Rdodds033

iTrader: (9)

Hey guys, i decided that i would rewire my stereo (it was a mess from last time). so this time i want to hook up a aftermarket center speaker but i need the center amp to work. I wired the LG/B wire to the Amp/antenna control, i also hooked up the G/O wire too.

The antenna comes up every time i turn the deck on and so does my other amplifier. All of my speakers work too.

I just hooked up a spare 6x8 up to the center to test it and it didn't work (i couldn't feel it move). I checked the Radio fuse in the engine bay and when i went to check the relay, there isn't one there. its a short connector... should this be here?? in all of the diagrams I've seen it shows a relay.


One more question... there is a grey wire that goes into the stock deck. anyone have any idea what this is?


Sorry if I'm not making much sense, I'm extremely tired!

Thanks for the help guys!

Wompa164

iTrader: (4)

Pez from NoRotors has confirmed that a lot of the FDs he has seen come with a jumper in place of the radio relay, so what you're saying sounds right. All of the FSMs / electrical diagrams show a relay, but on a lot of FDs there is no actual relay to be found.

Rdodds033

iTrader: (9)

I Jumped the constant 12v at the relay terminal to the power wire in the amp. It still wont work

http://www.tobias-albert.de/ta_rx7/r...ng_dia_big.gif

If you look at that it is the L/W and the B/R wire that i connected. i also checked the amp connector and it has 12v.

also, the speaker connections between the amp and the center speaker are good.

I'm not using the stock center speaker right now, i pulled one of my pioneer 6x8s to test on the center amp. I want to get the amp working before i order an aftermarket speaker.

this is the one i'm looking at getting, it is almost too deep by about 1mm. http://www.parts-express.com/pe/show...umber=290-204#

Rdodds033

iTrader: (9)

Any Ideas?

dblboinger

iTrader: (3)

Are you running a deck with 5.1 output? If not, you're wasting your time on the center channel. Besides, you're gonna get shut for sound quality out of any speaker you can fit in that center channel location. Do yourself a favor, scrap the center channel and put a triple gauge pod up there with a boost gauge, an air-fuel ratio meter and a decent water or oil temp gauge.

Rdodds033

iTrader: (9)

If my deck had a 5 channel output i would have no need for the center amplifier. the center amp combines the left and right front channel signals into one mono signal for a center speaker. the reason i want this amp working is to help fill the center of the car with sound, because i can hardly hear the right speaker in the door. If its not going to cost much (+-$20) then its worth trying IMO.

I already have a 3 gauge pillar pod with boost and AFR, thanks for the somewhat unhelpful suggestions.

Anyway, back on topic. I think I've tried every wiring configuration i can think of. Is there any way i can test the amp out of the car to rule out the possibility of a bad amp? I pulled the amp apart and i didn't see any noticeable burn marks, or bulging capacitors.

dblboinger

iTrader: (3)

Relax man, I was just making a suggestion. Still you're not gonna get much from a 2 3/4" speaker, which is what goes there. If you can't hear your right speaker then you should figure out why because in my FD the right speaker will blow your eardrums. What deck/speakers are you using?

Rdodds033

iTrader: (9)

Sorry, i took that the wrong way

I'm using a pioneer p4000UB with 4 pioneer TS-A class coax speakers. I'll probably add some sound deadner in the doors and B pillars to help with the sound.

I've been reading mixed opinions on the center speaker and would like to test it out for myself, I'm just trying to dig up some more info on the amp. My time has little to no value anyway :P

Maybe i can get a hold of a center amp from my buddy and see if it works with my current wiring.

dblboinger

iTrader: (3)

I just went out an looked at my car, a 93 FD. If you look at the connector that is inserted where the Radio Relay goes you will find the outer pins on the top row are jumpered
to the center pin on the bottom row. If you remove the connector though, you will find the bottom row center has no mate in the receiver side of the connector, therefore only the top row outer pins are pertinent. If you look at J-1 of the wiring diagrams you will see these pins are the B/R and LG/B leads, therefore this connector is routing +12vdc out of the deck to the center channel amp. The GY wire is most likely the ground for the center channel amplifier. The puzzling one is the G/O wire. If you chase it out on J-1/J-3 of the wiring diagram it goes to the Power Antenna. My guess is it's either +12 or ground only when the radio
is in use. The would cause the antenna to retract when using the cd/cassette, but I don't know what it is doing in the amplifier. It could be power to the center channel amp when using the radio. I would check to see if the LG/B wire goes dead when the radio is on. If it does them the G/O would be power to the center amp in Radio Mode and B/R would be power to the cente4r amp in the CD/Cassette mode. If you don't have these diagrams let me know and I can send them to you.

I'll take a peak and see if I have the center channel amp still laying around from my car. I just removed it not long ago, so it might still be floating around my garage.

dblboinger

iTrader: (3)

If, as you said, you had +12v at the center channel amp connector, my guess is you didn't have a ground OR the amp is bad. Where was the gray wire when you did this?

Rdodds033

iTrader: (9)

The amp is grounded by the mounting bolts, there is also another pin on the amp's connector labeled "ground". I tested continuity between that pin and the mounting bracket and its defiantly a ground. I even added a pin to that connector for an additional ground.

the G/O wire, when powered, extends the antenna.

I've tried powering the grey wire, the G/O wire and the LG/B wire. but i haven't tried grounding any of them.

I noticed when i had the amp apart it had 2 pins labeled. one was "MUTE" and another "MUTE OFF". I cant remember what wire was which exactly, but I'll take a better look tomorrow.

dblboinger

iTrader: (3)

Well, that's about all I can tell you about this. I'll check tomorrow and see if my old map is in the garage. If it's there you're welcome to it, for the price of the shipping.

dblboinger

iTrader: (3)

I checked with a friend about this and while he didn't know specifically about the center amp, he did tell me that the amp probably does not ground through the chassis. Just because it reads 0 ohms to the chassis doesn't mean it's grounded that way. He says all electronics on a Mazda are grounded through the wiring harness, not by the chassis.

Rdodds033

iTrader: (9)

It defiantly grounds to the chassis, it bolts up to the dash support that is used by almost everything in the dash as a ground. If you had it apart you would see a part of the circuit board that screws to the case of the amp for a ground. and when i said it reads 0 ohms through the chassis i meant from the pin labeled "Ground" (unused by Mazda) and to anywhere on the case.

dblboinger

iTrader: (3)

So have you made any progress?

Radial GT

iTrader: (16)

Wire it to right channel, that speaker technically is to the right of the vehicle's driver.

Rdodds033

iTrader: (9)

I've been working on some other, more important stuff lately. I'm almost in a spot where i can start working on this again.

The problem with wiring it to the right channel is how i would have to wire it. either way i wire it then it would change the resistance of both speakers (center and R channel), changing their power output. For example, if they are wired in a series then the speakers' resistance would raise to 8ohms, reducing the speakers power output by 1/2. in parallel it would be the opposite. the speakers' resistance would drop to 2ohms and the power output would double (and probably ruin my headunit).

I think to get this working would require a 6 pin relay and a new amp possibly. the only concern i have is that the outputs from the headunit could be too high for the amp. If we could work something out for that amp dblboinger that would be awesome!.

dblboinger

iTrader: (3)

Not necessarily. You are talking about wirng a speaker level output to the input of the center amp, right? The center channel amp would be designed with a very high input impedance, which will have very little effect on the "load" seen by the deck if the amp input is wired in parallel with the speaker.

Say for instance you're using a 8 ohm speaker and the input impedance on the center amp is 1M (typical value). Using the formula R total = 1 / (1/R1 + 1/R2) , you would find
R total = 1 / (1/8 + 1/1M)
= 1 / (.125 + .0000001)
= 7.9999936 ohms

The high input impedance on the center amp prevents you from severely overdriving the center channel amp. Say your deck outputs 20w @ 4 ohms (typical). If you're using an 8 ohm speaker, your power would be reduced to 10 watts. That would mean the output of your deck is 8.93 volts. Since loads in parallel "see" the same source voltage, that means you would be applying the same to the input of your center channel amplifier. The high input impedance drops this signal down to a useable level for application to the amplifier circuit, otherwise you get a lot of smoke!

Haven't had a chance to look for that amp, but I'll look today.

Rdodds033

iTrader: (9)

I think what Radial GT was saying is that, if i were to wire the center speaker into the R channel on the deck, completely bypassing the amp. I was worried that it would change the impedence of only the right speaker.

I guess my other option would be to get a 5 channel amplifier. I've been meaning to get a amplifier for my other speakers anyway. I guess i could just get a 8ohm center instead of a 4ohm so it wouldn't receive as much power as the other speakers.

dblboinger

iTrader: (3)

If you wire to the right/left speaker you will get right/left audio only. As I'm sure you know, center channel is L+R or sometimes L-R. If you're gonna do it, use an amp. All you would need is a small (15-20w/channel) bridgeable amp with variable gain. I know Orion use to make a good one, but I'm sure they sren't the only ones. BTW, I didn't find that amp. Sorry.

iamchango

iTrader: (1)

My FD does not have a working set of speakers or a working deck, so I have to buy a new set up for the car.

Along those lines, when it comes to money, would it be better to buy a regular deck with no 5.1 and get an amp to send the mono signal to center speaker (when replaced), or should I buy a deck that comes with the 5.1 system set up?

The reason I ask is because the I don't see the sound in the car being as even without the center speaker playing sound.

dblboinger

iTrader: (3)

I considered 5.1 in my car, but scrapped the ide when I saw the puny-*** speaker that is in the center channel location. In order for 5.1 to work properly the center channel speaker needs to have nearly the same sonic qualities as the front speakers. No way you're gonna get that out of such a small center speaker. Plus, it's really not needed in such a small space. My recommendation...ditch the center channel and add a gauge pod if you don't already have the recommended gauges (boost, air-fuel ratio and water or oil temp). I'm running 125w to my 4 channels + 2000w to my sub and it will run you out of the car @ half volume.

dblboinger

iTrader: (3)

Another thing....if you're serious about the stereo put in some Dynamat. It's a pain in the *** to do, but it dropped my ambient noise level around 15db.