I currently have head unit: Pioneer DEH-2750MP, front speakers: Pioneer TS-G1040R 4", and rear speakers Infinity 6"x9" ... I looking at getting a amplifier just for the rear to get abit more bass from it. BUT I have no idea how to judge a amp. for example "2 OHM Stable & Tri - Mode connection possible" whats OHM stable? i've seen some that states 2 while some states 4.....which is better?

Can anyone just sorta give a brieft guide to purchasing a amp?

Cheers

BASICALLY... your 6"x9"s should be 4ohm, most general retail pioneer type brand speakers are. Now, when you buy amps you should look for the RMS rating, which is generally alot lower than the 'peak' power rating. For example, a 700w Pioneer amp is about 4x60wrms. If you are after an amp for your rear speakers, I would recommend a small 2x50w rms amp which can be cheaply found for around $100 or more. A JAYCAR amp, 2x80wrms would be perfect for about $150. You can then upgrade to some nice 6"x9"s later and really let them hammer with 80wrms =)

I found this site which should answer most of your questions.

http://www.crutchfieldadvisor.com/ISEO-rgbtcspd/learningcenter/car/amplifiers_faq.html

Check it out. It's simple and useful