How do you measure the wattage output of your receiver

Discussion in 'Archived Threads 2001-2004' started by Jonathon Tillman, Apr 9, 2002.

  1. Jonathon Tillman

    Jonathon Tillman Stunt Coordinator

    Mar 20, 2001
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    When a receiver states that it has 120w per channel does that mean all the 5.1 channels? meaning take the two fronts, center, and surround sound speakers and multiply by 5? That would equal 600 watts. I don't think the subwoofer would count because I have it on a pre-out and it has it's own amp. Someone told me that only the 2 stereo speakers had 120watts per channel.

    I am confused. How do you rate it?
  2. David John

    David John Stunt Coordinator

    Nov 26, 2001
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    how do you measure?

    i think what you want to know is how much can your receiver output, correct?

    usually they state the maximum output per channel in either:

    -all channels driven (all 5 at the same time)

    -with 2 channels driven

    -each channel (only 1 channel at a time)

    this makes a difference since the power supply is limited.

    this could be from 20hz-20,000hz, or some just state them at 1k hz. which means at a limited bandwidth it produces 120 watts, but at the full bandwidth (20-20,000hz) it produces less. (they won't say how much)

    for example:

    5 x 120 watts all channels driven would be a total of 600 watts or 120 to each of the 5 channels.

    5 x 120, 2 channles driven, would mean it could output 120 watts to 2 channels, but if you were running all 5 channels the output would be less per channel (limited by the maximum the power supply could give).

    some manufacturers do this to inflate the numbers to make the output sound impressive.

    Sound and vision does tests of power ratings and many manufacturers come way short of their ratings with all channels driven at the same time.

    5 x 120 watts (20-20,000 hz) all channels driven would be the best rating meaning full bandwidth power to all 5 channels with all 5 channels being run at the same time.

    On most DVDs, you may rarely have all 5 channels being driven with full signals at the same time.

    So the ratings are tricky to understand and they can be very misleading too.

    I hope I didn't totally confuse you, or miss anything either.
  3. StephenL

    StephenL Second Unit

    Nov 21, 2000
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    It depends on the particular receiver. Very few receivers are capable of delivering their rated power to all channels simultaneously. Some receivers specify the power output with "2 channels driven" or "channels driven in pairs." More information about measuring receiver power:

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