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.

[theaudiohobby]

Hi Joe,

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

[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.

[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.

rw

Ditto here! Bass response down to 18Hz

[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

[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.

[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.

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

rw

[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

[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....

[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.



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.