watts per channel versus total watts

phalsedoom

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Oct 19, 1999
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What does that mean in terms of audio. And which is better? say 40 wattes per channel or 100 watts total.
 

office boy

Diamond Member
Oct 12, 1999
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100 watts total (how many channel?)
and that is is adding up the channels, so 40W per chan = 80W (on 2 channels)
get it?
 

AdamK47

Lifer
Oct 9, 1999
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Mono mode gives a higher output at the expense of quality that a dual channel would deliver, so the 100W rating would most likely mean that the amplifier is operating in a mono mode. If you want stereo sound, leave it in two channel mode.
 

Hector13

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Apr 4, 2000
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Is this for computer speakers or home audio equipment like a reciever?

For the latter (in both cases, really) it doesn't mean much. Having a nice Denon or Harmon amp that is rated at like 60 Watts a channel is much nicer then a SONY that is rated at like 120 or more per channel. Different companies rate these things differently. Some may use max output or RMS (root mean squared, I think) output to boltster ther equipment.

Just remember, quality is a lot more important then powere; I know I never drive my home speakers at anywhere near my amps rated power.
 

AdamK47

Lifer
Oct 9, 1999
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RMS = .707 peak or .3535 peak/peak

Most equipment should be rated using RMS values.
 

jamarno

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Jul 4, 2000
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With regular speakers, watts per channel is the most important figure, but things are different for amplifier designed to drive satellite tweeters and a center woofer directly (bi-amp) because the tweeters need much less power than the woofer. For example, a 200W/channel in a conventional system is no louder than a bi-amped system with 100W per woofers and 20W per tweeter.

The advertised power is not really RMS power but average power, which is taken by measuring RMS values of current and voltage. Peak power may be calculated with the peak voltage, or it may be the maximum RMS or peak voltage when nothing is connected to the amplifier.
 

Workin'

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Jan 10, 2000
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<< Having a nice Denon or Harmon amp that is rated at like 60 Watts a channel is much nicer then a SONY that is rated at like 120 or more per channel. >>

That's total bullsh!t. The FTC requires (for home audio, NOT cheap computer speakers) power ratings to be &quot;RMS&quot; and other measurement parameters to be stated. &quot;Peak power&quot; ratings are never seen in home audio gear. And they are meaningless for cheap gear.

Some manufacturers are more conservative in their ratings, as there is no law that says you have to test in one specific way. So, one manufacturer's 100W per channel amp may deliver a max output power of say 103.7W when tested a certain way, another company's 100W per channel amp might deliver say 119.3W when tested the exact same way. It's not like one company is lying and the other is telling the truth, though.

A typical power rating might look like &quot;100W per channel into 8 ohms, 0.01% THD, 20-20,000Hz, all channels driven&quot; or &quot;100W into 8 ohms, 0.01% THD, 1 kHz, one channel driven&quot; The difference between the two ratings is that the first one means the amp can deliver 100W at any frequency between 20Hz and 20,000Hz, while any other channels are also delivering 100W at any frequency. The second one is a much narrower (although still valid) measurement. The catch is that this spec means power output could be significantly lower if 2 or more channels are reproducing any sound at the same time, or if the frequency of the reproduced sound is different than 1kHz.

The key variables are:

distortion, THD in % - distortion usually rises drastically as power output limits are reached. 0.1% is completely inaudible distortion. Most high quality speakers have THD over 1%, and more than 10% for low bass frequencies

impedance, in ohms - power output is higher into lower impedance

frequency range, in Hz - it is more difficult to deliver power across a wide frequency range than across a narrow one.

time - RMS (current and voltage, not power directly, as jamarno correctly pointed out - but power=current X voltage) is measured over an extended time period. Many amps can deliver very brief (i.e., microsecond) peaks in excess of 1,000W. But after the filter capacitors for the power supply are drained, power output will be the stated RMS value.

Probably more than you wanted to know.......