B5 A4 with concert/Bose stereo budget aftermarket upgrade

I just picked up a 1998 A4 a couple weeks ago and was very dissatisfied with the stock stereo. I wanted IPod, usb, Bluetooth, aux in, all that good stuff, and I wanted it to sound better. But I didn't want to spend much money at all. My budget was under 200$ -- I had moderate success.

I'll try to do a fairly concise write-up of what I did and what I learned to make it easier for people in the future.

I learned that in the Bose/concert system in the car is all run off the stock amp in the back. The head unit sends out front left and right, and rear left and right low-level RCA signals. So you can use an aftermarket HU that has at least 2 pre-amp outputs. The "subs" in the rear deck aren't on an adjustable subwoofer channel. They are just signals taken from the front and rear signals, the amp must just have the crossovers it needs in it. The front speakers are 4" stock, I suspected I could jam a 5" in there fairly easily. The tweeters are about 1". The rear deck "subs" are 6.5". I didn't mess with the rear door speakers. All are 2 ohm.

I decided to try keeping the stock amp, adding a new stereo, and replacing the front door speakers and the rear deck subs. Here's the equipment I decided to install:

I just ordered an HU from crutchfeild, with a 20$ off coupon (offer code 3a825) 130$ shipped
Head Unit

and got all this for free:
Harness
Dash Kit
Antenna Adapter

Then I ordered 2 of each of these speakers from parts express:
Replacement subs
Replacement door woofers
And i had a pair of 2 ohm tweeters laying around from an old project. they are the ones out of this speaker set:
JBL GTO508C 5.25" 2-way Component Car Speakers - Sonic Electronix

The dash kit, wiring harness and antenna adapter were all correct, and were plug and play with no modifications. I just soldered up the harnesses, made sure to connect the remote antenna wire, and yanked the old stereo with the keys crutchfeild gave me, and plugged it in. Works great. The dash Kit just goes right in from the front, and it sits surprisingly flush and fits well. It's not perfect, but it's not bad either. I used the included spacer.

Impressions with new stereo and stock speakers: Eh. At least I have the inputs I need, and it sounds slightly better maybe.

The speakers were slightly more trouble, but not much. The rear deck subs were easy, I just pulled the old ones, and put the frame on the new ones, wired the voice coils in parallel to get 2 ohms, and took the connector off of the old subs and reinstalled them.

The front doors come off with 2 ends screws up by the windows on the edges, then you take the screw out from the handle in the center, pop out the plastic piece, then take the two screw under that out. Then slide up the panel, and disconnect the door latch mechanism, and all the wire plugs. The speakers are installed in the plastic panel (kinda lame)My car had some thin foam covering the whole back, it peals back easily to reveal the speakers.
The woofers are easily removed, just unscrew and unplug them. The tweeters arent hard either, there is a small red screw to unscrew from the back, then the whole handle/tweeter trim piece pops out the front, then a wire clip holds the tweeter in.

For the woofers, I picked up some foam rubber weather-strip and stuck it all the way around the edge of the woofer to make a gasket, then i drilled an extra hole in the frame of the speaker to that if 2 holes of the speaker aligned with the bottom two screw holes in the panel, my new hole roughly aligned with the top one. I then used the stock screw on the top, and two similar, slightly longer screws for the bottom holes. With some slight forcing, I screwed the screws in and the speaker fits nice and tight. I was worried about mounting depth, but it worked out fine.

The tweeters I had just fit right in where the old ones were and clamps with the stock clip and were in tight, but not too tight to smash the tweeter. It was a little ridiculous how well they worked out.

Then I just soldered up my wires, and reassembled the doors.

Impressions with new stereo and new speakers: Uh oh.... I've made a mistake... The tweeters were unbelievably harsh and out of balance. it was all I could hear. I couldn't even tell if the "subs" and mids sounded any better cause the tweeters were too harsh. I thought... well, experiment failed. Haha. But then I decided to mess with the EQ a bit on the stereo to see if I could adjust it to make it listenable. I found that if I turned the treble level almost all the way down it became halfway decent, even enjoyable to listen too, and if may even be better than stock. The more I listened to it and tweaked it the more satisfied I was. The mids are definitely better, and the tweeters aren't terrible when they are turned down. The subs in back may have been a slight improvement, but Eh...

I assume whats going on is that first of all, the crossover frequencies of the amp dont exactly match what the speakers would like. Maybe its trying to make my tweeters play too low and not giving the mid enough, or vica versa. Also the tweeter is more sensitive than the woofer, and without adequate crossover control, its touch to get them to balance.

Overall I'd say the project was worth it. For under 200 bucks and a day of work, it really does sound significantly better than it did. And I may just have a picky ear too, I'm used to dropping over 1000$ on a stereo system. But if you're serious about upgrading the stereo I highly suggest you save a couple more pennies, and put an aftermarket amp in to run the a nicer set of 5.25" component speakers and a more legit sub. Also, the doors are really crappy for putting good speakers in, so unless you want to mess with them, you're going to have a tough time getting it to sound amazing.

So anyway, this is way long so ill end it. Feel free to ask questions.

Pics:
New tweeter installed in stock location. Thats the old tweeter sitting next to it.

New door woofer vs old 4"er

Stock Mounting location

New speaker mounted

New subs going in.

 

I was looking at doing some stereo upgrades as well, but since I listen mainly to talk radio, not sure if it's really worth it... I'm 40 and been through my big stereo days in college, but still like nice sound. My 99 has the facelift DD symphony stereo already, so that opens up my stereo choices a bit as well.

My thoughts were replacing the stock HU and front door speakers and rear deck speakers... priced out at about $275 through Crutchfield for some decent stuff. I was planning on running the speaker leads from the new HU back to the stock amp and just wire them so they power the rear deck speakers (2 or 3 way) and front door speakers (2 way) using stock wiring (pinout is available, so it's easy to do).

So the rear door speakers and front door tweeters won't be used anymore.

I wouldn't think it would sound any worse... probably a lot better. Any reason why you stuck with the components for the front doors and didn't just put 2 ways in?

Another benefit for me would be because the PO only did the facelift halfway, I don't have a cig lighter, so I can't charge USB right now... a new HU would fix that, but I'm sure I could also wire something for around $5 that would fix that as well.

 

Well, I guess I did what I did partially in the spirit of experimentation. And partially because I already had tweeters laying around, and I just wanted to see if i could pair some 5" drivers with some spare tweeters and wire them up to the stock amp and make it sound ok.

Also, just by experience, I hate rear deck speakers, I think its an awful location for speakers... Subs rattle, and full range speakers just never should be directly behind your head. So with that said, i also hate having a full range speaker pointing at your foot. the stock tweeter location is far superior compared to putting a 2 way speaker down in the mid location, so i personally think you should take advantage of it.

I think for your project, you could still get a pair of reasonable 5.25" component speakers and run them off the head unit, then you'd retain your tweeter location. I think rear door speakers will do you more good than deck speakers as far as sound goes. But your front should really be the focus.

Another thing to consider is that i think the stock amp uses a common ground for all the speakers... im not sure if that makes a difference or not, but yeah.

 

so do those door woofers work with the delta bose set up also?

 

specifically the front door woofer because one of mine is busted and it needs to be replaced so really i just wanna know if i can replace mine with those or not and keep the stock HU

 

I assume that as long as you have the bose amp on the drivers side of the trunk up under the deck, then it will work.

For a cheap replacement i'd say it would be fine. I'd go ahead an pick up two and do both though so its more balanced. They are only 5$

 

It uses a common ground for the low level inputs.... I wouldn't be using those. Pinout shows + and - going to each speaker.

I don't see how a 3.5 rear door speaker would sound better than a 6.5 rear deck. But I guess you never know until you try.

 

Oh, i didnt realize they were that small, for some reason i thought i remembered reading that they were 6.5". And like i said, i never took off the rear door panels. 3.5" is pretty whimpy.

To be honest, your plan is probably a great route if your not concerned about too much bass.