Gain Controls

[mauibuilt59]

Here's the situation, you have an amp (or more) that powers your speakers and subs. The volume controls on your deck ranges from 0-35.

What is better....
turn up the gain on your amp so that it plays loud at volume 20?
OR
turn down the gain on your amp so it plays loud at volume 35?

I've noticed that many professional installers turns the gain on amps down, making you crank up the volume on your deck to make the music loud. I'm not sure if they do that to make sure you dont blow your amp/speakers....or they do that because the deck pushed out a more powerful signal or something.

[JaJay721]

The gain settings on your amp is not meant to be used as a volume knob. You're supposed to set it with the output voltage of your headunit for best sound quality and leave it there.

[mauibuilt59]

how can you tell at what setting sounds the best? trial and error?
There must be some kind of rule of thumb for the gain settings.

[Luc]

1) Turn gain down on amp completely.
2) Turn volume up on headunit to about 90% max.
3) Turn gain up until you start to hear the speakers distort.
4) Turn volume down a notch or two.
5) Turn gain up a bit more until distortion.

Why do installers always turn gain down? It's because you want to use the full, usable output of the headunit, especially helpful when it's a high-volt output unit, which gives "cleaner" signal. Otherwise, there's no point in high-output, everyone can turn the volume up 1/4 and have the gain way up, overworking the gain stage of the amp.

If you want it done professionally, hook up an analog oscilloscope on each speaker-pair output of the amp, play a test tone of about 4-kHz sine wave repeatedly, turn volume up as above, then adjust gain until you see the high and low peaks of the waveforms start to clip, changing to a square wave. That's when you are oversaturating the transistors, and when to turn the gain down. If you have no idea what I just said, just follow steps 1 through 5.

[mauibuilt59]

Ok....i found the answer to my own question.

Here is the proper way to optimize volume and clarity of your amp.
http://www.crutchfield.com/S-InXS0qYPNgB/tech/kb39.html


My alpine EQ has these set of lights, so with the gains on the amp all the way down, i turned up the volume of my head unit until the lights (green yellow then red) turned red. That probably meant that the max stable output was being put out by my head unit. Then i just adjusted my amp until my speakers distorted. Then turned the gain a little lower than that.

Not quite sure if there was a noticeable difference between having gain set so I could play music at volume 35, and turning the gain down to what i assumed was max output at volume 23. Nevertheless it sounds good after I adjusted it. Thanks for the responses

[Phi]

Originally posted by Luc
1) Turn gain down on amp completely.
2) Turn volume up on headunit to about 90% max.
3) Turn gain up until you start to hear the speakers distort.
4) Turn volume down a notch or two.
5) Turn gain up a bit more until distortion.

I've heard of that method so many times. However, I've got one stupid question that never seems to get mentioned...what should the bass and treble settings be at? negative, zero or max? I usually level everything off at zero. Is this correct?

[Luc]

Yes, defeat all tone settings, set them all to even/zero, because that would be the "unadulterated" reproduction of what the headunit puts out. After all settings are made at the amp, then you can adjust the tonal balances to fit your music styles, gangsta.

[Luc]

Originally posted by mauibuilt59
My alpine EQ has these set of lights, so with the gains on the amp all the way down, i turned up the volume of my head unit until the lights (green yellow then red) turned red. That probably meant that the max stable output was being put out by my head unit. Then i just adjusted my amp until my speakers distorted. Then turned the gain a little lower than that.

Not quite sure if there was a noticeable difference between having gain set so I could play music at volume 35, and turning the gain down to what i assumed was max output at volume 23. Nevertheless it sounds good after I adjusted it. Thanks for the responses

Just remember that the more sources you add in-line to alter the music, the harder the matching/adjusting of the sound. You can do 2 things: leave the EQ's volume at max, and just use the headunit's volume to control level, or vice versa. This way, you just use one volume control, and not two. If you get a fancy headunit later on, just take the EQ out completely.

[Phi]

Originally posted by Luc
"unadulterated"

You couldn't come up with a more technical word yet managed to find oscilloscope in your vocabulary?!

[oibone781]

the gain on my 1300 rms audiobahn amp is all the way up, does this process include subwoofers also?

[JaJay721]

Turn down your gains if you want to keep your amp and subs for a while.