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Intrepidly I go

Posted: Tue Aug 07, 2007 12:19 am
by Sawzall
I suppose its time to start the project log to document my foolish journey to upgrade my 2000 Intrepid. My budget is "frugal" - but just as important, I want to enjoy this project not only after completion but while doing it. I might be a little hard headed at times but I do appreciate constructive critisism, so fire away when it seems like I am being a knuckle head.

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. 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?

Posted: Tue Aug 07, 2007 1:15 am
by todd.brust
comments...well...sounds like the whole switching thing could be something interesting to work out...i might have to go back and see what you are trying to say and better understand but from my understanding...i think it is a job that can be done with relays(i think it'd be easiest to run the 3.5 and tweeter in the doors passively together so one switch to turn them off) ...have you decided on any speakers? and no tweeters in the sail? jusy the 3.5 and center channel? i am not very familiar with 5.1 sound and processing but would the center take care of the highs where the tweeters in the door normally would or will the 3.5s do that job? did i work that right or just make it harder for everyone to understand?

Posted: Tue Aug 07, 2007 8:02 pm
by Sawzall
It will be relays one way or the other - the question is will it be a micro controller and a remote or will it be actually flipping a switch.

Still working on the speaker decision - gotta listen to the Morels before I make up my mind. Do I buy a component set or roll my own with raw drivers? So far the Focal's are out front but still looking. As for the 3.5's, most of them are co-axials with limited bass response. I can actually put a 4" in the center. It has pretty high demands placed on it during movie dialog. TB makes a nice 3" driver that would likely work like a charm as well as the OEM replacement speaker from several different manufactures.

Gonna post a system diagram in a little bit so it should make more sense then.

Posted: Wed Aug 08, 2007 1:14 am
by todd.brust
yeah you do that! seems like you like to the challenging projects

Posted: Mon Aug 27, 2007 12:01 pm
by s3sqguy
LOL, "interventions?":)

Sometimes I think that after building this IB baffle 'what a pita a box would have been so simple'...just don't have that kind of time right now. But I got what I wanted now if I can just sort it out.

How about just using the door setup for your 5.1 fronts, maybe swapping signal before the amp? Maybe not a good idea, but if you have great speakers sitting there why use 'not as good' ones? Or that would be what I would ask myself anyway. Seems like you could even slip an 8"-10" sub in someplace for the 5.1 and get as much or more than the doors would make....or again use your main sub. Or is there an issue I am missing....

Posted: Tue Aug 28, 2007 8:36 pm
by Sawzall
In real 5.1 its critcal that all the fronts, and ideally, all 5, are either the same or voiced awful close. Also helps if you can keep them in the same plane***, thus the sail panel install. Since the first post I have been investigating what I can put in for the center channel. Got the upper dash panel off and it seems I can put a 4 inch without much hassle. Now that creates some opportunites. I can go with a really high quality full range 4 in the center with a broad pass band and then use the same 4 as a mid in the doors with a narrower pass band, helped out by a true tweeter and a woofer. The goal always is good SQ in stereo, then SACD and DVD. The FR125 looks awful interesting if I have room for some enclosure up in the dash. The options are many - the chances to hear drivers before hand few, so I may be better off going raw drivers that don't cost an arm and a leg up front. Wish I knew someone who had a closet full of "test" items (but then again, don't we all?) Finally located a dealer who is helping me out figure it all out.

Car is going into the body shop Friday so I got a couple of weeks before I have to decide on anything.

*** There are some recordings in 7.1 designed to be used with a "high" channel, meaning up above your head. This would be cool as hell in a car install, but there is zero equipment for it. Would be impressive.

Posted: Wed Aug 29, 2007 7:32 am
by Member02
wow... you really should do a 7.1 install... get some dc to ac converters and put a home reciever in your car

Posted: Wed Aug 29, 2007 9:27 am
by s3sqguy
Well I tried but you have good points.

I keep thinking it would be so cool to utilize a few or more of those tiny full range drivers, the 1"/2"/maybe 3" ones....but I guess an array in a car is not optimal since the wattage is so low with them. What if you run say 4 1" in a cluster, would that be a cluster?:)lol

Posted: Wed Aug 29, 2007 10:25 am
by s3sqguy
Doubtful you have room, but you could make a tiny MTM center with those little drivers.