# Is my receiver powerful enough for my speakers?



## CALWIRE (Sep 12, 2012)

Hey Guys,

I'm new and have some questions about receivers and speakers, specifically is my receiver powerful enough for my speakers? (am I running the chance of sending clipped wave forms to my speakers)

Receiver: Pioneer Elite SC-57
Speakers: Martin Logan ElectroMotion Series ESL, FX2, C2, Dynamo 1000 subwoofer

What I'm getting to is...Should I buy another more powerful external amp?

Any recommendations? 

Thanks

Jay


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## beep7886 (Sep 6, 2012)

Let me start off by saying welcome to the shack!!!

as for your question I am sorry you have received no replies....that sucks
unfortunately I have no knowledge on your particular setup, best of luck

cheers Brandon


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## Ile (Nov 23, 2010)

Your speakers have 91-94db/2.83V sensitivity, that mean 91-94db 3 feet away from speaker with about 1-2W (debends of speakers ohms).
Then every +3db needs double power, so you should be fine with your current 140W amp. Probably that is enough to bottom out those 5.25-6.5" cone drivers before clipping.

Manufacturer recommend +20W amp.

If you are after high spl's, you have wrong kind of speakers.


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## Dale Rasco (Apr 11, 2009)

Your speakers are rated at 6ohms and the SC-57 supports 4,6 and 8 ohms. That being said my Axiom M-80's are 4 ohms, which my reciever supports as did the SC-57 that I reviewed last year. In both cases I found that having the extra headroom from an external amp (Emotiva XPA-5) alleviates the "strained" characteristics that are common in these scenarios.


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## hjones4841 (Jan 21, 2009)

It really depends on how loud you want your system to play. If it is loud enough, then you don't need extra power. That said, the benefits of an external amp can be heard at moderate volumes. There are short term peaks in music and movies that can drive a receiver's amp into either clipping or the strained sound that Dale mentioned.

I have very highly efficient speakers that I at first was driving with my Denon. A few months ago, I had some extra cash and added Emotiva XPA-5s to the system. Even at lower volumes I think I can hear the difference, but maybe that is because I want to. At any rate, with the extra power available I know that the system won't run out of steam at any reasonable or unreasonable playback volume.


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## Gregr (Nov 2, 2010)

Hi Jay,
Where is everybody? Well, it is a little late for some. In any case, let me just say Welcome!
Hello and Welcome to Home Theater Shack (HTS). There are people here with direct experience with Martin Logan but until they have their say, let me first say..., that's a good question.

140 watts is usually enough power to drive some very complex loads and electrostatic speakers typically have been a very demanding speaker type in and of itself. However the newer electrostatics are very efficient. Looks like your ML theater setup has from 91db to 94db efficiency, these are some very nice numbers. What this means to you first off is you can play at low volume levels and actually hear music. What this means for reference levels listening at well maybe 90db to 100db (volume of a trumpet) is you will definitely not need 140watts to play at these levels. Your sub is active so it's low level demands are not a concern in fact your sub releases your system of speakers from the very power hungry low notes (crossing over at 80hz is common and recommended by some including me).

The early electrostatic speakers were typically inefficient with ratings for some of the larger planers just over 80-82db. These demanded good clean power to play at all and at least 150 to 200watts to play at 100db. However another concern was at reference listening levels with good clean power the planer speakers wanted to give you every detail of music making for some very complex loads. We thought a 1ohm load was a very difficult load to drive and it was, especially back in the 70's 80's.

Todays electrostatic speakers are efficient but I have read on this forum that Martin Logan speakers similar to yours can create demanding loads of .8ohm. I can't tell you what number of watts it takes to play a complex program at 60db to 100db for 3 hours. I do have a sense that when ML states these are designed to play with today's AVR's and I consider your Pioneer Elite will give some very clean 140watts of power, I believe you have a comfortable margin of headroom to spare which will will be handy for some of the more complex load sequences. 

Wait to hear from Jungle Jack and some of the professionals. But before you listen to any really loud music give your Elite and speakers a chance to get settled in. The amp and crossover dry capacitors are the most delicate items during break-in and actually go through changes in chemical structure


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## Gregr (Nov 2, 2010)

Oh! Electrostatics have had a reputation for being difficult and demanding to drive and that is because they were at 80db to 84db efficient. I am sure you got literature to read but here is some brief but to the point descriptions. Also your specs will tell you a great deal as well but here you get a sense of what that means to you.

http://www.audioadvisor.com/prodinfo.asp?number=MLKEMPKG

I say you have a nice system and I think well chosen..., enjoy them you've chosen well.


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## rab-byte (Feb 1, 2011)

I have an SC-05 paired with a UPA-2 pushing Vantages. I've had no problem with power. I also had no problem getting to 80db from 10ft away before getting amp. 

One thing to remember is that electrostatics just like horns control their dispersion. In the case of ML at 30degrees horizontal. Most of the acoustic energy is directed at you. This make your speakers sound louder then others.


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## CALWIRE (Sep 12, 2012)

Thanks All, 

I appreciate your answers!

:T :bigsmile:


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## tonyvdb (Sep 5, 2007)

Hello Jay, Welcome aboard. I agree with the above comments. Let me add that the Pioneer Elite SC-57 weighs 40lbs and although it uses a class D amplification system I would be very surprised if it could run even 7 channels to reference levels without distortion. My thoughts is it it truly can do about 100 watts per ch and driving the ML ElectroMotions is that they tend to have very wide swings in the Ohms putting a strain on any amp. Adding an external amp on just the front two channels is a very good choice if you have the funds.


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## rab-byte (Feb 1, 2011)

tonyvdb said:


> Hello Jay, Welcome aboard. I agree with the above comments. Let me add that the Pioneer Elite SC-57 weighs 40lbs and although it uses a class D amplification system I would be very surprised if it could run even 7 channels to reference levels without distortion. My thoughts is it it truly can do about 100 watts per ch and driving the ML ElectroMotions is that they tend to have very wide swings in the Ohms putting a strain on any amp. Adding an external amp on just the front two channels is a very good choice if you have the funds.


It will and it does the D3 amps are very robust and will deliver as promised. Yes you can get to 80Db all channels driven.


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## tonyvdb (Sep 5, 2007)

According to bench tests done here, it is capable of:

Five channels driven continuously into 8-ohm loads:
0.1% distortion at 115.1 watts
1% distortion at 132.0 watts

Seven channels driven continuously into 8-ohm loads:
0.1% distortion at 109.6 watts
1% distortion at 123.7 watts 

Respectable reading but not as good as they claim.


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## rab-byte (Feb 1, 2011)

Never is; but my point is that it will drive to reference levels. Also I like mcacc you can do a lot with it. It is not as robust as audassy but respectable nonetheless.


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## magic (May 23, 2011)

my Opinion get an AMP. 
Saying this, How do you play your system?, How close are you sitting? 
If you play it low volume, you don't have it on all the time then yea the receiver is ok.
but if you play it all day, or....You like to crank the volume up to experience the movies. Save yourself the hassle and get an AMP.


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