Receiver and Sub for Electrostats

[osha7677]

I just dropped a good bit of money on Martin Logan speakers. The sales people suggested a Pioneer VSX-70 receiver, and a ML Dynamo 500 sub to go with them. I am absolutely sold on the speakers, but I think the receiver might be a bit weak for electrostats, and the sub too tight for my taste. I am considering upgrading to the Pioneer SC-72, and right now the Premier Acoustic PA-150 has caught my eye (same price as the dynamo 500, but a 15" woofer instead 10" on the dynamo).

I will be using these 95% for home theater, 5% music. They are going in a large room (40' W, 23' L, 20' H) that currently has alot of echo. I plan on cutting the echo with acoustic panels and perhaps a few bass traps. The soundstage (my sofa) is about 18' from the TV and front speakers. This will be a 5.1 set-up with ML ESL loudspeakers, ML Matinee for the center, and ML motion 4's on the sides.

Just looking for suggestions on the receiver, does not have to necessarily be Pioneer. I don't need fancy bells and whistles here such as bluetooth, 10 HDMI inputs, etc... Just want something that will let these electrostats live up to their potential (they are rated as minimum wattage of 80W @ 6 ohms. The VSX-70 puts out 90W per channel @ 8 ohms (the 72 jumps this up to 130 W). I would like to stay under $1000.

The sub really has me stumped. My understanding is that ML electrostats have a "light and airy" sound to them, and I am sure the dynamo 500 being an accurate 10" would probably blend perfectly with them - but at the same time as mentioned above I want deep bass sound effects that doesn't come off as punchy. That being said, would a 15" subwoofer be "too out of line" with loudspeakers such as the ML ESL's? Would like to keep the sub under $500.

Audio fiends... let me know what you would pair with the ML's! And thanks in advance!

 

[markw]

What M/L speakers are you talking about? They make many different types with different requirements. In any case, ignore that minimum power spec and start looking a tamps that are around or above their maximum power spes.

That's a huge room you mention there. You really should face the reality that with a room that size, you're well beyond the receiver stage and start looking at a separate power amp, at least for your R/L mains.

And, I really don't know what you mean by "too tight" a sub. Tight is a good thing. Are you saying you want a loose, floppy sub that has overhang?

 

[osha7677]

The loudspeakers are ML ESL's (the small guys for around $1000 each). Center is ML Matinee. Surrounds are ML Motion 4.

Forgive my lack of audio jargon. In my youthful experience with car audio (this home thing is new to me) smaller subs produced more of a "punchy" sound, whereas larger subs seemed to sound deeper and of course moved more air.

That being said, I don't plan on playing movies at 100 decibels, but from what I have read the larger the room generally the larger size sub you want to go with.

Like I said... I'm stumped as a result of not being an expert... which is why I am here.

 

[osha7677]

ElectroMotion ESL. What pre-amp would you recommend if I went with one?

 

[markw]

I think you mean POWER amp, not PRE-amp.

Nice speakers but, like many planar speakers, not without their quirks. Not that's that's necessarially a bad thing (I like Maggies myself) but they do require a bit of special care and feeding. Here's a snippet from a review of them.

"Another aspect of the EM ESLs to consider before you bring a pair home is that electrostatics present a notoriously difficult load for amplifiers, with impedance that may drop down below 4 ohms when the speaker is fed certain frequencies. That’ll put some serious, if not impossible, demands on your typical budget A/V receiver, and maybe a few mid-priced models. You’ll ideally want at least a solid high-end AVR or a separate power amp—I used a Sunfire Cinema Grand—if you’re going to electrostatisfy your home theater. [Ed. Note: The EM ESLs did indeed dip to about 2 ohms at their lowest impedance; see HT Labs Measures.]"

Here's a link to the entire review. You might want to read it if you haven't already.

I think the ML sub would be a better unit than that one you're looking at. Size isn't everytning in subwoofers. Think quality over quantity.

Good luck.

P.S. That salesman should be taken into the parking lot and shot for recommending that receiver.

 

[3db]

I think you mean POWER amp, not PRE-amp.

Nice speakers but, like many planar speakers, not without their quirks. Not that's that's necessarially a bad thing (I like Maggies myself) but they do require a bit of special care and feeding. Here's a snippet from a review of them.

"Another aspect of the EM ESLs to consider before you bring a pair home is that electrostatics present a notoriously difficult load for amplifiers, with impedance that may drop down below 4 ohms when the speaker is fed certain frequencies. That’ll put some serious, if not impossible, demands on your typical budget A/V receiver, and maybe a few mid-priced models. You’ll ideally want at least a solid high-end AVR or a separate power amp—I used a Sunfire Cinema Grand—if you’re going to electrostatisfy your home theater. [Ed. Note: The EM ESLs did indeed dip to about 2 ohms at their lowest impedance; see HT Labs Measures.]"

Here's a link to the entire review. You might want to read it if you haven't already.

I think the ML sub would be a better unit than that one you're looking at. Size isn't everytning in subwoofers. Think quality over quantity.

Good luck.

P.S. That salesman should be taken into the parking lot and shot for recommending that receiver.

The reviewer who reviewed the MLs completely missed the most important part. Electrostat loads have a very high reactive impedance component and very little true resistance which means an extremely large phase angles. This places a heavy load on the amplifier. I rather drive a 4 ohm speaker with a low phase angle then a 8 or 16 ohm speaker with a large phase angle any day.

 

[osha7677]

Thanks for the info... but now I am really confused.

Martin Logan says minimum 80W, the stereo guys say 90W a channel will do it. You guys are talking at least 300W+.

Perhaps I should explain the circumstances behind their recommendation. First off, I had a budget of around $5000. Secondly, the room is a large echo chamber, and has open flow into the kitchen, loft, etc... There recommendation of these speakers was more for the directional aspect of them rather than the accuracy or loudness.

These electrostats were recommended as a result of my room and house, and the fact that I am not using them for music or extremely loud play. With THAT in mind, do you guys think the Pioneer SC-72 (130W per channel class D3 amp) will cut it at least until I can pony up the money for a separate power amp? Would I be better served by just investing that money in a better receiver and forgetting the amp?

I understand that OPTIMALLY I should spend another $10,000... but i am not doing competition with these.

 

[markw]

Again, I think your "stereo guy" was a bit disingenuous in his dealings with you. That's a huge room and "loud" is a relative term. Methinks that if the salesman was afraid that if he was totally honest with you about the power requirements you actually need to meet your needs with those speakers in that sized room, he might have lost a sale. You can believe what you want but think about it: What do I (or we) have to gain by lying to you?

I ran my Maggie 1.6's with a Rotel RB-991, 200 wpc @ 8 ohms, 300 @ 4 ohms. The reason is that when I tried to run them with my old NAD 214 (80 wpc @ 8 ohms, about 120 @ 4) it was sucked dry and made nasty noises. ...and my room was nowhere near the size yours .

Just make sure that whatever receiver you buy now has preamp outputs so you can add a power amp in the future.

Good luck. I've said about all I can on this.

 

[osha7677]

Please understand, NOTHING to do with me thinking you are lying to me. It is just that there is SUCH a difference between what the stereo guy and the manufacture is saying verses your opinion that I just want to confirm that...

1.) You understand THIS specific speaker. The Maggies are planer, 4 ohm, and use what looks like a textured membrane with a cloth cover. The Electromotions are curved, 6 ohms, and use a transparent smooth membrane with a grid on the front and back. Martin Logan actually says this speaker addresses the power issue with past electrostats, in part because of the impedance and in part because of the grid design.

2.) You understand I am not shooting for the stars here with performance, just want them to sound good. The third post in this thread about the Maggies is interesting. The poster says he tried them with a 130W reciever, then with a power amp, and didn't notice much of a difference. However I agree that to a trained and critical ear this could be a big difference, and maybe the basis for your opinion.

At any rate, thanks ALOT for the heads up on making sure my receiver can readily accept pre-amps. Im going to give them a go without the amp, and if i need it I can just add it.

Anyone who has experience with the electromotion ESLs please chime in with your experiences.

 

[TLS Guy]

Please understand, NOTHING to do with me thinking you are lying to me. It is just that there is SUCH a difference between what the stereo guy and the manufacture is saying verses your opinion that I just want to confirm that...

1.) You understand THIS specific speaker. The Maggies are planer, 4 ohm, and use what looks like a textured membrane with a cloth cover. The Electromotions are curved, 6 ohms, and use a transparent smooth membrane with a grid on the front and back. Martin Logan actually says this speaker addresses the power issue with past electrostats, in part because of the impedance and in part because of the grid design.

2.) You understand I am not shooting for the stars here with performance, just want them to sound good. The third post in this thread about the Maggies is interesting. The poster says he tried them with a 130W reciever, then with a power amp, and didn't notice much of a difference. However I agree that to a trained and critical ear this could be a big difference, and maybe the basis for your opinion.

At any rate, thanks ALOT for the heads up on making sure my receiver can readily accept pre-amps. Im going to give them a go without the amp, and if i need it I can just add it.

Anyone who has experience with the electromotion ESLs please chime in with your experiences.

Your ESLs are nothing like Maggies. Maggies are electromagnetic speakers, that have a low but uniform load and are as close to resistive as you can get.

Moving coil speakers present and inductive load. An ESL like you have purchased is a giant charged capacitor. Basically almost all amps are not primarily designed to have capacitors connected across their speaker terminals. The load presents massive deviations between the phase of voltage and current. Your speakers have an impedance of 1.6 ohms at 20 kHz. It is true that there is little power there, however those types of loads are very inclined to induce supersonic oscillations in amplifiers. Since the oscillations are supersonic, you don't hear them, but they blow the amplifier up. Electrostatic speakers are renowned for blowing up amplifiers. Peter Walker of Quad, who invented the electrostatic speaker back in the fifties always had to design his amplifiers to be unconditional stable under all loads to solve this problem. Quad have made electrostatic speakers for over 60 years now, and they are the best of the bunch. However it leaves Quad amplifiers as the only really solid recommendation to drive electrostatic loudspeakers.

Funnily enough, I was in Magnolia at the head office of Best Buy in Richfield MN just a few weeks ago. I tried to audition them. They were powered by MAC electronics. Problem is the dreaded red light on the MAC was saying fault. I was there in the afternoon and the salesman said they had just replaced the amp at 9:00 AM that day, as the previous one had blown up!

I have been doing this a long time, and I'm going to give you some advice.

Electrostatics are an acquired taste as they have a figure of radiation. This makes placement difficult, and the rear reflections have to be considered and dealt with. I have auditioned the ML electrostatics with the cone bass driver and I personally don't like them. To me the transition from the di-polar electrostatic membrane to the mono-polar moving coil speaker sticks out like a sore thumb. Peter Walker, who I knew personally never recommended this approach and his speakers had no cones. He did endorse a di-polar sub made by the Finnish firm Gradient designed specifically for his speakers.

My point is that electrostatics are for experienced listeners with a big budget. Given your huge room, which electrostatics do not like, your lack of experience and your limited budget, I'm certain you have been sold the wrong speakers for you. My advice is to return them.

 

[Budabear]

I own a pair of ML CLS speakers and from experience I know it takes serious power from a very good amp to push them. When I originally used these speakers I was driving them with an AR tube amp and pre-amp. There was a point when my amp was down and I needed a temporary replacement for it. I had a few amps including an Adcom 555 which is 200wpc. None of them could push the CLS's for any kind of decent non tinny sound. My tube amp was 100wpc and the speakers sounded quite beautiful with any type of music. Electrostatics typically don't have any base so I was also using a Velodyne ULD-15 which I still also have. Together the system was fantastic.

At a lack for having anything else I could try to power the speakers I hooked up my Sansui 9090DB receiver and was quite surprised. Not only did it work well with the CLS's but it brought out some major base that I wasn't away the speakers could produce. When I got out of tube equipment and went to AV I purchased a B&K 307 and even later a 507. These receivers also worked quite well with the electrostatics but didn't produce the base like the Sansui. I am not that familiar with a lot of today's amps however I can tell you that a Pioneer receiver, or the like will not work. You will have to consider getting something much better and it might take time for you to find something that will work. As for a subwoofer, you might want to check with Velodyne and see what they have that would be compatible to the ULD-15's but that would be quite costly. A Sunfire sub might also work but you will find that it will be mostly trial and error in trying to find a receiver or amp to work with the electrostatics. Fortunately for you I don't think today's ML's are nearly as good as yesterdays so it might be easier then I think. But if your ML are anything like my CLS's you will need serious power and when I say serious power I'm not just talking high power. I hope this helped some.

 

[Pyrrho]

Please understand, NOTHING to do with me thinking you are lying to me. It is just that there is SUCH a difference between what the stereo guy and the manufacture is saying verses your opinion that I just want to confirm that...

Both the manufacturer and the salesman are trying to sell you something. If what they say causes you to buy, they get what they want. The truth need not enter into the matter. More on that in a moment.

1.) You understand THIS specific speaker. The Maggies are planer, 4 ohm, and use what looks like a textured membrane with a cloth cover. The Electromotions are curved, 6 ohms, and use a transparent smooth membrane with a grid on the front and back. Martin Logan actually says this speaker addresses the power issue with past electrostats, in part because of the impedance and in part because of the grid design.

Martin Logan is lying. That they are lying is proven by looking at:

MartinLogan ElectroMotion ESL Speaker System HT Labs Measures | Sound & Vision

Notice, they measured the impedance of the speaker, and they say its minimum impedance is 2.03 ohms. Now, look at the formula here for calculating nominal impedance:

Electrical characteristics of dynamic loudspeakers - Wikipedia, the free encyclopedia

Z[SUB]nom[/SUB] = 1.15 x Z[SUB]min[/SUB]​

Plugging in, we get:

Z[SUB]nom[/SUB] = 1.15 x 2.03

​

Z[SUB]nom[/SUB] = 2.3345​

Those are nominally 2.3345 ohm speakers, not the 6 ohms that Martin Logan claims. You see, even though nominal impedance as a real meaning, it evidently has no LEGAL meaning, since many companies routinely lie about this in order to sell more speakers. If you buy these, you should buy an amplifier that is capable of safely driving 2.3345 ohm speakers (which, in practice, means you need an amplifier that is rated for use with 2 ohms).

Now, if we go with Martin Logan's claim about the minimum impedance, we get:

Z[SUB]nom[/SUB] = 1.15 x 1.6

​

Z[SUB]nom[/SUB] = 1.84
​

If we round this off, we are at 2 ohms. You don't think the people at Martin Logan are so stupid that they cannot do this simple calculation, do you? They are lying about the nominal impedance, plain and simple.

(As an aside, the Magnepan speakers that are rated at 4 ohms are honestly 4 ohms; as far as I know, Magnepan has never lied about the electrical properties of their speakers.)

The problem with low impedances is that they require more current for the same power, which tends to cause amplifiers to get hotter than they would with a higher impedance. This can cause them to overheat and fail prematurely. Worse case scenario is a fire in which you are horribly mutilated, but that is unlikely. But it is possible.

The reason that many speaker manufacturers lie about the nominal impedance is because many people would not buy a speaker that is rated at an impedance that is below the minimum recommended for the amplifier that they have. So their lies increase sales. And then when the poor sucker who bought their improperly rated product destroys their amplifier, that is just too bad for the poor sucker.

If your amplifier is destroyed, this is nothing to Martin Logan. They still made the sale, regardless of what happens to whatever amplifier you use with them.


Now, you might get away with something that isn't designed for such low impedances, if you keep the volume low (as you are then requiring less power), but I don't recommend using any receiver with these speakers. You should use a power amplifier designed for dealing with difficult loads.

2.) You understand I am not shooting for the stars here with performance, just want them to sound good. The third post in this thread about the Maggies is interesting. The poster says he tried them with a 130W reciever, then with a power amp, and didn't notice much of a difference. However I agree that to a trained and critical ear this could be a big difference, and maybe the basis for your opinion.

At any rate, thanks ALOT for the heads up on making sure my receiver can readily accept pre-amps. Im going to give them a go without the amp, and if i need it I can just add it.

Anyone who has experience with the electromotion ESLs please chime in with your experiences.

If you are going to do that, keep a fire extinguisher handy, just in case.