I have a mtx audio thunder 4202 amp is it just meant to use for sub woofer or can it be used for front speakers as well ? is it 2 or 4 channel and what does that men?

if the subs are different models or sizes don't install anything.
use the best subwoofer you have, if you use both you can have cancellation with uneven woofers or damage them. use a large ported box and tune it close to the music you listen to.
use a minimum of 4 gauge copper or cca wire. anything smaller and you risk burning the wire, the brand doesn't matter. use 14 gauge or larger for speaker wire and setup your impedance of your subwoofers in the pattern that will give you more power.
see here.
http://www.the12volt.com/caraudio/boxcalcs.asp

Ya. Just hook one sub to your amp (bridged) and hook the other sub (positive and negative) to the first subs positive and negative

Power hungry unit and the battery may not be enough for the amp, could be a bad cell in the battery.....

Is there a option on the chanels that say ''Bridged''? If so, you can hook the subs up in parellel or series to get different ohm loads. Usually the lower ohms, the more power amp puts out. Those subs can handle 225 watts RMS whitch means the power it can handle constantly. If the amp gives more than 225 watts RMs, you could be at risk of blowing the sub. If you could give me the model # of the amp, I can be of more help.

the amp is under to much pressure get a bigger 1

Hello rjmiller4039,

Although amps with 5 channels are pretty rare, you can get one. Alpine, Boston Acoustics, Infinity, JL audio, MTX, and Polk all have 5-channels ranging in price from around $350 up to around $1,000. The Alpine PDX-5 will output 75X4 watts RMS for the front and rear stereo channels and 300 watts to the mono sub channel. It is priced at $599.99 at Crutchfield.

Hope this helps.

Could be a blown speaker/sub or a wire is crossed in the sub enclosure.

HI DUDE .. U CAN ONLY SINGLE PC OF JL SUB BY BRIDGE MODE ... COZ UR MTX AMP HAVE 300WATTS RMS ....

bridge it and rear channel if you need to know how to bridge let me know

You will bridge the amp, and if the subs are all 8 ohm subs, you can probably wire them all in parallel, if they are all 4 ohm subs, you would wire then in series.