Heyy i jus bought 2 new 12 inch sony xplods im runnin them off a 760 watt poineer bran new amp with jus the factory deck no after market Yet and for some odd reason subs r not kickin THe way they really should to low and its wierd for some songs it will pound and others it wont :S could ne one hand out some suggestions plz

 

Here's your problem.

 

Sounds more like a issue with the box... was the box built for the subs?

Mark

 

If its the pioneer 5100T or the 5200T, that 760 is Max power (never to be achieved in real life).
That amp is stereo 125 wrms x 2 @ 4 ohm, 190 wrms x 2 @ 2 ohm, or, 380 wrms x 1 @ 4 ohm. And it has a LPF @ 85 Hz, adjustable bass boost (for kiddie-bass) @ 50 Hz.
Don't try to run it bridged @ 2 ohm. It will shut down.

So, if you have 2, 2 ohm woofers, in series (or one on each channel) for a 4 ohm load, you'll get 190 on each woofer.
Or, if you have 4 ohm woofers, put one on each channel for 125 wrms on each.

I run one 5100T on each 4 ohm woofer for 380 wrms each.

As to why some songs pound, others don't; some recordings have much more bass than others. New recordings are usually pretty good, a lot of old analog stuff never had anything below 60 Hz, so they couldn't put it on the cd if it wasn't there in the first place.
The problem with factory stereo's is you don't have a dedicated sub level control.

 

sonysystem: post what model of subs and amp you are using and we'll go from there. These days Sony isn't synonomous with uber high quality subs but anyone with some knowledge knows they can perform just fine and get loud enough to please.