How to adjust the wattage output of an amplifier ?

If a 4 channel amp outputs RMS 50w x 4 (4ohms), what amp settings control increasing or decreasing output wattage?

Does the gain control how much wattage is output?

When I was young I used to have the gain on maximum for my amps and I think that causes them run hot and burn up...... 


At what control (knob) setting are you getting the 50 watts RMS?

4 Answers

  • Like what KZ said, every head unit is different. Some head unit are weak and have a low RCA output. Some head unit are high and have an overrated output. Some head unit are adequately perfect.

    If your head unit is weak, then your subwoofer will also be weak. It won't hit hard and loud.

    The "bass boost" crossover on the amplifier is best set OFF. It should only be set if you have a weak head unit.

    You need to understand that a stock head unit doesn't have an RCA output. You need to replace it for an aftermarket head unit or do some wirings from your speakers to get signal into your amplifier.

    The first thing you need to do is find out where your head unit clips at or whatever you are using to connect into the amplifier's RCA input source.

    So what you need to do is find out how powerful your head unit is and then you can set your amplifier's gain to the output signal on the head unit.

  • KaeZoo
    Lv 7
    4 weeks ago

    The gain control exists because the source units' output levels aren't standardized. One head unit may have RCA outputs rated at 1 volt, another may have 4-volt outputs. If you're using a head unit with a higher-voltage RCA output, you'd reduce the gain control to compensate. So to answer your question, there is no spot on the gain control knob that always guarantees your amp will produce exactly its rated power with every head unit. In some cases you may get full rated power with the gain turned all or most of the way down; in other cases you won't get the full power unless you turn it all or most of the way up. 

  • 4 weeks ago

    The wattage rating of an amp is maximum continuous wattage.  That's playing a signal of steady amplitude (like a sine wave from a signal generator) at maximum volume.  Real content (music, voice, whatever)  has a dynamic range so the actual power is changing from instant to instant. So we're talking here about the loudest parts of the music.  And the way wattage is 'speced' (now I don't know how that word is spelled!  It's short for 'specified', pronounced 'specked'), you can usually exceed the max wattage for very short periods of time (milliseconds), in a very brief percussive sound like a drumbeat.

    The traditional way it was done is to have a preamp and a power amp.  The power amp is turned all the way up, and the volume is controlled with the preamp.  It's desirable to have way more power than you actually use, so in regular use the preamp is never more than about 50%--and that's the loudest parts of the music.  So with a 50 watt max, your average power is really around 25-30 watts.  This extends the life of the power amp.  You get less distortion, plus less heat in the final stage of the amp.  The problem with this arrangement is that you get the maximum noise in the power amp, but modern amps are pretty quiet.

  • don r
    Lv 7
    4 weeks ago

    Use the volume control to adjust the output. Gain controls the input, not the output.

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