Subs for electrostatics

[jtgofish]

Finding subs that integrate with electrostatics is notoriously difficult.Most sound too boomy and slow.I have made up one that uses an RCF L15/554k 15 inch in the RCF recommended ported box.A friend is using this with his ER Audio stats which are superb but can sound a bit thin.He is using a standard Chinese sub amp to drive this [150 watts].As these are really PA speakers and 100db sensitivity some e.q. is needed.The sub amp has a 6db boost at 35 hz which works well.The improvement is staggering-the sonic picture is now complete.
This sub amp also works well with my vintage Tosshiba SS30 speakers [the best dynamic speakers I have heard],and yet all other subs I have tried with these just can't keep up with their speed and dynamics.
I'm guessing why these RCF woofers work so well is probably due to their sensitivity,restricted excursion and cloth surrounds[always better than rubber]-although they are an expensive and highly regarded model.

JT

[theaudiohobby]

Finding subs that integrate with electrostatics is notoriously difficult.Most sound too boomy and slow.

Nope, integrating a sub with a electrostatic is straightforward as long as you are willing to leave the audiophile myths behind, most of the problems with integration stem from a lack of knowledge rather than any specific issues relating to stats in. Most subwoofers do not have a high pass filter, which I think is a necessary feature for successful subwoofer integration. Most of the issues folks encounter when integrating subwoofer with stats arise out of the broad overlap between the stat and the subwoofer operating bandwidths which leads to unnecessary and/or excessive midbass boost.

[JoeE SP9]

I have been using ES speakers since 1985. I have never had any problem integrating a subwoofer with any of them. I have always used an external electronic crossover with high and low pass filtering and bi-amped. I agree with the theaudiohobby. Boomy/tubby bass with an ES sub system is almost always caused by overlap. I use 85Hz as a crossover point between my subs and my ES panels and I have not a hint of boom or tubby sound. The transmission line subs I am currently constructing to replace the sealed boxes should be even better as they should be flat to about 18Hz if my figures are correct. This low end is achieved with no equalization at all. They are also relatively efficient.:cool:

[theaudiohobby]

Hi Joe,

which transmission line Subs are you constructing, at 18Hz flat with no equalization, it looks quite juicy ;) .

[jtgofish]

Very interesting.Things like the Quad ESL 57s have always had a reputation as being very difficult to match with a sub.Hence the development of open baffle dipole type subs ,which according to established thinking,seem to be the only type worthy of consideration.Could this be another audiophile myth?
The point I was raising related to using high sensitivity woofers as subs-something no commercial domestic hi-fi companies[except maybe Klipsch] have addressed.
Also another friend has the ER audio stats and has tried all sorts of subs with them including Focal drivers in a transmission line.None have seemed to integrate or sound right-certainly not even close to the RCF.


JT

[E-Stat]

I have been using ES speakers since 1985. I have never had any problem integrating a subwoofer with any of them. I have always used an external electronic crossover with high and low pass filtering and bi-amped.
I will respectively disagree. I've tried active subs using low pass filtering with Acoustats dating back to '77. My objection was related to the sub's different radiation pattern, not boominess. I tried settings down to 50 hz or so and was never satisfied.

That's why I enjoy the SL U-1s - they respond down to the twenties without augmentation.

rw

[Florian]

I will respectively disagree. I've tried active subs using low pass filtering with Acoustats dating back to '77. My objection was related to the sub's different radiation pattern, not boominess. I tried settings down to 50 hz or so and was never satisfied.

That's why I enjoy the SL U-1s - they respond down to the twenties without augmentation.

rwDitto here! Bass response down to 18Hz :p:p

[Geoffcin]

Finding subs that integrate with electrostatics is notoriously difficult.Most sound too boomy and slow.
JT

My Velodynes cross over at 40hz, and I've achieved a measured 20hz-20khz in room. I also have over 105dB of dynamics available across that range, and NO panel speaker can claim to be able to do that independantly.

[Florian]

I know 3 that can :)

But you wont get a perfect integration, eventough the Maggies are slower for a panel speaker.

[Geoffcin]

I know 3 that can :)

But you wont get a perfect integration, eventough the Maggies are slower for a panel speaker.

Slower in what respect?

Perfect compared to what?

[Florian]

I retract my statement. We will only fight and argue and get nowhere. If you would like to discuss this, please PM me. In my opinion, there is no subwoofer that can match a panel, and that many panels out there have more then enough bass power but will only reveal it in dedicated audio rooms build for the speakers.

-Florian

[Geoffcin]

I retract my statement. We will only fight and argue and get nowhere. If you would like to discuss this, please PM me. In my opinion, there is no subwoofer that can match a panel, and that many panels out there have more then enough bass power but will only reveal it in dedicated audio rooms build for the speakers.

-Florian

And in my opinion you are wrong. Except for the part about panel speaker having enough bass. In my opinion many DO for the most part. Unless your into organ music, or bass heavy techno. Still, I have an excellent recording of a drum solo with dual kick drums that will knock you over if I play it at concert level. Can't do that with just a panel speaker....

[Florian]

And in my opinion you are wrong. Except for the part about panel speaker having enough bass. In my opinion many DO for the most part. Unless your into organ music, or bass heavy techno. Still, I have an excellent recording of a drum solo with dual kick drums that will knock you over if I play it at concert level. Can't do that with just a panel speaker....Thats ok, i will agree to disagree. In my opinion you have not heard or felt the right panel speaker yet and that is why you disagree. There are not many, but there are a few that will play below 20Hz and exessive output in the low 20's that when setup right shake the foundation of your house. I have heard it and many of my friends have heard it, but these were not Maggies.

-Flo

[theaudiohobby]

I will respectively disagree. I've tried active subs using low pass filtering with Acoustats dating back to '77. My objection was related to the sub's different radiation pattern, not boominess. I tried settings down to 50 hz or so and was never satisfied.

That's why I enjoy the SL U-1s - they respond down to the twenties without augmentation.

rw

Key point to note here, a low pass filter alone will not do the trick, a low pass as well as highpass filters are required. Without a high-pass filter there will be a broad overlap in midbass, and that overlap may be problematic for a variety of reasons.

[E-Stat]

Key point to note here, a low pass filter alone will not do the trick, a low pass as well as highpass filters are required. Without a high-pass filter there will be a broad overlap in midbass, and that overlap may be problematic for a variety of reasons.
One of us is confused as to what that means. I use the term low pass according to the definition as found in Wikpedia:

A low-pass filter is a filter that passes low frequencies well, but attenuates (or reduces) frequencies higher than the cutoff frequency. It is sometimes called a high-cut filter, or treble cut filter when used in audio applications...Electronic low-pass filters are used to drive subwoofers and other types of loudspeakers, to block high pitches that they can't efficiently broadcast...

My low pass filter is selectable from 50 to 120 hz. I tried rolling off the woofer as low as 50 hz. (No output above that). As opposed to:

A high-pass filter is a filter that passes high frequencies well, but attenuates (or reduces) frequencies lower than the cutoff frequency. The actual amount of attenuation for each frequency varies from filter to filter. It is sometimes called a low-cut filter; the terms bass-cut filter or rumble filter are also used in audio applications. ..Such a filter could be used to direct high frequencies to a tweeter speaker while blocking bass signals which could interfere with or damage the speaker.

I see no reason to block the low frequencies with my subs. As for overlap, I don't have any sub subs.

rw

[theaudiohobby]

One of us is confused as to what that means. I use the term low pass according to the definition as found in Wikpedia:
...

A high-pass filter is a filter that passes high frequencies well, but attenuates (or reduces) frequencies lower than the cutoff frequency. The actual amount of attenuation for each frequency varies from filter to filter. It is sometimes called a low-cut filter; the terms bass-cut filter or rumble filter are also used in audio applications. ..Such a filter could be used to direct high frequencies to a tweeter speaker while blocking bass signals which could interfere with or damage the speaker.

I see no reason to block the low frequencies with my subs. As for overlap, I don't have any sub subs.

rw

Confused definitely not me :) , as the definition of of high-pass filter as defined by wikipedia is precisely what I and JoeE SP9 had in mind, the high-pass filter is for the benefit of the main speaker, it blocks low frequencies from the main speaker, without which the stat receives a full range signal and there will definitely (at least in most cases) be an overlap of some of the operating bandwidth of the sub, for smooth integration redirection of the bass frequencies away from the main speaker to the subwoofer is required, the same principle in operation in conventional 2-way speaker designs.

[E-Stat]

Confused definitely not me :) , as the definition of of high-pass filter as defined by wikipedia is precisely what I and JoeE SP9 had in mind, the high-pass filter is for the benefit of the main speaker, it blocks low frequencies from the main speaker, without which the stat receives a full range signal and there will definitely (at least in most cases) be an overlap of some of the operating bandwidth of the sub, for smooth integration redirection of the bass frequencies away from the main speaker to the subwoofer is required, the same principle in operation in conventional 2-way speaker designs.
Ok, so you are not referring to controlling the subs behavior alone. I am loathe to compromise the resolution of my U-1s by introducing more more cables and active stages just to achieve a half octave or so lower response (below 25 hz) or adding hearing damaging levels to the equation. My former Acoustat 2+2s don't even come close to the neutrality or resolution level that the Sound Labs achieves.

rw

[JoeE SP9]

Hi Joe,

which transmission line Subs are you constructing, at 18Hz flat with no equalization, it looks quite juicy ;) .
They are my own design. They are approximately 9ft long folded tubes.http://forums.audioreview.com/images/icons/icon6.gif

[JoeE SP9]

I will respectively disagree. I've tried active subs using low pass filtering with Acoustats dating back to '77. My objection was related to the sub's different radiation pattern, not boominess. I tried settings down to 50 hz or so and was never satisfied.

That's why I enjoy the SL U-1s - they respond down to the twenties without augmentation.

rw I have alway used 2 subs positioned close to my panels. This way the differing dispersion patterns are about as significant as with ESL's having built in woofers.http://forums.audioreview.com/images/icons/icon6.gif

[E-Stat]

I have alway used 2 subs positioned close to my panels. This way the differing dispersion patterns are about as significant as with ESL's having built in woofers.http://forums.audioreview.com/images/icons/icon6.gif
Like I said, it's not the same to me. I always used full range Acoustats, not the hybrid flavors.

rw

[JoeE SP9]

Like I said, it's not the same to me. I always used full range Acoustats, not the hybrid flavors.

rwTruth be told, the old original Model 3's were my favorites. They needed no sub! In my old room they were flat to 32Hz. They are just too wide for my present room.
I have been thinking of some 2+2's. Their radiating area being greater than the 3's I should get exceptional bass. I have never been completely satisfied with subs. On the other hand using an external crossover allows me to use a crossover point lower (85Hz) than most hybrids use. The 2's do sound very very good without low end reinforcement but for solidity a sub is a must. Thank you very much for making me consider spending more money on this managable insanity we call a "hobby". Also, ditching the subs would give me room for more LP's and CD's. Hoorah!!

[Florian]

Same here, i have tried subwoofers on my .5 Maggies (my first good speaker) and couldnt stand it. My big Ap's dont need subwoofers so it doesnt really matter to me. But from the systems i have heard, may they be planar magnetic, electrostatic or ribbon there is not a single one that has worked with a subwoofer, well those that needed one.

-Flo

[JoeE SP9]

Same here, i have tried subwoofers on my .5 Maggies (my first good speaker) and couldnt stand it. My big Ap's dont need subwoofers so it doesnt really matter to me. But from the systems i have heard, may they be planar magnetic, electrostatic or ribbon there is not a single one that has worked with a subwoofer, well those that needed one.

-FloIf I was only into chamber music and other lighter types of music the Model 2's would be more than sufficient. I just need some "kick butt" bass in regular doses.

[E-Stat]

Truth be told, the old original Model 3's were my favorites.
I confess a sweet memory of my first stats, the original model X, a three panel design back in '77. They were the predecessors of the Model 3 with the direct drive tube amps.


I have been thinking of some 2+2's. Their radiating area being greater than the 3's I should get exceptional bass.
That was my experience for over twenty years.


Thank you very much for making me consider spending more money on this managable insanity we call a "hobby".
Sorry for fanning the flame. ;)

I use subs in my two HT systems where they work very well. It's just that for music, I have been long spoiled by the utter coherency of a full range design.

rw

[Geoffcin]

Like I said, it's not the same to me. I always used full range Acoustats, not the hybrid flavors.

rw

The reason I ask is that I'm finally getting around to repairing my old Magnepan III's, and I was toying with the idea of using them as "bass re-enforcement" panels.

[Florian]

If I was only into chamber music and other lighter types of music the Model 2's would be more than sufficient. I just need some "kick butt" bass in regular doses.
I hear you ;-) Not all panels can do great low bass, to be honest there are only a handfull. My friends Acoustat 1+1's are dynamically very limited and a sub would not be a bad thing. But we are purists, and we can hear the subs sticking out so its a no no :-) But then again its none of my beer anyways and my sub 20Hz panel bass is Okidokey by me ;-)

[JoeE SP9]

Alright, Florian and E-Stat I hope you realize what you've done. I am at this moment trying to do two things. Find a buyer for my Model 2 SW's and find a good pair of 2+2's. My real problem is what do to with the two folded tube transmission line subs I just built. They are 66" tall and 24" in diameter. Their look is rather agricultural so they would never be seen in Architectural Digest. Oh well, they really didn't cost that much. Only the woofers are costly. Concrete construction formers are not that expensive. I guess I'll hold on to them until I find out what kind of bass response I get with the 2+2's. My previous experience with the Model 3's leads me to believe that I should get bass response that is flat to around 25Hz. I consider that to be sufficient.http://forums.audioreview.com/images/icons/icon6.gif

[E-Stat]

The reason I ask is that I'm finally getting around to repairing my old Magnepan III's, and I was toying with the idea of using them as "bass re-enforcement" panels.
I remember hearing T-IIIs back in '75 or so. Very impressive. Naturally, I would be biased (pun intended) to hear U-1s with matching UB-1s. :)

Lot's o' Sound Labs (http://www.soundlabowners.com/forum/messages/116.html)

Click photo link.

rw

[JoeE SP9]

The reason I ask is that I'm finally getting around to repairing my old Magnepan III's, and I was toying with the idea of using them as "bass re-enforcement" panels.I have always loved the tympani series. I once got a chance to hear a set with all of the panels including the bass panels. Bass to die for!http://forums.audioreview.com/images/icons/icon6.gif

[jtgofish]

The reason I ask is that I'm finally getting around to repairing my old Magnepan III's, and I was toying with the idea of using them as "bass re-enforcement" panels.

I was hoping to get some discussion started on what sort of drivers work best with electroststics.This has not really happened.I suspect that the typical sub drivers which feature 10 or 12 inch cones and long excursion heavy rubber surrounds are not right.The RCF uses a very stiff suspension with small excursion and cloth surrounds which makes for a much faster and detailed sound.Although this also means less low bass,this is compensated for by the larger cone area .
I think it is a topic wothy of further exploration.

JT

[Geoffcin]

I was hoping to get some discussion started on what sort of drivers work best with electroststics.This has not really happened.I suspect that the typical sub drivers which feature 10 or 12 inch cones and long excursion heavy rubber surrounds are not right.The RCF uses a very stiff suspension with small excursion and cloth surrounds which makes for a much faster and detailed sound.Although this also means less low bass,this is compensated for by the larger cone area .
I think it is a topic wothy of further exploration.

JT

With a larger sub, you have a lower max-x for the same volume. This translates into a faster responce time. Paradoxically larger is faster in this case. Also with a servo controlled sub you have vanishingly low distortion. The newer servo subs are even better at this than mine, with lighter accelerometers and higher sampling rates. Paradigm also makes a high quality servo sub. I think either of these would be a great match for an electrostatic for the person who wants bass re-enforcement.

[armyscout42]

LACK OF KNOWLEDGE AND EXPERIENCE AND EXPERIMENTATION IS WHAT I SEE AS THE PROBLEM OF THOSE WHO CLAIM THEY CANNOT USE SUBWOOFERS WITH ELECTROSTATS OR PLANARS. That is utterly nonsense. BOOMY they say? Well conventional dynamic loudspeakers are often boomy if you have improper equalization and room acoustics etc.

I suggest if you encounter boominess with an electrostat/subwoofer combo is to invest on some dakiom feedback stabilizers which will help clean up your system into a tighter and cleaner bass along with highs, mids etc.
You can also add on some wonderful dj, commercial and professional soundprocessors used for various applications including subs that most audio enthusiasts and even audiophiles do not seem to know...
go to www.123dj.com or dakmart for example and get yourself some aphex 204 aurel exciter w/big bottom, or peavey kosmos (hollywood studios use them for THX), BBE sonic maximizer with subharmonic controls such as 362sw.....

I highly recommend any of these, since I own them all! I am a sound processor/loudspeaker junkie and veteran....TWEAKING is my FORTE! 27yrs in the audio world... I will never go without TWEAKS, EVER regarding audio!

[squeegy200]

I currently have the maganplanar SMGs which are ideal for my small listening space.

In my attempts to integrate a subwoofer with the planars, I've found that subwoofer placement in the listening space is most critical. I don't know if there is any theory to substantiate my findings, but I found that the subwoofer cannot be placed anywhere near the planars at the front of the listening space. The presence of the primary sound energy from the front and its 180 counterpart from the rear of the panel will conflict with the sound energy from subwoofer resulting in muddy bass or offsetting cancellation. (It makes me curious to experiment with some of the dipole Subwoofer designs I've found in many discussions-but that is another topic)

But I found my most successful attempt at integrating a subwoofer has been placement behind my listening position at very low volume levels. It does not seem to collide with any of the cancellation nodes and I cannot perceive any out of phase sound pressure from my listening position. With the volume low, it still fills the lower reaches where my SMGs are weak but I do not perceive its presence nearby. It sounds as if all of the sound energy is eminating from the magnaplanar panels up front.

I don't understand it but if anyone can explain it, I would appreciate the education. It does seem to work.

[E-Stat]

(It makes me curious to experiment with some of the dipole Subwoofer designs I've found in many discussions-but that is another topic)
I think you and I are on the same page. It's not about boominess or anything that a black box can correct. I was never happy attempting to blend a pair of direct radiator subs with my last pair of bipolar electrostats. A concert drum never sounded "right".

I moved them to the HT system where they work well with a pair of Polk monitors. If I win the lottery, however, I'll buy a pair of Sound Labs UB-1 subs to match my speakers.

http://home.comcast.net/~ralphwallace/audio/ub1.jpg

rw

[squeegy200]

....If I win the lottery, however, I'll buy a pair of Sound Labs UB-1 subs to match my speakers. ....

rw


Holy Cow! Those look awesome!

[bubslewis]

I currently have the maganplanar SMGs which are ideal for my small listening space.

In my attempts to integrate a subwoofer with the planars, I've found that subwoofer placement in the listening space is most critical. I don't know if there is any theory to substantiate my findings, but I found that the subwoofer cannot be placed anywhere near the planars at the front of the listening space. The presence of the primary sound energy from the front and its 180 counterpart from the rear of the panel will conflict with the sound energy from subwoofer resulting in muddy bass or offsetting cancellation. (It makes me curious to experiment with some of the dipole Subwoofer designs I've found in many discussions-but that is another topic)

But I found my most successful attempt at integrating a subwoofer has been placement behind my listening position at very low volume levels. It does not seem to collide with any of the cancellation nodes and I cannot perceive any out of phase sound pressure from my listening position. With the volume low, it still fills the lower reaches where my SMGs are weak but I do not perceive its presence nearby. It sounds as if all of the sound energy is eminating from the magnaplanar panels up front.

I don't understand it but if anyone can explain it, I would appreciate the education. It does seem to work.


Interesting. I just purchased a pair of Magnepan 1.6's. Will not receive them for a week or so. I auditioned them without a sub and the bass output seemed sufficient (I like balanced bass but am definitely not a bass freak).

I currently have a modest 100 watt subwoofer. I'm not sure if I'll need it with the 1.6's, but I'm certainly going to test it out when the maggies get here. Is there an ideal position that a subwoofer should be placed in? It sounds like there are sub positions that should definitely NOT be used when teamed up with magnaplanars.

I'll certainly see how things sound by putting the sub behind the listening area or out beyond the side surrounds.

tx,
Bill

[JoeE SP9]

The problem with subwoofers and planar speaker does not have anything to do with boomy response. The different radiation patterns create a very slight discontinuity where the sound is crossed over to the subwoofer(s). You will only be able to hear this if you listen to some panels with a very good low and and the same panels augmented with a subwoofer. There is not a difference in the quantity of bass or the extension. There is a difference in the integration of the bass. With the sub(s) the bass does not seem to come from the same place. Without the sub(s) there is a seamless coherency that no other speakers seem to have.
If there is a boomy sound from a panel sub combination it is almost always caused by either too high a crossover frequency, too high a level on the sub(s) or both.:cool: