Hi, I am looking for 101 advice on getting our jam sessions setup for clarity in sound.
Please bear with me as I ramble this predicament.

I use a compter recording (SONAR + other stuff) setup for home recording and use headphones for that just fine. But we have a jam night crew and I am looking for the basic answers on how to get the best from our gear LIVE soundwise, with maye some small additional investments if necessary. please note this is just a fun thing so ambition is limited therefore I would greatly appreciate some basic steps and advice from all and anyone!
I have very basic sound engineering knowledge but smart enough to grasp concepts

Here's the scenario: *************
We have a Beringher 400w powered PA, 12 inputs with 3 XLR mic inputs to which we are currently feeding pretty much everything STRAIGHT in!
* 2 guitars, 1 semi acoustic, 1 elect,
* 1 bass
* Audio sampled drum pattern on a laptop (Audio line out from laptop sounds good actually, using Drumsite sw)
* Cakewalk sonar tracks for extras, my stuff backing etc.
* Maybe other instruments seeing as it is a jam night

I am trying to rethink my strategy to overcome the droning shite that sometimes eminates out of this messy mix.
That being said, would we be better off using our own amps? Thus singularising each sound output.
I have also heard that you can then route those AMP outs back to the PA and thus have the mix sounding better? BTW our jam space is small :-/

Can someone just outline me some cliff notes on what would help me get a cleaner output, avoiding the hums, feedbacks etc.
I also use a line 6 toneport on my acoustic guitar to some success.
And studying the use of gates and compressors etc.

I seem to get a great mix on my PC studio setup and like my modelled mic voice through the headphones, but it all falls apart come jam night. Why?

Give the basic scenario can someone draw me a hypothetical diagram what we should do to improve the live gig. We're not that good but we're not that bad for the fun we have, I just sense it could sound a WHOLE lot better if I knew what I was doing.

All honest good advice really appreciated remembering This is a hobby not a career for me.

THANKS!
Alan

By jam nights, do you mean you set up in a club/bar/why and then allow all comers to get up and play?

If so, you are approaching this in the wrong way. I used to run a bunch of these and the best idea is to supply a basic P.A. with at least two mics for vocals, plus a couple of backline amps for bass and guitar. Drums? Well in any true jamming situation it is likely to get VERY boring if all you have are drum loops or a beatbox, but that is your choice.
I would find a drummer and persuade him to bring his kit along.
Bear in mind that you get all sorts at a jam and don`t take anything along that you would cry about if it got broke.
Ground rules for avoiding sludge? NEVER EVER more than two guitarists playing at the same time. Keyboard players unless good and tasteful should have their left hand tied behind their collective back.
You really will have to use something like SM58`s for vocals and I would suggest you forget about monitors until you have the thing working right in terms of people showing up and acting like they are actually enjoying it (I.E. Staying!)

Backline amps would seem like a must, but there again if you stick only the acoustic and vocals thru the PA at least you only have to worry about other folks showing up with their marshall stacks making a mess fo things. Again, you have to be IN CHARGE at all times. This is not a democracy and it is YOUR gear they are using.

Drummers using someone else`s kit should be advised that they will be hit on the head as hard as they hit the skins after they have finished playing. (well it might work)

Nobody gets to play more than three songs unless hardly anyone shows up.
Oh and it is a LOT more fun if you don`t let actual bands get up and play like it is a mini gig.

The usual idea of a jam is to expand people`s musical horizons by exposing them to other people`s playing, not give no-hopers a chance to strut their stuff in front of a captive audience.
And finally, unless you are a masochist, NO Led Zep until the last thirty minutes.
Good luck!

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Me? But I`m such a loveable old bugger!

You mentioned that your space is small? How small?
Regarding your PA, do you have a stereo headphone out, or line out?
If you have all your instruments/vocals running into the PA, have you considered running the line out to the line in connection on your laptop for Sonar? I have Sonar 4 Producers Edition, so I'm familiar with what you are using.
I have done this in the past with multitracking I did years ago with a VCR, and it worked out pretty well for what I had to work with.
The other thing you could do is isolate the amps a number of different ways, which may help you with 'sound pollution' you are probably getting due to the amps not being isolated. However, that will affect the 'live' sound you have collectively in the room your playing in.

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I jam, therefore I am