How clean and at what SPL?
Very few speakers of any size (that I know of) maintain clean output (call it 10% THD) at 20hz at 90 db. If you really want that kind of performance from a small speaker, you'll almost certainly need a subwoofer.
Some people might argue that 30%+ THD is clean enough at 20hz (where hearing is very insensitive). That may be true, but it means that any answer to your question will be awfully subjective (and you'll still probably need a subwoofer). |
Hi Mapman,
Clean and flat = big driver. Best I've had is a 15" Hsu which was flat to 16 Hz after acoustic treatments and EQ.
However, it's really important to understand, below 400 Hz or so, your room becomes a very important part of "clean and flat" so much so that getting to the lowest octave is a completely different ballgame. The lower you try to go the bigger the dragons. This is why smaller 2 way speakers are often preferred to full-range.
It can be done and it's glorious, but it's not trivial. If you aren't willing to spend the time or hire qualified help, you are often much better off with limited output speakers.
Best,
Erik
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FYI, there’s a rule of thumb, that for any given driver, going down an octave causes 10x the linear cone travel. So, if you attempt 20 Hz with a 6" driver you’ll need it to move a foot back and forth or something ridiculous like that. :) This is why larger is better. Those who argue they are slow or not musical have not been able to integrate them properly which has nothing to do with the quality of the driver but not managing the room acoustics and EQ properly. You may also find this resource helpful: http://bass-db.gforge.inria.fr/BASS-dB/Also look for Room EQ Wizard where you fill find many bass geeks to discuss things with you. Having adequate drivers for a subwoofer is very important, but to my ears, the quality of the EQ matters much much more. So, JL to me is one of the best off-the-shelf subwoofer makers. Of course they use a high quality sub driver, but their auto-EQ is perfect. Personally, I do my own EQ, so I’m quite happy with Hsu VTF-15H MK II for $1,300 (including EQ). If I had all sorts of money and no time, I’d go with JL. Best, Erik |
Clearly larger active or powered speakers or speakers with integrated powered subwoofers are best able to do it but I’m wondering more about purely passive speakers even if only in a smaller room. I realize room acoustics play a big part. I'm also wondering more about low end extension and distortion levels assuming other external factors will need adjustment for truly flat response. |
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Headphones! Grado made a line source array that they showed at CES one year, just for fun. It made decent bass but it had a lot of drivers in it. Seems to me it was over 6 feet tall and they won't be manufacturing it. Otherwise you're simply going to have to have a big speaker. My speakers go to 20Hz and have two 15" woofers. You probably can do it with one. The smaller the driver, the more excursion it needs and that's your limit. Bruce Thigpen got around that limitation with his subwoofer fan. Click on the link below and then products (TRW-17): http://www.eminent-tech.com/main.htmlFrom the page: A
conventional speaker cones displacement must increase four times for
each halving of frequency to maintain the same output. This is why
conventional cone woofer companies are trying to develop “long
throw” woofers. Although inefficient, cone woofers work fine
above 40Hz. Below 40Hz however cone woofers quickly run out of
travel and the output diminishes rapidly.
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Barefoot Monitors are probably the smallest high performance speakers.
The MM27 has the smallest footprint and can compete with speakers many times their size. |
Physics can be a pesky thing, and the mutually exclusive nature of including "small" and "clean at 20 hz" in this post does seem a little paradoxical. I use 2 RELs in my hifi rig and they're sort of smallish I suppose, as are the drivers in my Silverline Preludes (3.75" woofers)…I have a 92 lb 500 watt Mackie studio specific sub (in my studio specific studio) with 2 12s (active and passive) that supposedly does 19hz…but it's on the large side. So, no free lunch. 20hz…hmmm…large Wilsons maybe? |
Check out Gershman Acoustics Avante Garde. Gets to 20hz or close and is not large at all. |
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The Excellent Deavialet Phantom is that type of speaker yhat can place with grace
Or knock or thump you in the chest 20hz test tones confirmed . my brother bought a pair of yhe easy release models from last year thin 2- 6inch pistons in a automobile like a Ducati twin engine horizontally apposed and and unit is only as big as a soccer ball but can knock out the sound pressures !! |
Yg Acoustics Kipod II Signature. Bass is covered by only an 8" driver in active sealed inclosure. Deep, deep bass. |
What are the smallest speakers that are clean and flat down to 20hz?
Also what bass driver or drivers do they use?
Thanks.
mapman Without being EQ'ed the lowest bass I have heard from a large sized bookshelf, has been a pair of Sonus Faber Extremas, that have an ABR using a Kef B139 with voice coil for switched resistive damping to tune to the room, with a pair of Krell 250 monoblocks up them. Cheers George |
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Also realistically speaking 20hz wave length is 56.6 ft long you need a combination of at least that in all directions to eliminate room nodes. so that much bass in any room with out treatment is going to give you issues. http://www.acousticfields.com/wavelengths-in-our-rooms/
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The ohm walshes do quite well in this area. I’ve heard response with test records down to 20 hz with 8 inch ohm Walsh drivers in the past. The smaller ones I have these days are 8 inch and the larger 12 inch. One individual on the ohm thread here reported response down below 20 hz recently I recall. |
Not sure what you mean by "small" and "flat." Zu Definitions go flat to 16Hz. They have a 12"x12" footprint. But they are also 50" tall. AudioNote ANE has bass down to 16Hz, but I think that there is a roll-off; and they use corners to reinforce the bass.
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Mapman
What are the smallest speakers that are clean and flat down to 20hz? Mapman what is your objective here ? Are you looking for a silver bullet, all in one speaker for 2 channel music, or are you talking about standalone subs. Very different considerations for both. I am running rooms with both scenarios. Cheers |
most things are spec’s +- dB so for example a speaker might be described as "flat" from 20 to 20kHz +- 3 dB. so it could be down 3 dB at 20 Hz which is half as loud at 20 Hz. No speaker is ruler flat thus when most speaker companies state their speakers are flat to 20 Hz they actually mean they are 3 dB down at 20 Hz or even -5 dB down at 20 dB or whatever. Also if speakers are spec’s in an anechoic chamber their actual performance in a real room will usually vary considerably.
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Atmasphere
The smaller the driver, the more excursion it needs and that's your limit. Bruce Thigpen got around that limitation with his subwoofer fan. Atmasphere - as you probably know I am a big fan of Bruce Thigpen. I consider him a genius. Bruce' sub is unique, it allows someone to feel a helicopter land in their space at 3 hz if they want. Be prepared to replace some windows, with neighbors knocking on your door. But even Bruce can't cheat Physics. His TRW sub is using the adjoining space next to the music room - as the box ! Mapman You know, this 20hz - 20khz audio thing.... imo it gets thrown around like car guys say 0 - 60 mph. How much real music even exists below 30 hz anyway ? Sure, we can look at the chart data. http://www.audio-issues.com/wp-content/uploads/2011/07/main_chart.jpgBut it only tells a small part of what is going on. At least on the forum discussions here. For the real answer, imo, you need to talk to each person to find out what they listen to. Some want to feel no loss in DB below 50 hz with their music. Some want it light and tight. This may be due to an apartment room, fragile kidneys, who knows...... but light and tight is not how live music sounds. Also I can tell you from personal experience the guy that is 50, listening to 2 channel music, is listening to different music, and has different priorities, than my 22 year old son. Now I am managing to convert him slowly. I know this because he keeps asking me for music. But he can't afford a house or his own place. His truck is his room, and it uses two JL Audio subs. And his generation likes the bass loud - real loud. Not because he is deaf. This is because they are using the whole truck as a speaker and standing outside of it when they socialize. |
I guess they're out of production now, but a meritorious mention for the Totem Mani-2's. Remarkable bass out of a relatively small monitor. |
I'm just interesting in what smaller speakers people have found are truly good down to 20hz and if so why.
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I've heard Mani's and liked those very much. I recall they had a unique bass driver design. |
Vandersteen 5a. Nipple-high at most.
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PMC's, which have a transmission line enclosure, can produce more bass for their size than other designs. |
Transmission line makes a speaker larger.
The cabinet on Barefoot MM27 is Cabinet: 20.5 x 9.5 x 15.5 inches (521 x 241 x 394 mm)
Overall: 20.5 x 10.5 x 17.4 inches (521 x 267 x 442 mm)
it is flat to 30Hz and will play louder more cleanly than 99% of what people have here. |
I thought the OP criterion was clean and flat to 20 Hz?
Perhaps he can specify what flat is to him: +/- dB ?
If the recording can contain it, and my room can contain it, I want my system to deliver it. |
Mapman, Even if you were to find 2 ch speakers or subs of any size that were flat down to 1hz +/- 0 dbs, the unfortunate truth is that the physics of acoustical sound wave propagation is going to ensure you don't perceive flat bass response in your room, assuming your room has walls, a floor and a ceiling. As long as your spkrs/subs are located along your front wall, there will be uneven bass response in the room; specific spots in your room that bass is exaggerated and specific spots that bass is diminished and even nonexistent. Sorry to rain on your parade but I've discovered there is a good solution, called a Distributed Array Bass System, that works amazingly well. These systems are sold under various names (SWARM, DEBRA, etc.). I have used the DEBRA system for about a year now and I'm completely satisfied with the results. I started an Audiogon thread in June of this year that goes into more detail and requested input from other users (there doesn't seem to be many Audiogon users that employ this bass system). Here's a link if you're interested: https://forum.audiogon.com/discussions/anybody-else-using-a-distributed-array-sub-systemYou can also google "distributed bass array system" that will list multiple sources of independent info, including sites on the specifics of how it works, white papers that discuss the theories behind it with empirical data as well as current sellers of these systems. I should mention that I was initially very skeptical due mainly to the cost ($4,000) and whether it actually worked as well as claimed. It took months of emails and phone discussions with the seller before I decided to give it a try. I am now very grateful I bought this system that works so exceptionally well for both my 2 ch music (especially on high-res music files that are thankfully without 'loudness wars' dynamic limitations) and HT. This system has given me solid, deep and tuneful bass that sounds equally good from all 6 seats in my 23' x 18' room. It is somewhat expensive (I rationalized it by comparing it to the cost of 2 high-end powered subs I was previously considering) and it takes the better part of a day to properly setup in a rather detailed and extensive process. But I now consider it a bargain and realize the extensive setup process is critical for good results. Lastly a disclaimer, I have absolutely no affiliations, financial or otherwise, in the development or sales of these systems. Just a very satisfied customer, Tim |
Good stuff folks, keep it coming.
noble I just want to know the small speakers capable of it in a typical room.
I’m familiar with the swarm approach. That’s probably the most effective approach in the end if done right I’d say..
30hz isn’t bad as long as the size is small accordingly. I could probably live with that. But 20hz or even lower maybe is best. |
I really mean the speaker does not roll off much or at at all at 20hz in a typical room. How flat it is or not will largely depend on room acoustics from there right? If it can only be done in a smaller room fine, just say so. I'd expect one capable of it in a smaller room to be physically smaller than one for a larger room. |
^That's why speakers should be anechoic spec'd. It gives us a standard neutral base line. Now you just need to provide us with your specific criterion, so the equation can be completed. +/- 3 dB seems to be fairly standard, though better is well, better. :-) |
3 dB at 20 Hz which is half as loud at 20 Hz To be audibly half as loud is usually considered 6-10db on account of the ear being on a logarithmic scale. I really mean the speaker does not roll off much or at at all at 20hz
in a typical room. How flat it is or not will largely depend on room
acoustics from there right? If it can only be done in a smaller room
fine, just say so. The room will have some influence certainly, but if you really want 20Hz response **with any sort of dynamic range**, its not going to be a small speaker. Note emphasis. |
Headphones are small and can go down to 20hz. They're pretty small speakers.
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atmasphere
3 dB (down) at 20 Hz which is half as loud at 20 Hz
To be audibly half as loud is usually considered 6-10db on account of the ear being on a logarithmic scale.
actually decibels are already logarithmic; hearing is not on a logarithmic scale. the microphone used to measure the SPL is a listening device and measures what the human ear actually hears. If the SPL is 3 dB down at 20 Hz then you will hear 20 Hz as half as loud as any frequency that is measured as 0 dB. If 20 Hz was found to be - 6 dB it would be 1/4 as loud as a frequency at 0 dB.
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Yes 20 hz and dynamic range which is why I tend to think larger drivers and speakers for that. But how small can they be?
Zu has yet to bowl me over in demos in regards to having that low end dynamic "meat on the bones" as I like to say but demos to date have been less than optimum conditions most liklely? |
Mapman,
atmasphere stated:
"
The room will have some influence certainly, but if you really want 20Hz response **with any sort of dynamic range**, its not going to be a small speaker. Note emphasis."
As far as a speaker being relatively flat down to 20hz, with 'any sort of dynamic range'. I completely agree with Ralph and I seriously doubt many even exist, certainly no small speakers/subs. You're chasing a ghost and I think you may know it.
As far as 'the room will have some influence certainly'. I completely disagree with Ralph on this because he is seriously underestimating the effect the room has on bass response and has chosen to ignore the mountain of scientific data compiled on this subject and the single solution that has been proven to be successful in evening out and improving bass response in any room(Distributed Array Bass systems). The room will be THE MAIN influence of how bass is perceived. Even if your room is as big as a football field, and you have only 2 spkrs/subs along the front wall (and even if they're launching perfectly flat waves at 20hz from these 2 points) the extremely long 20hz sound waves will reflect off of room boundaries eventually and cause peaks and nulls at specific positions in the room. Given the exact room dimensions l x w x h and the boundary surfaces' materials, acoustical engineers can determine exactly where you will have peaks and nulls.
Sure, if the spkrs/subs and the listening position are kept in the middle of this huge space and away from room boundaries, these affects will be mitigated significantly but bass response will still not be even throughout the entire room. The smaller your actual listening room, the more peaks and nulls will exist. No amount of room treatments (bass traps, absorption panels and diffusing panels) or room analyzers/corrective sound processors (the ones that use microphones at the listening position for measuring and then equalizers to adjust frequencies to remedy inaccuracies like Room EQ Wizard and all the other systems built into receivers) may be able to help a bit at 1 specific listening position but do virtually nothing for the numerous other positions in a room.
Only multiple subs (experts say the more the better but a minimum of 3 subs) strategically positioned at setup process determined locations within a room will remedy bass peaks and nulls in a room and each room is unique since every room has different dimensions. Trying to do this on the back-end with bass traps, panels, mics, analyzing software and corrective equalizing (with sub locations initially selected haphazardly and literally at convenient open locations along the front wall) surprise, surprise, definitely does not work and is like trying to put out a fire with a squirt gun.....Go Figure!
I apologize if I sound like I keep beating this horse/drum but the subject has apparently struck a nerve with me and I feel the ned to tell my story. About 10 yrs. ago, I spent countless hours experimenting with positioning 1 and later 2 subs trying to get good bass response in my medium sized room with mixed results. My first breakthrough occurred when I moved 1 of my 2 subs out into the room between my listening chair and the front wall about halfway down the left wall. I didn't know it at the time, but I had accidentally stumbled upon my own limited distributed array sub system. Later, after months of internet research on how to achieve good home audio bass response, I discovered research white papers and articles from Dr. Earl Geddes, who has a PHD in Acoustical Sciences and currently is the CEO of GedLee LLC which is a consulting firm that specializes in acoustics, audio, home theater and noise control. This info concerned his research into achieving good bass response in business and home environments for both music and ht.
I have also learned a lot by talking and corresponding with James Romeyn of James Romeyn Music and Audio in Utah. James studied under Dr. Geddes for several years before opening his own company that trades in musical instruments and is a dealer for Audio Kinesis. He is the person who convinced me to buy the Audio Kinesis DEBRA distributed Array Bass system and give it try.
My main point is that my search for a good home audio bass system was not as simple as walking into an Audio store and buying a distributed array bass system. It has been more of a long journey that culminated with a satisfying discovery and excellent solution. I'm writing this reply to illustrate that I've been at the same stage that many Audiogon members seem to be at; that is, posting on this forum searching for answers to their system bass performance woes and seemingly believing the solution will be to just buy a certain brand and model sub, plop it down at some convenient open space along their system wall, and their system will suddenly have good bass response.
I know you have been a member here for a long time and know, through encountering and reading many of your posts over the years, that you have a wealth of knowledge on a variety of audio subjects and have always communicated knowledgeably, articulately and conveyed relevant and helpful info in your posts.
Precisely because of this, I was surprised you posted what you were in search of on this thread. I thought you would understand the futility of what you were in search of. I was fairly certain that you knew very few speakers are capable of flat response down to 20 hz and the likely hood of finding a relatively small speaker/sub capable of doing so would be approaching impossibility.
In conclusion, my current thought is that you posted your question just to have a little fun by finding out what kinds of replies your paradoxical question would solicit.
Am I correct?
Thanks,
Tim
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Mapman
Yes 20 hz and dynamic range which is why I tend to think larger drivers and speakers for that. But how small can they be? Mapman From my experience depends on multiple factors. 1) Appropriate room size - to allow the bass wave to happen. 2) Capable speaker design/boxes. Physics here isn’t as picky about the shape. But the box volume and tuning (pipes in the box) need to be there. 3) Appropriate amps 4- Appropriate EQ.** Standalone subs provide you with 2 - 3 - 4. This is why audiophile subs came out of the HT and Car domains and dominate 2 channel setups now - imo. ** Meaning controllable cut off points, phase, and DB control to boost as appropriate for music between different genres, and even within the same genre. Give this to me in a remote control from my listening position or forgetaboutit ! :^) Ever see pics of Fully capable speakers you know go down to 20 hz but for some reason there is a sub or two tucked away in the pic? Some problems with this picture. Well you are hardly ever shown the whole room so anyone who has been through this can understand why it is happening. Could be 1) room is too small or less likely - too big 2) speakers have wife constraints and can not be put on the room loading points 3) amps can’t deliver the goods. 3 reasons at the top of my head. I also agree with what Tim said about the multiple sub effect and room nodes. Some all out designs go one further and place woofers at the top of the tall speaker to deal with room nodes. Just some thoughts |
noble100,
Thanks for those kind remarks.
Yes we are on the same page on what is best. Also with Atmasphere on the size factor.
That is why I ask the question. I prefer simple and small, not large and/or many.
Totem Mani 2 has always interested me in this regard with its unique double bass driver design in a reasonably small monitor package.
For floor standers I feel my Ohm Walsh speakers with 8" driver for smaller rooms and 12" for larger are still my personal overall sound quality benchmark in this regard. There is a newer model the 5015 that adds built in powered subs which I suspect has to push the limits as well. But I’m always looking and wondering. Plus I think its an informative discussion in general.
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Barefoot MM27 with two 10 inch woofers, two 5.25" midrange and a tweeter in a compact 20.5 x 9.5 x 15.5 inches cabinet are the closet thing to what the OP claims to want. It is like a bookshelf two way but having two JL fathom 110 built into each speaker - that is four 10 inch woofers!!!
These will easily outperform Ohm Walsh and any other speaker suggested here in terms of low end response, dynamic range and overall clean extreme high SPL - they are without doubt the smallest truly full range speakers on the market.
There are some nice speaker suggestions above and Totem, for example, make great speakers, as do Ohm, but in this rather stringent requirement of smallest and full range there is a clear leader that makes other speakers that "sound big" look like kids toys.
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Shadorne Barefoot is one I am not familiar with. Those seem to add the powered subs, in fact 4 separate powered bass drivers per speaker in a small package indeed. hard to argue with that. Thanks for identifying those.
Seemingly a smaller package but would they outperform the OHM 5015? Those go for about 10K. Totally different beasts otherwise but with 4 powered bass driver per speaker could be. They do show -3db down at 30hz in teh specs though which would seem to indicate the size is limiting them to some extent in regards to low end extension if not low end dynamics otherwise. |
Here is link to info on OHM 5015: http://ohmspeaker.com/speakers/beta/Specs say +/- 3 db at 16hz. I have OHM F5s which is same cabinet, same main driver (12"), minus built in 15" powered sub and is ported not sealed. Also smaller similar Walsh 2s with similar driver but 8". F5 can be adjusted to room size but is overkill for smaller rooms only. |
As far as 'the room will have some influence certainly'. I completely
disagree with Ralph on this because he is seriously underestimating the
effect the room has on bass response and has chosen to ignore the
mountain of scientific data compiled on this subject
I think actually we're on the same page. But Mapman is talking about 20Hz response and so am I. That's a bit different than **perception** of bass, which is very much affected by the room (for example I have a room resonance at 26Hz in my room, which tends to reinforce bass impact, but its at 26Hz no 20Hz. I tend to be very literal it that helps...). IOW the room isn't going to change the actual frequency response of the speaker, although it will affect to a large extent the **perception** of bass coming from the speaker. Duke LeJeurne of Audiokinesis makes an excellent subwoofer system he calls 'The Swarm'. It is a set of multiple subs that can be distributed so you don't have problems with bass in some parts of the room (like the side wall) and not in others (like the listening chair). As a general rule of thumb I usually regard the room as half of the overall system sound. If the SPL is 3 dB down at 20 Hz then you will hear 20 Hz as half as
loud as any frequency that is measured as 0 dB. If 20 Hz was found to be
- 6 dB it would be 1/4 as loud as a frequency at 0 dB. Actually in the above case being down 3 db it would take double the amplifier power to make up the difference but the ear would not hear the -3db as half as loud. If the speaker were 6 db down then that tends to sound closer to 'half as loud' and would take 4x amplifier power to correct. |
geoffkait: If the SPL is 3 dB down at 20 Hz then you will hear 20 Hz as half as loud as any frequency that is measured as 0 dB. If 20 Hz was found to be - 6 dB it would be 1/4 as loud as a frequency at 0 dB.
to which atmasphere replied,
"Actually in the above case being down 3 db it would take double the amplifier power to make up the difference but the ear would not hear the -3db as half as loud. If the speaker were 6 db down then that tends to sound closer to ’half as loud’ and would take 4x amplifier power to correct."
Uh, the microphone hears what the ear hears. Forget the amplifier! You’re making it too complicated. You’re hearing 20 Hz at 3 dB down. Half as loud. Example - Suppose you were listening to a jackhammer and you measured the SPL where you were standing to be 110 dB. Then you stepped backwards - a few steps at a time - until the SPL measured 107 dB it would be then half as loud. 3 dB down. Case solved.
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Actually here is what the ear hears and its far from flat at the extreme top and bottom range of our ears in particular: http://www.independentrecording.net/irn/resources/freqchart/ear_sensitivity.htmFor example according to this what measures correctly as flat at say 20 hz will be heard down more than 70db by the typical human ear in the worst case at the lower volume limit of human hearing. Less so but still down at higher volumes. So significant equalization/boost is needed to "hear it as flat". How much depends on volume. Same true with the high end. Whereas a microphone used to measure the levels accurately would have flat response end to end. Our ears are far from that as shown in the chart. |
mapman OP
"Actually here is what the ear hears and its far from flat at the extreme top and bottom range of our ears:
http://www.independentrecording.net/irn/resources/freqchart/ear_sensitivity.htm
For example according to this what measures correctly as flat at say 20 hz will be heard down more than 70db by the typical human ear. So significant equalization/boost is needed to "hear it as flat". Same true with the high end."
That’s absurd. You will pay big bucks to hear 20 Hz 70 dB down? Are you crazy? 70 dB down is almost as low as the noise. Besides, you're the one that says it's flat at 20 Hz. Hel-loo!
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Its not absurd at all. Its a well documented fact.
Turn the volume up and things are better but still far from flat.
Equalization is the only practical solution if one truly cares beyond that.
It helps to manage expectations though to realize and understand that what we hear is not the same as what measures as flat.
If the speaker rolls off at extreme frequencies, then we hear even less.
The ability to not roll off at frequency extremes and make things even worse is what separates the men from the boys.
Compensating with equalization is then analogous to using performance enhancing drugs. that is assuming the amp and speakers can handle it. That's a different story. if they can't, then the results will surely not be good.
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Wow, those Ohm speakers remind me of my old BIC Soundspan 600 speakers. |
@mapman
There is no need to boost everything to flat of equal loudness as music is produced for human hearing in the first place / so it is balanced accordingly and a speaker should be flat overall.
One issue with flat to 20 Hz is that rooms give a natural 6db per octave boost as you drop below about 40 Hz. So ideally a speaker should have some roll off if it is to perform flat in a room. A speaker flat to 16 Hz like the ohm f-5015 is likely to sound awful in most rooms without EQ.
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