System that sounds so real it is easy to mistaken it is not live

@lewm You're referring to the B1 subwoofer. One of our customers ran a pair of B1 subs between his A1s. It was helpful to get the bass excursion off of the main panels so it could be lower distortion.

Please don’t try to state what you not0 even experienced because what you posted about is that you have not the experience to listen true bass down to at least 16hz with out almost distortion and at near 120dbs.

@rauliruegas That is so funny- ROTFLMAO!!

Its funny because you clearly have no idea what you're talking about, which in this case is what I might have done or experienced in my life!

Sheesh  🤣

Dr West often recommends the Atma-Sphere MA-2 for his products and so about 80% of our MA-2 production drives SL speakers. We've shown at CES and THE Show multiple times with Sound Lab (starting back when CES was still at the Sahara in the early 1990s), and gotten Best Sound at Show (Dick Olsher); I've heard Sound Labs with our gear a lot over the last 25 years and I'm on a first name basis with him and others there.

I'm not denigrating Parasound or any other solid state amp in my comments. Dr West did recommend Parasound to anyone who suggested that they don't want tubes. I get that. Of course you know that we have a class D amplifier we've been selling the last year and a half; we get asked if that amp will drive Sound Labs and my answer is the same as if it were any other amplifier:

'It will drive Sound Labs but will not make the power and might seem a bit bass shy simply due to the impedance of the speaker being 30 Ohms in the bass.' That statement applies to all solid state amps that operate as voltage source on Sound Labs and that includes the Parasound (FWIW when I've visited Sound Lab they had a Boulder amplifier).

Now the speaker allows you some adjustment of output levels- it has bass jumpers for changing that level a bit and a Brilliance control. So unlike a lot of ESLs its a bit more adjustable to the voltage response of the amplifier. But its going to be bass shy with solid state amps because solid state amps tend to act as a voltage source.

How this works is the impedance curve of the speaker varies by a factor of about 10:1 from the bass to 20KHz. So its about 3 Ohms at 20KHz (somewhat dependent on the position of the Brilliance control) and 30 Ohms in the bass. It is a little different from other ESLs in that it employs a crossover for two transformers used to interface between the amp and the speaker panel- one for highs and one for lows. So the impedance curve has a bump in it that corresponds to the crossover to the HF transformer. ESLs don't follow the same speaker design rules that box speakers do, starting for the most obvious reason that there's no box with its accompanying resonance.

After 4 months I suggested my friend try subs to look for an improvement and before that nothing was wrong with the bass but true self powered subs goes lower than what is need and SL can't goes down there.

Latter on he changed the Majestic line for the top Ultimate that sounds alittle better but with almost same problem in the low bass.

@rauliruegas In this statement you are again confirming our experience. The large Sound Labs like the A1 and Majestic have no trouble whatsoever playing the deepest bass effortlessly. They go right down to 20Hz. But if the amplifier used to drive them behaves as a voltage source (for example, but not limited to the Parasound) it will be found to be bass shy. This is simply because the amp can't make power into such a high impedance in the bass as occurs in the Sound Lab.

So it is common with Sound Lab owners who use solid state amps to look to subwoofers to get the bass right.

till that day we try to improve the SL quality room levels performance ( obviously with subs. ).

@rauliruegas If you were running an amp like that, I would expect that you might want to use subs. That is a very common experience people have with ESLs and solid state in general. If you have the right amp those speakers have excellent bass on their own! To be clear I was not making an indictment on the Parasound in any way other than what you seem to be corroborating here. 

the JC 1+ puts around 300 watts at 16 ohms and can handle even higher  impedance with absolute aplomb.

@rauliruegas That amplifier is designed to operate as a voltage source. The Sound Lab has an impedance peak of about 30 Ohms in the bass. That means that if the JC-1 makes 300 Watts into 16 Ohms it will be a little bit more than half that into 30 Ohms. Being a voltage source, it will cut its power by half with each doubling of impedance.

Their output impedance is on the high side but I am not using them to make low bass so, that is not important.

@mijostyn 

The Sound Lab has its highest impedances in the bass region. That is why solid state amps struggle to drive them- they can't make the power. For the MA-2 though its a walk in the park- they play bass very well on that speaker!

@rauliruegas It might be a good idea to have the suspensions of the drivers renewed. Its hard to imagine drivers that old that are working right unless they are either all paper or use a latex-impregnated cloth surround.

There's probably a Nobel waiting for someone to show the inverse square law doesn't apply to sound from any source.

@dogberry In a line source when you are close to the speaker the sound you are hearing is coming from right in front of you. As you move further back, more of the driver(s) sound is able to reach your ears, so the sound pressure appears to not fall off as quickly. In fact its seems almost constant, but if you got far enough away (not possible in most rooms) you'd find that is obeying the inverse square law.

Years ago I built an OTL guitar amp that employed four 8" drivers snuggled as close together as possible in a vertical line. This was meant so that the musician wouldn't have to play seemingly quite so loud for the amp to project nicely and it worked quite well for that- you could hear the amp as easily at the front of the stage as you could in the rear of the club.

One last thing only buy gold plated connectors or you will develop a hum when the tin connections gets tarnished.

@5windowcoupe Tin and gold share a property which is they boh are resistant to corrosion! This is why tin is often used in connectors and the like. If your tin connections are getting corroded, you've got some kind of chemical involved that is responsible or the connectors are so worn that the copper beneath has been exposed. Tin is often preferable to gold since it is so much harder and therefore harder to wear off when the connector is plugged in and out.

Your Soundlabs has a sensitivity of 89db SPL at i meter

@rauliruegas Being that the Sound Lab is a large curved panel, you have to add 6dB to the rating to find out the effective sensitivity when you are back about 10 feet. The reason is that at 1 meter most of the output of the speaker is not picked up by the microphone. Roger's sensitivity numbers on his website doesn't tell the whole story, since sensitivity is a voltage measurement and so impedance is pretty important. The Sound Lab is 30 Ohms in the bass (the sensitivity is stated for 8 Ohms), meaning its efficiency is actually higher by a good 3-6dB in the region where most of the power exists.

The speaker isn't hard to drive for any other reason than impedance. If you have amps that can drive the impedance the numbers @mijostyn provided are entirely realistic in many rooms.

The fun thing here is knowing that microphones, electronics and headphones have been so real sounding they can fool a jaundiced audiophile and have been able to do so for decades.

I can recount several experiences where this was underlined in spades. I won't do all of them, here's one (ask if you want more): I was doing an on-location recording of a choir concert about 30 years ago, using an Ampex 351-2 tape machine, a set of Phillips small diaphragm tube condenser mics and a set of $20.00 Radio Shack headphones. After the intermission the choir was gathering at the other back stage door from the one at which I was stationed. Apparently they were going to do a number where they walked in while singing. So I rolled the tape. All of a sudden someone started singing behind me; I figured they were a soloist going to enter the door where I was. I looked around but no-one was there; I had missed the soloist entering the stage earlier (luckily got the tape rolling in time...)!

I could never get the machine to do that off of the tape playback, but off of the mic feed it was easy. Sometime if you get a chance, get your hands on a Zoom recorder or the like and headphones and see how easily you can talk while its in record mode. If you tend to shut up when someone else is talking you may find it hard to talk in this situation until you get used to it, especially if your voice is delayed. That's how real sounding mics and headphones actually are.

When we use speakers playing in a room and using a recorded media its another kettle of fish and much harder to get that spooky real thing I referred to in my first post on this thread.

@lewm It takes a whole lot bigger can to get them all back inside!

When you say “improve on live sound”, what does that mean?

I can't speak for anyone else, but IME if the stars align with the right recording and system setup, you're not dealing with a noisy audience! Plus the mics are placed optimally whereas at a live performance you deal with whatever location you got.

Since I play the guitar, no nothing can capture the live perfromance3 of my Les Paul into Marshall amplifiers.

@bigkidz The guitar player in my band plays a Les Paul hollow body into a Marshall Major(!) on a single Marshall stack (he used to use two but geez...).

If your speakers have sufficient efficiency (mine are 98dB so slightly more efficiency than the Marshall stack) you can reproduce such a thing very convincingly 😁 Best done with no-one home...

Have you ever listened to a stereo system that produced a sound that would make you believe it was a real live music or live band performance at front of you?

No. But I have experienced sounds coming from the stereo that had me thinking someone had broken into my house and was mocking me prior to axing me to death by singing along with my stereo. That caused me to swivel my head around pretty fast- and no-one was there! Spooky.