other and about 20' apart from the nearest sub along the front 16' wall. So, since some of my subs are more than 14' apart and exceed your rule of thumb, you're suggesting I should have bass phase issues in my room.
The Swarm amp/control unit does have a continuous phase control adjustment. I set this by inverting the phase on both of my main speakers and setting the phase control to the position at which the bass sounded the weakest at my listening seat. I then reattached the speaker wires to in-phase and the bass sounded equally very good throughout my entire room and at the 6 seating positions in my room. Do you think this is why I don't detect any obvious bass phase sound quality issues in my room?
Although I've never heard one, I do understand from what I've read and from your comments that subs configured in a line array are capable of even better bass performance than subs configured in a distributed bass array. However, my music listening and HT room also doubles as my living room and devoting the entire 16' wall of my living room to a line of subs is not practical. I'm not stating I disagree with the high quality bass capability of a line array bass system. I'm just stating that I'm willing to sacrifice optimum bass response performance in my room for the extremely good bass response performance of a distributed bass array that blends much more inconspicuously in my living room.
Tim
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Mijostyn wrote: "The statement that the ear (which should be ears) have very poor time domain response is 180 degrees wrong." You are correct! I did not proofread carefully. Here is what I should have said: "Because the ear has very poor time domain response AT LOW FREQUNCIES..." The ear is indeed quite sensitive in the time domain at higher frequencies. Mijostyn again: "Speakers + Room do not equal a minimum phase system." Yes they do at low frequencies, which is what I said. This according to Floyd Toole and Earl Geddes. The in-room frequency response tracks the time domain response. The phase behaviors of individual reflections don’t matter when viewed in isolation, but their sum is relevant as it shows up simultaneously in both the in-room frequency response and in-room time domain response. It is the sum that we hear. Mijostyn: "With the drivers acting as one the bass drum impact will strike the listener in phase with the greatest force resulting in the largest smile. The decay afterwards is of no great significance." This is what our intuition tells us, and our intuition is wrong. We literally cannot detect the presence of bass energy from less than one wavelength, which is 22.5 feet at 50 Hz (ballpark resonant frequency of a bass drum). A study was done in which less than one full wavelength of low frequency energy was played over headphones, so there were no room reflections, and it was UNDETECTABLE. And it took MANY cycles before the ear began to register the pitch. By the time your ears BEGINS to hear the impact of that bass drum played over your system, so much time has passed that any minor arrival time differences are inconsequential. The decay is of enormous consequence because it shows up as a frequency response peak. And this is because speakers + room = a minimum-phase system at low frequencies. If the decay is slow at some frequency then the bass sounds fat because there is a response peak at that frequency. Mijostyn: "I know of one person who set up his four subs as I suggested and he thought it made an improvement." The improvement may not have been for the reasons you suggest. I strongly suspect that what happened is, the frequency response improved. The in-room frequency response is what dominates our perception at low frequencies (though the in-room frequency response is merely a manifestation of the in-room time domain response, and vice versa). Duke
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Hi Duke,
You will have to give me some time to think about it. Humans are extremely sensitive to phase. It is why we have two ears 8 inches apart. In nature it is how we locate danger and why a listener can put himself perfectly in phase with two speakers just by moving his head side to side a little. So the statement that the ear (which should be ears) have very poor time domain response is 180 degrees wrong. Now most of us can accurately locate a test tone at 60 Hz. Anyone can prove this to themselves by unplugging all the subs but one.
Blindfold the listener and in the middle of the room spin them around a few times, play the tone and ask them to point to it. Below 60 Hz and it gets progressively more difficult. Now this is a test tone, not music which is more complicated. If you put two subs in front of you and reverse the wires on one putting it 180 degrees out of phase the bass output decreases dramatically everywhere in the room. With more subs out of phase at various angles things get more complicated. Next in regards to very low bass, sensory input is not just coming from your ears it is also coming from visceral sensation. If I set off an M80 50 yards away from you you will hear it and feel it at the same time. All frequencies travel at the same speed. Regardless of what your ears are hearing if your woofers are out of phase with each other you may hear bass but you will not feel it. Speakers + Room do not equal a minimum phase system. They equal a confused phase system as you have the primary signal from all the drivers and their reflections bouncing all over the place. With the drivers acting as one the bass drum impact will strike the listener in phase with the greatest force resulting in the largest smile. The decay afterwards is of no great significance.
So I suggest to those interested in this thread who have SWARM systems to play around with positioning and see what happens. This is a group experiment. I only know what happens in my room with my system which is different acoustically than most of yours. I know of one person who set up his four subs as I suggested and he thought it made an improvement. But, others indifferent situations may not feel this way. Or maybe not:)
Mike |
Mijostyn wrote: "For the drivers to act as one they can be no farther apart than 1/2 the wavelength of the crossover point." You do an excellent job of explaining your suggestion, but imo the issue it addresses is not one that a distributed multisub system is concerned with. With a distributed multisub system, "the drivers acting as one" is definitely NOT the goal. We want each sub to interact with the room very differently from the others, and that is accomplished by spreading them far apart. So not only are there subs more than a half wavelength apart, they will also (almost always) have different path lengths to the listener(s). Because the ear has very poor time domain response, such that it cannot even detect the presence of bass energy from less than one wavelength, a bit of smearing in the initial arrival times of the different subs is inconsequential. What DOES matter a great deal from a perceptual standpoint is how the notes decay. Since speakers + room = a minimum-phase system at low frequencies, when we have fixed the frequency response we have simultaneously fixed the time-domain response. Imo this is something that a good distributed multisub system does well. (The ear hears low-frequency ringing quite well, but such ringing is always accompanied by a frequency response peak, and vice-versa. Anywhere in the bass region where there is a peak, whether it originates from a speaker anomaly or a room anomaly, the energy in that region takes longer to decay. It is actually the frequency response peak that we hear, not the ringing - the slow decay - itself. But when we have fixed the one, we have simultaneously fixed the other.) Duke |
Wow this topic has legs. I like to simplify things. First of all it is not a sweet spot. It is a sweet line 90 degrees from the center of the speaker axis.
On this line the speakers are in perfect phase with each other and will cast an image of the recording to the degree that the system is capable.
Now because of standing waves and interference patterns the frequency response below about 100 Hz on this line can vary up to 10 db. It depends on room dimensions and the way the subwoofers are used.
You can hear this easily in your system. Just play a test tone at say 60 Hz and walk back and forth across the room and you will be flabbergasted at how the volume changes within just a few feet. When I was using two woofers I dealt with this by moving my listening position along the "sweet line" until I felt the bass sounded right. Doing this even with room control is a benefit because it will cost you much less amplifier power to correct the response at your listening position. With a point source system and one favored listening position 2 subs can do the job fine and as Raul suggests I think two good woofers is better than 4 bad ones.
But, when it comes to other situations like having multiple listening positions along that line or having line source or linear array speakers you run into trouble. It is difficult to compensate for two positions and two point source subs will not project as well as line array speakers so the sound gets thinner as you move away from the system. This is where multiple subwoofers come into play. It seems that the SWARM group wants to place their subs anywhere in the room. This will smooth out the frequency response throughout the room but depending on the distance between to subs may cause phase issues. Here is a rule of thumb. For the drivers to act as one they can be no farther apart than 1/2 the wavelength of the crossover point. So say you are crossing over at 100 Hz. That is about 10 feet at sea level. If your subs are less than 5 feet apart they are acting as one and no matter where you are in the room they will always be in phase and as long as additional subs are closer than 5 feet to the last one in line they will always be in phase no matter where you are in the room. If you make the array longer than the lowest frequency you want to reproduce you have created a line source subwoofer. At lower cross over frequencies say 80 Hz the distance would increase to 7 feet between subs.
Now in my case I need a subwoofer linear array to match the output of my ESL linear arrays and the woofers are arranged across the front wall with the outside subs in the corners. I am doing this to make the array function to below 20 Hz but a point source system does not have to worry about this. So, what I am suggesting to the SWARM people is to place their woofers in configurations so that one is no farther than 7 feet from the next assuming you cross at 80 Hz, 5 feet if you cross at 100 Hz. This will make all of them in phase no matter where you are in the room and should increase the dynamic response of the bass. Try it and let us know what happens. This rule is used by designers that use multi driver arrays. If you study various designs you will always notice that tweeters are always closer together than midranges which are always closer together than woofers. We are just extending the same principle to subwoofers and the much longer wavelengths involve. Pheyew that was tiring.
Mike |
raulruegas:
"Fortunately I already made my choices on room/system choosing what for my MUSIC/sound priorities, still today, gave and give me the best trade-offs for a high quality overall level performance. Truly satisfied, not " perfect " but always perfectible."
Hello rauliruegas,
You're obviously very fortunate. You made an informed choice and picked the set of tradeoffs that makes you happy.
Congratulations, you only have one thing left to do; enjoy the heck out of your high quality system with your music of choice.
Enjoy,
Tim
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Dear @audiokinesis : Fortunatelly I already made my choices on room/system choosing what for my MUSIC/sound priorities, still today, gave and give me the best trade-offs for a high quality overall level performance. Truly satisfied, not " perfect " but always perfectible.
R. |
Audiorusty wrote: "With as good as a DBA system is, there still will be only one sweet spot in the room." Imaging will of course be best in the sweet spot. But it is possible for the imaging to hold up fairly well across a fairly wide listening area, and for the tonal balance to hold up well just about throughout the room. This all depends on the directional characteristics of the main speakers and how they are set up, and the details are somewhat counter-intuitive. * * * * Raulirugas wrote: "I’m just talking about the myth that we can’t detect the direction for frequencies 80hz down ( two channel with two subs. ) and this is not true." Detectable under specific conditions that are not representative of listening to music reproduced in a home listening room, yes. Worth trading off the advantages of a good distributed multisub system for, well I guess that depends on your priorities. Just about everything in audio involves tradeoffs. Make an informed choice and pick the set of tradeoffs that makes you happy. Fortunately in audio if a particular choice doesn’t make you happy, you can choose again. Duke |
Dear @audiokinesis : "" in which a distrubuted multisub system falls short..."
I’m just talking about the myth that we can’t detect the direction for frequencies 80hz down ( two channel with two subs. ) and this is not true. Our brain/body can, @tyray explained twice .
What is true is that some people can’t detect it but other can do it.
Even with frequencies/instruments that speakers puts at the center of the imaging/soundstage is difficult to detect if the sound comes from the left or rigth speaker.
Knowledge/experience to know what to look for is what tell each one of us the true not that myth per se.
Inclusive other gentleman posted that not playing music but test tones proved that our ears can detect 50hz.
No one knows the whole body/brain abilities on that myth subject when even the scientifics say the human been knows how the brain works only at around 18% of its overall capacity ! !
Audio is surrounded of to many myths many of them by our self ignorance levels or just for not know what to look for.
Some times is more problematic due that we own different kind of room/systems and obviously different ears/body/brain sensitivity to different frequencies and to different SPLs.
Noble 100 is spreading " everywhere " that low bass non detectable myth and that says he can't do it but that he can't do it does not means no one else can.
Audio is complex issue, especially on what we are perceiving and a home system behavior is different of what happens in a MUSIC hall or a small club.
R.
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Thanks Tim,
You did answer my question. With as good as a DBA system is, there still will be only one sweet spot in the room. This is what I figured but I wanted to make sure that I wasn't missing something.
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Hello audiorusty,
The use of a distributed bass array (DBA) system is a very good solution for distributing low bass evenly throughout the entire room. Unfortunately, there’s not currently an equally effective solution that will distribute the mids and highs throughout the entire room, at least not while maintaining good stereo imaging throughout the entire room.
Since using and understanding the exceptionally high quality bass performance of a DBA system, I now view my system as two systems, a bass system and an ’everything else’ system, with ’everything else’ meaning the mids, highs and stereo imaging.
I recommend installing the bass system and getting that performing optimally first since it has traditionally been the hardest system aspect to get sounding right in most home systems, due mainly to the extreme length of bass soundwaves and how this results in audible bass issues in domestic sized rooms, and because high quality bass is the solid foundation that most music and high quality home audio systems are built upon.
Once the bass is performing optimally in the room, the next priority is to position the main speakers, in relation to the dedicated listening seat, to optimize the midrange, treble and imaging performance. This has traditionally been a much easier system aspect to get sounding right in most home systems, due mainly to the much shorter length of these midrange and treble soundwaves and their resultant highly directional nature. All that’s normally required is precise positioning, including toe-in angles, along with room treatments to control the first reflection points and perhaps some room treatment along the front and back walls.
All soundwaves of all frequencies reflect or bounce off of room boundaries (floor, walls and ceiling) until they run out of energy and collide with themselves and other soundwaves along their reflected paths within any given room. However, when bass soundwaves collide it’s perceived as a bass peak, dip or null, while when midrange and treble soundwaves collide it’s usually perceived as an airy quality except when they have a negative effect on imaging at the designated listening seat.
The final steps are directed at integrating or blending the bass system’s sound with the ’everything else’ system’s sound as seamlessly as possible. This is accomplished through precisely adjusting the volume, crossover frequency and phase control settings collectively for all four subs on the amp/control unit for an AK Swarm or Debra DBA system or individually for each of the four subs on a custom DBA system.
Tim
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Audiorusty asked: "Since a DBA system can evenly distribute low bass evenly to all parts of a room are you also able to distribute the mids and highs evenly to all parts of the room or are you still relegated to a single listening sweet spot in the room due to the directionality of the mids and highs?" Are you asking about speakers in general, or about my speaker designs in particular? Duke |
Duke, Thanks for the reply.
I need to re-ask my first question since I wasn't clear. Since a DBA system can evenly distribute low bass evenly to all parts of a room are you also able to distribute the mids and highs evenly to all parts of the room or are you still relegated to a single listening sweet spot in the room due to the directionality of the mids and highs?
Thanks |
tyray: "And apparently I guess this type of interaction with someone on this thread is okay - if you have the swarm and have read the studies of Earl Geddes. Well I’m here to tell you it’s not. I did look up this term though: Psychoacoustic Phenomenon Pseudo Stereo Deep Bass Apparently it does not exist. I really wanted to ask is this psychoacoustic phenomenon only in playback and the recording studio environment? But I guess I can’t cause I don’t have the Swarm and haven’t fully read the studies of Earl Geddes." Hello tyray, Psychoacoustics is a legitimate scientific field of study that is very relevant in understanding how and why the use of multiple subs significantly improves the perception of deep bass response below 80 Hz in virtually any room. I clearly stated on my 8/15 post on this thread, however, that the term "Psychoacoustic Phenomenon Pseudo Deep Bass" was a term I named and used to describe my perception of an affect I noticed utilizing multiple subs in my systems. This was a facetious term that I made up trying to be a bit humorous. Sorry for the confusion, but I honestly didn't expect anyone to take this as a legitimate term. To answer your question, psychoacoustics is an important factor in recording, such as the proper number and positioning of mics, and it's also an important factor in playback, such as the proper number and positioning of subs for good bass performance and the proper positioning of the pair of stereo main speakers in relation to the designated listening position for good midrange, treble and imaging. I believe I understand you didn't like me questioning whether a Richard Vandersteen quote on their website, that I believe contains numerous errors and falsehoods, accurately represented his thoughts or was just promotional advertising prose. We may never know the answer to this but I was just sharing my thoughts and opinion. I also believe that you understood I wouldn't like your dismissing my statements on psychoacoustics as "psycho bass babble bullshit". I disagree but believe you're free to state and share your thoughts and opinion. I agree with you that we are all here to share thoughts and ideas with each other. But I also think we need to agree to do so in an honest and free manner while also agreeing not to be too easily offended.
Thanks, Tim |
H
Your primary concerns seem to be a subwoofer that will match your speakers presentation, its just a modest office system but your open to the idea of swarm system.
You should be looking for a DSP sub that uses a calibrated mic (not a smart phone) to make auto and manual adjustments to multi band EQ, variable phase, crossover slop and freq, adjustable Q, etc.. A sub that has the connectivity to daisy chain its equalized signal to non DSP powered subs for your own swarm if desired.
Check out JL Audio F series and their CR-1 crossover $$$ read the CR-1 manual. SVS has a new DSP line, Syzygy, Martin Logan, Velodyne Plus did it all but they're no longer available.
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@bdp24 wrote: "would you expand on your recommendation of introducing a 90 degree phase difference between left and right subs?" This is an idea I learned from a paper written by David Griesinger many years ago. David recommended two subs, one directly to the left and one directly to the right of the listening area, up against the side walls. With the phase 90 degrees apart (in "phase quadrature"), this would approximate at the left and right ears the somewhat out-of-phase low frequency waves one would experience in a large hall. The result is a greater sense of being immersed in a large acoustic space, which means the ear is not perceiving as much "small room signature" super-imposed on top of the recording. As you hear less of your room’s signature, you correspondingly hear more of the ambient space on the recording. Wouldn’t say it’s a huge difference, but as long as it doesn't bust the budget I think it’s arguably a worthwhile improvement. Duke |
Excellent, thanks Duke. If you care to, would you expand on your recommendation of introducing a 90 degree phase difference between left and right subs? That's a new one on me!---Eric. |
@bdp24 asked:
"Is for the subs to be wired/operated in mono mandatory in a swarm sub system?"
Not at all.
"In other words, does the swarm not "work" (reduce/minimize bass peaks and nulls in the room) if the subs are run stereo?"
Works just fine in stereo. The only reason my commercial Swarm system is normally mono is, I can hit a more attractive price point by driving all four units with a single amplifier. As an option the Swarm can be supplied with a second amplifier.
"Or is it just a matter of that with a steep enough filter (say 4th-order, 24dB/octave), there is nothing to be gained by running the subs stereo?"
If the bass is summed to mono on the recording anyway, which I believe to almost always be the case, then imo there is nothing to be gained by running the subs in stereo. But imo there is something to be gained (greater sense of envelopment) by using introducing a roughly 90 degree phase difference between the subs on the left-hand side of the room and the subs on the right-hand side of the room, and doing so requires two amplifiers, in which case you might as well do stereo. That way if you know you have a recording with true stereo separation all the way down, you can quickly dial back in normal phase using the phase controls on the amps.
"Is running two subs at the front of the room (in the neighborhood of the loudspeakers) in stereo, and the third and fourth in mono, a viable option? THAT would make using a shallower low-pass x/o filter on the subs (for whatever reason) possible."
You can do that, but imo it doesn’t really make a shallower low-pass filter more feasible. Imo the main reason for using a steep low-pass filter is to prevent the subs from passing upper bass and lower midrange energy loud enough to betray their locations.
If your subs have fairly shallow (12 dB/octave) built-in lowpass filters, you might try this: Use a lower low-pass filter frequency for the subs that are closer to the listening area, since these are the ones most likely to be heard as separate sound sources in the upper bass/lower midrange region.
Duke |
Duke, here's a simple question for ya: is for the subs to be wired/operated in mono mandatory in a swarm sub system? In other words, does the swarm not "work" (reduce/minimize bass peaks and nulls in the room) if the subs are run stereo? Or is it just a matter of that with a steep enough filter (say 4th-order, 24dB/octave), there is nothing to be gained by running the subs stereo? Is running two subs at the front of the room (in the neighborhood of the loudspeakers) in stereo, and the third and fourth in mono, a viable option? THAT would make using a shallower low-pass x/o filter on the subs (for whatever reason) possible. |
audiokinesis:
"The point is not whether there is an unrealistic test condition in which a distrubuted multisub system falls short. The point is, how does it perform when used under normal conditions?
Duke"
Hello Duke,
Yes, I believe that's the goal of most of us if not all of us:
"How does it perform when used under normal conditions?"
Rauliruegas,
As I've stated, the AK Swarm/Debra 4-sub DBA system performs exceptionally well in my 23'x16'x8' room and seamlessly integrates with my fast and detailed Magnepan main speakers (which for years have been infamous for being difficult to integrate well with conventional subs) for both 2-ch music and HT.
My main concern is music and I don't think I can overstate how well it performs on all of my CDs and it performs even better on my high-resolution 24bit/96KHz direct to digital FLAC music files.
This combination transports me to a fairly wide and deep 3D soundstage in my living room of the musicians and the recording venue, usually jazz or blues in a small club or Sound Liason's larger European direct to digital recording studio, that's ultra-realist sound quality, I believe, can be largely attributed to the bass quality, impact and dynamics that's normally only experienced with music heard live and in person. Thank you, Duke.
I consider this state of the art bass performance but I understand that similar results can be achieved at a single dedicated listening position utilizing two high quality subs that are properly positioned and configured, like the approach you chose. Here's a link to a Todd Welti, of Harman International, that confirms this:
https://www.harman.com/sites/default/files/multsubs_0.pdf
Later,
Tim
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@rauliruegas wrote:
"Position at a normal one seat position and play music ( digital or analog ) with very low bass recorded information and then through several tests/evaluations lest us know if you can or can’t detect from where comes the sound you are listening... Main speakers off(no sound.)."
Well of course under those conditions (playing music through the subs with the main speakers OFF) you can hear where the subs are! This is because the lowpass filter on the subs are not brick walls.
But with the main speakers on, the output of the mains will be so much louder than the output of the subs that it will effectively mask the location of the subs, even if the subs are letting a little bit of upper bass/lower energy leak through.
The point is not whether there is an unrealistic test condition in which a distrubuted multisub system falls short. The point is, how does it perform when used under normal conditions?
Duke
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Dear @audiokinesis : " I agree ".
I don’t know from where you take that " I agree ". I think that you can make some tests with two of your subwoofers crossed at 30hz and with different SPL on each test. Position at a normal one seat position and play music ( digital or analog ) with very low bass recorded information and then through several tests/evaluations lest us know if you can or can’t detect from where comes the sound you are listening.
Tests using first one subs at a time and then the same with the other and you can follow with both at the same time. Main speakers off(no sound.).
I already dit it and I think that only true personal tests we can have an answer. Every one with subs can do it. Please don’t ask my conclusions, we have to make our work/job.
R.
Btw, this is what I posted here about mono/stereo:
"""
Atmasphere that has first hand experiences on the overall recording proccess posted in other thread what oput true ligth on that mono/stereo subs issue:
""" Its not so much the limitations of the format as it costs a lot of money to pay an engineer to work a way around "out of phase bass". If you spend the time with the recording, you can usually find a way to master it without having to process it. But that takes time and at $500/hour most often bass processing is used. This is a simple circuit that senses when bass is out of phase and makes it mono below about 80Hz for a few milliseconds until the event has passed. This makes mastering LPs less expensive!
But CDs do exist where out of phase bass exists. This can happen because a microphone is out of phase with the rest of the recording when a bass guitar or bass drum is recorded. For this reason, the recording engineer has a phase inversion switch on every channel of his mixer but he may not have thought to use them.
If the recording is done in its entirety with only two mics, out of phase bass will not exist. """
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@noble100 wrote: "Are you making a distinction between the perceived true stereo bass that I'm currently experiencing and your mention of "a second amp can be added to give you true stereo bass"?" IF the recording has true stereo bass, adding the second amp would allow you to reproduce left and right channel bass separately, instead of summed. That's a big IF.
"On several other threads no one, including myself, was able to name a single recording on any format containing true stereo bass. Are you aware of any?"
I don't own any, but my understanding is that Ralph Karsten has said the vinyl recordings he makes have stereo separation all the way down. And I believe him! Duke |
Audiorusty asked: "A question for the DBA folks; How do you get the mids and highs to spread out evenly through the room to match up with the bass at all locations in the room? Also does a DBA affect impact?" The bass doesn’t sound like it’s coming from everywhere. The bass sounds like it’s coming from wherever the bass instruments are in the soundstage. We get our localization cues from the higher frequencies that the main speakers produce. In my experience impact is improved with a good distributed multi-sub system. This is because smooth bass is "fast" bass. We hear peaks as "slow bass" or "boomy bass", and we hear dips as "weak bass" or "lack of impact". (Dips are usually less objectionable than peaks.) Our natural instinct is to think that having multiple arrival times from the various subs degrades the bass impact, but that’s not what happens. The ear DOES NOT EVEN DETECT the presence of bass energy from less than one full wavelength, and bass wavelengths are many feet long. So by the time we even begin to detect the presence of bass energy, the bass has already reflected off of room surfaces multiple times. We do not hear a "first arrival sound" in the low bass region because by the time we hear the bass, we are already hearing the room’s effects. But what happens to the trailing edge of the notes (how quickly and smoothly they decay) is very important to the sense of impact, and this is where a good distributed multisub system excels.
To put it another way, we cannot hear bass apart from the room’s (detrimental) effects, so we might as well take the room into account. By spreading multiple bass sources around the room, one might say that we get the room to work "with us" somewhat instead of "against us".
Last year at the Rocky Mountain Audio Fest we got a nice compliment from an extremely competent cable manufacturer with decades of audio show experience. He asked us to play his reference recording of "Fanfare for the Common Man". He said ours was the most natural reproduction of that recording he had heard at a show, and in particular he said "THAT is what a tympani sounds like - THAT is what I hear at the symphony". Duke |
Duke,
Thanks for taking the time to review my thoughts on multiple subs. I'm glad you validated my understanding, with the 80 Hz revision, since my thoughts are all reflections of my personal experiences using your 4-sub DBA system.
You stated:
"I wouldn’t say "all", but I would say "almost all". (If we’re talking about a Swarm/DEBRA system, a second amp can be added to give you true stereo bass)."
Is there such a thing as true stereo bass? I'm still a little fuzzy on this issue. I run all my subs in mono and perceive true stereo bass on all recordings regardless of format. This is due to the process I mentioned in my summary, of our brain's ability to associate the fundamental deep bass frequencies reproduced by the 4 subs in mono, that are below 80Hz and not able to be localized, with the deep bass’s higher harmonic frequencies, that extend well beyond 80 Hz, which are reproduced by the main speakers that are able to be localized. This is what I'm currently experiencing on my system that I would describe as true stereo bass.
Are you making a distinction between the perceived true stereo bass that I'm currently experiencing and your mention of "a second amp can be added to give you true stereo bass"?
Also, when I asked you whether the bass is summed to mono on frequencies below 100 Hz on all vinyl and cd recordings?
You said you wouldn’t say all, but almost all. On several other threads no one, including myself, was able to name a single recording on any format containing true stereo bass. Are you aware of any?
Thanks again Duke,
Tim
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Hleeid, Before you do anything I would suggest reading http://www.soundoctor.com/whitepapers/subs.htm I think you will find them very informative. A question for the DBA folks; How do you get the mids and highs to spread out evenly through the room to match up with the bass at all locations in the room? Also does a DBA affect impact? Thanks |
@noble100 wrote: "Duke... I was hoping to get your honest opinion on my thoughts on how I understand multiple sub systems function in general as well as my understanding of how bass is recorded on CDs and vinyl."
In general I agree with what you wrote, so let me just toss out a few comments.
" We all are unable to localize deep bass frequency soundwaves..."
My understanding is that’s generally true in a room. The figure I use is 80 Hz, rather than 100 Hz. I think Floyd Toole uses 80 Hz. This doesn’t necessarily mean that one cannot detect the location of a sub which is crossed over significantly lower, say at 40 Hz, because crossovers are not brick walls, so upper bass/lower midrange energy can give away a sub’s location if it comes through loud enough. Therefore in my opinion a steep lowpass filter on the sub helps to hide its location.
"the bass is summed to mono on frequencies below 100 Hz on all vinyl and cd recordings."
I wouldn’t say "all", but I would say "almost all". (If we’re talking about a Swarm/DEBRA system, a second amp can be added to give you true stereo bass).
"Our brains are able to associate the fundamental deep bass frequencies reproduced by the subs, that are not able to be localized, with the deep bass’s higher harmonic frequencies, that extend well beyond 100 Hz, which are reproduced by the main speakers that are able to be localized. This psychoacoustic association allows us to localize the deep bass in the soundstage, for example the kick drum is located in the rear center and the upright bass is located in the front to the left, which would not be otherwise possible without this psychoacoustic association our brain’s are capable of."
I agree.
Duke |
Btw, first step/tread on that music quality learning ladders is to attend as many live music events we can, second can be to listen as many other home systems as we can and other truly revelatory thread/step is to listen live music seated at near source position that’s where normaly " seated " the recording microphones ( 1m to 3m. ) and we have to do it not one time but several times.
All those steps are a learning lessons to understand the true meaning of quality in the MUSIC/sound reproduction on each one of us room/systems and at the same time we will use those lessons to through the time be up-dating/grading our system., fine tunning the system.
Again, I’m talking of systems dedicated to listen only MUSIC not along HT option.
R. |
Hello rauliruegas,
Did you read the responding post I directed to you yesterday 8/15/19? If not, here is a direct quote addressed to you from my earlier post:
"I agree with you that using better quality subs will only improve the quality of bass reproduced. I think this is true whether one uses a single sub or multiple subs."
I appreciate, respect and understand the importance of good quality in almost everything, especially in things I decide to purchase or am considering purchasing. What I don't appreciate, respect or understand is why you believe you made it clear to me, with my own facts and statements, that my system is of poor quality. I must have missed that deftly executed revelation you so kindly presented to me, using my own words no less. Well played, mi amigo, well played.
Later,
Tim
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Maybe problem is that each one of us usually can think that what we own is the " best of the best ". That does not exist quality levels where belongs each room/system
There are low/poor quality, lower quality, medium or so so quality, top quality and the like. Quality is a ladder that where we need to learn how to go up step by step.
I already left clear with his own facts/statement why noble100 system is a poor quality level and he needs to learn about that ladder quality steps/treads because many of us just do not want that low qualityn levls.
Knowledge levels through first hand experiences helps a lot to learn about..
R. |
Dear @audiokinesis : What you posted was exactly this that I pasted from other thread: """
""" You can get good bass in one sweet spot with two equalized subs """
the words: not 3-4 but 2 were only to emphasis that you talks of two subs. In the same way the word " enough " that for the 99% of good low bass range at one seat position with high quality levels is enough. I don't care about HT needs. For two channels systems dedicated to listen only MUSIC the name of the game is QUALITY all over the room/system frequency range. To other gentleman I posted in this thread: """
Example: https://systems.audiogon.com/systems/615 do you think that the owner of this two channels room/system could " live " with 2-4 or what ever number of subs you name it of Rythmik subwoofers/DBs instead those self powered/active subwoofers towers that can go down to 3hz with almost no distortion levels at full power? """ that's top quality level in a dream dedicated MUSIC room/system. Obviously that only a few gentlemans ca own and enjoyb that quality levels but other audiophiles can do it some steps down with optimal quality levels that gentlemans like noble can't even imagine what really means quality. I already posted here that his attituted is a " robotic " one because he has a tatoos of number 4 and one model by SVS that even is not a true subwoofer. Regards and enjoy the MUSIC NOT DISTORTIONS, R.
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Hello millercarbon,
Very good post, well worded, sincere and I definitely know it's honest and accurate. I think Duke helping you with advise even though he knew you were building a DIY clone of his 4-sub Audio Kinesis Swarm system was unexpected, unselfish,says a lot about his priorities and was just very cool.
Enjoy,
Tim
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There is more than one way to implement a multi-sub system. For a long time the idea of using any sub in my system wasn't an option. Didn't see the need for them and systems I heard that had a sub(s) in them were not to my liking.
The idea of the distributed bass array made sense to me. It certainly had some science and research behind it. Whether one agrees with it or not is another matter. Since I work with someone who also makes speakers I ran the idea past him. He agreed in principle and actually read Geddes work and supported it. So I figured at that point what did I have to lose. With his help I was able to put together my own array and it has made a significant difference in my room and my system. I should also note that while I do use 4 speakers in my array, my friend just uses 2.
Since this topic has been popular around here of late I have learned even more. I have tweaked my array with the assistance of another member here, mijostyn, to leverage the specific type of speaker I use. Again, a marked improvement. It's good to have options and I would also agree with Raul that quality trumps quantity. It is unfortunate that around here we sometimes have to sift through some unpleasant minutiae to get value from what is posted, but that's what filters are for.
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@millercarbon
I completely understand you and appreciate everything you have to say. But I have to respond to someone who actually has the swarm system and understands it and has a working knowledge of it and basically calls my a lier - without himself doing his own research - I’m going to take up for myself whether you or no one else does. He does the op, this thread and even Duke a disservice. Let me remind you of the lie Tim posted about me: ’I seriously doubt someone as knowledgeable and experienced as Mr. Vandersteen would make the numerous obviously false statements contained in your supposed quote of him you cited above in your last post. Please verify this quote as valid by referencing your source for this quote. I’m almost certain you’ll be unable to do so, however, and you’ll likely just fail to ever provide any reference, never admitting to your deliberate false quote ...’ What am I supposed to do? I thought we are here to share ideas from one another? In a respectful courteous manner? Am I missing something here? Not make up vicious lies. This is a small snippet of what I’m calling psycho bass bable bullshit: ’Hello cleeds,
Very interesting that you responded before tyray and that the supposed direct quote from Mr. Vandersteen is actually from his website’s promotional information for the 2W subwoofers. I read the linked website info and it reads more like the work of a professional advertising copy writer promoting a client’s product that he doesn’t completely understand, which is actually the case, than a knowledgeable and experienced speaker designer sharing his expertise on how his subs are able to take advantage of his knowledge of speaker design and how bass soundwaves behave in a typical home room environment to provide high quality bass reproduction. The quote from the Vandersteen website referred to by tyray and yourself, listed below, contains too many errors for me to believe that Mr. Vandersteen would vouch for its accuracy. It seems much more likely the numerous errors are the result of an advertising copy writer plying his trade on a subject and product he has a general lack of knowledge about. I seriously doubt Mr. Vandersteen even scrutinized the content of this promotional quote since I doubt he would approve this much misinformation. I’ll explain the errors and my reasoning below after the advertising quote.’ And he goes on and on and on...
And you quoted Stevie Wonder?
-Not the science behind the swarm.
And apparently I guess this type of interaction with someone on this thread is okay - if you have the swarm and have read the studies of Earl Geddes. Well I’m here to tell you it’s not.
I did look up this term though: Psychoacoustic Phenomenon Psuedo Stereo Deep Bass Apparently it does not exist. Especially when Pseudo is spelled wrong. I really wanted to ask is this psychoacoustic phenomenon only in playback and the recording studio environment? But I guess I can’t cause I don’t have the Swarm and haven’t fully read the studies of Earl Geddes.
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Hello Duke,
I'm glad you chimed in and shared your knowledge.
If you don't mind and have the time, I was hoping to get your honest opinion on my thoughts on how I understand multiple sub systems function in general as well as my understanding of how bass is recorded on CDs and vinyl. Basically, I'm asking if you agree with my summary below?
We all are unable to localize deep bass frequency soundwaves, that is determine where the sound is coming from, that are below about 100 Hz but we're very good at localizing higher frequency soundwaves in the remainder of the audible spectrum, from about 100 to 20,000 Hz.
This is the reason there's no such thing as 'true stereo' deep bass and why the bass is summed to mono on frequencies below 100 Hz on all vinyl and cd recordings. If you doubt this, try to find a single vinyl or cd recording that is not summed to mono. This means it's pointless to configure subs in a stereo configuration with one located by the left main speaker and one by the right.
However, thanks to psychoacoustics and our remarkable brains, it is possible to create the perception of stereo bass in our systems. Here's how it works:
Whether you use 2, 3 or 4 subs, run them in mono and optimize the bass at your listening seat. The bass below 100 Hz won't be able to be localized but there are bass harmonics or overtones of the deep bass fundamental frequencies that extend into higher frequencies that are reproduced by the main stereo speakers and can be localized. Our brains are able to associate the fundamental deep bass frequencies reproduced by the subs, that are not able to be localized, with the deep bass's higher harmonic frequencies, that extend well beyond 100 Hz, which are reproduced by the main speakers that are able to be localized. This psychoacoustic association allows us to localize the deep bass in the soundstage, for example the kick drum is located in the rear center and the upright bass is located in the front to the left, which would not be otherwise possible without this psychoacoustic association our brain's are capable of.
Thanks,
Tim
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Up until some time nearly a year ago I had never heard of using more than one or two subs. All my personal experience was based on one sub, plus maybe once or twice hearing two somewhere. Based on all that it seemed getting really good smooth articulate bass, by which I mean bass every bit as good as the midrange and treble, was for whatever reason impossible.
I still think this is the case. My current understanding is the reason this is impossible is, briefly, what Duke stated above. Its a natural physical consequence of the physical character of house-sized rooms.
The DBA idea seemed at first unlikely to work. But a lot of the threads I came across were like this one, where if you could somehow wade through the BS and sniping there were mentioned real research articles and work by guys like Geddes, which anyone interested can scroll up and see yes indeed once again he's mentioned. The question is will you dear reader take time out of your busy day opining and parroting and go and look it up and read it and actually try and understand what its all about.
Which I did. Which whatever it is, it sure ain't religion.
Duke at one point when I said I was going to do this he thanked me for having faith. My reply was I had read enough and understood enough to know for certain and without doubt its going to work. This really is no different than someone teaches you math. You can then determine how many oranges each of 6 people can get if you have 24 oranges. Its not faith and it sure ain't religion. Its physics.
And psycho-acoustics. Humans do not perceive sounds anything like the meters so many wanna-be audiophiles put so much faith in. Which yes that is exactly the correct use of the term. Or maybe like Stevie Wonder said its superstition- when you believe in things you don't understand.
We don't perceive volume equally flat, go look up Fletcher-Munson curve. We don't perceive location equally with frequency either. We are really good at localizing midrange and treble. We can hear even just a millisecond snippet. At low bass frequencies we can't even hear them AT ALL until and unless its a full wavelength. At 20 Hz that means 1/20th of a second.
The full range of sounds we are trying to create is so different in physics and perception it simply cannot be faithfully recreated with just the one approach. No two speakers can do it. No two speakers with any sub however good can do it. Two good speakers with four or more subs? No problem!
I've been using mine for a good six months now. One of the most amazing things I am still getting used to is the way really low powerful bass can present so many different ways. Sometimes its the low acoustic of the recording venue. In that case its so diffuse as to be completely unlocalizable. It is enveloping. It is what people mean when they talk about good bass expanding the sound stage to completely envelope you. Other times it is so precisely localized within the sound stage its every bit as palpably solidly there as the singer or drum or whatever.
Never, ever, does it sound like the bass is coming from any of the five subs in my room. Often times early on I would walk right up to one and not believe it was even working until I put my finger on the driver.
There's a lot going on here that is very new and very different. Its a lot to get your head around. People interested will be well served to avoid the silly comments from people who haven't tried it and therefore haven't a clue, and instead read those who have and those who did the very impressive pioneering research that made this most revolutionary discovery in audio in many years. |
Tyray wrote: "When your Swarm first came out I and bunch of others were impressed at such a brilliant thinking out of the box idea. I completely believed and understood the science behind it." Thank you very much. If there was any "brilliant" thinking on my part, it was in quickly recognizing the merit of the distributed multi-sub concept when Earl Geddes described it to me, and in immediately asking him if I could license his idea (he replied, "No, you can just use it," so I try to give him credit when the opportunity arises). I also appreciate the Richard Vandersteen quote you posted above: "... multiple subs automatically give a linier response in the room. This should be amazing as we have always been a supporter of multiple subs." Indeed, I recall Richard recommending stereo subs long before I heard about using four distributed subs from Earl. Was Richard the first to propose that two subs are significantly better than one? I think he was. I have always liked Richard’s speakers very much, and feel honored that a few of his customers have chosen my somewhat unorthodox little subwoofer system to go with them. Duke
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@hleeid'
'Should I take advantage of the temporarily empty office to lay down carpeting?'
My buddies that have man caves and and not only use their system for playing music but watching movies too - swear by adding carpet.
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Apologies to all! I didn't mean to stir up so much drama!
But I sincerely appreciate so many of you responding to my query. This is still an exciting journey for me. I have enjoyed and learned quite a lot each of your postings.
So I have decided to empty my office, place my main speakers and perhaps two woofers, experiment with placement, acoustical room treatments, etc.
Looks like my next homework assignment will be researching the various subwoofer configurations (forward firing, down firing, vented, ported, sealed, anything I missed?)
Should I take advantage of the temporarily empty office to lay down carpeting?
I will try to "furnish around" the speakers and then experiment again.
Many thanks!!
Hans |
@rauliruegas,
When I got first got my front firing vented PSA V1801 subs I hooked up ONE on the left side front corner wall of my listening room and it replaced a down firing (almost vintage) SVS PB12-Plus/2 12.3 subwoofer. I could tell right away the location of that sub. And the same with the previous sub the SVS PB12-Plus/2 12.3 subwoofer. Was it subtle yes, but you could tell.
Not only could I tell the location of the ONE front firing vented PSA V1801 and the ONE SVS PB12-Plus/2 12.3 subs - placed in the far left corner - I could tell, feel, sense, hear, locate or whatever that the sonic wave, force or sound of the down firing sub was coming from the bottom of the down firing sub! There is a difference! I would suspect that is why so many sub manufactures make so many different types of directional firing subs.
Then when I set up the replacement front firing vented PSA V1801 sub I immediately noticed, could tell, feel, sense, hear, locate or whatever that the sonic wave, force or sound was coming out of the front of the sub front firing speaker! The only thing I have to go on is my own empirical experiences.
And that SVS PB12-Plus/2 12.3 sub? I still have it - as I have come to love that thing and the bass it brings! I just have come to like the ’sound’ of a front firing sub better.
I also have to mention that the above subs are beasts! And have a force of sound that can crumble motor in a brick wall and the sheer force (decibels) of the sound is probably what I ’feel’. And maybe I’ve been fortunate enough to actually have experienced a ’quality’ (sub) woofer too.
@audiokinesis
Mr. Duke,
When your Swarm first came out I and bunch of others were impressed at such a brilliant thinking out of the box idea. I completely believed and understood the science behind it. It’s just that when someone attacks, demeans, and literally calls you (me) out with their own psyco bass bable bullshit that is based on untruths and then goes and runs behind your outstanding design - sometimes you just gotta hit a bully in the nose and stand up for yourself.
The attacks here - I suspect are not the first. In fact there may be hundreds of B.S. posts by this poser - directed at others on Gon standing behind and using your Swarm technique - and others, without a leg to stand on his own.
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@rauliruegas wrote:
" Even the AK SWARM manufacturer/owner posted in this forum:
""" You can get good bass in one sweet spot with two equalized subs """. Not 3 or 4 but TWO."
I probably said the first part, but just to be clear I DID NOT say the second part ("Not 3 or 4 but TWO"). Imo three or four subs intelligently positioned are superior to two, whether or not EQ is involved.
Quoting rauliruegas again:
"Again, even the AK designer/owner from where came your 4 bass array configuration posted in this same forum that two subs for two channel stereo MUSIC are ENOUGH."
I don’t remember saying that in so many words, and if I did, the word "ENOUGH" is highly subjective and I should have been careful how I used the word.
The basic problem is, the room imposes a significant peak-and-dip pattern on a subwoofer at low frequencies. The peaks are especially undesirable because they take longer to decay and can make the bass sound slow, boomy, one-note, etc.
We can move the subwoofers and change the peak-and-dip pattern, but we cannot eliminate it by positioning alone.
We can use bass traps to absorb bass energy and reduce the magnitude of the peaks and dips.
We can use EQ to reduce the energy going into the peaks and maybe even boost the energy going into the dips, which can work well at one location, but will usually make the bass worse at other locations because the peaks and dips will be at different frequencies.
We can use multiple subs spread intelligently around the room so that each produces a significantly different room-interaction peak-and-dip pattern, and the sum of these different patterns will be pretty smooth, and this smoothness will hold up well throughout the room. In general two subs intelligently distributed are twice as smooth as one, and four subs are twice as smooth as two.
I see no reason why these different approaches cannot be combined.
I really haven’t spent much time figuring out the best way to use two subs, because imo the improvement in going from two to four is worthwhile (assuming approximately the same total expenditure). If someone is limited to using two subs, then I suggest they go to one of my competitors. Not that I’m an expert on all of the subs out there, but ime Rhythmic makes some very nice ones.
Duke
guy who makes the Swarm |
Hello rauliruegas,
Regarding bass phase and recordings not done with only 2 mics or CDs with out of phase bass, my opinion is that we really have no control over that and can't do anything about it except avoid listening to poorly recorded music content.
Regarding whether we can localize bass under 80 Hz using our ears and brains or any other body parts, I know I can often feel sharp 55 Hz strikes on a kick drum with my body but it doesn't inform me where it came from within my system soundstage. I believe I perceive the kick drum, that I can feel and hear, as being located in the rear center of my system soundstage because of the higher frequency harmonics/overtones of the 55 Hz fundamental tone, that reach above 80 Hz that we are able to localize, and our brains are able to relate or associate them to the fundamental tone of the kick drum strike and determine its location within my system soundstage. In other words, we are only able to localize fundamental bass tones with frequencies below 80 Hz if the harmonics/overtones related to that fundamental deep bass tone that are above 80 Hz are also heard, usually through both of our main speakers.
I understand this is a complex thought to convey and I hope you understand what I wrote.
I don't consider this true stereo deep bass but rather what I've termed Psychoacoustic Phenomenon Psuedo Stereo Deep Bass.
I agree with you that using better quality subs will only improve the quality of bass reproduced. I think this is true whether one uses a single sub or multiple subs.
Tim
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Dear @noble100 : After reading your last post that I was unaware of I only can say that you are incredible?/terrible man, because before your post you posted to me:
" that I agree with you and then request you just cut it out. ""
even that the OP already posted he use his system only for MUSIC two chnnels experiences you insist in that the best " room bass response " ( 4 subs. ) when what the OP needs is only good bass response at one seat position, nothing else. Got it?
You posted in reference to other gentleman:
""" disregarding his entire post
He obviously lacks the knowledge and experience required to be giving good information or advice to anyone about attaining good in-room bass response performance .... """
I proved with your own statements/words that you neither has that knowledge levels you think you have but even that fact you diminished the opinion of that gentleman. Go figure ! ! !
Again, even the AK designer/owner from where came your 4 bass array configuration posted in this same forum that two subs for two channel stereo MUSIC are ENOUGH. But you follow/insist entilted in : " one solution good for all " and you ask for I cut about ! ? ! ? ! ? and till now you just do not understand why quality subs levels is so critical/vital to listen MUSIC ONLY ( not HT as you. ) in two channels room system at one seat position to blend to the mid/high one position frequency ranges.
QUALITY not quantity as you like. QUALITY QUALITY QUALITY , tha’s the name of the game. You are totally wrong not only because your 4 bass array but because you are accustomed to very very low quality levels in your room/system.
First learn and listen to room/system with top quality performance levels before following making posts with your true bs information.
Maybe you have some personal limitations that preclude your understanding about. Sorry for you.
R.
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Finger mistake: "" So we can be totally sure we can’t identify direction of very low bass frequencies. """
must says:
We can’t be totally sure we can’t identify source direction of very low bass frequency range .
Additional to what I posted we have to remember that our body/skind body is full ( by mm2. ) of nervous terminations that not only sense temperature or pain but SPLs level too and are really sensible about.
R. |
Dear @cleeds @noble100 @hleeid : Atmasphere that has first hand experiences on the overall recording proccess posted in other thread what oput true ligth on that mono/stereo subs issue:
"""
Its not so much the limitations of the format as it costs a lot of money to pay an engineer to work a way around "out of phase bass". If you spend the time with the recording, you can usually find a way to master it without having to process it. But that takes time and at $500/hour most often bass processing is used. This is a simple circuit that senses when bass is out of phase and makes it mono below about 80Hz for a few milliseconds until the event has passed. This makes mastering LPs less expensive!
But CDs do exist where out of phase bass exists. This can happen because a microphone is out of phase with the rest of the recording when a bass guitar or bass drum is recorded. For this reason, the recording engineer has a phase inversion switch on every channel of his mixer but he may not have thought to use them.
If the recording is done in its entirety with only two mics, out of phase bass will not exist. """
In the other side we can think that we can't be aware the direction where are generated fundamental frequencies as low of 40hz-20hz or even lower.
Well certainly not through our ears but a human been not only hear through the ears but from all body: ears, skin, bones, skin hairs, head hair and the like. The skin hairs are truly sensitive to very low bass frequency and we have a fenomenal transducer name it brain.
So we can be totally sure we can't identify direction of very low bass frequencies.
Now, I read through the AK site the quality myths about low bass range and I disagree with.
When we are talking of two channels system MUSIC dedicated listen quality of the subs drivers and the overall subs design is way important because MUSIC start with the fundamental frequency but what we really listen is where MUSIC belongs that are the harmonics of that fundamental frequency/note and those harmonics will be developed with the quality level depending of the quality level of the fundamental note reproduced by the susb.
Harmonics are what put the color and rythm in live MUSIC and home systems. As better quaklty be the subs as better will be the room/system experiences we have.
The first 3-4 harmonics are the ones due its SPLs the ones normally we can listen but the 7-8 or even up harmonics puts some kind of small/tiny " colorations " to what we are perceiving.
So we can't disgard the quality of the subs. Not all drivers and driver materials has the same qualiity level that's why manufacturers choose diffrenet build materials from different metalic ones to kevlar or puilp-paper. Obviously that the amp and crossover electronic quality design and quality parts are very important too.
In a two channels MUSIC only normally we are looking for quality because the main speakers have a high quality levels and if the harmonics developed by the subs are not at same quality level then we can't really enjoy the listening experiences.
@hleeid , first determine where you can get the best ubication for your speakers through listening tests. Where do you achieve the best listening experiences in the mid/high frequency range? and after that it will be more easy to find out ( by tyesting it. ) the two self powered subs you need.
Regards and enjoy the MUSIC NOT DISTORTIONS,
R.
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Hello Hans,
I just wanted to let you know that taking any of tyray's advice on his last post is done at your own peril. There's so much bad advice and false information in his post that it would take me hours to catalog them all and explain each of them to you. Unfortunately, I don't currently have the time to do this. So, I suggest you're better off just disregarding his entire post
He obviously lacks the knowledge and experience required to be giving good information or advice to anyone about attaining good in-room bass response performance. I believe he just doesn't know what he doesn't know.
From what I could learn online, your Ologe 5 are high quality speakers that are just lacking high quality low frequency output below about 48 Hz.
I have no doubt that your overall office system sound quality performance will be significantly improved by a single good quality sub, properly positioned and configured, since it will provide the missing frequency range from 20 to about 50 Hz. But my experience is that 2 subs will sound twice as good as 1 sub and 3-4 subs will sound twice as good as 2.
The reasons multiple subs perform so well is due to the total bass output duties being shared so that no single sub is operating near its limits, the combined bass power and impact being increased, there being increased power reserves for better bass dynamics and the presence of multiple points in the room producing bass results in the perception of smoother and faster bass response that better integrates or blends with the main speakers' midrange and treble output.
In your situation, I would describe your choice as between good, better or best. In other words, between 1 sub, 2 subs or 3-4 subs.
If you're currently unsure or don't want to take a risk, I'd suggest a good way to begin is with 2 SVS SB1000 subs, 2 SVS PB1000 subs or one of each because I'm certain this type of sub setup will deliver significantly better overall sound quality performance, costs $1,000 or less with no shipping costs, allows a 45-day free in-office trial period and, if not completely satisfied with their performance, offers a full refund with free return shipping.
I understand you've decided to take some time to get your room straightened out. When you're ready and whichever option you eventually choose, however, I'm still willing to help you with step by step procedures for optimum sub hookup, positioning and the setting of sub volume, crossover frequency and phase settings. Just send me a pm when you're all set.
Later,
Tim
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