Guys,

I have recently updated my car system with the following amps:

US AMPS XT800.4v2 (car spearkers)
US Amps XT800.2v2 (sub box - 2 12"s)
(aftermarket speakers all the way around - kenwood 3way up front and kenwood 2way in sails).

The system is all wired up nice with proper powers, grounds and 12ga speaker wire and it sounds so much better. What I need help with now is setting up the following on the amps:

2 channel sub amp (bridging the speakers (kenwood 12" kfc-w3005 - 4ohm 700w peak)) - already done)
- Level
- Sub sonic
- HPF
- LPF
- Bass EQ
- X-over

Now my HU does have a sub out (preamp) and I can set the feed to 80HZ or 120HZ, so which one do you recc?

Second, here is the 4 ch amp (1 each for 1-2 ch and 3-4 ch)
- Level
- Sub sonic
- HPF
- LPF
- Bass EQ
- X-over

I know there is really an art to this and no exact setting, but can you help me get started with some good start points for each and then how to tweek each setting depending upon my taste. Also, don't knock my sub amp choice as I am not looking for shear power just a nice bumb to the bass. Thanks for all your help and any advise is much appreciated.

 

What I do (and just got done doing about 10 min ago) is turn the gain on the amp all the way down. Now turn your head unit up until your other speakers start to distort, then turn the volume down just a little. Now go turn your amp gain up until either the subs become distorted or its too loud for your tastes.

Since your running your mid range speakers off an amp as well, just turn the volume all the way up on the head unit and adjust that amp first, then the subs.

 

Also, on your sub amp, set the LPF/HPF switch to LPF. This will block out the higher frequencies and cut down on distortion.
The subsonic filter is designed to block any frequencies lower than the sub was meant to reproduce. Look at the frequency response of your subs and set it for what your subs can't handle. I'd probably set it around 25-30hz or so, personal preference really.
The bass eq is a booster for 45hz on your amp. This is also personal preference. Setting it too high can give a response curve that isn't as linear as it should sound, with a big increase in volume at that frequency. How loud it is at that frequency will depend on many things, but I'd recommend you start it pretty low.
The crossover will determine what frequencies your amp will let through to the subs. I like mine set fairly high to better blend the sound in my system, around 120hz to match my head unit's crossover. If you start hearing voices or higher frequencies through your subs, set it lower to block them.

As for the mid amp, it's the same thing, but kind of in reverse. You want to let the high frequencies pass through, so the switches for LPF/HPF should be set to HPF. Subsonic should be set low or even off if possible. Bass eq is personal preference as is the xover. You want it to match or closely match your bass amp so you don't get a gap in frequencies. If your sub takes anything 120hz and lower, you want the mids to do 120 and higher.

You want to try and blend the frequency assignments between the mids and bass. I've always used the Bass Mechanic cd's to start tuning my stuff. I don't even know if they're available now, but you might be able to find an mp3 of some on the 'net. Try to find a track that sweeps from high frequencies to low, there should be a smooth transition between the mids and subs once it gets to that point.

I'd recommend you set the sub out to 120hz unless you get a lot of voice/high frequencies through the subs, then try 80, but i think you'll lose some punch at 80.

 

Very simple, but very effective!
Just make sure to set all your tone and loudness controls to the flat/off position before doing this, an set your amp X-overs(at least for main speakers)before doing this too!

 

Thanks everyone, I setup the amps, and WOW I love it. Waiting for the seats to get done, so I can get it all put back together and take her out for a drive. Sometimes, sitting in the garage listening to the radio is just not the same - .