I finally removed the stock Delco-Bose stereo and all 4 speakers. Now the question is: what is the size speakers I need to buy to properly replace these? I did see the stickied C4 Audio FAQ thread but I'm a little confused on this part that describes the 84-89 speaker size: "84-89: 6.5" round or even 6x9 can fit in the doors. You will need a "notch" filter, set at 160 Hz, to soften the blow. According to Kale, the door acts like a resonance chamber at the frequency."

I'm pretty sure 6x9 has no chance of fitting in that door?? The speakers themselves look to be about 4". What sizes can fit in the door and in the rear? If anyone's upgraded their soundsystem and can offer some guidance I'd appreciate it. Help me from being stupid

 

old radio didn't work?

 

I just finished a total removal of the Bose system in my 85. I used Alpine S-S65C 6.5" components up front, Alpine S-S69 6x9 coaxials in the rear, a PWE-S8 compact sub, ILX-W650 double din head unit and KTA-450 compact amplifier.

These speaker adapters work perfect for the doors https://www.ebay.com/itm/Exact-Fit-F....m46890.l49292

For the rear 6x9s I was able to use the original mounting ring once the Bose speaker assembly was removed.

I mounted the sub with clickbond fasteners onto the back wall of the cargo area. I didn't want to drill through it because of the gas tank location.

 

I'm using a factory Delco radio with 5 band EQ. I mounted 6.5" 8Ω speakers in the doors and 6x9" 8Ω speakers in the rear, using the factory wiring. To mount the speakers in the doors and use the original front grilles I fabricated a mounting bracket for each door, which I riveted to the fiberglass door shell. Very happy with the set up, and it sounds 1000% better that the original Bose set up did.

 

When I yanked the Bose out, I went with Kenwood everything, 6x9s in rear, 6.5" rounds in the doors.

 

Nope, amps were no doubt blown and I was going to try to repair them until I just decided to upgrade the whole sound system for a better use of money.

 

That's a great setup! Gauge cluster looks great, how did you turn it that color? Thanks for the info.

 

There are colored polarized film overlays that you can insert in the digidash unit to change the color, or you can do various LED upgrades.

My 86 had a red film overlay in the digidash to make all numbers show in red.

 

Being able to make custom brackets is the way to go Any idea if I could use 6.5" in the rear with the factory mounting brackets? Or would that not fit?

 

My project started the same way as yours. I had one blown amp and the headunit was starting to act up (randomly go to static, erratic volume control). I planned to repair the original system but I figured I might as well just upgrade and do everything I want. Even with just middle of the road stuff, it is plenty loud for me in a small car like the C4.
​​​​
The speaker adapters I bought for the doors are awesome. They are pvc so they won't rot, they mount just like the bose enclosure (only much smaller and lighter) and they are predrilled to accept the factory speaker grills. I even went extra cheesy and ordered some metal Alpine decals to place where a bose logo would normally be.

It appears they also make an adapter to put 6.5" speakers in the rear. For only $11, if they have it in stock I would certainly go for that over making something custom.

http://www.car-speaker-adapters.com/...earch_consumer (just enter year, make and model and the adapters they sell for the C4 will come up.)

I bought the color film off Eckler's, it is made by a company called Corvette Craft and I believe I received one of the last ones. Their website went down a few days after I bought it and I have heard from several people that it is now discontinued. It requires almost complete disassembly of the gauge cluster and it replaces the factory yellow, green, red color film. It is actually a fairly nice part, it's a shame they are discontinuing them.

 

Wow! Thanks for all the information, truly. It does seem that our projects started very similarly I'll definitely be ordering the brackets for the front and rear from this website. I see they also offer a 50% refund if you send installation pictures?? Great. As for the film, that's something I'll be keeping in mind as well. It looks so cool. Thank you.

 

Can I give you guys a tip? Those of you running 6x9's in the rear?

I've had 6x9's, JBL 2 ways in the back of my 'Vette (a '92) since I've bought it. I've never loved them for two reasons:
1. In order to get any kind of "good sound" or any punch out of them, they're way overpowering the fronts. If I adjust the fade such that the system sounds balanced front/rear, then they seem lame/weak. At NO point, do they make good bass ...of any kind.
2. They're too harsh/abrasive to my ear. Piercing/annoying upper mids, all for not great highs.

I had installed two amps previously; a 4 channel JL Audio (to which the fronts and 6x9 rears were connected) and a JL Audio mono block sub amp, to which I'd had a 12" sub connected. A few years ago, I broke the cone of the 12" sub so I took it out and the sub amp had been unused. Therefor, for the last few years, I've been listing to a potentially LOUD, 4 speaker system...but not great sounding a good sounding one and no bass.

I got an idea, tried it and it worked surprisingly well:
I removed the rear 6x9's and cut the wires going to their tweeters, then wired the 4 channel amp's rear wires directly to the tweeter (through it's cap to limit bass). Then, I connected my unused wires from my sub amp, to the 6x9 magnet/cones of both 6x9's. What I've got now is the 6x9 cones working on a low frequency controlled by the sub amp -they're no longer producing any mids or highs...just bass and that's it. The tweeters are still producing the same sounds they always have, but are adjustable via the FADE function. I've found that they are acceptable when turned down quite a lot, just to "fill" in the rear a bit.

Now, the 6x9's pound pretty hard -hard enough that you can feel it through the seat back. The overall experience is much better and I feel that I'm using far more of the 6x9's potential, the way they're wired now, and in the C4.

Just thought I'd share a free "mod" that I am quite happy with.

 

That's weird... I didn't know stereo speakers were like guitar amp speakers where you have to push them to get them to sound good...

More like "smash them in the ***** with a sledgehammer" in the case of the guitar amp, but you get my point.

 

Yeah, IDK that you "have to push them harder"....here is the problem:
1. The front speakers (on a '90^) fire into your pant leg. From a "hole". Plus they're typically smaller sized. Bottom line? They're hard to hear.
2. The rears, have a 6x9 which produces way more volume from the same wattage and they're in an enclosure (which helps volume)....so when faded the same, the rears are way too loud.

3. The crux of the problem: To get decent, punchy bass from the rear, like most any speaker, you gotta turn 'em up some. Unfortunately, then they become overbearing with mids, upper mids and highs that you don't want and don't balance with (over power) the front's output. You're getting "blasted" from the rear w/a full range signal, just to try to get some punch.

SO...if you remove all of the mids, upper mids and highs from the 6x9 cone and only ask that cone to make bass, then you can adjust the gain/bass/cross over point, to get what you want from that cone, independent of all other frequencies. Let the tweeter fill in a little highs from the rear for a properly balanced "surround" effect, and drive most of your vocals/mids and highs from the front...the way it should be.

It's really amazing what the 6x9 cone is capable of (bass wise) when you remove all of the other frequencies and just let it "work" on that, alone.



.

 

The door speakers are in such a bad place I consider them unusable. I put 3x5's in the dash (you can just cut the plastic under the grill if you have the Bose) and 6x9's with an amp in the back. To me, it sounds great. The dash speakers reflect off the windshield for clear highs and mids while the 6x9's fill in the bass.

 

Welp, you're on the ball with what to do with this, so would you mind helping me pick out a system? NOBODY around my area has any idea what they are doing with C4's... And most of them are scared to death of the Bose system so I can't get pro help here... And I know Jack and Squat about car audio.... Like... ZERO.

I do have a solid electronics background though. I can solder, replace board-level components, do wiring, etc...

 

I'm happy to help any way that I can, but a system is a personal thing...and also depends on what you already have and want to keep?

I'd say, ask me specific questions, or tell me what you've got, what your vision/mission/goal is and I'll try to help.

I don't think the "6x9 hack" is the best way to go....I'm going to change what I've done this spring. I posted it b/c I think it's the best way to get the most performance from your 6x9's when you already have that set up in your car. The OP, Vader, and anyone else who has a sub amp, a 4 channel amp and 6x9's in the rear could see a substantial gain in performance by re-wiring their 6x9's the way that I described. But if building from scratch, a real sub(s) is better.

 

Ok!!! Thanks!!!

Here are my goals:

1. Apart from the head unit, 100% invisible install. No extraneous sub boxes, uses stock speaker covers, no visible amp or wiring.

2. Android compatible, with a touch screen so that I can display Google maps on it from my phone.

3. No cutting up the center bezel to fit something like a double din head unit. So... The unit needs a screen, but the screen has to fit in the allotted space or be something like a flip-out or detachable (if such a thing exists).

4. Sound quality... Middle of the road... I'll spend $$$ where necessary or where there'a clear return, but am not an audiophile. So, not junk, but also not "top of the line" is where I want to fit in.

5. Speakers... Whatever you recommend. I would probably shy away from 6×9's in the rear for the reasons you describe... So probably round... But we also do have those two grills in the dash pad to work with!


Othter notes... The interior is gutted right now. I'm doing new carpet, and replacing the driver side door trim panel and window regulator, so now is the time to do this! After this, the interior will be 100% done. I did the suspension and brakes last year so finishing this off lets me start to plan the engine and transmission work for next year.

Thank you again for any advice you can give!!!

 

What year car is this?

 

1985

EDIT: I should probably add that there is an aftermarket single space head unit in it now, with a filler plate and the 4 speakers are in their original Bose enclosures. Myabe something along the lines of this for a head unit:

Pioneer AVH-3500NEX DVD receiver at Crutchfield