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.  

   




128x128mijostyn
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.