Speaker/Amp wattage clarification help...

[Fumanchu]

Hello!

I have a question I would like to ask regarding my HT setup or more to the point my recommended Speaker/Amp wattage, considering I have had this setup for quite a few years now you would think that I should know this..

However, here goes...

I listen to DVD-A/SACD and normal CD's as well as watch around three dvd's a week (I realize the amp is not particularly great with stereo, but at the time seemed like a reasonable trade off... at the time).

I am using:
5x Royd Minstrel SE speakers
with a recommended amplifier power of 20-80 watts.

The amp they are connected to:
Yamaha DSP-A2
Rated at 100 watts RMS (not including the front effects).

I never have to push the volume above 40 on the master volume dial, at the time this combination made sense to me as having listened to them together at Audio-T (amongst other options), I knew I would probably not damage the speakers.

Should I actually be driving the speakers using the recommended wattage from the manufacturer with a lower rated amp to get the best sound possible?

Or, do I not need to be too concerned (as I have always thought) about:

a). Possible quality of sound with a lower rated amp.
b). Possible damage to the speakers considering they don't get thrashed.

Any advice would be most welcome.

Thanks.

 

[j_garcia]

Take a look at this thread: http://forums.audioholics.com/forums/showthread.php?t=42249

Your case is a little different, however the same info applies. More power will not damage your speakers as long as it is a clean signal. The main reason is because with an abundance of clean power, you won't have to crank it to get the levels you need out of them. Driving speakers with too little power and asking for levels in excess of what an amp can deliver is a sure path to blown drivers.

 

[trnqk7]

The amp will only deliver as much power as is needed to drive the speakers to the volume level you want to listen at. So, just b/c it says it can do 200W RMS or 100W RMS (just for example), doesn't mean that you are getting that much power all the time. Too much available power is only a problem if you try to play the speakers too loud, pushing them past their power handling limits (electrical) or excursion limits (mechanical) or if the signal is distorted that is being sent to them. Driving speakers past power handling limits (feeding them too much CLEAN power) would be quite difficult to do in most peoples homes-it would be EXTREMELY loud, to the point of being uncomfortable in most cases. It's far better to have more available power than needed to try and insure clean, non-clipped power supplies are available than to not have enough power.

 

[Pyrrho]

There is a myth that keeps coming up regarding speakers and power. Your speakers do not know the difference between distortion and "clean" power. Excessive power can destroy speakers, regardless of whether it is distorted or not. And if it is not excessive, it will not destroy the speakers, regardless of whether it is distorted or not. The grain of truth in the idea that it is better to have a high powered amplifier is best explained after I repeat something I said from the thread mentioned above:

If you crank up the volume control all the way, and put on some music, it is virtually certain that you will destroy some of your equipment, and very possibly your ears as well. And, very probably, the destruction will be immediate.

Assuming that your speakers are accurately rated (which is very doubtful, as such ratings are not standardized), and assuming that the receiver is rated according to the required standards (continuous RMS output), then you could destroy them with your amplifier, even according to the ratings. You see, that receiver can put out 130 watts continuously, and the speakers can only handle 100 watts continuously (even if we believe the rating, which is probably optimistic BS). Additionally, speakers can handle different amounts of power at different frequencies; typically, tweeters can handle far less power than woofers, and so if you put on a test tone of, say 15 kHz and fed your speakers 100 watts of that tone, it would be very surprising if you did not destroy your tweeters.

As a practical matter, you do not need to match the power ratings for a speaker and a receiver. I have used, for many years, a receiver rated at 160 watts RMS per channel with speakers rated to handle about 60 watts. Just because a receiver is rated for a certain output, that does not mean that it is putting out that much power at any time ever. It is a claim about what it is capable of doing. How much power it will put out at any given moment will depend upon many things, such as the strength of the input signal and how far up the volume control is turned. Generally speaking, if one puts on music that is at a fairly constant level, one can turn up the volume until one starts to hear distortion, and then turn it slightly down until one hears no distortion, and that will be the maximum safe volume for the system. (Naturally, I am assuming that you are using speakers that are an appropriate impedance for the amplifier you are using.) Of course, if you then used a higher input signal, it will not be safe to have the volume control at the same setting. It is a way of finding the maximum safe volume (sound) level, not a way to find a maximum safe position for the volume control.

Anyway, do not worry about the power ratings of speakers too much. Just listen and enjoy the music, and if it sounds distorted, turn it down. And if you put on something that is very dynamic, such as the Telarc CD of Tchaikovsky's 1812 Overture, try it out at a fairly low level first, and only gradually try higher levels. Otherwise, when the cannons start, you could destroy things.

When an amplifier is pushed beyond its limits, it typically has a great increase in harmonic distortion—that is, its output signal contains multiples of the frequencies that are input into it. So if one has, for the sake of simplicity, let us say a two-way speaker system, if the input signal contained frequencies that were directed to the woofer, since it is creating multiples of those frequencies, some of these multiples will be directed to the tweeter. And in almost all cases, the tweeter can handle far less power than the woofer. Consequently, the tweeter is often blown in cases where there is high distortion. Please note, however, it is the excessive power to the tweeter that destroys it; putting the same amount of power to it that is an undistorted signal will do equal damage.

 

[trnqk7]

There is a myth that keeps coming up regarding speakers and power. Your speakers do not know the difference between distortion and "clean" power. Excessive power can destroy speakers, regardless of whether it is distorted or not. And if it is not excessive, it will not destroy the speakers, regardless of whether it is distorted or not.

When an amplifier is pushed beyond its limits, it typically has a great increase in harmonic distortion—that is, its output signal contains multiples of the frequencies that are input into it. So if one has, for the sake of simplicity, let us say a two-way speaker system, if the input signal contained frequencies that were directed to the woofer, since it is creating multiples of those frequencies, some of these multiples will be directed to the tweeter. And in almost all cases, the tweeter can handle far less power than the woofer. Consequently, the tweeter is often blown in cases where there is high distortion. Please note, however, it is the excessive power to the tweeter that destroys it; putting the same amount of power to it that is an undistorted signal will do equal damage.

I believe we addressed this already(see below) didn't we? Although kudos to you for saying it in a bit more eloquent way.

The amp will only deliver as much power as is needed to drive the speakers to the volume level you want to listen at. So, just b/c it says it can do 200W RMS or 100W RMS (just for example), doesn't mean that you are getting that much power all the time. Too much available power is only a problem if you try to play the speakers too loud, pushing them past their power handling limits (electrical) or excursion limits (mechanical) or if the signal is distorted that is being sent to them. Driving speakers past power handling limits (feeding them too much CLEAN power) would be quite difficult to do in most peoples homes-it would be EXTREMELY loud, to the point of being uncomfortable in most cases. It's far better to have more available power than needed to try and insure clean, non-clipped power supplies are available than to not have enough power.

 

[Fumanchu]

Thank you very much, for the replies and information.

Usually I would just browse the web for such information but sometimes there is nothing like getting the 'exact' information you require from asking.

Especially when it's written in a way I can understand!

Thanks all.

 

[Seth=L]

Oh, and your speakers won't sound better with a lower rated amplifier, in case that was still in question (it's not that kind of matching game).

 

[Pyrrho]

Oh, and your speakers won't sound better with a lower rated amplifier, in case that was still in question (it's not that kind of matching game).

Indeed. The only advantages to low powered amplifiers are that they usually cost less and use less power. If power capability is the only difference between two amplifiers, they will sound exactly alike except when one is overdriven into distortion. Then, if the speakers can handle it (and if one's ears can, as people who lose hearing "with age" are really usually experiencing the delayed affects of loud sounds earlier in life), it is better to have more power.