I was considering buying some Infinity Kappa 5x7's. How good do these sound? I will be getting them very cheap, so it not really a value thing.

 

They are pretty good speakers. I find infinity tweets to be really harsh but it all depends on personal preference, and I like a really laid back tweeter.

 

Should I get a four channel amp to power them? If so what brand? I work at a Bestbuy and I understand a majority of the stuff we sell there is horrible. For a deck I'm thinking of a Pioneer 7800.

 

The stuff you sell there is not horrible, it is just marked up by 40-60% and therefore way overpriced. That is why you get it so cheap.

You really should get a 6.5 comp set for the front and a 2 channel amp and ditch the 6x8 idea all together. If you are stuck on 6x8's get a 4 channel amp to power them.

 

I have always thought infinity was a little harsh for my tasts as well....... they can make your ears bleed if you are not carefull.

 

Old Infinity, 3 years ago and beyond I loved, new stuff is still good but, not the same to me. If you are getting them make sure your looking at the Kappa series, the Reference is, well not so hot. Components on an amp are definatly the way to go.

 

How about infinity perfect's 6.5 all around? How would I get them to fit in the current hole? What brand amp should I go with?

 

As much as I hate best buy, if I worked there and had the discount I would buy these.

Front Comps: http://www.bestbuy.com/site/olspage....=1166840026793

Amp http://www.bestbuy.com/site/olspage....=1170289779116

You really don't need rear fill. Anyone that knows car audio will tell you it is not neccessary. If you can't stand having an empty hole there, buy two comp sets ditch the tweets for the rear and low pass the speakers around 500hz. You will also need a 4 channel amp that is 100x4.