The BBE will only work if you have a main in/out loop (or a main insert), otherwise you can't hook the BBE to the entire mix.  You could hook it to the player or the mics individually.

Second part of your question, no.

Ok, can you use another mixer and use this just for an amp - yes, I think you can.  You'd use an external mixer and bring the inputs into the amp1 input and amp2 input (read your manual to determine if they are balanced/unbalanced/hi-z or other).  As an alternative you can bring your outputs off a board like the Mackie Onyx 1620 which offers a microphone level output off the mains that you can bring into the mic inputs on two of the channels on the Peavey.  You could always use one of the stereo inputs on channel 5/6 for the input as well.  Not pretty, but functional.  ?Remember to pan your inputs to the appropriate side(s) if you plan to run stereo.

There is no final effects loop so you can't use the sonic maximixer, compressor or other signal modifier on the final output.  Trying to use the tape input/output to do so would result in a terrible feedback loop.

You just said you wanted better sound out of the unit.  What is the problem with the sound now?  It might just be the way you have it set up currently that's causing the problem and not a problem with the unit itself.

I was able to look at the manual a little closer.  You can hook the Sonic Maximizer up via the front panel.  Run the "main out" into a channel on the BBE, & the output into Poweramp In on the mixer.

I don't know why you'd really need to run an external mixer - unless it was a higher quality, but then the quality would be defeated by using the internal amps & PR speakers.  But you can do that as well using the XR internal power amp.  Just take the main outputs of the external mixer & run them to the Power amp in on the XR.  I was mistaken earlier when I said this wasn't possible.

What I was saying was the the mixer itself is a decent mixer that is already built in.  Getting a better external mixer won't really gain much of an advantage in sound quality because the final components aren't going to change.  75% of the sound quality comes from the amps & speakers.  Not trying to put anything down in your system, but the PR speakers are on the low scale of the Peavey line & the built in amp is pretty low powered in itself for effective club work - yes it will produce sound & get loud, but it won't be "clean" sound.
Better amps & speakers will make a huge difference in the sound quality over a new mixer at this point - even before the Sonic Maximizer (although this will make a noticeable difference).

Update I just bought a sonic maximizer A BBE482I

here's the manual gator, it may help. it has how to hook it up to the mixer amps we both have.

http://img3.musiciansfriend.com/dbase/p ... 180913.pdf

I got it for $149.00 online at musiciansfriend dot com  http://recp.rm05.net/ctt?kn=8&m=99333&r=ODE1NTQ2NTMxS0&b=0&j=NDQ4MjA2NjYS1&mt=1
the sale ends on 9/12
 I should get it in the mail in 2 days and update ya'll on how it helps

Gator: Lonnie wasnt saying anything was crappy he was just correcting a thought. re read what he said and it will come to you.
using a higher quality mixer would just defeat the purpose running it right back into the peavey.

Im going to go ahead and hook the max up the way Lonnie recommended without the extra mixer. Ill let ya know how it sounds.

I think my first componet to my new system will be yamaha S-15`s? Any good suggestions would be appreciated for other componets such as amps mixer etc.. Again I thank you for your time and info..[/b]

Well I tell you what, if you think it sounds good with what you have now, you will be floored to hear it with a good set of speakers & amp.
The Yamaha S115V "Club" series speakers are nice.  Couple that with a QSC RMX1850 amp & you will be amazed just with these 2 upgrades alone.

Again, though, for $99 retail, $79-89 on ebay, the BBE 362 sonic maximizer makes a big difference in your final output.

He can't hook it up on his final output, he has a powerd mixer.  It has to go into his main in/out loop.