Write-up: stereo system install

Has any progress been made in the dash and the rest of the interior or are you waiting for the exterior to be done first.?

Waiting on the paint. Then back to the interior.

OK, you finished the paint months ago. We need another fix of your handiwork. How is it coming along?

Okay guys I know I've been away for a while. Work has been crazy and I have not had much time to work on the car. I've also been working on another project. I have this week off and hoping to get some work done.....

First off the computer I have for the gauges has died and the company isn't in business any longer. I have a solution though. I am going to use dakota digitals new style gauge cluster. Here is a screen shot.


I have also never been 100% satisfied with the shape of the dash. With the new cluster I have the perfect excuse to rebuild the dash. I am also going to change the speakers a bit.
I will be changing to a scanspeak 9" sub on each side of the dash.



I will have some pics later of the progress.

Here is the start of the new dash. I went about the fabrication a little differently than last time.

First I attached a piece of right angle steel from one side of the car to the other. Then I attached a base for the top of the dash. This will be how the dash is mounted.



Then I had to decide on the shape or profile of the top of the dash. Believe it on not I spent a lot of time here.



Now to reproduce several of them to use as "ribs" in the construction.



Here is the first rib installed.





Now for some foam blocks and shaping.






Here you can see the shape that the top of the dash will be. Just need some more sanding before laying the glass.



Weather permitting, I will lay some glass tomorrow. Once the top is glassed I will go back and make the housing for the new instrument cluster and the speaker locations.

Wow, very nice; you do us proud! So, with the new dash shape, I don't see where the mids will go. Are you going to kick panel mount the components? I'm hoping so!

The speakers will be in the same location, still vented into the fender well via an aperiodic vent, but I am going from the 6 1/2" speaker to a 9"sub on each side. When it is done though you won't be able to see any speakers at all. The grill covering the speakers will be the same shape as the dash is now so everything will have a nice smooth contour. No one will ever suspect there are any speakers in the dash, much less subwoofers.

My goal is the same as the outside of the car........I want it to look like it could have come that way from the factory. I am after a look that if someone got in the car having no idea what a riviera interior is supposed to look like, they wouldn't think I did anything to the car. I know it is hard to imagine the dash having a stock "ish" look, but it will. Just to give you an idea I rebuilt the entire dash in my last car. It also had speakers in the dash (two midrange drivers and two midbass drivers). Here is a couple of pics of the finished product.

wow! didnt you like the riv dash? BTW,how much does the stock riv dash weigh?

Nice work, and it's not so hard to believe you will pull it off after seeing the result of your last install. I bet those 9"s will sound great firing through the fender wells, and I bet you'll be flat down to 20 cycles easy. If you go back to '93, there was a guy with a Pontiac LeMans who was the first to score a perfect flat RTA. He used two OZ 8" subs mounted D'Appolito style up front. If you remember, this was the one with the steering wheel in the back seat.

About 8 years ago I did a much less complex install for my '70 Olds coupe, and I'm no pro, but my intent was the same as yours - keep the stock look so no one would expect anything. I mounted a set of SAS Euphonic 6.5" components in the kick panels (Southern Audio Systems, back when they actually made some decent speakers. Remember the revolving tweeter?). Not even close to the degree yours will perform, but mine sounded so sweet even with no subs. I have a bridged Punch 40i powering each side. Clarion remote control 10 CD changer in dash, no head. Never did finish the speaker grills, lol.

See pics: http://www.cardomain.com/ride/663078/1970-oldsmobile-98/page-5

Cool stuff. Nice work. I bet it did sound great. I was a fan of those speakers back in the day.....

Here are a few more pics of the build in the chrysler, as well as, a couple of customers cars.

http://www.cardomain.com/ride/803525/1999-chrysler-300m

I've got another set of 5.25" SAS in the Riviera's doors, and a third set new in the box, saving for the future!

Very nice work on your cars. I've always wanted to to do something like that, but never got there. I have a pair of Infinity BETA 8 subs, four BETA 4 mids, and a pair of NHT 1" silk domes, all brand new and in the boxes. Plus a few older a/d/s PowerPlates and AudioContol EQs. Thought I'd put them all in a car someday, but now I think they might work well for a pair of home speaker towers. We'll see...

Anyway, when you get this job done, I'm sure it will be one of the best Riviera installs out there. Have you seen the pics of the Riv with custom kicks and dual woofers in each door? I think I have the pics around somewhere - they are from back in 2003 or so. One of the better 8th gen Riviera installs I've seen.

Aren't your car audio speakers designed to run at 4 Ohms? Home audio is 8 Ohms isn't it? Won't that damage your speakers?

The speakers would not be damaged, the danger is in damaging the amp. The 4 ohm load could overheat or damage the circuits of a receiver rated for 8 ohms. Better power amps can drive 4 ohm loads, whether in the home or in a car.

Wiring two 4 ohm speakers in series results in an 8 ohm load. Since I have 4 mids (2 per channel), it would work. The NHT tweeter is 8 ohm. For the 4 ohm subs, I would be using a separate power amp that can handle the load, or run them in series as 8 ohm mono. The rules can change when you wire speakers differently, or when using active crossovers and multiple independent amps - compared to traditional passive filters driven by a single amp.

There is no problem with running drivers of different impedance in a car or home, just depends on how you are going to use them. In fact some of the factory GM drivers are 10 ohm, some of the factory honda, and nissan drivers are 2 ohm.

In building home speakers I have used 8ohm tweeters, 4ohm mids, and 16ohm midbass. Then designed a x-over to allow all these drivers to work together.



Sometimes it is more important to try to match the efficiency of the drivers rather than the impedance.

Here is the latest.

Masked off the inside of the car. I don't want to get resin on the steering wheel, center console, or the seats.
I then applied 4 layers of fiberglass cloth on the front of the dash. Once this cures I will remove the dash to smooth and glass the back part of the dash. It will be much easier to do this part of the dash on the bench rather than trying to get in between the dash and windshield.

Got the dash out. Worked out great. Five bolts hold the top of the dash in ( screwed through the piece of right angle steel). It is solid when it is in and it is easy to remove. I'm very pleased so far.

Let me apologize for the mess in the shop. I have twice as many projects going on as I have room for. That always seems to be the case though.


Anyway, smoothed the foam, taped off the back to get a good fit to the windshield, and applied 4 layers of fiberglass cloth to the rear part of the dash. Then applied another 4 layers to the entire piece. It should be plenty strong now. Once this cures I will trim the edges, reinstall in the car, and proceed to the next step.

damn sqrivi! thats a great job!
is this going into the riv? and whats wrong with the riv dash? its preety nice dont you think?

Yes this is going in the rivi. Nothing wrong with the stock, I just wanted something that would work better for the audio install. Plus I enjoy making things a little unique.

sqrivi wrote:

Yes this is going in the rivi. Nothing wrong with the stock, I just wanted something that would work better for the audio install. Plus I enjoy making things a little unique.

How does the windshield defroster work as part of your customized dash?

The defroster is completely functional. I just have not cut out for the vent yet.

sqrivi wrote:

The defroster is completely functional. I just have not cut out for the vent yet.

thats awsome buddy! btw,how much does the stock dash weigh compared to yours?

Honestly, I don't know how much the stock dash weighs. I don't even have a good guess. It's been almost two years since I pulled the stock out.

The current build so far is less than two pounds.

sqrivi wrote:

Honestly, I don't know how much the stock dash weighs. I don't even have a good guess. It's been almost two years since I pulled the stock out.

The current build so far is less than two pounds.

ok. after its finished how much will it weigh? just curious

I don't know for sure, but I imagine it would be less than five pounds. I will try to keep track.

I can't quite imagine what you have in mind, but based on the exterior I can't wait to see this come together.