Electrostatic speakers?

[Newman]

Driving that awful capacitive ESL load is a big problem. Pushing several nanofarads around through a high turns ratio step up transformer is a drag. I can see why an amp would get indigestion real fast on a diet like that. Maybe the way to get a good ESL is to design the speaker with its own amp built in, and the amp would be specifically designed to work with that panel. High current capability would be a main item on the amplifier's to do list.

If you are referring to a custom amp that avoids a step up transformer, that is a thought that crosses every stat-man’s mind, as it seems to be the obvious and right thing to do. But apparently, it isn’t so in practice. They just can’t be made to deliver the drive of a high-power SS amp into a high quality step up transformer.

 

[Jazzman53]

Hi Jazzman53, I've admired seeing your speaker builds over the years and reading your very knowledgeable insights. In the latest iteration, how do your speakers fare playing loud volumes and also handling dynamics? Is there a max spl spec for these speakers? In addition, is there a disadvantage sonically to the segmentation method which you are implementing to increase dispersion?

[/QUOTE]

My panels are larger than most hybrid ESLs and the are designed for very high efficiency. I would not use them for a party outside on the back deck but they have plenty of slam and energy in my living room. The Segmented ESL Calculator program I used to designed them calculates the max output to be 103 decibels at 3 meters. That's plenty loud for my ears and in fact I have never cranked them to max volume because that would exceed my pain threshold.

My first and numerous ESL builds were unsegmented flat perf panels. I had not heard segmented panels when I decided to build a pair, and I was quite skeptical and concerned that inserting 100k+ resistors between the wire groups would not negatively impact the sound quality I was accustomed to (with unsegmented panels).

But within seconds of hearing first sound from the segmented panels (Diana Krall's "A Case of You"), I couldn't believe that I heard NOTHING to indicate that the resistors were there-- only a significantly wider sweet spot and a balanced response, requiring much less EQ'ing than an unsegmented flat panel. My electrical engineer friend, Martin, was in the room at the time, and he commented that "you don't hear what the resistors shunt away"-- still trying to figure that one out. I can only tell you that sound from a symmetrically segmented ESL panel is very clean and spooky-real.

 

[Newman]

The Segmented ESL Calculator program I used to designed them calculates the max output to be 103 decibels at 3 meters

That‘s pretty bad. When I listened to my One Loud Track For The Night last night, my SPL meter was reading 114 dB at 3 metres peak value, even though the average was in the low 90’s.

I would hate to be unable to listen to an occasional loud track. Too limiting.

cheers

 

[Jazzman53]

Hi @Jazzman53 , this is interesting. As mentioned, I have an analog preamp in my chain (before my Venu360). In your setup, where do you do volume control ?

To my knowledge; a Logitech Transformer is the only streamer with a volume-controlled digital output. So; it can and does serve as a digital preamp in my system. On all other streamers I know of; the digital outs are merely pass-thru's.

You should be aware though, that using the Transporter as a digital preamp reduces its bit-resolution somewhat. The Transporters volume control acts on the digital stream, not the output stage, even when using the analog outs.

If you use the analog out (into an analog preamp), with the Transporter's volume set to maximum, the output will be full resolution 24-bit converted to analog. In this setup the volume will be controlled downstream at the analog preamp.

If using the Transporter as a digital preamp via it's digital volume control; the bit resolution is reduced by 1-bit for each 6db of downward attenuation on the volume control (i.e. lower fidelity at lower volume). I use it this way and it still sounds freaking wonderful.

In my setup the Transporter is feeding a DBX Driverack Venu 360 crossover/DSP. I tweak the output gain on the DBX such that at my typical listening volume, the volume control on the Transporter is about 75%.

 

[Jazzman53]

That‘s pretty bad. When I listened to my One Loud Track For The Night last night, my SPL meter was reading 114 dB at 3 metres peak value, even though the average was in the low 90’s.

I would hate to be unable to listen to an occasional loud track. Too limiting.

cheers

You must be deaf by now... no one who's heard my speakers cranked up has every asked me to turn them up, only down.

 

[Sir Sanders Zingmore]

To my knowledge; a Logitech Transformer is the only streamer with a volume-controlled digital output. So; it can and does serve as a digital preamp in my system. On all other streamers I know of; the digital outs are merely pass-thru's.

You should be aware though, that using the Transporter as a digital preamp reduces its bit-resolution somewhat. The Transporters volume control acts on the digital stream, not the output stage, even when using the analog outs.

If you use the analog out (into an analog preamp), with the Transporter's volume set to maximum, the output will be full resolution 24-bit converted to analog. In this setup the volume will be controlled downstream at the analog preamp.

If using the Transporter as a digital preamp via it's digital volume control; the bit resolution is reduced by 1-bit for each 6db of downward attenuation on the volume control (i.e. lower fidelity at lower volume). I use it this way and it still sounds freaking wonderful.

In my setup the Transporter is feeding a DBX Driverack Venu 360 crossover/DSP. I tweak the output gain on the DBX such that at my typical listening volume, the volume control on the Transporter is about 75%.

thanks, so in the absence of a Transporter I guess I’d have to do volume control in software on my computer. This is something I’m too scared to do

Have you considered a unit such as the miniDSP SHD?
As far as I can tell it can stream, apply crossovers, apply Dirac dsp. As well, it performs volume control after dsp and crossovers in the analog domain (I think it’s analog anyway)

 

[Jazzman53]

thanks, so in the absence of a Transporter I guess I’d have to do volume control in software on my computer. This is something I’m too scared to do

Have you considered a unit such as the miniDSP SHD?
As far as I can tell it can stream, apply crossovers, apply Dirac dsp. As well, it performs volume control after dsp and crossovers in the analog domain (I think it’s analog anyway)

BTW; a Logitech Squeezebox Touch also has a volume controlled digital out... and you can still find them pretty cheap on Ebay. I had one and it sounded really good.

 

[Newman]

You must be deaf by now... no one who's heard my speakers cranked up has every asked me to turn them up, only down.

Wishful thinking mate. And maybe you need to watch Amir’s video on sound levels…a bit of education never hurt anyone.

 

[steve f]

You must be deaf by now... no one who's heard my speakers cranked up has every asked me to turn them up, only down.

Also remember that line sources like ESLs only drop off at about 6DB per meter. I’m in agreement with Jazzman that I’ve never felt the panels “run out of steam” on my ESLs.
pin a conversation with Roger Sanders, he stated that a few people managed to ruin the 10” drivers in his earlier TLs. I found that surprising. Nobody has ever destroyed one of his panels.

 

[TLEDDY]

I have a pair of Quad ESL, the original electrostatic loudspeaker. These are late editions from the end of their production run. To me, I have found nothing that has compared within reason. They are still in original condition and work fine. A couple of years ago I gave them a thorough cleaning and was advised that if they continue to work, no other things need to be done. I dread the day when they stop working. I have put a lot of hours on them this past year with the lock down and worry that I will miss them when it comes time to move back to the city.

They truly are remarkable and hard to believe they were developed in the 50’s.

The good news for you is there are new and rebuilt panels available! I own rebuilt Quad 57s (4), so - don't worry!

 

[Newman]

Nobody has ever destroyed one of his panels.

Looks like you’ve been drinking the kool aid on his website.

See if you can find a specification there for the maximum output at 1 metre and 20 Hz before arcing or limiting. No? Well well.

 

[egellings]

A buddy of mine had a pair of KLH brand 'stats. He sawed holes in the wall, each the size of the speaker, and placed the stat's in the holes so that all of the back wave went into a bedroom. He basically made the speakers a part of the wall and sealed the seam between the speakers and the wall. He closed the bedroom door and the bass was quite impressive.

 

[Jazzman53]

Also remember that line sources like ESLs only drop off at about 6DB per meter. I’m in agreement with Jazzman that I’ve never felt the panels “run out of steam” on my ESLs.
pin a conversation with Roger Sanders, he stated that a few people managed to ruin the 10” drivers in his earlier TLs. I found that surprising. Nobody has ever destroyed one of his panels.

I recall hearing that too. In fact; Roger states on his website that none of his PCB stat panels has ever failed. The stators are machine slotted and the conductors are encapsulated in glass so I can see how they would be quite arc resistant and reliable. A reviewer in one of the audio magazines wrote that Roger's speakers have no protection circuitry and he cranks them to live performance levels with no apparent concern. Also; I'm pretty sure Roger uses a very high resistance diaphragm coating to allow constant charge mode operation, which further mitigates and doesn't sustain arcing.

I'm not surprised he's blown some woofers, however. I've gotten carried away with the volume and blew several Aurum Cantus MkII 10" woofers ($$ ouch) in my old beam splitter ESLs, but I never hurt the insulated wire ESL panels at all.

 

[steve f]

I recall hearing that too. In fact; Roger states on his website that none of his PCB stat panels has ever failed. The stators are machine slotted and the conductors are encapsulated in glass so I can see how they would be quite arc resistant and reliable. A reviewer in one of the audio magazines wrote that Roger's speakers have no protection circuitry and he cranks them to live performance levels with no apparent concern. Also; I'm pretty sure Roger uses a very high resistance diaphragm coating to allow constant charge mode operation, which further mitigates and doesn't sustain arcing.

I'm not surprised he's blown some woofers, however. I've gotten carried away with the volume and blew several Aurum Cantus MkII 10" woofers ($$ ouch) in my old beam splitter ESLs, but I never hurt the insulated wire ESL panels at all.

Roger switched to the same monster Seas L26RO4Y woofer (don’t know if it’s the 2 or 4 layer voice coil version) that Linkwitzlab uses.

 

[Wes]

no conventional EM driver has the ultra-low moving mass/inertia of an ESL

If a conventional EM driver can achieve a flat response to 20 kHz (beyond the (sine wave based) hearing of most audiophiles) then is there any advantage to the ultra-low moving mass/inertia of an ESL, Maggie, or plasma driver?

 

[NTK]

https://purifi-audio.com/2019/12/10/a-fast-driver-needs-a-light-cone-or-does-it/

 

[milezone]

https://purifi-audio.com/2019/12/10/a-fast-driver-needs-a-light-cone-or-does-it/

"There’s little point in elaborating the intricacies of membrane design here because you can simply look at the frequency response graph. If a driver’s response is smooth and continues a long way, it’s ‘fast’."

A Beyma 15P80Fen 15" woofer with a moving mass of just 88g is ~flat to 3khz. Similar is true of drivers like the TAD TD1601A, Altec 416, JBL 2226H all of which feature low mms cones. These drivers will not perform as subwoofers in the way that heavier drivers will yet provide a lot more flexibility for crossover design extending further and distorting less than heavier 15" counterparts in the higher frequencies of their range. All other factors being equal, low mms cones will accelerate faster and thus produce a faster impression. In this instance the slower cone will produce a worse approximation of the bass frequency it is rendering with respect to time, where as the lighter cone will produce a tone closer to the source content. In addition to the crossover advantage, these sorts of woofers are more optimal for matching with compression drivers which have the same characteristics of 'speed' -- requiring less damping of the compression driver to phase and time align it with the woofer. That said, the ability to time align and crossover in DSP before amplification mitigates the issues associated with a passive network between an amplifier and a driver.

 

[Jazzman53]

If a conventional EM driver can achieve a flat response to 20 kHz (beyond the (sine wave based) hearing of most audiophiles) then is there any advantage to the ultra-low moving mass/inertia of an ESL, Maggie, or plasma driver?

As I've said before; its fair to question my objectivity because I design and build ESLs.
I'm going to offer my opinion anyway:

I agree that the latest EM driver tech is better than ever, and pretty amazing. However; I think physics still favors the ESL, and frequency response is only part of the sonic signature.

Transient response and slew rate (decay rate) are where lower mass gives an edge, and I think the higher slew rate is what gives an ESL its characteristic spooky-real sound. That is; the ultra-low mass/inertia diaphragm is so effectively dampened by the [much greater] air mass it's coupled to, that it simply doesn't ring.

I've discussed this at length with Roger Sanders and he offered this analogy:
Imagine striking a bell with a hammer and observing its ringing and slow decay to silence. Now imagine submerging the bell in liquid mercury and striking it with a hammer. There will be relatively little ringing, and rapid decay to silence because its effectively dampened by the greater mass it's submerged in.

An ESL diaphragm isn't lighter than air of course but it's significantly lighter than the mass of air it's coupled to and moves. In this respect physics favors lower mass.

BTW; a Maggie diaphragm isn't really low mass because it uses a looped wire voice coil that's bonded to and moves with the diaphragm.

 

[Sir Sanders Zingmore]

Looks like you’ve been drinking the kool aid on his website.

See if you can find a specification there for the maximum output at 1 metre and 20 Hz before arcing or limiting. No? Well well.

do you mean 20Hz? The sanders panels cross over to the subs well above this.

My anecdotal experience: A couple of times I have accidentally sent full volume full range (ie bypassed the crossover) to my sanders panels. We are talking 500w sanders amps here.
The fuse blew on the amps before I could hit mute. The panels were absolutely fine.

 

[Jazzman53]

do you mean 20Hz? The sanders panels cross over to the subs well above this.

My anecdotal experience: A couple of times I have accidentally sent full volume full range (ie bypassed the crossover) to my sanders panels. We are talking 500w sanders amps here.
The fuse blew on the amps before I could hit mute. The panels were absolutely fine.

To my knowledge; a Sanders ESL is the only speaker in the world that comes with a lifetime warrantee-- you can't call that hype when it's backed up.