Setting gains on amps. Only for people with real experience and knowledge.

[SPLV 10+ year member]

After an hour or two of skimming through what seems to be a gazillion threads on how to properly set the gain on amplifiers, I'm still a bit confused. Apparently, there are several methods used in setting the gain. A search on Google only added to the confusion as various sources had contradicting theories on adjusting the gain on amplifiers. With that said, forgive me for being too lazy to weed out junk information. I need real no-bullsh*t-directions on how to properly set the gain for my system.

A DMM and oscilloscope is available for me to use.

Click to read more...

 

[wu501 10+ year member]

browse through this thread...plenty of info there.

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

 

[FoxPro5 5,000+ posts]

Make sure the gain on all amps is at the lowest possible setting.

Run a test tone CD (recorded at 0 dB) and use your o-scope to determine at which volume level your HU begins to clip at for each driver pair (tweeters, midrange, midbass, sub - if you run this many drivers.)

Then record the HU volume setting for each channel.

Now unplug all the speakers and put your DMM in the speaker outs of the amp. Record the voltage you read when you repeat the above test. For ex, if your tweeters began to clip at 45/50 on the HU, then write down the voltage rating with the HU at 45/50 on the tweeter channel.

Repeat for all channels.

Forget about the amp gain for a second.

Plug in your speakers and put in the hottest CD you listen to on a regular basis. Is it loud enough for you while sitting in your drive way?

Now drive down the highway at 70 mph. Still loud enough?

If not, slowly turn the gain up on each channel until you feel the music starts to loose linearity, sounds harsh, too thin, or is just too **** loud. Take time to play around and get used to it.

Once you're satisfied with that output, then repeat the DMM testing at the same HU volume with your newly-adjusted gain. Compare the before and after voltages on each channel.

What you've done is established how much headroom you'll have on the HEAD UNIT, not the amp. It's not that clipping is bad, it's not knowing how to use the volume on the HU that will get you in trouble. Well, unless you turn your music up from the gain pentameter while crusing down the street.