question about overrated amps and setting the gains

[TrlcKed_OuT 10+ year member]

ok so if you have an amp that u think is overrated than how do you set the gains?? just set it to what its "rated" power but just listen for distortion or what sorry for the noob question and this is just a theroredical (sorry on the spelling) question and not something im incountering

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[btdickey99 5,000+ posts]

what amp are you talking about?

 

[TrlcKed_OuT 10+ year member]

well like stated im not in the dilemma i was just curious how you would do it

 

[DBfan187 5,000+ posts]

oscope

 

[Twilight 10+ year member]

If you don't have access to an oscilloscope, try this:

- Wire your speakers together on one channel for an 8 ohm load (if your speakers are 4 ohm) to reduce the power going to them and prevent clipping damage.

- Burn a test tone (such as 1kHz) on a cd and play it on repeat.

- Gradually turn up the gain until you hear distortion. Then, turn it down a bit until the distortion disappears.

- Wire your speakers back to 4 ohm (as normal).

- Get a digital multimeter, set it to measure voltage and measure the voltage being sent to the speakers.

- Find the power handling of your speakers. Multiply it by the impedance (4 ohms in my example). Then, calculate the square root of this number.

- Compare the voltage you just calculated with the one you just measured. If it is significantly higher, lower the gain until you reach the voltage corresponding to your speaker's power handling.

This is how I set the gain on my Lanzar amp, which is somewhat overrated. Of course an o-scope or bench testing on the amp would be much better, an audio shop could probably do that for you if you're unsure.

 

[Twilight 10+ year member]

This thread has a lot of cool info about setting gains

http://www.caraudio.com/forum/showthread.php?t=63933

 

[ufd869]

level matching.

i don't have an oscope

 

[helotaxi 5,000+ posts]

One of the other tricks that works in theory is to set the DMM to peak instead or RMS and turn up the gain until the peak voltage stops increasing. That is the point where the amp is theoretically clipping. Back it off just a bit from there to make sure there is no clipping. At that point you are getting peak power from the amp. Depending on the amp it could be horribly distorted at this point even though it isn't clipping.