receiver wattage

Discussion in 'Archived Threads 2001-2004' started by jeff cr, Apr 8, 2002.

  1. jeff cr

    jeff cr Agent

    Mar 2, 2002
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    okay, so i hear that manufacturers fudge their wattage spec's on their recievers. i am curious to see how mine stacks up. it is a 100wattsx5 Sony Strde-575. can you just crank the volume to max and take a reading with a voltmeter and use ohms law to figure power or is it more complicated than this? thanks
  2. Bob McElfresh

    Bob McElfresh Producer

    May 22, 1999
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    It's a bit more complicated than that.
    All receivers will put out more than their rated power, but at a cost of higher distortion.
    Because the input signal is a sine wave, power can be measured either Peak-to-peak, or RMS (which takes into account the area under the sine wave).
    The frequency of the signal has an effect, as does the speakers.
    The number of speakers being driven has an effect.
    In general, the major companies (Yamaha, Dennon, Onkyo) tend to be honest about their power numbers. In a few cases where the magazines measured the power, they were only off by a few watts.
    Whats more important is that YOU learn to read the fine print. A good power specification will look something like this:
    85 watts RMS per channel, 0.03% distortion, 20-20,000 hz, 8 ohm non-inductive load, all channels driven.
    85 watts looks wimpy, right? But it really means 425 watts continous power, low distortion driving 5 speakers all day long.
    So you gotta read the fine print.
    You might also read the following from a previous thread:
    Good Luck.
  3. JohnnyG

    JohnnyG Screenwriter

    Dec 18, 2000
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    I have no idea how your receiver model stacks up but in this Sound & Vision report the Sony STR-DB1070 (rated at 100W x 6) put out 115 watts with one channel driven and 31 watts per channel with all channels driven.
  4. Wayne Ernst

    Wayne Ernst Cinematographer

    Feb 24, 2002
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    Although "enquiring minds" like to know the true wattage, are you happy with the levels of sound that the receiver produces? When playing your receiver while watching a movie or listening to music, is there still more room left on the volume control before distortion would set it? This could inform you of how much additional headroom is available in your receiver. I think the fact that a receiver sounds good to you and you're happy with it is the important part - above and beyond what Sound and Vision along with others might publish about your receiver.

    On the other hand, getting to read these numbers and understand them is a good trait. Most certainly, you'll be using them before your next purchase.

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