Stereo/amp tuning - how to?

[jhiestand]

Just got new amps (mono sub amp, 4 channel for boat speaks) installed, just in time for the holiday weekend but still need to tune the system. In a nutshell, seems like the procedure is to ballpark the hi pass and low pass's around 90-150mhz, turn amp gains all the way down and then turn volume all the way up on head unit to just under distortion level. Then do one amp at a time turning gain up until just under distortion levels.

Is this right? I picked both my amps to provide a little more juice than my speakers are rated for so would I be in any danger of blowing speakers? I also am not 100% sure how to judge where the x-overs should be set. I've read that they do need to have a little bit of overlap, though, to prevent a dead area in frequency range.

Any tips?

[jonbassham]

RE: Stereo/amp tuning - how to?

Here is the explaination i was given from Duane the owner of NVS when i got my addictions:

Not sure how experienced you are in setting up systems but in case you're not here is how I at least start.
All gains down to min.
All EQ's to zero or flat, even the head/source unit.
Subs Off (disconect the amp remote turn on) select music/programing that has full spectrum of frequencies.
Ensure that power capacity (batteries) are at full charge.
Begin program playback with volume on source unit slowing going up. stop at 50% Let things warm up while you check to make sure everything is operating properly.
Then take the volume on the source unit to about 85% With the Hi Pass crossover set at about 200 Hz, adjust the gain such that you are not overdriving the speaker. Hopfully no more than 20% from 0. Let me know if you are having to go higher than that.
Assuming all is still good, slowly turn the Hi Pass filter down and you should settle somewhere around 150 or so. Making sure all is still good with no clipping or distortion, find out when the speaker starts to become inaccurate, then raise/lower the Freq, or raise/lower the gain or a combination of the both in very small increments. Be sure to leave the volume high. Setting things up at the hi output level will ensure that if someone else is on the controls they won't accidently overdrive the system.
This is still a rough setting, fine tuning can take an hour or more and several tracks/beverages. Just be carefull not to overdrive anything and you'll be all good.

[jhiestand]

Thanks for the tips. I took an initial stab at it, but am putting in some new speakers so will probably go through the drill one more time.

I found a good FAQ on rec.audio.car that really details what's going on with amp tuning for us n00bs. Sections 5.5 and 5.6 especially helpful with regards to setting the gains and x-overs.

http://www.faqs.org/faqs/car-audio/part4/