OK, I want upgrade the AP2 sound. An installer I talked to thought that I could try adding more power first, then determine if the stock door speakers need to be replaced or not. I kind of think that if I am in the door doing sound insulation work anyway, might as well replace the factory speakers at the same time. Since I already have the separate tweeter location, I can easily go to component speakers (with either inline passive crossovers or some kind of active crossover solution). What is the best bang for the buck component speaker with good low end that will easily fit? In terms of coaxial speakers, I read the recommendations on this site for the HAT Mirus, went to their website, and was impressed with the way they write up their manuals (good, nerdy engineering type info). The Imagine would be the comparable component speaker. The low end of the frequency response specs didn't seem especially impressive, though. (Could be because they actually list the frequency response at a certain number of dBs, which some companies don't.)
Also, I wanted to keep the factory HU. Since I am adding an amp, I don't need to upgrade the HU's power. I realize I am giving up the latest connectivity options, unless I buy more connection kits. But, am I giving up any sound quality by feeding this HU's output to a good quality amp?

 

I don't think the stock HU has RCA preouts, so you would have to use speaker level outputs which are inferior. You should upgrade the HU.

 

I've seen you post on a couple other threads GNK, and I also have to ask what your attachment to the stock HU is. You seem interested to keep it in every post of yours I've read, but the thing is really a POS. With an aftermarket HU coupled with a Modifry DCI, you won't lose any of the dash controls, and will probably end up with something that looks a lot better and is infinitely more functional.

 

if you want to keep the stock head unit you can get a sound processor like audison bit one or jbl ms8 which would allow you to interface the head unit to the amp. but they are really for cars with no option to fit an after market din head unit, for cars with non din setup or integrated climate/navigation systems.

 

Yes, I was thinking of including a sound processor. To let you know where I'm coming from, I changed out the stock HU on a Boxter that feeds the factory amp to a JVC KD-815. I was happy with the new functionality and the improvement in sound quality (at least with the parametric EQ adjustment capability). I was happy that I found a unit with variable color that could match the stock color. I was not so happy with the glossy finish and lack of hard buttons.It might seem I'm being stubborn but I am willing to change my choice with good reason.
So let's change the question slightly. This is based on the Modifry DCI being the most compatible with Kenwood and Alpine.
Which gives the best sound quality, and the best functionality (by which I mean ability to equalize for frequency response and time alignment, possibly ability to select between two settings from the driver's seat):
1. Stock HU + Audison BitOne (or equivalent) + amp
2. Kenwood Excelon + amp
3. Alpine + Imprint + amp

 

I wanted to keep the factory HU. Since I am adding an amp, I don't need to upgrade the HU's power. I realize I am giving up the latest connectivity options, unless I buy more connection kits. But, am I giving up any sound quality by feeding this HU's output to a good quality amp?

 

The first thing I would do is to trash the headrest speakers, those things suck! With exerience from another Honda I just replaced all the cheap 5 oz magnet speakers with some decent quality High Effeicentcy speakers, a low budget move. Then I put about $800 bucks into a Focal subwoofer and amp and together it sounds great. My S has and Invidia exhaust sooo I am never goin to have a sound studio in there. By taking about POS those head rest speakers in my 06 sound like a set of air buds tuned up all the way not in your ear. I am sure there is thread on trashing those somewhere if somebody wants to point me there. Thanks

 

After all of this discussion about the stock HU coloring the sound and only providing speaker line outputs, I am going to ditch the idea of keeping it.
What I am thinking now is to get the $350 Pioneer HU (Crutchfield price) that has auto EQ and time alignment along with the kit to keep the steering wheel controls active. That replaces the need to get an Imprint or Bit One or similar, I think. I'll install this first, then see if I want to add an amp. I probably will, since the 14 RMS rating for this unit is on the low side. Some other HUs (like Kenwood Excelon) have manual time alignment, but what software have people used with this? Then I will look into replacing door speakers with a component system and whether to do sound insulation.
Opinions on good bang for the buck component speakers for the doors in this scenario? If I run the HPF and LPF settings rom the HU (ignore rear channels) then I don't need the crossovers.

 

I'm assuming you are talking about the Pioneer DEH-80PRS head unit, I think I would be cheaper if you get it from J&R.

 

That's right. The website list price is the same. I assume you mean that if you CALL you can get a lower price. Thanks for that info.