Attached is a crude pic of modified doors done in MS Paint - pretty brutal stuff but I don't have my drawing tools with me here in Toledo so its the best I can do for the moment.
SQ of "normal" CD sound is Objective #1. All the rest is gravy. So here goes description of system as I have figured it out so far - working on a system diagram, but its a bear in MS Paint:
Head Unit: Sony MEX DV2000 - real neat unit. Plays DVD-vid, SACD's and CD's (No DVD-Audio for the obvious reasons, but thats not a real loss). Has 5.1 processing and RCA outs for all channels. No internal amp for the center channel which creates an issue, but will get to that later. Its Satellite and HD ready - both add on's are fairly inexpensive. No "slideout" monitor, but thats OK since in this car I have two DIN slots available - the old head unit and the old 4 disk changer. Unit can be setup with and without display. Nice unit for a street price of $190.
Front Stage: SQ being number one I am focused on what I can do with the doors. Kickpanel install is just not an option - no room. Currently has 6.75 in lower door and 3.5" in sail panel and center channel. For DVD use I intend to upgrade all the 3.5's to best available units and connecting them to a small 4 channel amp, say 25 x4 (real watts are used throughout - no "Maximum Output While Being Struck By Lightening" ratings). Use Channel 1 and 2 for Sail Left and Sail Right, bridge 3 and 4 for Center Channel.
Now for Stereo output - First choice is to really tear up the doors and go with a 3-way system. (see attached pic) Put tweeter at lowest and furthest possible point for listening position, then mid and finally putting a 7 or 8 inch woofer in center area. Still stuck with a significant path length difference but a hell of alot better than in sail location. Depending on the woofer I end up picking, I really want to cross these over as low as reasonable - target is 80Hz at least. Amplification - 4x50, splitting it up for one channel for each Mid and Tweeter and then a larger 2x100 amp for each woofer (maybe larger, we shall see). Building out the doors gives me roughly .6 gross cubic feet of possible enclosure space, which should be fine for a lot of drivers.
Rear Fill: it will be upgraded 6x9's in the stock locations after sealing the package shelf off. Will use the internal amp to run these. Should be enough.
Subwoofers: still undecided about this one. Either I will use two (2) 12" in a sealed box OR two (2) 10" in an Autotuba, which is a horn loaded design by Bill Fitzmaurice. http://www.billfitzmaurice.com/AutoTuba.html Two 10's hornloaded would be absolutly oppressive if you wanted it to be. Giving up a lot of room is the only disadvantage. The amp needs depends on the choice of enclosure. 2x100 is plenty for the horns. (we can discuss why horns are great if you have the room in another post - notice I said discuss
)Signal Processor: I am pretty sure I am going to use a DEQ2496 for signal processing on the stereo side- Other than the powersupply issue, its an easy choice.. I know of no other way to get 61 bands of EQ and a matching FFT RTA as well as time correction in a less than $300 box.
Crossovers: - well, there are going to be plenty of them available since pretty much all high quality amps have them built in - but given the next issue, I may end up rollling my own to some degree....
Switching inputs and outputs: Here is where it gets interesting. For playing 5.1 media, I want to turn on the 3.5" speakers in the sails and center channel, turnoff the tweeter and mids in the doors and maintain the woofers in the door, and use the LFE subwoofer output from the headunit to both subwoofers. Use the internal 5.1 processing in the head unit.
During stereo playback, I would want to turn off all the 3.5's, turn on the door mids and tweets, maintain the woofers in the door, and run the subs from the outs of the DEQ2496 in stereo. I suspect there is equipment out there for this already, but if need be I can roll my own. Easy way would be with simple high quality mechanical relays, more fun way would be to do it electronic switching using a sub-micro processor like a PIC or one of the zillion other chips. Basically its the switching part of a pre-amp so designs on PCB exist.
Another complicating issue is the wiring methods of DCX on this car. There are two medium quality runs of wiring to the doors right now. The hard part is that the car uses connectors to go thru the metal frame of the door, so getting additional runs (or upgraded speaker connections) will require a new hole in the doors. Looking thru the ol' Digi catalog shows several good options of bulkhead type connector that I can put on the door frame and the door. I would then be able to use 12 and 14 ga. wire.
As you can see, I am not creating a simple project for myself - but if I am gonna go to the effort, I might as well do it right. Its a lot more fun that way anyhow.
Comments? Suggestions? Interventions?
