In my '04 TSX, I had an installer add a MRP-240 to drive my fronts and rear 6x9's (all upgraded to SPS-170's and SPS-690's). The amp is under the passenger seat.

When listening to CD's, I get plenty of tight bass. It's lacking on the low end but I didn't expect that out of the 6x9's. Overall there's great improvement.

When listening to XM, I really don't get the equivalent bass and punch that I do when listening to CD's.

I'm thinking I need to add a sub? What are my best options? I guess the easiest is kill the 6x9's and use the 4 channel amp to drive a sub. Question is, will this amp have enough juice to run a decent sub and run the fronts? What kind of sub would you suggest? For space and power reasons a single sub would probably be best.

Is this something I could DIY? How would I wire it to maximize power? Thanks!

 

How is your XM connected to the '04 system? If it's FM Modulatated, bypass that and go direct. If you are already direct (SHOND or equivalent) get a line driver (PAC Turbo1 ) especially if the volume is too low.

To improve sound overall:

That amp doesn't have a ton of bass power. I'd suggest trying those 6x9s as woofers only by trying the xover for the R on LP, that would let you drive them a bit harder, and let you use your fader as a woofer level control for when you need more.

Finally, there are better 6x9 woofs than those - the MBQuart 269s (which are almost unavailalbe), and I think my avincar av69w1's could work well on that amp too. Easier than a sub box and use your current amp.

 

elduderino, the XM is a line-in connection. I had some problems with noise and finally worked it out by pulling power directly from the head unit instead of the fusepanel and by repositioning a GLI. This was resolved after I had a PAC Turbo1 installed and for some reason it died after a few months. This was before the amp install. I have a Phoenix Gold LD22 line driver that's been sitting around, I guess I'll give that a shot and check xover settings. I appreciate the quick response, I'll let you know how it goes.

 

Wired in the line driver this morning. That seemed to help a lot with the XM radio. Of course the downside is it seems to have uncovered some residual noise. The noise doesn't change pitch when I rev the engine so it doesn't sound like the alternator noise I got rid of earlier. Maybe I'll try moving the ground. Right now it's grounded to a bolt in the center console. Probably not the best location.

I also played with the amp a little. The xover for the rear was already set at LP. I noticed the gain and bass settings were as low as they get. I played with them a bit and the bass distorted pretty quickly. I guess that's because my 6x9's suck? elduderino, tell me what's different between your 6x9's and the alpines I have.