Well... you could have done much worse - its actually good enough to power a low-end system.
What you have is enough to power standard 6x8 aftermarket speakers to a good volume level. If you try to drive component speakers with this amp, you might find that the music doesn't have sufficient dynamic range - it could sound flat or not very lifelike.
If you find your amp doesn't have enough juice, save up your pennies and get a Alpine MRV-F407, which is probably one of the best 4 channel amps ever built. If you're using a sub, MTX makes a five channel amp which has plenty of power and fits on the wide half of the 60/40 split on a Contour rear seat. In both cases, ignore the printed spec go with what's printed on the "birth certificate" that comes with the amp (my MTX is twice the factory specs at 54x4 + 180x1 RMS @ 4 ohms and 12.5v).
You should be able to get either one of these amps new for under $400 or buy a used one for $200-280 on eBay. I got my MTX used on eBay for $191.50. (Tip: save the box and packing materials from your Sony amp in case you decide to sell it at some time in the future.)
Remember, when you are installing any high powered amp, don't skimp on the wiring - especially the amp kit and RCA cables. You're amplifying whatever signal ends up back there, so make sure it's a clean one!
Finally, in the unsolicited tip department, If you want a great head unit, try the Pioneer DEH-P9300, which you can pick up online for about $375. Among its many other talents, it's AutoEQ will automatically set a flat EQ curve for your car. It also looks good in a Contour/Mystique dash. Highly recommended.
Happy Tweaking!
Originally posted by Mike Murphy:
Hey guys I was just wondering what you have heard of the Sony XM-404EQX. I know that many of you will say that Sony is over rated and that Alpine is the way to go, but I was just wondering what you had to say about this fella'
Thanks guys - Murph