True power per channel of amp

Discussion in 'AV Pre-Amp/Processors & Power Amps' started by turnthatdown, Apr 15, 2018.

  1. turnthatdown

    turnthatdown
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    Good evening guys,

    I have an Onkyo tx-nr828 AV reciever,
    could anyone tell me the true "watts per channel" please?
    here is a sample of the spec.

    AMPLIFIER FEATURES
    • 180 W/Ch (6Ω, 1 kHz, 1% THD, 1 Channel Driven, IEC);
    215 W/Ch (6Ω, 1 kHz, 1 Channel Driven, JEITA)
    • WRAT (Wide Range Amplifier Technology)
    • H.C.P.S. (High Current Power Supply) Massive High Power
    Transformer
    • Discrete Output Stage Circuitry
    • Optimum Gain Volume Circuitry
    • PLL (Phase Locked Loop) Jitter-Cleaning Circuit Technology

    it is a 7.2 system and at first glance it looks like all 7 channels are 180w per channel,
    im not so sure!!

    This all came about as im thinking of some Klipsch rp-280f speakers and wanted to make sure my reciever was subitable for the job.

    reagards
    Matt
     
  2. mick24402400

    mick24402400
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    The specs are for 1 channel not 7 channels driven
     
  3. turnthatdown

    turnthatdown
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    so in real world terms what is the power output to each driven channel?
    assuming at least 5 channels are permently connected.
     
  4. Rambles

    Rambles
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  5. turnthatdown

    turnthatdown
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    BOOOOOM, perfect for what i need to know.
    looking at about 100 watts per channel at 5 channels @ 8 ohms.
    im very happy with that.
    thanks for your help,much appreciated.
     
  6. saster

    saster
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    The only TRUE figures, are the ones that shows 20 - 20kHz, all channels driven at 8 ohm and at a MAXIMUM of 0.1% distortion. Not many receivers lists those numbers these days :)
    In modern receivers you are lucky if you get 7x50w (even if listed as 180w x 7).

    One thing you can do, is to look at the specs and find what is listed as max power consumption.. Then multiply that by 0.7 (as amps are only <70% efficient .. a bit more if class D).
    Then divide this by number of channels. Then you have more realistic numbers :)
    Sure, you can increase this with a large capacitor bank, but receivers usually don't have those.
     
  7. saster

    saster
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    The Klipsch rp-280f have a sensitivity of 98 dB.
    This means that 1 W out of the amp will produce 98 dB out of your speaker.
    Then add 3 dB from room gain.
    Then subtract 6 dB per meter listening distance from the speaker.

    So 1 W will give you 83 dB at listening position.. you'll be fine :)
     
  8. turnthatdown

    turnthatdown
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    Great comments guys [emoji2]
    Thank you
     
  9. Rambles

    Rambles
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    The Klipsch are unusually very sensitive speakers, so do not require a lot of power. The 98db sensitivity means it will take 1 watt to produce 98db at 1 metre.

    Movie soundtracks are generally mixed at 85db reference level (0 on most AVRs) with 20db of headroom at peaks.

    The further away you are, and the more you turn the volume up, the more power is needed. For those speakers, at 4 metres listening distance it would take 80 watts to achieve the 85db + 20db headroom.

    But, that doesn't take into account room reflections and the fact that you may be using an active subwoofer and applying a crossover to the speakers to direct the bass to the subwoofer which would reduce the power requirements from the AVR.
     

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