Which is better for a DBA (Swarm); powered subs or unpowered?

hleeid

Did you prefer the LS 50's or the LRS's with your Swarm?

Thx

all yore 30z are belong to me

@audiokinesis 

"My recollection is that Toole was referring to a Harmon subwoofer integrator processor which optimized the gain, frequency response, lowpass filter, phase, delay, and equalization based on in-room measurements. I assume it does what they claim."  

Duke, thanks for the answer. I think Toole was referring to an integrator, but I don't know it was the integrator process. On chapter 13 "Making (bass) waves - below the transition frequency" he shows several examples where 4 subs are used in a rectangular room and optimized (through an optimizator) to minimize seat to seat SPL variation at 5 seating positions. The optimizator adjusts overall level (dB), delay (ms), and EQ at a given point (frequency, Q, level). It's not clear to me if said delay was introduced through DSP or just a "phase" adjustment.

I can measure with REW and optimize with MSO for example, but if actual delays are needed then I would need a digital processor to incorporate these.

Tympani are typically tuned to about C3 ≈130Hz with a 65Hz sub harmonic. Not really much in the sub range.

While tympani aren't really big on deep bass notes, the rest of this statement is incorrect. Tympani are tuned as needed, not just to C...

So, I am the new Swarm(er) noble100 mentioned.

3 ceiling facing subs (3 inches from ceiling) and one on the floor.
10’ x 14’ room with minimal acoustic treatments.

So far, outstanding improvements with Magnepan LRS and Ologe 5 speakers.

Switched over to KEF LS 50s non wireless last night and have been listening to them all day today.

Makes the somewhat diminutive LS 50s sound like true floor standing monitors. As with the other speakers, my listening room seems (sounds?) bigger.

Like they say, "Seeing is believing". So is hearing and listening!

Want to believe it?
Go listen to a system with a properly set up Swarm.
Then listen to that system without using the Swarm.

There's just no going back.

Toole is one of my favorites. He was awesome in Lawrence of Arabia. 

@m-db asked: "Wasn’t Dr. Floyd Toole adamant regarding cables lack of any measurable difference hence no sonic effect in the audio chain?"

I vaguely recall something like that. (My own experience with cables, which includes conducting a blind listening test, is otherwise.)

But imo it would be a mistake to dismiss Toole’s expertise in loudspeakers, acoustics, and psychoacoustics over a disagreement with him about cables.

@m-db: "Did Earl Geddes design for Behringer (processor) or simply use their processor?"

He simply used their processor. 

My understanding is that the concept came long before any of the specific pieces of the puzzle. 

Duke

Two questions:
Wasn't Dr. Floyd Toole adamant regarding cables lack of any measurable difference hence no sonic effect in the audio chain? Am I misstating this?

Did Earl Geddes design for Behringer (processor) or simply use their processor? 

@cleeds wrote: "The price for that smooth, even, neutral bass is that your bass will be monophonic."

This is a misconception probably arising from the fact that the "regular" configuration for my price-conscious Swarm system only uses a single channel of amplification, and from my statements that true stereo bass is quite rare (which is controversial and has been disputed). For a few hundred dollars more, some Swarm users have added a second amplifier, though imo the most significant advantage of the second amplifier is that it gives you the option of introducing a 90 degree phase difference between the subs on the left-hand-ish side of the room and the subs on the right-hand-ish-side of the room. This can be done whether the signals going to the left and right amps are mono or stereo.

As others have noted, even if you do have mono bass, you never hear it as "mono bass". The localization cues are essentially all north of the subwoofer region, though spatial (hall size / envelopment / immersion) cues can be present in true stereo bass. The left-right 90-degree-phase-difference thing is a technique for synthesizing this sense of immersion in a large acoustic space; credit to David Griesinger for the idea, which does not depend on the recording having stereo information down in the subwoofer region. Nor in my experience does it result in a same-for-all-recordings acoustic signature; if anything, imo it unmasks more of the differences in spatial "feel" from one recording to the next.

@lewinskih01 wrote: "Would the ability to time-adjust each of the 4 subs improve sound? Like Toole described in his Sound Reproduction?"

My recollection is that Toole was referring to a Harmon subwoofer integrator processor which optimized the gain, frequency response, lowpass filter, phase, delay, and equalization based on in-room measurements. I assume it does what they claim.

Earl Geddes used to offer essentially the same services to his customers. He had them make measurements of each of their subs and then used a proprietary algorithm to calculate the settings for a Behringer processor. My understanding is that he could get in-room smoothness from three thusly equalized subs comparable to what he could get from four conventional subs. Since I’m no Earl Geddes, I still use four subs. (I have never claimed and hopefully never implied that the Swarm is "the ultimate" way to do the distributed multisub thing.)

If I had the choice between having the ability to time-adjust each sub and not, I’d choose to have it just to maximize my options... but wouldn’t want to trade off anything else that matters to get it. The arrival time differences in a normal size listening room are small enough that they are below the ear’s detection threshold at low frequencies, but it still might be beneficial.

I don’t have any experience with time alignment of subs, but do have some indirect experience with time mis-alignment:

One of my most-experienced-in-very-high-end customers has three of his Swarm subs spread around the room (with one in a front corner) and the fourth is right smack behind his listening chair (on an isolation pad). This essentially maximizes the arrival time differences, yet he finds it to be the best-sounding configuration.

So based on the information I have at this time, I would prioritize good in-room smoothness over arrival-time-alignment, but it would be interesting to try having both.

Duke

In my listening experience with my DBA system after adding the fifth sub it was like my room disappeared and only the music was left with at ambiance of the place it was recorded . I would call DBA active room treatment . Must be heard to understand its effect 

cleeds-The price for that smooth, even, neutral bass is that your bass will be monophonic. 

noble100-Even though all 4 subs are run in mono, the bass will still be perceived as stereo.

Right. And thank you, Tim.

The issue of is the bass stereo or not is beside the point. The simple fact of the matter is DBA bass is exactly as focused and localized and 3D as anything and everything else. This from a guy who will put his system up against anyone's in the area of imaging. Any time. No problem.

Recording after recording I'm hearing bass that is never once anything less than seamlessly integrated with the sound field. Each awesome deep drum whack on Jennifer Warnes Bird on a Wire has its own unique location, reverberation and resonance. Its felt exactly as a drum that size would be, as coming from one spot then energizing the whole acoustic space.

Please note I say "acoustic space" not room. Because if I say room people will think I mean my room. Wrong. I'm talking the acoustic space where the recording was made. My system and in particular the DBA part of it effectively take my room out of the equation. My room for all intents and purposes is not there. You for all your ears are telling you are not in my room. You are in acoustic space. 

Duke explains the tech better than anyone. I can only relate what I'm hearing. What others have heard. You cannot be more wrong than to say DBA sounds like mono. It may very well be mono. But it does not in any way shape or form sound mono. So maybe that is hard to understand. Oh well. It is what it is.

I will say this though. This will be a whole lot easier for people to understand if the ones who haven't ever experienced it and therefore really have no idea what they're talking about would wait to comment until they can correct such a glaring weakness in their approach.

"it is quite obvious that these individuals have never experienced the extremely high quality bass response performance this concept provides in practice in typical home rooms. noble100 Tim"

This and all the individuals personal variables of room, system, experience, and personal taste seems to have created a circumstance with the home audio hobby that lacks a general acceptance similar to what's in the pro audio tool box.  

Despite the obvious differences between home and pro audio there are some important common parameters at play.

Tim, good sticky post. 

While we’re awaiting a presumed response to lewinski01’s questions about 4-sub DBAs from The owner of Audio Kinesis, Duke Lejeune, I just wanted to add a quick comment:

I mostly agree with cleeds comments on his previous post. Based on the comments on this thread thus far from posters questioning the efficacy of 4-sub DBA systems, it is quite obvious that these individuals have never experienced the extremely high quality bass response performance this concept provides in practice in typical home rooms.
There is no smearing, booming or localization. If you can perceive the bass as originating from one of the subs, the system has not been setup properly or the crossover frequency control is set too high-usually above 80 Hz. What you will perceive is powerful bass down to 20 Hz, realistic and natural bass dynamics. The bass will be detailed, accurate in tone and timber and integrate seamlessly with your main speakers regardless of their brand and type.
Even though all 4 subs are run in mono, the bass will still be perceived as stereo. I can explain in detail how this is possible on a future post if anyone would like to know. Individuals have the choice of either buying a complete 4-sub DBA system kit or creating their own custom 4-sub DBA system utilizing their choice of subs. Parametric equalization, room treatments, DSP and auto room correction hardware and software are definitely not required but can be used optionally if preferred.
I’ve been using my AK Debra 4-sub DBA in my system for more than 5 years now for both stereo music and 5.1 surround for HT. I honestly can’t think of how this excellent bass system solution could be improved except with even higher quality, and much more expensive, subs being used.      From my perspective, the only other criticism of a 4-sub DBA I consider valid is that you do need to have, or make, the space for 4 subs in one’s room. I had no trouble accommodating the 4 relatively small, 12”x14.5”x28”and 40#, AK Debra subs in my 21’x14’ room but I realize others may have difficulty.      However,Duke has stated that only 1 of the 4 subs needs to be positioned on the room’s floor, the other 3 subs can be wall mounted on shelves even within a few inches of the ceiling. I know another Audiogon member, named Hans, just successfully and recently installed an AK Swarm DBA in his small office using this method.

Tim

After reading this post I had to join in . I will describe my sub bass system as I have implemented it I don't know if it is right or wrong but sounds great in my room . The room is a L shaped room in a Manhattan apt. the room is mostly concreate construction .12 ft wide by 18 long opening into a 12 x 12 entrance foyer . The system  is on the long wall for living arrangements . I am using 6 subs at present time . My sub bass system is controlled by a DSPeaker Antimode 2.0 for crossover , volume & room correction function . I run my subs in stereo . The two main subs are on Isoacoustics sub stands . The main speakers sit in top of the subs also on the same type stands all my speakers and subs are sealed . The main subs are REL Q201e that I converted to passive now being powered by a Crown XLS2502 amp . I run the fronts at a slightly higher volume then the other active subs in the room . I have the option of low or high level inputs to the DSPeaker and preferer the high level it sounds more cohesive . I can adjust the total sub volume , crossover & slope with a remote control .I have not done any measuring I just use my ears as I feel I am the only one to satisfy . RC 

@audiokinesis 

Duke,
Glad you joined! Would the ability to time-adjust each of the 4 subs improve sound? Like Toole described in his Sound Reproduction?

I've gone from 1 Rel to two sealed DIY 12" Rythmiks in a digitally active 4-way stereo system, where the subs play mono. I'm thinking of adding two more Rythmiks, which have a number of adjustments from the plate amp including phase. I was wondering if the addition of a box receiving the summed mono subs signal and adjusting time on each would further improve things vs "just" adjusting phase on each. 

Regards

luisma31

... their particular claim of "big bass" and "thump thump thump" and "appreciated by bass heads" IMO it is an insult to the DBA, one of the features of the DBA which I appreciate the most is that quite differently from single or dual non integrated subs the amount of bass you need is very very minimal per sub hence not "thump thump thump" at all.

That sort of criticism of DBA is from those who haven’t heard it set up properly, or have not heard such a system at all. I agree that the one big advantage of DBA is the ability to create smooth, even, neutral bass. It is very appealing.

The price for that smooth, even, neutral bass is that your bass will be monophonic. That’s actually a small sacrifice to make because so much LF is recorded as mono anyway. The problem arises when DBA proponents insist that all bass is monophonic by virtue of it being non-directional. That widely-held belief - supported by claims in magazines such as Sound & Vision and Secrets of Home Theater - can easily be demonstrated to be wrong.

Still, mono bass can sound very, very good, and can lay a strong foundation for the rest of the music. I just prefer to have my LF in stereo, just like the rest of my system, and my speaker system is especially adept at achieving that.

This turned out to be one of the best swarm discussions thanks to the DBA detractors arguments and opinions

Cheeg, I'm not an expert on this matter just a learning user and by empirical evidence having experimented single and dual big not integrated subs before and a DBA of 4 smaller subs now I can tell you I prefer and advocate for the DBA big time.

By the way, although I respect the knowledge showed by the detractors of DBA and also respect (but not share) their opinions, their particular claim of "big bass" and "thump thump thump" and "appreciated by bass heads" IMO it is an insult to the DBA, one of the features of the DBA which I appreciate the most is that quite differently from single or dual non integrated subs the amount of bass you need is very very minimal per sub hence not "thump thump thump" at all. Sometimes you will hear the term "the subs disappear" in my case how I understand this "practically" is bass is "natural" like where u are going to an "acoustic" concert.

I use 2 SA1000 with 4 audiokinesis subs and gain on my amps (parallel connected) is at 50 percent on a 36 by 19 room

Oh one last thing if you are indeed a basshead one SA1000 with 2 (8ohm) subs in parallel will clip sometimes after 90 percent gain so using one sa1000 with 4 subs might be a challenging proposition

Ieales wrote: 

" DBA proponents are not charlatans, but neither are they correct as the the ability it to produce time coherent bass. " 

Arrival time coherence in the bass region is not critical, but decay time coherence in the bass region is. 

The ear is incapable of even registering the presence of bass energy from less than one wavelength. And the ear is incapable of registering pitch from less than several wavelengths. This from a Journal of the Audio Engineering Society paper which I no longer have access to. 

So the ear simply does not have enough time-domain resolution in the bass region to detect arrival time differences of a few milliseconds. 

So let’s look at the decay times. The longer a sound lasts, the louder it is perceived to be. So bass frequencies which take longer to decay sound louder. 

Also, since speakers + room = a "minimum phase" system at low frequencies (according to both Floyd Toole and Earl Geddes), when we know the frequency response, we know the time-domain response. Thus is it the peaks which take longer to decay into inaudibility. This implies that the frequency response is particularly important at low frequencies. 

Which indeed turns out to be the case. If we examine a set of equal-loudness curves, we see that they bunch up south of 100 Hz, such that a 6 dB change at 50 Hz is perceptually comparable to a 10 dB change at 1 kHz. This in turn implies that improvements in the frequency response in the bass region pay subjectively large dividends. 

In other words I believe that a good distributed multi-sub system addresses the issue that matters the most to the ears; namely, the in-room frequency response. 

Ieales again: "By FAT I mean that unless time correction is implemented the separate sub signals will arrive spread over several milliseconds... 

"IMO, it’s as unlistenable as MP3... 

At RMAF 2017 we displayed using a distributed multi-sub system in one of the standard (small) hotel rooms. An industry veteran cable manufacturer, with several decades of experience, handed us his thumb drive and asked us to play a recording of Fanfare for the Common Man. When it was over, he told us that was the most natural rendition of the tympani he had ever heard in any room at any audio show. He said it sounded just like what he heard when he went to a concert. 

(Incidentally in my experience the term "fat" is normally associated with a frequency response peak and its attendant long decay time, so it IS a time-domain issue - but applicable to the DECAY behavior, not the ARRIVAL TIME behavior. Our ears cannot react fast enough to hear "fat" in the arrival of bass energy).   

So I’m going to go out on a limb and claim that Ieales’ statement that a distributed multisub system is "as unlistenable as MP3" is an exaggeration. If he wishes to prioritize arrival time that is fine with me, we have a difference of opinion on that subject. 

Duke

I (hesitantly) decided to go with the Swarm after reading through the postings here (in particular from millercarbon and noble100) and other sources. These are very knowledgeable people with real world experience.

Now with all 4 subs singing, bass is extremely present, dynamic, fast and very clear. Everything I read in the posts were true and not exaggerated.

Indeed. 

I think I’ve decided to go with the Dayton SA1000 and two 10” or 12” passives; any suggestions on a decent quality sub for ~$300??? I’ve heard someone on this site recommend the Dayton Audio subwoofer kits on Parts Express ($265 for the 10” Ultimax, $311 for the 12”); has anyone heard them, or anything else in this price range?

Mine are the Morel 10". https://systems.audiogon.com/systems/8367
Two are the Parts Express sealed kits. The other two are the same kit, expanded vertically to increase volume because they are ported. I would not hesitate to just go with whatever Parts Express sub/cabinet kit you like. Just be sure to pay attention to impedance especially if you will be running multiple (4) off one amp.

Thank you all for your comments, it’s been an interesting discussion (at least for me). I think I’ve decided to go with the Dayton SA1000 and two 10” or 12” passives; any suggestions on a decent quality sub for ~$300??? I’ve heard someone on this site recommend the Dayton Audio subwoofer kits on Parts Express ($265 for the 10” Ultimax, $311 for the 12”); has anyone heard them, or anything else in this price range? 

Hi Cheeg

I have a lot better understanding of the issues, but am no closer to deciding whether I should buy a Dayton and cheap passives, or buy two better quality actives and save my pennies for 2 more. Maybe the answer is "it doesn't matter"

It kinda doesn't. It's really a personal preference. Your room is not big enough to create any timing issues amongst the subs to be audible unless you are really sensitive to timing issues. The extra flexibility with the powered subs is not a big difference over the passive subs, it just gives you a little more wiggle room if you don't or can't place the subs in their ideal location. It's the number of drivers that make the magic, not whether they are powered or passive. A lot of people have passive and a lot have powered and both camps are very satisfied with the results. They both have pros and cons which is what I was trying to outline, evidently not very successfully. You really can't make a wrong decision, it boils down to which pros and cons appeals to you the most.

All of my subs are on the floor, with two at the back wall between the speakers and facing each other, about 3' apart. The others are spread out along various parts of the wall and facing toward the room. I am trying to figure out a way to get one or more of mine in the air but in my room it isn't easy. I might need to build some pedestals.

I have also thought about trying one or more subs in a down firing position, but would be curious as to how far from the floor the down facing woofer should be. Same would be true about the woofers facing the wall.

Here is some info to help anyone sort out the "Swarm" .

https://jamesromeyn.com/audiokinesis-speaker-models/debra/

He makes a licensed clone of the Audio Kinisis Swarm. It sums up the design philosophy quite nicely.

I am thinking about building my own at some point in the future.

@cheeg FWIW - I have just received an set up my Swarm DBA in a small 10' x 14' room with excellent results.

I previously tried different subwoofers, none of which could provide reliable quality bass. The room is just too small and easily overwhelmed with the lower frequencies.

I (hesitantly) decided to go with the Swarm after reading through the postings here (in particular from millercarbon and noble100) and other sources.  These are very knowledgeable people with real world experience.

Now with all 4 subs singing, bass is extremely present, dynamic, fast and very clear. Everything I read in the posts were true and not exaggerated. 

I would start out with the Dayton and two passive subs for now.  Add the other subs later.  You'll be that much closer to an awesome DBA.

Also, 3 of my subs are placed up on shelves facing the ceiling.  Duke from AudioKinesis suggested this arrangement as it augments dispersion in the vertical plane.

Saves floor space too!

Good luck in your quest! 

When it was over, he told us that was the most natural rendition of the tympani he had ever heard in any room at any audio show.

Tympani are typically tuned to about C3 ≈130Hz with a 65Hz sub harmonic. Not really much in the sub range.

That does not mean you can tell where the bass is originating absent knowing that the two sides behave differently.

By extension,1 sub at the same level midway between their normal positions, two subs with mono input, two subs with with correct input and two subs with reversed input will all sound the same?

Methinks, and knows, not! At least for subs XO ≈80Hz.

Ieales wrote:

" DBA proponents are not charlatans, but neither are they correct as the the ability it to produce time coherent bass. "

Arrival time coherence in the bass region is not critical, but decay time coherence in the bass region is.

The ear is incapable of even registering the presence of bass energy from less than one wavelength. And the ear is incapable of registering pitch from less than several wavelengths. This from a Journal of the Audio Engineering Society paper which I no longer have access to.

So the ear simply does not have enough time-domain resolution in the bass region to detect arrival time differences of a few milliseconds.

So let’s look at the decay times. The longer a sound lasts, the louder it is perceived to be. So bass frequencies which take longer to decay sound louder.

Also, since speakers + room = a "minimum phase" system at low frequencies (according to both Floyd Toole and Earl Geddes), when we know the frequency response, we know the time-domain response. Thus is it the peaks which take longer to decay into inaudibility. This implies that the frequency response is particularly important at low frequencies.

Which indeed turns out to be the case. If we examine a set of equal-loudness curves, we see that they bunch up south of 100 Hz, such that a 6 dB change at 50 Hz is perceptually comparable to a 10 dB change at 1 kHz. This in turn implies that improvements in the frequency response in the bass region pay subjectively large dividends.

In other words I believe that a good distributed multi-sub system addresses the issue that matters the most to the ears; namely, the in-room frequency response.

Ieales again: "By FAT I mean that unless time correction is implemented the separate sub signals will arrive spread over several milliseconds...

"IMO, it’s as unlistenable as MP3...

At RMAF 2017 we displayed using a distributed multi-sub system in one of the standard (small) hotel rooms. An industry veteran cable manufacturer, with several decades of experience, handed us his thumb drive and asked us to play a recording of Fanfare for the Common Man. When it was over, he told us that was the most natural rendition of the tympani he had ever heard in any room at any audio show. He said it sounded just like what he heard when he went to a concert.

(Incidentally in my experience the term "fat" is normally associated with a frequency response peak and its attendant long decay time, so it IS a time-domain issue - but applicable to the DECAY behavior, not the ARRIVAL TIME behavior.  Our ears cannot react fast enough to hear "fat" in the arrival of bass energy).  

So I’m going to go out on a limb and claim that Ieales’ statement that a distributed multisub system is "as unlistenable as MP3" is an exaggeration. If he wishes to prioritize arrival time that is fine with me, we have a difference of opinion on that subject.

Duke

ieales

... Sound waves do not interact and sum ...

Actually, they can sum, and they can also subtract. Using out-of-phase signals, for example, is how active noise reducing headphones work. Phase is also part of why LF signals can be directional.

An ambient recording in one made in an acoustic space that is not treated do remove all reflections and does not have additional reverb added.

Like a pipe organ in a cathedral.

ieales"why would I lie? I’m not selling anything."

Accusing someone of deception, lies, and/or misrepresentation, deceit or even fraud is a common argumentative technique used frequently in politics but also frequently used, exerted, and applied hear by those who lack facts, understanding, and knowledge by accusing some one of lies it makes it easier to dismiss, reject, and disqualify they’re claims, statements, and representations and then when the insult is over they demand specific research, studies, or data from you it is all to put you on the defensive and conceal they’re own ignorance, misunderstanding, and immaturity these people are best ignored.

It is true that some people like "big bass" all around them thump thump thump so "swarm" or "dba" is good for them the more drivers and the bigger the better for them on the way to Perfect Sound Forever it is about BIG BASS not accuracy as has been shown, demonstrated, and revealed here because they don’t know what accuracy is they think all bass is omnidirectional and of course they can "prove" it with their monophonic bass systems!

1. why would I lie? I’m not selling anything. I want to stop people being preyed upon by charlatans. DBA proponents are not charlatans, but neither are they correct as the the ability it to produce time coherent bass.

Re other frequencies @ 30Hz. You are correct.
30Hz level ≈75db 4m from sub at seating position.
Microphone about 10cm from driver as measured by REW.
60Hz 0.372% -49.3db
90Hz 0.063% -64.3db
120Hz 0.032% -69.8db
150Hz 0.020% -74.0db

4. Air is air. Sound moves through it. There is not enough energy imparted to have laminar flow.

8. Sound waves do not interact and sum. A microphone diaphragm registers 2 waves. If the waves interacted claimed, where there is a null, where did the energy go and how was it recovered for the peak a few feet away.

I have heard DBA, but the mains were so awful, the system was unlistenable. The mains were a well respected [ lord knows why ] ≈$15k make that spread the sound like mayonnaise.

I have a slight advantage in that I sat in the engineers chair and mixed. When the vocal extends between the speakers, the hi-hat is about 3 feet wide, the foot is pillow and the electric bass is a nebulous strolling conglomeration of frequencies, I suspect something is not quite right. Of course, it is possible that it is all the studio monitor systems were wrong.

People like speakers with terrible impulse response, ports, 24 midrange drivers, etc. They are free to like DBA. It’s just not and never can be accurate from a time perspective.

I’m not sure that there’s much benefit to actually being able to reproduce LF in stereo

On true stereo recordings in an ambient space, it is essential. One can do an experiment with a pair of subs with a couple of Y-cords. Drive both inputs on each sub from a Y-cord so L feeds L&R on the left sub and R feed L&R on the right. Adjust level to account for the extra signal. Now rearrange the Y-cords to drive each sub with both channels so the L goes to L and R goes to R on each sub.

The difference is easily heard.

BTW, CDs are mastered from the original tapes. The 2 channel masters did not have the bottom summed.

heaudio123"You have not cited one source. Not one at all. A source is a research paper, not a name. Fine I source Floyd Toole. Is this how it works? Names mean nothing. An paper or similar they have published with actual tests that prove your hypothesis"

This is a very common, frequent, repeated type of approach from todays "millenials" and other children who need their "knowledge" prepared, presented, and predigested for they’re consumption the effort, burden, and work is always on some one else to meet their "needs" which are special, unique, and invariably very urgent they are unable to study, research, and formulate original ideas, concepts, and constructs of they’re own commonly.
Anyway you are wasting you’re time with cleeds he is a hemorroid or infected boil on this site you need to explore Tru-Fi and until you understand, comprehend, and can put in to practice and function it’s basic precepts and work with the properties of sound you will be like a blind child groping in the dark for understanding even as you proclaim knowledge, experience, and understanding.

Tru-Fi is all about the properties of sound and many components intended, designed, and marketed for use in Music Reproduction Systems are unable to completely, thoroughly, and properly reveal these properties in fact many are fully deficient, unable, and incomplete as has and can be shown to those who experience Tru-Fi although as I have previously explained, discussed, and stated Tru-Fi by itself is insufficient without introducing the proper mechanisms to adjust, compensate, and correct for ICSS distortion.
heaudio simply repeats previously digested "truths" but any one can do that of course here is one "Perfect Sound Forever!"

heaudio123

Moore is an MSEE whose expertise was codecs and perception who worked on MP3 codec.

Yup, Johnson too. It looks like you have some reading to do!

Come on, you keep throwing out names but not one, not one actual source that supports your claim. 

I've cited two sources. That's exactly two more sources than you've cited.

You are the one making the extraordinary claim ...

No, I'm sharing with you research done by others. That's something you've failed to do.

I will post many papers that support the accepted position ...

Yes, you've promised that previously.

This is a most entertaining, enjoyable, and remarkable conversation between 2 people who do not know of what they talk about in fact "cleeds" doesn't even own a Music Reproduction System! This type of argument, disagreement, and debate is because no one involved uses anything approaching a Tru-Fi approach to sound reproduction which demands and requires understanding, knowledge, and familiarity with the properties of sound and the properties of components used to try and reproduce that sound. Now as developed Tru-Fi has profound, deep, substantial flaws mostly because it fails to accommodate, adjust, or even recognize ICSS distortion but  even in the absence or failure to address that distortion in can be shown, demonstrated, and revealed that low frequency reproduction is inherently directional but much less so than higher frequencies which may explain another aspect of this argument here. But many audiophiles are like children who's knowledge, experience, and understanding is incomplete and based on "cartoons" (audio magazines) which as not intended to be taken as valid, reproduceable, scientific research.

heaudio123

Sound and Vision is not a scientific resource ...

Agreed. So please cite a scientific study that supports your claims.
Look at actual scientific studies.

I can post many studies ...

But you haven’t yet, you simply repeat your claim. Meanwhile, I provided a scientific resource for you to begin your study about directional bass. Have you read any of Moore’s work? He’s written hundreds of papers about how human hearing works. You might want to read one or more of them, rather that continue to repeat your opinions and claim them as fact.

Have you ever heard of James Johnson? (Lucent, Microsoft). He’s done quite a bit of work on this! Look for what he's said and you'll have answers to questions you haven't even thought to ask yet!

heaudio123

.. you wouldn’t know how to set up a proper experiment for subwoofer or low frequency localization. You told me you participated in multiple experiments. Why don’t you know exactly how to set up the experiment to deliver valid results?

You’re begging the question here, a logical fallacy also known as "circular reasoning." You can Google that for an explanation.

My opinions are not "opinions". Actual research in this area, i.e. proper experiments are pretty clear w.r.t. localization and frequency especially with real music and a lot of them have been done ...

You cite no reference, and are probably relying on sources like Sound & Vision for your opinions. And that’s fine, until you claim your opinion as fact.

I suggest you do some background research first and then - if you dare - conduct an experiment or two, perhaps with test tones, or perhaps by making your own recordings.

For your research, study what’s known as the occlusion effect - there’s a lot of research on this, Cambridge Neuroscience and Prof. Brian Moore among those who’ve studied it. That will be a good start for you - but it’s only a start.

heaudio123

Why would I need to make recordings of my own?

You don’t have any such need, of course. Nor do you have any need to conduct any valid listening tests. If you prefer, you can continue to vaguely cite the opinions of others, and assert your opinions stated as fact.

How am I going to make a recording of anything real that only has frequencies sum 80hz or only 30hz.

I have no idea. I’m not aware of any music that only contains frequencies that low, so I’m not sure why you’d ask that question. Is your question a red herring? If you want to test with only those low frequencies, you could use test tones, I guess. Or, you could use recordings that contain a full ranger of frequencies, including extreme LF.

... Lots of experiments have been done on this ... Proper ones ... Not your typical anecdotal. You can’t localize 30hz.

Yes, many experiments have been done. I’ve been involved in a few; their outcomes far outweigh your opinions stated as fact.

To be fair, bass is often summed to mono on commercial recordings, and I’m not sure that there’s much benefit to actually being able to reproduce LF in stereo. But: That doesn’t mean it can’t be done.

heaudio123

... you are either lieing about testing people for directionality at 30hz or your speaker had high distortion and there was frequencies well above 30hz ... You can't localize 30hz. It is impossible.

Actually, @ieales is correct - it is possible to localize a 30hZ tone, and it's been demonstrated. To be fair, it's more difficult to localize LF than higher frequencies, but as you note:

Your ears and brain do not process bass the same as higher frequencies. Timing is less important.

Quite so, and you may be more correct than you realize! What makes low frequencies  directional are differences in phase, and yes, this can be demonstrated, too.

Want proof? Go out and make some of your own recordings. Play them back on a high end system. Perhaps experiment with binaural recording. You might be amazed at what's possible.

PS: for the comparison above, no signals over 100 Hz need apply.

LOL - so many opinions, so little consistency!  It would be interesting to test out these hypotheses using 3 subs, at different distances from the listener, set up so 2 of the subs together have the same volume as the third one alone.  Run the same mono source to all three, and use an A/B switch to flip between the single and the pair.  Anybody want to bet on the outcome?  (hint; I don't think any 2 people on this site would agree)

1. I've never tested anyone who could not localize a 30Hz tone playing from one channel or another.

2. The reason low frequencies are summed is for stereo playback to keep the stylus in the groove.

3. Nope. If the bass is mono, it still bears a time relationship to the rest of the spectrum

4. Sound is sound and behaves the same across all frequencies. Waves don't collide. They pass right through one another. We may hear or measure a null, but that is a mechanical artifact. Move away from the null and the signal level returns to the same level.

5. If our brains summed and averaged, we would not be able to perceive low end at all.

6. never read that. Please supply a reference. Not by DBA advocate, s'il vous plait.

7. 200ms!?!?!? Surely you jest. That's almost a ¼ note @  120BPM.    Again, please supply a reference.

8. Again waves don't collide. They get absorbed.

There’s also no performance, imaging or quality concerns dependent on the direct bass sound waves from any specific, or combination of subs, arriving at the listener’ ears first.

If that were the case, one could place a sub anywhere in a room and hear no difference.

Subs are not brick wall devices. They output significant energy well into the mid-bass. If they are not coherent with the mains, they smear the impulse response.

Perhaps DBA work with time incoherent mains where everything is a huge bucket of mush and when crossed over below where there is any significant program, but with time coherent mains and crossed over much above 40Hz, they never can.