How much power is to much power?

When is an amp overkill for a speaker? More specifically, I have 91db speakers and I'm considering two SS amps, one 140 watts and the other 200 watts. Are they both too much? Is it too much simply because you're paying for extra power but don't need it, or because it's a detriment to the overall system sound?

What kind of music do you listen to? How would you descibe your room (dead/live). What furnishings & acoustical treatments do you have? How big is your listening room?
Too much is never too much. Too little power is actually more dangerous than too much due to being more susceptible to clipping and distortion. Clipping may damage your amp while distortion is what will damage your speakers. If I am not mistaken.
I listen to primarily classical (from piano to orchestral) and rock. My room is a loft, about 700sf with high ceilings and 30 feet of windows, it's definitely a live room. I've a few acoustical treatments, but nothing major (nor do I want more). So 200 watts is not necessarily necessary but it's also not a bad thing? Correct?
While we're waiting for some of Audiogon's more technically astute members to respond, I can tell you that based on my experiences, the 91db specification doesn't tell the whole story when determining amplifier compatibility. Your speakers impedance needs to be taken into consideration too. That information can be hard to get. The manufacturer will probably give you a nominal and minimum resistance value but a plot covering the speaker's entire frequency range would be much more useful. FWIW, my current speakers are rated slightly higher than 91db and I couldn't be happier that I moved up from 70W to 200W amps.
Very difficult to have 'too much power'....But why bother?
You have fairly hi sensitivity speakers. 50 or 60 hi-quality watts should do the trick, unless you want to induce ear bleeds.
My speakers are 92 db efficient and I use 700 wpc monoblocks. I do not listen loud, but these speakers have a notoriously difficult load and need a lot of current.

The SS amps that you are comparing may not be different or the 140 wpc may have more actial power. Check out Levinson 33H "150 wpc" amps as an extreme example.

What amps are you looking at and what speakers do you have and how big is your room.
to much power.......sounds like a toast, to me.
I'm using 1000 watts into 4 ohms for my 91dB speakers. It's not a matter of speaker sensitivity or loudness, it's a matter of controlling the drivers. Speakers like Vienna Acoustics, B&W, Wilson, Dali and others have the best overall and bass response when the amp really damps and controls the large drivers, so, with these type speakers, generally more power will equal more control and better sound.

OTOH, some speakers are so efficient, approaching 100dB that you can drive the speaker with 10 watts and really control it with less than 100 watts.

What speakers are you driving?

Reynaud Twin Signatures, will possibly upgrade to Reynaud Offrande in the not to distant future. The amps in question are vintage Accuphase c-200/p-200.
FWIW the difference in power, translated into db's from your speakers is about 1 1/2 dbs. hardly audible to many people even when they are listening well within the power range. For example if you clipped at aprox 140 wts you'd be producing peaks of aprox 113db. At 200 wts you'd be producing peaks of about 114db. To get exposed to those kind of peaks you be listening to an average constant SPL in the high 90's. Tell me you NOT doing that!

I'd ignore the difference and get the best sounding one. I sure wouldn't pay a lot of money to get the extra power capability. And, if you need some current to drive a hard load, a high current amps with a rated output of 50wts would still be more than you would probably ever use.

BTW Phaelon is right (except that I have 92db speakers and, unlike him, I'm happy driving my speakers, in my home, with 40wt and I have done well with 86db speakers and 50wts). You do need to take speaker impedence/phase issues into consideration when you are selecting an amp to drive them.

FWIW, if you've got the money, and you are not giving up sound quality, having high power reserves in not a bad thing. But high power high quality amps cost a disproportionate amount of money for the power you get but don't use.
As Newbee say, listen.

During you listening sessions include music with heavy, low bass, including synth, acoustic bass and electric bass. Quite often, switching from one amp to another is very noticeable in the bass.

Likely the areas where you will have the most need for additional power is in large orchestral classical pieces. This is due to the wide dynamic range of such pieces. But the difference between a 140 watt amp and a 200 watt amp is not going to matter a whole lot. For example. when I listen to a Beethoven symphony, the sound peaks of about 105 db spl draw right at 400 watts from a mcintosh amp. However, a good portion of the non peaks draw less than 40 watts and the quieter parts are in the 0.4 to 4 watt range. I state this a an indication that the benefits of the extra power come in more when there is an order of magnitude or more difference between what is available. Does one really need that much power? Not in my opinion, I just like it. My own bottom line for what its worth, which is based only on my subjective philosophy, is so long as you have enough power to be able to hear the quietest part of a work, and, without changing the volume setting, the loudest (or most power hungry - which will be a lot of bass) part of that work does not result in clipping, you have enough power to appreciate the music. The best test I can think of offhand is Mahler's 2nd.

When you get away from big orchesteral works and particularly if you are listening to music without a lot of bass, for example a piano sonata, your power requirements are drastically reduced.

One solution to get some of the best of both worlds, is pick up a pair of decent headphones for the occasions where you want to listen to something at higher volumes than your amp may be able to provide.

In sum, I would not make the choice of the two amps you mentioned based on the difference in their power specs but rather on how they sound to you at listening levels that they support.

Remember, also, that some opinions as to what is desirable are extreme, especially where it comes to power and loudness. In a perfect world I'd have an amp and speakers that could go to 140 db. - problem is that I know me and I know that all I'd be hearing inside of a year is ringing due to tinnitus from acoustic trauma.
As I always say to this kind of question "nothing exceeds like excess...."


A Accuphase P200/P300 don't even worry about it....if there qaulity drivers the amps won't be a problem...btw the Accuphase amps have built in protection circuits for driving unsafe loads.
I like Musicnoise's post and agree about the Mahler, but actually think that just about any well recorded Mahler will do. The Finales of #1 and #6 will test any system.

I'm a little surprise about the comment about piano sonatas. Well recorded piano has tremendous dynamic range, including loads of bass.

Newbee says::
FWIW, if you've got the money, and you are not giving up sound quality, having high power reserves in not a bad thing. But high power high quality amps cost a disproportionate amount of money for the power you get but don't use.

Exactly my point. With reasonably sensitive speakers, you simply have little need for mega power. Sure, I'd love a pair of Mac monoblocs or a pair of BelCanto Ref1000's.....a full kilowatt each into my Maggies, but why bother? With my Maggies at what....? 85db, I'd need 4x the power for the same result as Jtnicolosi with his 91db speakers.

Take the difference in money, and buy some more music and maybe work on the room.
Power is a testosterone experience in that some like big things, in this case power/watt numbers. Here is the math. To go up 3db, you need to double your power. At 91db, you are at 1 watt and you would be at 8 watts when you are at 100db...that is loud. The only advantage to power is whether it is highly biased into class A, then you would be running into class A up to perhaps 10-20 watts before switching into AB. All the watts will keep Edison, PG&E and company happy. Bottom line is that more power=more noise==more problems due to more transistors or more tubes=more money. I like lower power as long as it is controlled. Me, tubes, tubes, tubes. Jeff

You listen to the two kinds of music that require the greatest power reserves - classical and rock. You need lots of power. Think about it, rock is typically performed with several thousand watts of power, huge speaker systems and full drum kits. The wall of sound and chest thumping beat is what gives rock music its power to move you, whether it is in your living room, a bar or a stadium. Classical music, especially full orchestral pieces, rely on 80+ musicians drawing strings, blowing on woodwinds and beating on kettle drums and cymbals. Crescendos in classical music require tremendous amounts of fast power to replicate the scale and speed of all those different instruments and energy operating in unison. Not only that, but multiple speaker drivers to move significant volumes of air don't hurt either.

The problem is a trade off between adding more components (capacitors, resistors, diodes, etc.) to increase power, and the value of simple circuits in terms of noise and distortion. Smaller scale and lower energy music like acoustic jazz and vocals requires less power to reproduce lifelike scale and transients, and the extra power capacity just adds unnecessary noise. I agree with some others here that an important issue for you is the need to reproduce low frequencies at a realistic scale. For the kinds of music you like, I think the sensitivity of your speakers is less important than the amount of low frequency energy present in the signals you are trying to reproduce, and the ability of your amplifier(s) to lord over the woofers in your speakers and move air.

140wpc versus 200 wpc is not really as critical as the current and dampening factor provided by the amplifier. For example, the Naim Nait 5i with 50 wpc channel provides as much or more control in practice than many 100+ wpc amps, because it seems to be able to deliver current quickly and efficiently to the speakers.

How much power is too much power? In your case, more than you need to reproduce the music of your choice, whether it is the Who or Mahler's 2nd, with convincing scale and drama. For classical and rock, I doubt you will find that point of diminishing returns below about 100 amps of current delivery and a dampening factor of about 500, regardless of the sensitivity of your speakers.
I have had two types of problems with excess power:

1. Too much gain for my speakers efficiency due to not being able to turn the preamp down enough (KEF speakers, CAT pre, Symphonic line amp). CAT's rather crude volume pot gradations of 3 db or so made one click too low and the next, too high. Also, if you use a TacT or some other digital volume control, a high powered amp into some speakers will have you throwing out bits of resolution when you turn it down, due to the digital nature of Pots.
(I know, I know, for all you TacT afficianadoes out there, TacT manipulates this in the software or something, but I don't need to hear about that here. Take it to the TacT forums. I'm making a point, not selling or defending TacT products.)

2. Many and esp, less expensive volume controls don't "track" the two channels well at lower settings, say below 10-11 o'clock or so. These controls need to be up higher in their range or you will have erratic channel balance.

That's why we call them "systems", each part is more or less interdependent on the other parts. All that said, I like big power sometimes (Soundlabs with Perreauxs at 850 per side, Genesis 501 with Pass 350, totalling 1200 watts per side) I don't mind power.

However, I'm using Lowthers at 105 db in the cabinet and 2 watt 45 tube amps, or even weirder, my First Watt f4, which has a -.5 db gain structure! That's perverse to my last 3 decades seeking power and gain, but lower power=fewer gain stages=cleaner power is a convincing argument when you've acturally heard it.

Nonetheless, you're looking in the big horsepower league. If that's what your system needs and responds to, then I agree: "one can't be too slim or too rich" and you can't have too much power, IF it is under control and properly applied.

Different horses/different courses.
I'm definitely not the most estuste audiophile, or even really an audiophile, but to me wattage is somewhat like horsepower in a car. You don't need a lot of horsepower to get to the speed limit, but most of us still would like to have some extra if we need to push it. I'd rather have and not need, than need and not have.
A million watts is probably too much.
For your current speakers 140 is far enough - same if you upgrade. Frankly if you need more SPL then get a bigger speaker (three way) rather than overdrive a small one - your little speaker will be mostly distorting when driven hard.

FWIW: If you are looking at really old amps then it may be worth having it checked out and possibly replacing the caps.
A million watts is probably too much.

A million isn't exactly a lot of power. This Crown give me a feeling of power! Power! Forgive me a cruel chuckle, heh, heh, heh, power
09-13-08: Shadorne said:
"For your current speakers 140 is far enough - same if you upgrade. Frankly if you need more SPL then get a bigger speaker (three way) rather than overdrive a small one - your little speaker will be mostly distorting when driven hard."

More power is not about SPLs, it's about control of the drivers, particularly in the bass. Listen and decide for yourself.

For some audiophiles and some politicians:
To much power you say?
"No such thing" they answer
There's something to be said for effortless sound....1800 watts a side. But it is a two edged can waste a tweeter. I know...years ago I played Copland's "theme for a common man". Cranked er up and the gong toasted a tweeter....learned my lesson.....Kinda like jumping on a Porsche turbo with the HP on the lurk....bad idea.
Read carefully and keep it as your guide:

All The Best
Great info here everyone. I think I know what direction to take... the good thing about buying used is I can always resell without taking much of a loss. I'll update you.

What does "more control of bass" mean? If you meant sufficient current to drive the bass woofers without more distortion, then it is equivalent to a higher SPL. If you meant a higher damping factor, then it is independent to the wattage anyway.

I have learned the following things recently.

I bought my current speakers, JMlab Alto Utopia, with the impression that they are easy to drive: 91dB and 8ohm load. But my KT88 monoblocks, 50wpc, couldn't drive them well. Upon more investigation, I found the speaker impedance drops to 3.2ohms. This means that bass will need 2.5X more power than the mid-range.

Then I bought a Counterpoint SA100 and upgraded it to NP100. Note that NP100 has several upgrade levels and they all have the same rating, 100Wpc into 8ohm and 170Wpc into 4ohm, with a damping factor around 40. I have tried the following upgrade levels: Basic, Basic Gold, Premium Gold, and Platinum. They sound *very* different even though they all have the same outout ratings.

So what have I learned?

1. The matching between power amp and speakers is very important.
2. The amp rating can be misleading at times.
As to the magazine article referred to- I beg to differ that the phase angle is all that important - the proper term for what is imporant is the group delay.

I think it all depends on the speaker and amp combo. The Spectron Musician III SE in mono-block delivers 2400watts @ 4ohm. I do have to set the volume nob down than when I had only one M3 SE stereo amp, but the level of detail, effortless sound and fitness is world class.

Reports of blown tweeter fuses on the Maggies 3.6R are not that uncommon. I've read cases where the tweeter fuses blows up with an 800watt amp. I mostly listen to Jazz and Classical music, so it's unlikely that I'll go up to uncomfortable levels. But listening as loud as my room allows, I've never blown up a tweeter fuse with the 2400watt Spectron mono-blocks.

You can check the technical details of safety features for this amp, which may help to explain why I never feel anything forced upon the sound. All I perceive is the easiness of the music, just like a live musical event.
Vett93, You have learned something of great value, I think. Now to have an even more complete understanding of amp/speaker matching, consider that not only do speakers have an irregular impedence so do amplifiers have an output impedence that is irregular. Not so much SS which usually have a very low output impedence and its not a real issue, but tube amps can, and do, have output impedences that are fairly high and can make a substantial difference in what you hear from speakers. It's has been discussed here before so some night when you can't sleep, it will give you something to research. :-)
09-13-08: Vett93 said:
"What does "more control of bass" mean? If you meant sufficient current to drive the bass woofers without more distortion, then it is equivalent to a higher SPL. If you meant a higher damping factor, then it is independent to the wattage anyway."

I'm talking about effective damping, not damping factor. DF is part of the equation, but a 100 wpc with a damping factor of 1000 isn't going to control the woofers as well as my 1000 wpc amp with a DF of 1000. Someone up the thread said something along the lines that watts are like horse power. There's something too that.

Uncontrolled bass is too bloomy and resonant. An amp that grabs the woofers and prevents them from uncontrolled ringing is what's needed.

It depends.

On room size, how loud you listen. That's about it.

Realize that power alone is not always the answer. The amp has to be able to deliver power smoothly into the speakers variable impedance at different frequencies. Amps that double in power from 8 to 4 to 2 ohms do this best. Some speakers are more difficult to drive due to complex impedance loads at various frequencies. Others are less demaning.
What does "effective damping" mean then? :-)

I think what you are referring to is not damping. Rather, it is the sheer power.

I have 4 amps in the house, from 8Wpc 300B SET to 200/400Wpc into 8/4ohm load all SS power amp. The damping factor ranges from 5 to 700. I would not say a higher damping factor will yield the best bass for all kinds of music.

I've found that for Jazz and string music, a mid level DF will yield the best bass to my ears. A high DF means a dryer bass, again to my ears.
I think ‘power’ is overrated in most situations. It is not necessary to have “1000 watt monoblocks” to achieve good [or great] sound. The Lavardin IT, rated at a modest 50 watts per channel in integrated form has sounded more organized and composed than some 500-watt (very expensive) monoblocks in side-by-side comparisons. It is true that some speaker designs require more power, and there are some esoteric brands that build speakers with these requirements. In your case this is not the case (sorry). But power is not the whole picture. Personally I would never buy a speaker with such requirements.
You probably like a little bloom in your bass, which is not uncommon. I listen to lots of music with tons of bass and I play in orchestras and bands with "real bass" so I don't like any added bloom.

DF is a technical term that doesn't adequately explain the ability of an amp to control the woofers. If your SET amp had a damping factor of 1000 it still couldn't control many woofers.

A SET amp may not control a woofer at higher SPLs but that has little or nothing to do with damping, which is a function of an amps low output impedence.
TEST:: take a bare driver...woofer prefered. Thump it with your finger. Rings nicely, right?
Now, take a short piece of wire and short out the connections. Thump it again with your finger. Little or no sound, right?
The woofer basically damps itself when its 'load'...the output of the amp, has low enough impedence. The rest goes up as heat.
As for control, doesn't audible distortion play into this? If you had a dual trace scope connected and could compare the input signal and the actual speaker motions, you could visualize it. the traces match?=good 'control'.
Traces don't match? Bad control.
Baroque_lover probably doesn't need much power because, given his nom de plume, he only listens to baroque music. The demands are totally different from Mahler or even a Beethoven piano sonata.

He's right, he and I wouldn't buy the same systems because we have different priorities. IF you listen to very dynamic music, then power can be very important, particularly if you speakers can use the power.

Yes, some bloom in the bass is nice. I've found live music has "bloom" too. The question is not if you need added bloom. Rather, if your amp had some bloom, would that sound more like live music to your ears?

The Lavardin amp can indeed sound like 500W monoblocks if the speakers are *very* sensitive and have a flat impedance curve.

My NP100 Platinum feels a bit lack of power when I play Beethoven Symphony No. 9, especially towards the ending. This is a time that I wish I had more power......
Exactly Magfan. High power with low distortion equals control. A high DF helps only slightly in the control of the driver. The amplifier starts the drivers, accelerates them and decelerates them and stops them, all at a complex variety of frequencies. Doing all that with low distortion and ample power is key to control of the drivers.

DF is simply load impedance divided by source impedance.

Nothing more.
I think that DF is slightly more than nothing, but not near so much as most audiophiles attribute to it.

My understanding is Df matters but there is a wide tolerance in values that will work in any particular application.

You have to listen and judge. At least with dynamic drivers, if the bass sounds mushy or soft, a higher damping factor may help but the actual value does not matter that much.
I thought Magfan's test validated my view. LOL

A shorted woofer is like an amp with extra high DF. It does not make sound because there is no force continuously driving it. That is control!

Try to put a 4ohm resistor with high wattage rating in serious with your speaker. The amp still has the same output power. But the bass will be very distorted.

QED! :-)
Yep:Vett93, that was the point.
Now, extend the model to include speaker 'Q'.....
Hello Stevechan:

"DF is simply load impedance divided by source impedance.

Nothing more"

Agree, withjust one very small clarification: this ratio is measured at one given frequency (industry standard). I believe its 1 kHz but I could be mistaken. My point is that if DF = 1,000 at one frequency then it can be 0.001 at another.

Thank you

It is unwise to postulate. Then again, how else could someone justify their $9,000-1000wattperchannel-superintegratedamplfiier?


The speakers in question were the Totem Acoustic Forest.

I will reiterate: power is overrated and there is more to amplifier design then watts.

Yes, there's such a thing as 'too much power'. It all happens when your amp is so powerfull over your speakers that the sound is 'choked' and the speakers can't breathe.

I know many will disagree, but I experienced this phenomenon a few times along my audio years. Too much power and too little power is not a good thing.

I had to recently abandon a powerful 100 watter tube monoblock for a 30 watt stereo piece for just the same reasons. My speakers performed best with he 30 watter tube amp despite their spec numbers. Add to that, the sonics of the new amp were inherently better.



Thanks for sharing your speaker info. I used to have a pair of Accoustic Zen Adagio speakers which are similar to yours. My 50Wpc KT88 monoblocks drove them with ease.

The much larger woofers in my JM Lab Alto Utopia need more current to drive. Consequently, you need a higher power amp.

Saying an amp is too powerful is like saying a car too fast, a girl too pretty, too much money, too much fun, etc. :-)