Is there any reason why a more powerful amp should sound better?
- Thread starter davidro
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Well, if you don't mind a non-expert taking a shot at answering, or at least giving some observations. I'm simply a person with a big amp. It has been a bit counter-intuitive. It sounds like its less-there, than a smaller amp. Which is to say, I notice less constriction of dynamics, things sound more effortless and open, and something like a crescendo just hits out of nowhere but subsides just as fast. I expected to think "wow, this is power!" but I don't. If anything, the particular amp I have seems more nuanced. Things actually sound, subjectively, less loud. Maybe as there is a lack of compression from so much power being on hand for loud passages? 400watts into 8ohms, down to about 1600 into two...
musichal
poet emeritus
First, I have to say that I totally disagree with the whole notion of "all else the same" or "all else being equal" type of question, which then almost forces a discussion of hypothetical components. IME, the one thing you may depend upon in comparing audio products is that all else is NEVER equal. Pardon me for expressing that peeve.
A more powerful amplifier does not guarantee better sound any more than a more powerful engine guarantees a better driving experience. Too many factors are involved, such as the particular speaker to be driven. There are many examples of lower-powered amplifiers sounding better than higher-powered models, and many examples the other direction, also. How much power a speaker requires to sound its best can be a big factor, but is not the only one.
I believe that, with some brands, the more powerful amp has the likelihood of sounding better than it's weaker brothers simply because a higher cost may help ensure a more advanced design and higher parts quality, but not even this can be assumed. Sometimes, it seems to me, the lower price can result in a particular KISS design that just comes out better than expected - the Adcom GFA-535 leaps to mind for me; it certainly was well-received by many audio reviewers and audiophiles. I bought one and loved it.
All in all, I guess the answer to your question is "No." But I may prefer, "It depends."
A more powerful amplifier does not guarantee better sound any more than a more powerful engine guarantees a better driving experience. Too many factors are involved, such as the particular speaker to be driven. There are many examples of lower-powered amplifiers sounding better than higher-powered models, and many examples the other direction, also. How much power a speaker requires to sound its best can be a big factor, but is not the only one.
I believe that, with some brands, the more powerful amp has the likelihood of sounding better than it's weaker brothers simply because a higher cost may help ensure a more advanced design and higher parts quality, but not even this can be assumed. Sometimes, it seems to me, the lower price can result in a particular KISS design that just comes out better than expected - the Adcom GFA-535 leaps to mind for me; it certainly was well-received by many audio reviewers and audiophiles. I bought one and loved it.
All in all, I guess the answer to your question is "No." But I may prefer, "It depends."
SaSi
Seriously Illogical
You are right in what you say (that the higher powered unit also offers additional advances that influence the end result), however the bottom line is that the higher powered model does sound better. Perhaps not totally because of the higher power - and headroom that offers - but it does.
One experiment I did and equalizes all other factors as much as possible was to try a single 2x70W power amplifier to drive a pair of 200W speakers (KEF 105) and then try two of the same amps in bridged mode where they deliver 180W output. At higher volumes - where the 70W were exhausted during peaks - the bridged amplifiers delivered an audibly cleaner sound. Relaxed and seemingly less loud - due the the lack of compression perhaps - than the 70W mode.
In my experiment, everything was the same - except power output. The amplifiers were the same utilising the same components.
musichal
poet emeritus
Well, owning fairly powerful amps myself, which I procured exactly because of that effortlessness and dynamic response of which you speak, I agree. I also have experienced the same effect which you described when bridging amplifiers which had that capability. Perhaps I should have qualified my answer to the OP's question more clearly; I only answered as I did due to my experience with some less-than-stellar, but powerful amplifiers which were dated and not that great at inception. The old if-the-first-watt-doesn't-sound-good saw was in my mind. Also, I was not thinking so much of staying within a single brand for the comparison.
Bridging does get about as near to all else equal as you can get in the real world, and I applaud your thinking of that, though my limited understanding of it has been that it is not precisely identical from a sonic standpoint - though whatever differences there may be, other than more power, went undetected by me with those amps I've bridged. At any rate, I certainly agree that more power usually yields improved sound quality.
Bridging does get about as near to all else equal as you can get in the real world, and I applaud your thinking of that, though my limited understanding of it has been that it is not precisely identical from a sonic standpoint - though whatever differences there may be, other than more power, went undetected by me with those amps I've bridged. At any rate, I certainly agree that more power usually yields improved sound quality.
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Saratoga48
I need that radio
no----
yaya97
Super Member
Very interesting. This is maybe why Mcintoshs are powerful maybe....
NumbDiver
Super Member
The answer is simply..."it depends". If you are talking about a theoretical/hypothetical situation, or real world.
In the real world, there is no such thing as 'all else being the same'. Take for example my Krell KSA80. They also made KSA100, 150, 250, 300. They are all more powerfull. NONE sound nearly as good. Different circuitry, more output devices make for more non-linearity in the larger amps...on and on. However, there are some speakers my amp will sound terrible trying to drive, due to lack of power.
Now, if we take that same amp, and say we're going to use the same speaker as a test speaker, but we're going to reduce the efficiency by 20%. Will the "additional" power the higher efficiency setup has, allow for better sound? That answer is a very clear...maybe.
It depends if the speakers reactance and such, tax the amplifier's power supply to the point it's no longer working as efficiently as the other situation. Is it no longer operating in Class A? Are the rail voltages getting pulled down during dynamic passages? Is the output transformer in a tube amp saturating? IF and that's a huge IF, everything is truly equal, and neither amp is taxed...they will sound equal. But real world that is never the case.
In general, with build quality being equal; the lesser gain amps with fewer output devices and less circuitry needed to keep things linear, will be a better sounding amp. If the load does not stress the power supply, and the amp can act as a pure voltage source (or current source in the case of 'stats or the like), they will sound the same if ALL other things are equal.
In short, simple amps usually sound better (like the Pass F5 or single-ended output amps), due to the signal's manipulation thru the amp. But those amps cannot drive many speakers, due to their lack of gain. If you need more...you need more. But really high gain amps rarely can compete sonically with lesser gain counterparts.
Big amps sound better for a simple reason. They are better able to force the speaker cone movement to faithfully reproduce the shape of the electrical signal.
Recall that the speaker is an electric motor. It pumps air. The more control the amp has over the pump the better the sound will be in the air.
A small amp will have less control over the speaker cone than a large amp. It's like a small electric motor having less control over a piston than a large electric motor would.
Even when the small amp is not clipping its sonic quality will be limited by slew rate, i.e. it can't move the speaker cone fast enough to reproduce the music. The net result is a smaller amplifier will sound flatter or duller, e.g. more like Muzak, than a larger amp.
This is the reason that concert venues need tens or hundreds of thousands of watts. They have a lot of air mass to move. They need big amps to run the big motors (speakers). If a concert speaker rated at 2000W, 4 ohms, and containing 2x18" woofers were connected to a 20W amp then the sound would be flat. The 20W amp simply could not manhandle the air mass around the 2x18" cones.
While that example is extreme the flattening effect of small amps is also audible in residential speakers. While it would be easier to hear with large floorstanding speakers there are several people on AK that have done the experiment with bookshelf speakers and clearly heard it with those too. It's solid science.
Recall that the speaker is an electric motor. It pumps air. The more control the amp has over the pump the better the sound will be in the air.
A small amp will have less control over the speaker cone than a large amp. It's like a small electric motor having less control over a piston than a large electric motor would.
Even when the small amp is not clipping its sonic quality will be limited by slew rate, i.e. it can't move the speaker cone fast enough to reproduce the music. The net result is a smaller amplifier will sound flatter or duller, e.g. more like Muzak, than a larger amp.
This is the reason that concert venues need tens or hundreds of thousands of watts. They have a lot of air mass to move. They need big amps to run the big motors (speakers). If a concert speaker rated at 2000W, 4 ohms, and containing 2x18" woofers were connected to a 20W amp then the sound would be flat. The 20W amp simply could not manhandle the air mass around the 2x18" cones.
While that example is extreme the flattening effect of small amps is also audible in residential speakers. While it would be easier to hear with large floorstanding speakers there are several people on AK that have done the experiment with bookshelf speakers and clearly heard it with those too. It's solid science.
As a counter to everything I said above- my 15-18wpc Leben integrated subjectively sounds better than my 400wpc Levinson. Depends on the mood I'm in (and the efficiency of my speakers). I was giving reasons why I liked that amp, but there are plenty of examples of smaller amps that sound better than more powerful ones. As said above "it depends".
The subjective part is true, but so is the science of sound reproduction.
Flatter sound is Muzak, the difference is that Muzak flattens frequencies on purpose. Sometimes we want elevator music. Sometimes we want punch. Depends on the mood. But the only way to get punch is to have enough power to move the air fast enough to make it sound like punch.
Explain the mechanism by which a small amp working within it's range has less "control" over a speaker than a larger one. Explain what you mean by control.
Yet many large area direct radiators with very powerful motors are highly sensitive and work quite well with low powered amps, indeed many using such speakers find low powered amps preferable. Evidently they don't need "manhandling" like a Miller 8 pack being moved by a gang of boilermakers.
NumbDiver
Super Member
Two points:
-Amplifier topology and power supply have more to do with driving (and stopping) a large woofer; as well as dealing with funky reactance of cabling/crossover/driver/cabinet issues. Having additional wattage at the ready IMO is for most amps, really having more power supply at the ready.
-We need to define "a small amp", because I believe you and I are really on the same side of this. My Krell is a small amp by most AKers definition, as are my Levinsons. The Krell is a mere 80wpc into 8 ohm. The Levinsons are all of 100w each. Heck, a Pioneer SX-1280 is 185wpc. That's a lot BIGGER. Or is it? Each one of my measly amps weigh around 100lbs each. The Levinsons each have a pair of 600va transformers. My amps are not small. They can control a woofer better than most (assuming they are asked to drive a given speaker to a certain SPL, based on efficiency and amplifier gain).
But I agree that big amps push and stop woofers better. I'm just trying to define Big and Small, and not necessarily match them with words like gain.
Yes?:thmbsp:
A smaller amp will not be able to move the cone fast enough to faithfully reproduce the music signal. Even when it is within its range, i.e. not clipping, it will be limited by slew rate.
barkerd
Super Member
an experiment done in the 80's tried to blind test and faithfully reproduce a single snare hit against a live drummer and snare : they ended up needing 600 watts of power to do it . For a microsecond the peak required that kind of power. For most that go from your average 30-60 watt piece to a full on 200 watts or better the music tends to "open up" ....there is no clipping of the signal ...hence the comment someone made of hearing the big amp less ....it can handle what it is given without adding much of its own to the sound ........ceterus parabus
1W is smaller than 10W.
10,000W is smaller than 100,000W.
That's what I mean by big and small. I'm using the terms in their relative sense.
Electrons move at the same speed regardless of the amplifier power. It is not the same as horsepower in a car.
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