Sound Labs 645-8, A Review

I finally got the Sound Labs dialed in and have been listening for over a month. They are 8 foot 645's, the first pair ever made. Standard 845's were to wide for my situation. 645's are 4 inches narrower at 36 inches. I called Roger West, CEO of Sound Labs and asked if he could make me a set of 8 foot tall 645s in Majestic trim to which he immediately replied, "no problem." Two months later I had my speakers. He did not charge me a cent extra for the custom work.

The speakers arrived in two serious wooden crates with the interface/bases in two separate boxes. In spite of serious packing one speaker had a small area of the finish rubbed down to primer on the side trim, fortunately an easy fix. 
The speakers were a breeze to assemble and set up but it does take two people. You have to be careful with the grill cloth. It is as light as shear stockings. On the interface panel there are four controls. The bass and midrange controls are heavy duty rotary switches. The brilliance control is a Zero to 8 ohm 100 watt potentiometer and the bias level control is a smaller potentiometer. All of this is sealed from the environment. The build quality of the interfaces is first class, neatly wired point to point, circuit boards need not apply. The transformers are massive. After several hours of listening I had room control calibrated and the speakers adjusted to suit my room. Bass down 3 dB, Midrange 0 dB and brilliance set at 2 ohms (measured).,

At the end of a particularly loud listening session playing Mellon Coli and the Infinite Sadness, I smelt insulation burning.
After 10 minutes of sniffing around I got the the left channel speaker which was where the smell was coming from. The interface was very hot. I could keep my hand on it but barely. The speaker sounded fine. I called Roger and he informed me it was probably the brilliance control. Which it was. It left this world the next day. Roger got a new one to me the very next day. In the mean while I installed 150 Watt 2 ohm resistors bypassing the brilliance control. After an hour of loud playback the interfaces were even hotter! Something was wrong. It was my room control unit. It had inadvertently boosted 20 kHz 12 dB which the JC 1's handily plastered the Sound Labs with. ESL impedance drops with frequency. Up at 20 kHz the impedance is less than 1 ohm. The amount of current at +12 dB 20 kHz was ridiculous and I fried the brilliance control. It was not in any way the speakers fault. Modern room control units place a limit on the amount of boost that can be applied. TacT was the very first to do room control and there were no limits placed on the DSPs. 
It did not bother the transformers at all. I replaced the brilliance control in case I wanted to return the units to stock and permanently mounted the 2 ohm resistors with thermal grease. I also bypassed all the switches leaving the bias control alone. I have to reiterate that this was my fault and regular systems and modern room control would never do this. Bypassing the controls probably does nothing to improve the sound but, it makes me feel better. Now with the system blasting for hours the interfaces just get a little warm. Roger was ready to send me new transformers! Could not ask for better communication and treatment.

Now for the serious part. Some things are hard to qualify. Such is the sound of these speakers. There are significant differences between these and the 8 foot Acoustats I use to have. The physical differences are; the Sound Labs have almost twice the surface area of the Acoustats but in reality, because the individual panels are much narrower and form a 45 degree arc you are listening to a much narrower speaker from 500 Hz up. Because ESLs beam you are really only listening to the membrane tangent to the axis of your ears, the resonance frequencies of the individual panels are much different than the Acoustats because the panels are smaller and of varying size. There is no one dominant resonance frequency, the Sound Labs disperse sound evenly over a 45 degree arc relative to the Acoustats 10 degree arc. They are much less selfish, you can plainly hear the speaker right up against the opposite wall at the distance of the listening position. Everyone must remember that I cross over to four subwoofers now at 110 Hz 8th order. 
I hesitate to call these speakers neutral, maybe balanced is a better term or seamless even better. There is a uniformity across the frequency spectrum. Nothing calls attention to itself. The overall presentation is an effortless neutrality that initially sounds dull but, it is most definitely not. The high frequencies are there in spades they are just not sprayed all over the place. When you sit down and close your eyes the speakers disappear. The Instruments and voices float individually in space. Small details that were previously overlooked become evident. Distortion is vanishingly low. 
The Allman Brothers Live at The Fillmore, a recording I previously thought was sort of muddled blossomed into the first band I ever heard live at the Boston Tea Party. Butch Tucks and Jaimoe the two drummers were always difficult to distinguish. Not any more. Each one occupies his own space left and right. You know who each cymbal belongs too.
Dicky Betts and Duane occupy their own space and the interaction between the two becomes obvious. Everything is as big as life. 
Many people think ESLs lack dynamics and power. Return to Forever Returns is a fabulous reunion live recording in modern terms. At 95 dB average volume when Lenny White slams his snare drum you can feel your hair move and his bass drum slams you in the gut. You can here every note of Stanley Clark's bass even when he runs 16th notes. The special character of his bass comes through loud and clear. Close your eyes and you are there at that concert. I was there in 1975, Burlington, VT. Given the right power these speakers are as realistically dynamic as any I have ever heard and no speaker I have ever heard matches the ability of the Sound Labs to cast an image. They will also unmercifully disclose errors in engineering like putting cymbals at opposite ends of the stage giving the drummer 9 foot arms. Another favorite is putting the low registers of a piano way on the left and the treble keys way on the right with nothing in the middle. Very realistic. 
I do not know of a speaker better at uncovering subtle details. You would think Haley William's Petals for Armor was just another pop record. The synthesizer ditties winding through the background are brilliant. This record is a pop synthesizer symphony. It has to make Trent Reznor jealous. Herbie Hancock's Sextant is mesmerizing. Details I have never heard clearly before became obvious. If I get into classical music I will be here for hours tongue twisted. I am a string quartet fanatic. Cherubini brings me almost to tears. With these speakers I could go through an entire box of tissue. Each instrument occupies it's own space and the interplay between them becomes more obvious, more amazing.
Another wonderful characteristic is that I have yet to hear these speakers get sibilant. Not even a hint of it. Not on female voices, saxes or violins. They remain effortlessly smooth regardless of the recording. How do they do that? I am not even using a BBC curve. I now have no need for one. 

So, you might think I am very happy with these speakers and you would be right. The Sound Labs are the last stop for me. Not only are they the best speaker I have ever heard but they are an outstanding value easily outperforming speakers costing 6 times as much. I have never heard a speaker image like this. 

Thanx to Roger West for putting up with me. It was a pleasure torture testing his loudspeakers. A gentleman and a scholar.  


Awesome Mijo, I was under the impression you were an owner of Soundlab for years, in any case congrats and enjoy
Good you got it figured out quickly. From your description I can almost hear how outstanding the music sounds. Congrats!

for posting the review. A friend of mine has Sound Lab speakers, and as you indicate they are a great speaker.

If only I had a bigger room
@jperry , I had a room size problem also. 545s are only 24" wide and Sound Labs will make them any height for you. I highly recommend going for 8 footers. You would have a speaker 4" wider than my old Acoustat 
2+2's. The interface and imaging would be exactly the same as what I have. The speaker would roll off the bass a little earlier and that is about it.

luisma31, I've been talking about getting them for years. I finally got that window in my financing to do it.

I should also add that Lewm was very helpful during the darkest days. There was a period I was thinking that maybe I should not have sold the Acoustats. Then again I have never been satisfied with any speaker right out of the box. There is always a period of adjustment when you are working to get the speakers as close to your ideal as you can. When you are using room control and have 1/2 octave EQ capability it takes even longer. One of the reasons these speakers are imaging at their best is I spent hours matching the response from 100 Hz to 10 kHz to within 1 dB of each other. This requires a calibrated mic and individual EQ for each channel. The short sine wave signal is still rattling around in my head.
The frequency response of the best speakers (tight tolerances) can match perfectly in an anechoic chamber but, put them in a real room and all bets are off. Their response can vary as much as 10 dB at various frequencies, maybe even more under some circumstances. Since location is highly volume dependent what you get is a vague image like a blurred picture. Small details are lost in the haze. I did not understand how significant this problem was until I started messing around with microphones and digital signal processing. Having only worked with ESLs this way I suspect dynamic speakers are capable of much better imaging given the same treatment. I have never heard a dynamic speaker so treated. I know the image will be smaller but that does not mean it can not be just as accurate, you will be sitting further back in the venue. I would love to be able to treat gammaman's Magico S7's this way but his Mac theater possessor which has Lyngdorf's Room Perfect only has a treble and bass control, no equalizer programming. Maybe after hearing the Sound Labs I can get him to go for a Trinnov. I can also show him the variance between his speakers when I get over with the microphone. 

Thank you all for the Kudos. They should really go to Roger West and Sound Labs. 
Thanks for sharing Mijo. I have been interested in Sound Labs for years but never had a listening room that could accommodate—I do now and am considering a second system that goes in a whole different direction. Would love to audition a pair if someone is willing—I’m in NW NJ and have had both shots! Also, curious about what amplification really makes these sing. Currently loving my high sensitivity dynamic speakers with low power tubes but will want something very different for an ESL-based setup.
I should also add that Lewm was very helpful during the darkest days

Lewm he is a great resource, IIRC he has 645's I think, he is always willing to help providing (neutral non colored) advice.

Their response can vary as much as 10 dB at various frequencies
 I wasn't aware they were so much room dependent and hard to integrate. The Trinnov it is supposed to be good, I looked into it as well the others DEQX, miniDSP and the such, don't want to derail your SL thread, I settled for digital and looking into a multichannel DAC capable of DSD512 / PCM1024 minimum and there is none currently, the OktoDAC looked promising. The thing is most of this digital chain if you can you should keep it simple and using good digital tools, others disagree of course but I love HQPlayer, I can do EQ with parametric EQ any way I want, I can do convolution room correction with room response filters (which I can also apply to the EQ) and I can keep everything within good digital parameters (digital filter reconstruction and good SINAD), so at this point I just decided not to look into the Trinnov and keep using my HQPlayer and look for a multichannel DAC to separate subs and mains and eventually down the road do active crossover.All this is great but what you do with analog (vinyl of course)? certainly you can put analog into the digital domain and then do corrections there (the heresy, get your pitchfork and put my head on a spike) this is where there is a compromise I think. Maybe if you want and have the time go with your RoomEQ project (including current implementation) on separate thread?Very interesting what you are doing.
The amount of current at +12 dB 20 kHz was ridiculous and I fried the brilliance control
 I'm sorry I forgot to comment about it, thank you for posting this, it is one of the things we forget about your systems, at the end everything is electrical and we (I) forget about how critical these parameters can be. Very instructive.
I have been interested in Sound Labs for years but never had a listening room that could accommodate

@dodgealum people I respect they all praise Soundlab, I would personally love to audition these on a proper setup as well. My speakers (not Soundlab) were designed by Duke LeJeune (audiokinesis) he is a very very clever fellow, and I immensely respect him as a person and as an engineer. He was/is also a Soundlab dealer and always mentioned how great these are.Mijostyn posted how critical the room could be though so yes proper auditioning would be required.
I have a pair of M645s in my small listening room. Best speakers I have ever owned. 
I know you are enjoying yourself! Just an absolutely open window to the sound. Oodles of detail, yet so natural. Congrats on the purchase!
Good work! IMO the Sound Lab is one of the top five speakers made anywhere and certainly is state of the art for ESLs. Its wide bandwidth, extremely transparent, and obviously very fast. The impedance curve, particularly in the bass, can be challenging to solid state amps because the latter cannot make power into higher impedances.
It was my room control unit. It had inadvertently boosted 20 kHz 12 dB which the JC 1's handily plastered the Sound Labs with.
@mijostyn I am curious why your room correction was doing this. Did it have troubles detecting the high frequency output of the speakers?

@atmasphere , The  SoundLabs have a peak at about 13 kHz the level of which depends on the setting of the brilliance control. Above 13 kHz they start to roll off. Where I liked the brilliance brilliance control set 20 kHz was down 9dB. Room control corrected that to 3 dB down but, it corrects each channel individually then it adjusts the gain of each channel to match. In order to maintain the best definition the system was designed to push everything up as close to 0dB as possible or you start losing bits.
The right channel corrected to a lower gain so the unit pushed it up towards 0 dB increasing the correction another six dB. Then you have a hammer head like me playing Smashing Pumpkins at 100 dB with a 400 Watt amplifier the end result being a fried brilliance control. Manually correcting the filter fixed that problem. TacT had the very first room correction system. It did not place any limits on the amount of boost that could be applied. Modern systems like DEQX and Trinnov won't allow this to happen. \

Luisma, I do not think the Sound Labs are any harder to integrate into a room than any other speaker except maybe for their size. If anything they are less sensitive to rooms because they are dipole line sources. They only send sound front and back. Not to the sides, up or down.  The only room treatment I use is two rows of acoustic tile directly behind the speakers. The phone stage is attached to a Benchmark ADC 1 which digitizes it in 24/192 and sends it to the TacT where it is processed just like everything else. 

@dodgealum , I live in Southern New Hampshire. If you are every up here you are more than welcome to stop by! Although I think you could do just fine with a 100 watt class A amplifier these speakers are known to sing with Atma-Sphere's MA 2 and the Parasound JC 1+. So, you might as well go the full Monty! 
TacT had the very first room correction system.
Accuphase made one too that we used at the 1998 Stereophile show. That was when I realized that if you had a standing wave, room correction wasn't going to fix it if the manifestation of the standing wave was a null rather than superposition.

You need moabs, what’s wrong with you ?

Seriously, as a poor man ESL afficiando, I praise your well thought out review.

@atmasphere , I don't recall that unit but you are right. There are room issues that digital EQ can not do much about without wasting a lot of power. Smart acoustic management remains crucial for the best performance. Because of my room design I have very minor nodes so there is nothing major that has to be done in the bass. It was entertaining that my problem occurred at the highest frequencies. But room control which is really speaker control serves to flatten the frequency response of the speaker in the room and more importantly allows you to match the frequency response between the speakers and give the speakers the sound you like.  After years of this I have learned exactly what to do with certain problem and I know exactly the frequency response curve I like to hear. But the physical characteristics of the speaker also remain very important. Some speakers you are never going to get a good image out of even with careful matching.
Congrats! In my biased opinion as a Soundlab owner, you've made a great choice ;-) 
I've had my A3s for about 5 years and consider myself lucky to have them every time I listen. Having heard many systems at luxury price points, very few bring me as close to the music as mine and those of others using Soundlabs. Regardless of musical genre, loud or quiet, they pull in you in ways that most speakers don't. 
FWIW, I have learned that the live end / dead end room treatment theory explained by Dr. West on is an important consideration. The widely quoted recommendations on room treatment are based on probably 95% of users working with dynamic cone drivers. You're off to a great start treating the wall behind the speakers first. This is by far the most critical, with some diffusion behind the seating being #2. I would suggest playing around with additional absorption and some diffusion behind the speakers if you get the chance to squeeze out that "last 1%". I found a nice enhancement with some DIY wood Skyline-style diffusors that were a fun and easy project that gets me many compliments from non-audio geeks, as "nice modern art', lol. 
FWIW, I agree that Soundlabs are not harder to work into a room if you've got a decent sized space. Side wall, ceiling and floor interactions are less than you'll find with most speakers. You will definitely get benefit from pulling them off the back wall like most speakers, but I find this to be true with most dynamic speakers too. Cheers,
@sbank , I think you are right. If you just use carpeting and absorption behind the speakers (Dr West' Recommenation) You are 100% of the way there with the Sound Labs but, the subwoofers are another matter. Having designed my house I made the media room wit no back wall. It is open to the kitchen which is open to the dinning room. The first full wall is some 75 feet away. My subwoofers also like the Sound Labs, form a line source and are right up against the front wall which like the Sound Labs limit room interaction. There is some comb filtering but walking around the room you can not hear it. 
I can't use diffusers because there is a theater screen between the speakers. 
The position of the speaker away from the front wall produces a comb filtering effect in the bass. Moving the speaker just changes the position of the nodes. You can easily see them if you measure the speaker in the room. These bumps and valleys stay the same regardless of where you are in the room. Bass bounces of the front wall and joins the main signal 6 feet (my speakers are three feet from the wall) or 0.6 ms later at various phase angles depending on the frequency. The bass is either boosted or cut. So, between 100 and 300 hz looks like a roller coaster +- up to 5 dB. I have the ability to EQ the bumps out. I also cross to subs at 110 Hz which eliminates the problem at the lowest frequencies. Where you think your speakers sound best is an individual thing. You also have the bass control on the back of the speakers. 
The position of the speaker away from the front wall produces a comb filtering effect in the bass. Moving the speaker just changes the position of the nodes. You can easily see them if you measure the speaker in the room.
Classic standing wave behavior.
@mijostyn , 
How's it going there? Give us an update if you can pry yourself away from the music. Cheers,
sbank, I just finished listening to the deluxe version of The Who's Live at Leeds. They were something else. Gammaman was over for the weekend and I think he was pretty impressed. He just got a pair of Magico S7's and is debating switching from McIntosh gear to Parasound JC 1+ and perhaps the Trinnov Amethyst. That would be amazing.
Back to the Sound Labs. They are the apex of the design I have been fond of for over 40 years so, I am obviously biased. They throw a big beautifully focused 3D image. Voices and instruments hang in space. They are very detailed without anything being emphasized. Dispersion is even over 45 degrees which is plenty to cover a 16 foot wide room. Although like any good system the image is most focused dead center you never lose the opposite loudspeaker and there is always center fill while moving about the room. At the listening position close your eyes and the speakers disappear. You are not listening to a HiFi any more, just the music. John Lee Hooker is on now "Your doctor put you on milk, cream and alcohol."  John Lee is in the room. I can honestly say I have never heard a system sound better. I only took me 54 years to get here.
One other interesting issue is that in spite of their size they disappear. They become part of the room. 
So, what is next? My new table, a Sota Cosmos Vacuum is supposed to enter production in a few weeks. When it gets here I have to mount the arm and cartridge a Schroder CB and a Soundsmith Voice. Then I hope to have my new subwoofers completed by the end of the Summer.
Assuming they perform as expected that will be it for me. Maybe a new cartridge once in a while. My Oppo is getting old so I might go for a McIntosh MVP 901. But, that is about it.
Very cool! That will be a fantastic table. I'm very happy with my Sota Nova. Frank Schroeder is quite the artisan, I had the pleasure of spending some time with him a number of years ago at CES. If funds were no object, I'd be lining up right behind you for one of his tonearms. 
You've got to post some system pics after you get it all running. Cheers,
Great review. I just pulled the trigger on Majestic 645s (standard height) and can’t wait to hear them in my room.

achipo, Excellent Evan. Have you had  ESLs before and what are you going to drive them with?
I have never owned electrostats.  I first heard Sound Labs in 1986.  They were playing in the back room of a stereo store and I thought there was a live jazz combo back there.  I walked in to find the Sound Labs playing.  I still remember it vividly.  Albert Porter calls it "the bathroom effect" as guests visiting the bathroom hear the stereo a few rooms away and think it's live music.

I ordered a pair of AtmaSphere MA-1s to drive the SLs.  Part of me would like the bigger MA-2s, but I don't have the power, room, or want to deal with the heat, so I'm determined to make the MA-1s work or move to Pass Labs 600.8.  I'm running 2 12" subs and a dual 10" sub in a Swarm configuration, so that will help fill out the bottom octave.