Amp for Sound Lab 645s?

[Alsatian]

Hello CJ gang,

I'm considering purchasing a pair of Sound Lab 645 electrostatics and will need a more appropriate amp. I'm considering an ARTsa or perhaps an ART 150. I don't think I need more power as I don't listen very loud. One of the things I love about the Sound Labs is how articulate they are at low volumes. Does anybody have experience with these combinations or with other big ESLs? I believe that some of the folks have used Martin Logans. I think that the new 150 amp would have a better bass response, but is there a significant improvement in the mids and highs as well?

Paul

[admin]

Hi Paul,
First, welcome to CJO, it's great to have you with us.

Lots of us folks on here are planar speaker fans and that includes myself. I previously was using a Martin Logan Vantage ESL speakers and currently I use a Magnepan 20.1. So not sure how much bigger you can get than the 20.1's,... well, the 30.7's I suppose. Anyway, there is a magic that happens with CJ and planars that you just need to experience. No doubts about it. When done right, it is absolute heaven. I can write pages on why CJ gear and planars are a good match, but it's easier to actually write about when it's not a good idea. So I'll do that instead. Pretty much it comes down to:

1) If you need a wide multiseat listening position, planars are typically not a good idea. The ideal listening position is very narrow with planar speakers.

2) If you have a room where you can't put the speakers off the front and side walls by a few feet. Speaker position is important in all setups, but planars are extra sensitive to positioning due to their dipole nature and relatively non-dispersing sound wave propagation.

Otherwise, they are great. The sensitivity of 90 db with the SL 645's is actually better than my maggies (which are 86 db). You mention that you don't like to listen loud anyway so I can assure you that it won't be an issue. Both the ARTsa and ART150 will have plenty of power to drive those speakers adequately. It's also not just about the watts, but also the quality of the power, especially with the significant resistance swings on planar speakers.

Let us know what you decide and again, welcome to CJO!

[Alsatian]

Hi Admin,

Thanks for the welcome. I have thought a lot about the room and placement of the speakers. A looong time ago I had a pair of Acoustats.

[roberto]

Hola Alsatian and welcome,

As Admin pointed out, here you will find some of us with planar speakers. I am a very happy user of a Martin Logan CLXs and Conrad Johnson does a magnificent job driving them. I use an One Twenty SE power amp along with an ET-7 preamplifier. Being the Sound Labs 634s with about the same sensitivity as the CLXs, you will not have any problem to drive then, and also using less power on the amp. You can't go wrong with CJ. I assure you a long term time as a user with CJ.

The harmonic texture, the right size of the musical instruments and voices are fantastic. The wide stage with staggering sensation of 3D is granted easily. The voices are projected to the air with incredible realism. No sore throats are here. You can understand very well what the left hand vs the right are doing on a piano. The size of a violin without any strident sound is amazing. You can listen all kind of music but what you will noticed is how easy is to call the musician(s) name while playing their instrument. You will get they're feeling, the way that only them can play that way.

The CJ sound is full of details and tons of resolution. The timbre, the stage presentation, the dynamics, the non fatigue sound are some of the characteristics lovely found into the CJ sound. Try to get the SE (special Edition) model. Your wonderful Sound Labs speakers deserve it.

Happy listening!

[AnotherJohnson]

I looked at the Sound Lab web site last night. A few weeks ago we went through this with Magnepan.

I was surprised, and not surprised, by the similar ideas presented by both companies. Three points stand out in my mind.

First, both companies say that room size is not a factor in choosing which model to buy. In other words, buy the biggest you can afford because you will get more of their goodness with their larger products.

Second, don’t worry about the walls. It’s not important. If you have to, you can put them up against the wall, but use lots of toe in (30 degrees was suggested by Sound Labs).

Third, don’t worry about the amps. Tube or solid state? Either is great. Power necessary? Hardly any at all. Too much power, not a problem.

I’m skeptical… but I understand the marketing guys who write this stuff.

And, of course, everyone likes what THEY like.

I think that there are speakers too large for small rooms. I think the proximity to walls has a strong impact. And I think your amp better be able to deal with the inherent minuscule impedance of the upper registers associated with stat panel loads. But that’s just me. My thoughts have evolved over the last 47 years of experimenting as a mature adult with deep enough pockets to get near the table.

The OP asked about colorations based on amp choices. I think the colorations will be dominated by the room and speaker placement.

As for the ART amps, they should fair well. They seem to be a good match for just about anything, being very stable and able to deal with very low impedances should the load present them.

There are other good choices too. I would be partial to CJ and ARC. Some would prefer Krell, Levinson, or even McIntosh.

[admin]

Yeah, I'm a little skeptical about such broad recommendations. I mean, I get that any manufacturer wants to tell their customers to buy their largest (ie most expensive) speaker and they can use it in any room with any amplification. That's certainly convenient advice and opens the broadest market. I'm sure my nearest Ferrari dealership will sell me one of their super cars even though I tell them I live up in the mountains on dirt road.

My personal experience is that room size and placement are incredibly important if you want to maximize the sound quality from planar speakers. I will say that you don't need 500 watt monoblocks to drive them properly. There is wiggle room with that and I prefer quality watts over quantity. So I think there are a lot of options for amps that still bring out the best in these speakers.

[AnotherJohnson]

In both the ARC 50th Anniversary book and The Wilson Way DAW commemorative book there were stories about the politics of amps and speakers.

In the ARC book it is told how ARC and Magnepan were joined at the hip early on. If the dealer wanted either line, he also had to take the other. This lasted about five years when both companies decided they were losing sales. Dealers like what dealers like, and some did not want a commitment to both ARC and Magnepan. It was potentially more lucrative to decouple.

In the Wilson book it is told that very early in DAW’s commercial activities, a dealer sold a pair, and David’s trip to do the install was the norm. David went to the home and was asked his opinion about electronics to drive the Wilson speakers. David, not yet seasoned in the craft of craftiness, was honest and shared his own experience.

Unfortunately, the speaker dealer had different ideas, and since he was not the dealer for Dave’s suggestion, he was angry when he lost the electronics sale.

The book says he warned other dealers that Dave had scotched his electronics deal, and did everything he could to badmouth Wilson Audio. The book says the negative campaign was effective, and that Wilson lost speaker sales because dealers did not want him doing an install and messing up half their sale. It took more than a year to recover.

So the noncommittal approach seems to be the safest for both amp and speaker companies.

[Alsatian]

I don't have any experience with Maggies, and I'm not entirely sure how the multiway ribbons compare to electrostatics, so I can't comment on that. But I don't think there are many other speakers like Sound Labs in the market today. I imagine the older Martin Logan CLS/CLXs were pretty similar, but quads are a lot smaller and have the bass and treble panels. I know you can stuff a big pair of Sound Labs in a pretty small room and get good sound as long as there's room behind the speakers (I believe 5 feet will give you enough of a time delay to minimize comb filtering effects and there's always absorption and diffusion room treatments), and you can put the listening position at least 3 feet into the room. They really don't need much room to the side, especially if you angle them a bit. Maybe the biggest issue about putting them in a smaller room is not auditory, but visual.

As far as amps goes, I'm old school and am only considering tubes. I think it's easier for a stout tube amp to deal with the low impedance high frequencies because there isn't much energy there than it is for most solid-state amps to deal with a pretty broad 40 ohm impedance in the bass where there is. I suppose you could see what the new class D amps could do. I know they're getting better and some of them are very powerful, but that's just not my thing… I also want to use electronics that add a little body to the sound since ESL's can sometimes sound "ghosty", if that makes sense, and that doesn't say class D to me.

Thanks for the suggestions and comments. We'll see where this ends up. Part of the fun of the hobby…

[admin]

Do you have a Magnepan dealer near you? Although they sell "expensive speakers", they are a very affordable brand that gives a lot of bank for your buck in their lower offerings. They have a long history of making great speakers. If possible, I would at least give them a listen before making a final decision.

[Big Dog RJ]

If you're planning on getting the ART150, that'll be all you would ever need in terms of "amplification," it's truly superb!

Although I prefer the tonality of KT120's, which is a personal preference, the KT150's offer some serious levels of dynamics that will drive any speakers regardless of load.
The power supplies and trannys designed on the ART series amplifiers are top notch! No compromises whatsoever!

So with the ART300'S or ART150 you're in very ultimate hands in terms of power amplification, it doesn't get any better. Unless, you were considering the ART108A's, pure Class A bias operation but that's a different dimension.

Cheers, RJ

[SteveFord]

The speakers need to be sized to the room.
Otherwise you get the trombone in a phone booth effect.

[Big Dog RJ]

Excellent point! And you'd be surprised as to how many get this basic equation all so wrong...

Trying to make big speakers fit into small rooms, just not going to work no matter how much acoustic materials are used, along with Dsp and other fancy room correction software. Same goes with small speakers in large rooms, although you can create a dedicated listening space within the large room. This is far more achievable than compared to squeezing in large speakers in small rooms.

Definitely not a good idea. The room must be considered as a separate component by itself. These basic elements are missed quite too often. I can't stress enough on how important it is but many seem to ignore this, and they think their systems sound great....! So be it, we can only try.

Cheers Steve,
RJ

[AnotherJohnson]

Trying to make big speakers fit into small rooms, just not going to work no matter how much acoustic materials are used, along with Dsp and other fancy room correction software. Same goes with small speakers in large rooms, although you can create a dedicated listening space within the large room. This is far more achievable than compared to squeezing in large speakers in small rooms.

Definitely not a good idea. The room must be considered as a separate component by itself. These basic elements are missed quite too often. I can't stress enough on how important it is but many seem to ignore this, and they think their systems sound great....!

+1

This is more important than which great amp or preamp you choose. And the bigger the room, the easier it is to set up a defined listening space within it. With large OR with small speakers.

Your ears, your system. But … as has been shown over and over again, many audiophile’s find a compromise that they like, and preach to the rest that it’s the greatest thing since sliced bread.