How to Adjust Amplifier Gain

The function of gain controls is one of the easiest to learn yet is almost universally misunderstood. Improper understanding of them leads to more product failure and more listenener dissatisfaction than will ever be appreciated.

Setting the gain controls properly is very easy, and is best accomplished using 2 people. The owner of the car, sitting in the drivers seat (or obviously a competant installer) and a person adjusting the controls according to instruction from the listener.

In a simple set up, with a 2 channel amp and no other amplification (including the source unit itself) do the following:

Turn the gain all the way down.

Now, turn the source volume control to somewhere between 2/3's and 3/4's (in other words, MOST of the way, but not all the way up)

Slowly increase the gain control, finding the maximum setting allowable w/o the presence of perceptable distortion.

If you have a left/right gain, you MAY want to tweak the left just a pinch lower to increase your PERCEPTION that the left in right are of equal volume (although their actual output should be equal with both gains set identically)

Thats it. Now leave it alone. You'll get true and maximum attenuation from your source unit's volume control.

A gain control DOES NOT increase the output of an amplifier, per se - It helps select the position on your source volume control where your amp output will be maximized.

If you change your speakers, repeat the process, otherwise, don't let your idiot, know-it-all friends touch it.

A multiple amp setup is almost as simple. There the gain controls are again employed to give you maximum swing from your source controls including volume, balance, fade, and possibly sub bass volume.

So, start with the amp that will be responsible for your staging, or imaging and adjust according to the previous instruction. Set your volume to your normal listening level (unless normal for you is 150db, in which case you might want to tune your system at a somewhat moderate level). Then, put your balance, fade and bass controls into neutral setting. Now, slowly increase the gains of those amplifiers, bringing them just to the level where you feel they are in perfect balance with the rest of the system. Rotate them above and below that threshold a few times until you are satisfied that they are in balance. Now leave them alone. Make all future adjustments from your source controls.

Gain controls ARE NOT for the purpose of increasing volume. They are for the purpose of giving you maximum use of your source controls while making it easy for you to default your system to 'normal' by putting your controls in a neutral position.

How To Adjust Your Amplifier Gain Control