Help with setting up amp levels

[Ben P]

Okay Ive just about finished my boot install and thankfully everything is working ok.

The problem is I dont know how to set up my amplifier levels/gains to work most effectively and was hoping somebody might be able to help me do this. Below is all the info about my system:

Head unit 3 x 5volt pre-outs

Amp1 - Alpine T407 2x40(ish) watt RMS

This amp is powering my front Infinity components which are about 85watt RMS

Amp2 - Sony 4x40Watt RMS this is powering 2 pairs of Sony 6x9s in my parcel shelf. (they are 200w max not sure about RMS probably about 100w) I have set the High Pass Filter on.

Amp3 - Vibe VP2. This is powering 2 12" subs which are both 150w RMS. The amp produces 2 x 100 RMS and is wired in stereo to the subs.

None of the gain/level controls on the amps are marked in volts all are just numbered from "0-whatever" or "min-max"

How to I set them up properly so that everything will sound good and I wont blow anything when I turn the volume up.

Thanks for any help

 

[theICEman]

The best technique in my experience is to crank your head unit volume up to approximate 3/4 of its maximum, choose music with as wide a range of frequencies as possible (ie. music with bass/percussion/vocals), and then adjust the gain on each of the amps one at a time gradually up until the maximum they will go without distorting. After youve done this, turn the head unit volume down a little and then adjust any amp which is feeding any speakers which seem to be louder than others down a little (to make sure you have a balanced sound stage) and voila! All your levels are set to match each other for levels and give you your max output without clipping damage to any amps/speakers. Also, you should use a low pass crossover for the subs, but for the rear shelf speakers youre better having the x-overs switched off so that they can give you mid-range as well as highs. A high pass filter is usually only for use with tweeters.

 

[Ben P]

Cheers mate, I was worried that if I has my 6x9s giving a full range output that they might not sound very good with all the bass coming from the 2 subs. Someone told me that the bass notes can cancel eachother out or something?

I will try it though, as I think youre right, I do seem to have lost some midrange and the rear output is a little bit tinny.

 

[theICEman]

The bass noted wont cancel each other out. The only effect will be that you wont hear much bass coming out the 6x9s because itll be drowned out by the subs. It certainly wont detract from the overall sound tho! The 6x9s are designed to be run from a full, unfiltered frequency signal and this is what will make them sound their best.

 

[Ben P]

Thanks for the help mate. Ive just reset the crossovers and it sounds much better!

Im very pleased with the results.

Thanks again

 

[theICEman]

No problem mate, anytime.