Speaker power rating and amplification???


Stage one: I own a pair of B&W DM604 S2's that have a power rating on the rear of the speaker listed at 150W. Stage two: I have an Acurus A150 2 CH amp that has a power rating of 150W per CH. Question: Is this too much power for the speakers? What considerations need be addressed here. I also have an Acurus A80 with a rating of 80W per CH if the A150 is too much power. Any suggestions on how to correctly match power to speakers and are there any rules of thumb to be followed here? I don't want to do any damage to the speakers with too much power.

Thanks for your time and advice.
nissancrazy
that shouldnt be too much power for your s2's. more importantly find out the speakers efficency rating. the lower the number, the harder the speaker is to drive, or in other words, the more power you need. anything over 90db (sensitivity is rated in decibels) is considered high efficiency. lastly, what impedence are the speakers...Ohms...usually you'll see an amp rated at 100w at 8 ohms, and 200w at 4. 4 ohms are harder to drive, and therefor need the additional power. im sure youl get a lot of answers, with much more detail and specifics..
Check the efficiency rating on the B&W DM604s. If the rating is 87db or higher, either amplifier should drive the speakers efficiently without qualification. The A150 would probably provide a tighter grip with transients that demand higher power. Played at reasonable volumes, the A80 will drive the speakers effectively, but will not be quite as efficient. However, in many amplifier lines that I have auditioned, I find the more reasonably powered amps to be a tad sweeter sounding. I purchased a Threshold T-200 way back when, and preferred the musicality of this amp over the T-400, so I own 100 Class A watts per channel at 8 ohms. This amp puts out close to 200 watts per channel at 4 ohms.
I believe that your B&W speakers are rated 8 ohms. If they were 4 ohm speakers, they might be more difficult to drive and then the A150 would be the clear winner.
Too much power isn't really ever going to be a problem. Too little power used injudiciously may be. That's the rule of thumb that I learned many years ago, and I still think that it makes good sense. I've run many a setup with amps powered way above the "suggested" speaker rating with no problem whatsoever. Unless you turn the thing up to 11, fret not.
Thanks for the responses. The speakers in question are rated at: 90db, which I am assuming from the above comments means that either amp will do a good job driving the speakers? I plan on attempting to utilize both before making a decision on which to use. Strange finding, the owners manual states Power handling: 25-200W continuous into 8ohm while the back of the speaker shows 150W max. amp power?
Low powered amplifiers driven to clipping are more likely to damage a speaker than too much power. Distortion is what takes out most drivers unless there is a severe mismatch in terms of power sent to the speaker. In your case, either will work just fine.
Careful use of the volume control will ensure that you don't damage the speaker. At a reasonable volume, you will be operating either amplifier within it's linear range, ie, you will not clip. Accordingly, you will not damage the speakers. All other things being EXACTLY equal (and they never are;), you would probably be hard pressed to tell the difference between the 150W amp and the 80W amp. At 90dB, you are in good shape with either, enjoy.

Ron
If a car has a top speed of 150Mph its going to an effortless trot when driving at 60Mph. I do believe you will be able to tell the difference between the two amps and would prefer the 150W one.
Rlips
Thanks for the reply. I am currently running the A150 and have noticed "more dial" regarding volume. Also the speakers need not be turned up as far on the volume dial to get the same level of output as when powered by the Pioneer. The soundstage has improved, and there are details in the music not heard before, all of which are good things.
Thanks for the advice and just an aside your system looks amazing, bet it sounds even better.
Your welcome. Just to clarify, the "dial" position is not related to the power output of the amp, rather, it has to do with the voltage gain of the amp. All things equal, usually lower voltage gain and more "dial" is better; you want to take the voltage gain as early as possible in the pre-amp), this will typically result in a lower noise floor.

Of course, the best guide is your ears, for whatever reason, you hear more detail and better imaging, these qualities alone would be the reason to go with a particular amp, regardless of power rating. And, it may be, as you move up the line, the circuit is different.