A good amp, new door speakers, and a good sub without going the route of using a digital sound processor? While I just about have my mind set on the sub and new speakers I want to use, I could either get an amp with support for high level inputs built in, or spend a little less for another amp, but use a JL Audio CleanSweep. All 4 of the last vehicles I've ever owned had an aftermarket stereo and a system built to my liking, but for my new 13' Mustang, I want to keep the factory look and features. It does exactly what I want, it just sounds like *** with the factory junk speakers

My choice for an amp is either the JL HD900/5, or Alpine PDX-V9. The JL has high level input support built into the RCA inputs, the Alpine doesn't have high level inputs, but has very similar power specs and is cheaper. The sub I'm going with will be JL's stealthbox with the 13W3v3. Choice of speakers is still up in the air...

 

The only thing I'm unsure of on the base system, is if it still has the speed sensitive volume limiter/bass reducer built in to the factory head unit or amp. I'm not sure where that processing is done.

If it doesn't, you'll be fine. Either of those amps are a fine choice. I would spend the extra money on a clean sweep (or similar) just to level out the factory EQ though.

 

I'm using the Alpine PDX-V9 and the JL Audio Stealthbox in my build if you want to read along....

 

As I understand it, I think the JL Audio cleansweep will help keep a constant flat eq curve when the volume is changed. I am curious though as to which part of the high and low eq curves are changed when adjusting the bass and treble on the factory radio. When I turn up the bass, it sounds like it only adjusts the high range of bass output, like say from the 100 to 200hz range. May have to invest in a decent eq to run in between the cleansweep and the amp...

I have a JL audio CPL108 which is a 8W3 sub in a slot ported enclosure that I used for a short time in the Dakota I had, tried selling it on craigslist but heard no interest in it what so ever from anyone. So I may just use it in the stang to hold me over until I can get the JL Audio stealth box.

 

I don't believe the OEM radio has crossovers for the door speakers. The OEM Shaker amp does for the door subs.

I upgraded to the Shelby Kicker amp, which has crossover points for the door speakers, door subs, and the sub out for the trunk.

If you are wanting to use crossovers in the OEM system, you are going to have to get a signal processor. JL, Bit 10, and Rockford Fosgate make great ones. AudioControl makes one, but have not seen it in action yet.

 

Aftermarket amps already have crossovers. The Cleansweep signal processor I'll use only outputs a full flat frequency curve on both front and rear outputs. The amp will do the job on separating the correct frequencies to the speakers and the sub.

EDIT: Oh, and the stock base radio outputs the full frequency range to each of all 4 speakers in the car, which will make something like this type of install easier to deal with since it doesn't have separate subs or tweeters to tap into.