billholton

Help! The stock door speakers in my '88 convertible are distorted. Replaced the speakers but still no better. I'm sure there is an amp somewhere (I've found the one in the back for the headrest speakers) but I can't seem to locate it. Is it under the dash somewhere? Any help would be appreciated.

vaughnc

so turning down the bass doesn't help? I know my door subs do that above 35%, so I have to turn down the bass.

The amp is in the spare tire compartment or under the radio (din slot #2).

THe problem is you can't adjust the "pre-amp volume"/voltage for the sub amp. It may be possible but I just haven't looked into it.

HOZZMANRX7

iTrader: (43)

in a '88 convertable at least, door speaker amp is located under the dash on the drivers side.

Whats good to know is that the head unit carves out only the low's to feed to this amplifier. So, tapping off this signal feed is excellent to feed a Sub-woofer bazooka tube. And, the bazooka tube lays great under the read deck cover of the Vert.

As to the noise, if you replaced the speakers with new and still getting it, then there is probably something loose (screw, bracket, etc.) that is buzzing from the thump of these speakers. Just look around carefully in the immediate area of the speakers and you'll find it.

Good luck!

Icemark

On the 88 vert the sub amp is between the drivers speaker and the power steering computer under the drivers dash.

The sub amp (BTW) has a built in crossover that cuts out anything above 200 Hz.

HOZZMANRX7

iTrader: (43)

What my friend Icemark said.

billholton

Thanks! I've looked under the dash and there is a silver box under the driver side dash towards the left. I wasn't sure if this was it or not but I'll look again.

Regarding the note about the head unit, that sounds like a good possibility. Does anyone have a wiring diagram (my '88 vert has the am/fm cd and cassette combo), or can someone tell me exactly what wires to tap into?

I had a guy at a local car audio shop look at it and he came up with about a $1500 solution (keeping the stock head unit!) that was more than I wanted to put into it.

The "noise" I referred to is really distortion - I have to turn the "AEC" (bass) control completly off or else I get distortion from the door speakers. Speakers are mounted exactly as original and tightly so speaker vibration is not the issue. Either the amp is messed up or possibly the feed from the head unit?

Anyway, thanks for the info so far and any additional info would be appreciated.

Icemark

What speakers did you use to replace the stock woofers in the door???

Most 6" coax speakers that would fit won't reproduce the low freqs that you need, not too sound distorted.

billholton

Just a follow up and thanks for all the input. I located the amp under the dash on the drivers side and removed it. I was pretty sure that the amp was my problem so the next step was to figure out the wiring diagram to the various amp plugs so I could wire in my own aftermarket amp.

Check out http://www.mazdaformance.com/rx7.htm if you ever need parts diagrams or tech data for your 7. Somebody has spent a lot of time converting these manuals to pdf format and they are very helpful.

Anyway, I figured out the wiring scheme, and dug out a 10 year old or so Denon amp from my basement. I think it was a 40w unit x 2 channel. Next problem was where to mount it since it was a heck of a lot bigger than the factory amp.

Mounting under the dash was out of the question, so I found a cubbyhole on the passenger side of the spare tire storage area. It fit real nice, but the only hassle was running cables from the front underdash to the amp and then back again. I went ahead and ran a separate 10gauge power wire direct from the battery with a 30 amp inline fuse and used the original amp power wire as the "remote" wire to turn the amp on and off.

Results were fantastic! Remember, I had no Bass at all from the woofers, as I had to keep them turned off due to the distortion. A little bit of sweat (the better part of a Saturday) but it was well worth it. A fairly easy fix if anyone is experiencing a similar problem.

Thanks again for all the help.

dolemite85

Alright instead of making a new thread I'll just use this one.

I have an 88 vert and one day the door speakers stopped working. Later on I put in an aftermarket deck and thought that might fix the problem, it didnt. Well I read up and found out there is an amp under the drivers side dash. (what the hell does it look like? I think its the silver box but im not sure.) Anyways I bet the amp burnt out, but I was reading a couple of other threads and they say to just wire the deck to the speakers. Meaning I wouldnt need to replace the stock amp right? How do you wire the deck to the door speakers?

TheBigOne

To answer your question from waht I understand from the entire thread.

The speakers you had in the door were no good. So you replaced them with new speakers right? And the stock system's amp is crossed over.

Are the replacement speakers you used co-ax? Do they have a woofer and a mid or tweeter? IF so then the cracking may very well be from the mid or tweeter.

Ususally Co-ax speakers already have capicitors wired in to the tweeter or mid, but... they can only surpress so much wattage. Sounds like to me that the speakes you installed were co-ax speakers and you cranked them up and the wattage fron the amp exceeded the wattage rating on the capacitor and it could no longer supress the lower hz.

If you cant return the speakers or are just do away with them and but new ones do this first.

Snip all wires going to any of the mids or tweeters.

Basically you will only have sound from the woofer. This should solve your problem.

Now after all that I really thing its your amp going bad. Treat yourself to a new deck and throw out that stock ****!

TheBigOne

You wouldn't be able to. Your stock deck's signal is at a different "signal level". Its like trying to hook up speakers to your RCA wires that come out from an aftermarket deck. Which these are just used to provide a signal to your amp.

Just buy a deck at Best Buy for like $99 bucks and save your self a headache.

DrkOps187

what does the amp look like in a 88 vert

jake1191

iTrader: (1)

i just bypassed all my stock amps and hooked the speakers either into the new headunit or the aftermarket 4 channel amp. everything is crisp and clear even at full volume. if you run new speaker wire to the doors and all other speakers you can remove the amps and save some weight at the same time like i did

Rob XX 7

iTrader: (8)

small silver boxes, if memory serves me correct they say Pioneer on them?

DrkOps187

never mind i found the amps, i just run some new wire and put 2 6.5 speakers in each door, i got 2 subs and an amp left over that i am selling if n e one is interested