setting my amps (gains, eq, freq)

[Ladythump]

I have a 5v preout head unit.... a 4 channel amp producing 75 watt rms @ 4 ohms. My speakers are 50 watt rms. My gains are hardly turned up, maybe a 1/4 of the way, does that sound right. It's hard to hear the distortion when setting. Now sure I set them correctly. Also, my sub can hardly be heard when the volume is low, but when the volume is cranked, the sub shakes the boat.

[Juice75]

It's hard to say if the gain is right or not. The way I've been told to set it is:

1. Turn the gain all the way down
2. Turn the stereo volume up until you hear distortion, then back it down a little
3. Now turn the gain up until you hear distortion, then back the gain down a little

This should be the optimum setting.

There's a couple of solutions for the bass at low volume. You could get a bass control knob, then turn it up to increase the bass. Or try turning the 'Loud' setting on the radio on when the volume is low. This will increase the bass output at low levels.

These are just a few ideas to try out.

[AndyDeeJay]

If you knew someone with an oscilloscope, you could borrow it and look at the audio waveform. You can see distortion before hearing it. That way you can easily match the levels.


The "loud" function is dynamic and is the answer to a not so well known physical phenomenon with hearing- it increases the bass and in some cases the treble at low volume levels but not at mid or high levels. This is the exact inverse of how the human ear hears.

See Loudness Curves (Fletcher-Munson Curves).

My clarion stereo doesn't have loudness - Hopefully it will get wet and I can justify changing it. Don't tell my wife

[bkw4287]

If you have a crossover built into the amp it would help a lot. I'm not sure of the size sub you are running or the exact size of mid/highs, but a pretty generic setting would be to cross the sub channel (mono) over at 140hz and put the mids/highs around 100hz, and see how that sounds. You are definitely not throwing a lot of power at them so go ahead and put your amp gain at half way. The only reason to put it down to a 1/4 would be if you had a huge amp and didn't want to clip the speakers.

[Ladythump]

the amp does have a crossover built in and I have it set up HP (i think) -
my amp does run 75 watt rms while the speakers are only 50 watt rms. Right now the amp is set on 1/4 turn clockwise.

bkw4287, you recommend going up to a half??

[Hollywood]

Other manufacturers recommend setting the gain this way. Start with the gain at 0, turn your volume up 3/4 of max. Now slowly turn your gain up until you hear distortion, then to be safe back it down just a tad. This way you're not running the head unit at max power (most distortion) while your amp is set real low.

[bkw4287]