Living with an Acoustical Line Source

reeltrouble1

The Sound Lab Millieneum

The underlying theory of electrostatic speakers is actually quite straight forward. The laws of physics teach that "like" electrical charges repel one-another and "unlike" electrical charges attract one-another. But this is easy to say and much more difficult to execute. First, stretch a very thin membrane on a rigid frame. Then coat it with a low-mass electrically-conductive substance. After that fabricate stiff flat electrodes called stators and then insulate them to prevent discharge. The audio signal applied to each stator is identical with the exception of phase, one signal is 180 degrees out of phase with the other. So as the signal voltage on one stator increases positively, it attracts the negative electron charge on the membrane. The signal voltage on the other stator is increasing negatively and, hence, repels the charge on the membrane. Thus, a "push-pull" force is exerted on the membrane. When the audio signal reverses, the push-pull force also reverses. Since the membrane is compliant, the push-pull electrostatic force applied to it causes it to move. Thus, air is moved and sound is created in the image of the electrical driving force. Wallah it works, straight from Mr West and his site with a bit of paraphrasing.

So what do you get? Well imagine if you would a string running from the floor to ceiling of your listening room, and then imagine that if you plucked the string it produced full frequencies with superb transient speed, no coloration, openess, detail, and a coherence of the sound only produced by a single driver. Oh yes, and we can cut the string and still keep everthing since the speaker although large, in my case about 6 ft tall is not as tall as the whole room. You end up with an Acoustical Line Source.

So what sets Dr. Roger West's speakers apart from the pack? Well, he facets the "curved" face, putting many smaller flat panels together to form the panel needed for quality sound, this sectioning not only allows for deep bass (mine go to 30hz) it also eliminates so called one note bass ELS so often have a problem with if they can play bass at all or need to use a supplemental bass system. There are many other innovative technique's that the Sound Lab company patents and incorporates in their speakers, if you interested check it out at http://www.soundlab-speakers.com/products.htm

Of course nothing can be perfect. These speakers need tremendous power to work properly and like all high end products they are so complex and sensitive that changes to air temp. humidity, and environment do effect the bias charge of the panel, so you have to be willing to adjust the bias as needed and keep a dehumidifier in your room. A small price to pay as far as I am concerned for the sound you get.

Now speaking of power, the speaker has measured to dip as low .5 ohm during treble passages. The bass impedance curve is also not all that smooth. As many know this caused me to have to let my beloved BAT amps go. In their place are now Wolcott Presence 220 watt monobloc, with, yep variable damping of both high or low frequencies to meet your need, an amazing design to say the least. Eight excellent EL-34 power tubes with some innovative driver design and an auto-bias circuit, all add up to a terriffic tube amp. As we know.........TUBES RULE.

I have included some shots for you to see the new amps, cant get the speaker shots up right now, but I think I posted them in another thread. No doubt that an audio trip with an ELS speaker of your choice is highly recommended, but in particular Sound Lab, one of the most unknown yet one of the best Electro-Stats ever built.

RT1

reeltrouble1

Shot of the backstage.

RT1

dkg999

I want to be Ted when I grow up!

Very, very nice!

Face

Very nice Ted.

Funny that you post this now, I was recently impressed by another speaker who use the same principle of many small panels that make up one large one, the Kingsound Prince 2. Panels definitely have a certain magic to them that box speakers can never have.

Enjoy!

hearingimpared

Nice write up Big Brother.

reeltrouble1

Yes Mike, each panel within a facet has separate stators resulting in each segment of the membrane being individually charged both front and back. So although all portions of the membrane and each of the stators are connected electrically to the same power supplies and see the same signals, by dividing the membrane up into separate panels of varying size allows the speaker to distribute the resonance of that membrane. A number of varying sized panels will have smaller amplitude resonances at different frequencies than just one large panel with one large amplitude resonance at one frequency, additionally, this distribution of resonances of the membrane allows resonant energy to be available to boost bass responce more uniformly further reducing bass drumhead effect.

A bit hard to understand the above until you look at the speaker, amazingly the membrane is less than 100 millionth of an inch thick, extremely compliant with low mass. I am hearing deeper into the music, layering is excellent as claimed the speakers are very coherent unlike any box I have ever heard.

dorokusai

Since when was Soundlab an unknown loudpseaker?

reeltrouble1

You seen any SoundLab ads?? Reviews in the rags in say the past five years??

Sure a nut case like you knows about them.

Anway a quick check of CP notes seven hits in seven years here, no matter, I am sure we can talk some more about wire.

RT1

Fireman32

Very nice Ted. I hope to hear it one day.

reeltrouble1

Cool Dave, most everyone is welcome to come down, listen to the tunes and enjoy the area.

I am working on something new for the audio room, should be nice. But first I have to complete another project.

RT1

janmike

Congrats Ted. That would be a trip worth making. So, more PC's being added?

dorokusai

reeltrouble1 wrote: »

You seen any SoundLab ads?? Reviews in the rags in say the past five years??

Sure a nut case like you knows about them.

Anway a quick check of CP notes seven hits in seven years here, no matter, I am sure we can talk some more about wire.

RT1

In my denizen style existence I've heard 4 pair in my travels, one quad setup and one local. Outstanding loudspeaker and in this crowd, certainly an apple amongst oranges. Good on you for bucking the system.

Why would Club Polk be the marker of something rare?

nooshinjohn

nice setup. I look forward to the learning about your additions...

reeltrouble1

dorokusai wrote: »

In my denizen style existence I've heard 4 pair in my travels, one quad setup and one local. Outstanding loudspeaker and in this crowd, certainly an apple amongst oranges. Good on you for bucking the system.

Why would Club Polk be the marker of something rare?

Guess I was trying to raise the bar a bit. What was I thinking!!! I am though wearing a speedo undergarment as the boxer drawer was a bit lean this morning.

I did read about some sort of mulitple speaker set-up with SoundLab at CES with Ray Kimber's rig, the reviewer noted it as best in show. But it was just a couple paragrah blurb in TAS I believe, the set-up was uber hi-fi at a price tag of around a half-million. But you can find SL for much less if you take your time and I got mine for a very reasonable price comparitively speaking.

For those who do not know my interest in planars was sparked/boosted when I went to the Doro-Polkfest and heard a fine pair of Maggie's, so what's the point??? Well instead of looking at the pictures of a Fest, get to one, say the next one, I believe it may be BDT's, I always provide him support, not to let any cats come out of the bag early, but I would not be suprised if there were Planar, Ribbon, SDA, Bookshelf, like nothing you may of heard before run by some very nice electronics. Sure the monitor 7's still will hold a place, plenty of Polk stuff will be on hand.

OK, so back to Sound Lab, if you learn about Dr. West, he is in many ways your rather typical audio eccentric/genius, audio is his passion, not his job, he just wanted to build nice speakers for folks, he had no interest in becoming a super audio company and is a very laid back fellow, easy to find and he frequently will write you himself if he sees a question over at SL owners forum.

ELS speakers are just so different from boxes, first off the impendance curves are something, the speaker rises to 50 ohms or better in the bass, not so good in general for SS amps, (ever wonder what a 200 watt ss puts out at 50K) still some owners use Krells or Arye's with good results, however, tube amps from Wolcott, Atma-Sphere (OTL), VTL and such are among the most coveted by Sound Lab owners. One thing for sure these speakers will let you know if there are any problems upstream, but in a rather polite way.

steveinaz

Ted,
What are the large boxes behind the amps?

reeltrouble1

Steve,

Those are the tube cage covers, purely cosmetic, I prefer to see the tubes so I set them behind as you see them, now the large boxes attached to the speakers visible in the backstage shot hold all the electronics for the speaker panels, a large toroidal transformer, capacitors and so on. There is no crossover as we know it, there are some rotary dials and pots to adjust frequency levels up and down. Speaker level connections and the bias circuitry for the panels.

steveinaz

Holy crap. Wicked setup man.

megasat16

Hmm....Planar with Dipoles Radiation and Tubes...:)

Ted, you sure your tubes can handle this?

disneyjoe7

Very Nice, and well worth the trip

reeltrouble1

megasat16 wrote: »

Hmm....Planar with Dipoles Radiation and Tubes...:)

Ted, you sure your tubes can handle this?

My Tubes Rule.

RT1

Hawkeye

I certainly appreciate this write up. Not too much out there to read about the SL. I don't think I could ever go back to the box again in spite of the "finicky" reputation of ESL's. I also keep an air purifier on in the room because we have a dog that sheds and I enjoy a cigar every now and then when listening. Smoking is not the best thing for the membrane but I try to keep it to a minimum. Does SL recommend running the vacumn over the panels or do they all have a fiber cover?

I considered the Quads but I understand there is a quality and or service issue with them recently. Next month I'm going to listen to the ML CLX and see how well the bass is reproduced. I'm certain the mids and highs will be as stellar as ever, hopefully far ahead of the Spire, but the bottom is questionable until I actually here them.

Thanks again for your write up.

Gordon

george daniel

Congrats Ted,,I just looked at the pic's,,are the amps EL-34 based?

Vette C6.r

Hate to see you electric bill Reel.

Well worth whatever it is.

megasat16

reeltrouble1 wrote: »

My Tubes Rule.

RT1

The only tube that rules for me has color temperature of 9000 Kelvin.

If your tubes doesn't shine that bright, take the glass cover off to see it'll light up more.



Nice setup, man! Congrats you are enjoying it.

amulford

reeltrouble1 wrote: »

My Tubes Rule.

RT1

You better put a knot in them puppies. Sounds like you're ready to get your **** kicked by the missus. How long do you think she's gonna go on cleaning those spots out of the carpet???

tonyb

Very nice Ted,but for me,they seem too finicky and that would drive me nuts.Anyway,good music is good for the soul,no matter what you have.Enjoy!!

reeltrouble1

george--yes the power tubes are EL-34, I am using Svetlana winged C, nice tube.

Hawk--no have not seen a vacuum recommendation for the panels, I just keep the dust off and no smoking or animals in the shed. I did read about the new ML coming out, the overall review was positive.

One thing for sure, any kind of good music is captivating, I certainly have been having some fun with all the vinyl, jazz and classical.

RT1

Hawkeye

RT1, It is interesting that there is a thread going on now at the ML club comparing the the SL to ML. Of course there is an obvious bias toward ML, there is one guy there who has owned several pair of SL. I pasted the link in case you may want to read his comments. Quite a fair discussion.

http://www.martinloganowners.com/forum/showthread.php?t=8720

Gordon

organ

Beautiful amps. Must cost you a fortune to re-tube them. EL34's are awesome tubes.

reeltrouble1

Read the link to ML, agree totally different speaker design, I would however not want people to think the Sound Labs are all huge speakers, yes, they do make some that are nearly 9ft tall, however, mine measure a bit under six feet and are around 30" wide and fit well in my present room.

The fellow who said he has "heard" them (SL) and found them cool, was rebutted by the others, I would agree, the speaker is neutral with extreme clarity but the treble is very sweet sounding, by adding or removing bias from the panel you can change the sound, however, what is really happening especially with sand amps is as you remove bias you lose sensitivity, with the high impedance in the bass the amplifier cannot keep up and the sound distorts with the very low impendance for the treble again the amp struggles. The best sand amps for these speakers incorporate many capacitors for energy storage in their design. Tube amps do a bit better with the voltage swings the tube make possible, but as I said earlier selection of the amplifier and other upstream gear is key. The BAT Pre-amp I use does have nice synergy with the Wolcotts along with the Musical Fidelity KW SACD and a heavily modded Rega P-25 TT.

EL-34 tubes are readily available, somewhere around 25 each, average around five years lifetime depending on use, so retubing is not really all that expensive to me, there is one of the driver side tubes the 6gw8 becoming a bit rare, each amp takes two, right now they are running 75 each but they last up to 10 years, the other two driver tubes are common 12ax7, available all over the net, the circuit design does not require matched tubes additionally tube rolling is not recommended as the design does not allow tube coloration of the signal.

Here are some more shots of the speakers.

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F1nut

I'm glad the move has worked out and that you're enjoying the music again. I'm looking forward to getting my ears on your rig, but please remove the garlic from the room as I found it very distracting at PF.