NP993

So, I was really tired of the factory speakers, which as we all know are one of the great 993 travesties, somewhere between Monroe shocks and valve guides that are worn at 40K miles.

I found speakers at my local Best Buy that fit perfectly in the front, and almost perfectly in the rears. The fronts sound great. The rears are on and working, but at about 20 percent the volume of the fronts (at most).

For the rears, I took the factory speaker assemblies off the car, removed the main speaker and the smaller speaker (I have the hi-fi option) in each, mounted the new speaker, snipped the factory ends off the speaker wires, crimped on spade connectors, and plugged them in. The rear speakers are Kenwood 4" 3-ways. These: http://www.amazon.com/Kenwood-KFC-10.../dp/B001Q9ER9Y

The fronts are Pioneer 5 1/4" 2-ways. These: http://www.amazon.com/Pioneer-TS-G13...9785823&sr=1-1

I'm not a radio guy and don't get why the rears are so quiet compared to the fronts. It's not even close -- you basically have to turn the fronts off with the fader to even know the rears are working. Why would there be such an imbalance, and what can I do about it?

The rest of the system is a CDR-220 head unit and stock everything else. I know this probably has to do with the amount of wattage each speaker requires or something like that. Like I said, I'm not an audio guy.

CaptainGSR

I'd recheck the wiring. You might have mixed up something.

NP993

It's not the wiring. We're not dealing with the ECU here. It's two spade connectors that plug onto the back of a speaker. As simple as it gets, and yes, they're firmly attached, and there is indeed sound -- just at a much lower volume than the fronts.

Ed Burdell

Out of phase?

boulderbobo

I'm not trying to be a smart *** but you did check/adjust the fade control on the HU?



Bob-

Kika

Could be a few things:
as mentioned above, check the fade on the head unit first, the check the phase, if they are not in phase, then that might do it.
next, did you get the same impedance speakers as the ones they replaced? mismatched impedance would definitely give you problems.
Is there an amp or are the rears running off HU power? if you have an amp, check the gain settings.

Barney1

The improper impedance will give you low volume. 8 ohm, 4 ohm. Like asked above. If the car came with 4 ohm, and you put 8 ohm the speakers will have a low volume. The higher the number away from the factory speaker, the lower the volume.

bart1

I think Barney is on the right track. However, I was thinking the factory speakers were about 12 ohms on the HiFi rear speakers and I imagine you installed 4 ohm speakers. Theoretically that should triple the power going to them, but maybe you are overloading the amp. I would suggest going to an aftermarket amp when changing the audio in these. I have a set of Dynaudio components sitting around because I haven't decided to do it the right way.

NP993

Huh, very interesting. I take it there's no way to adjust anything (it's not the fader on the HU, that was the first thing i checked). So do i just buy an amp? Will that make everything work properly? This really is not my strong suit...

NP993

Also, what's the deal with speakers being "in phase" -- what does that mean?

911Jeff

Speakers have different efficencies, or sensitivities, meaning that they will play a different volumes given the same amount of power. Ths difference you describe seems more that just a sensitivity issue, but that may be part of it.

NP993

I found out that both pairs of my new speakers are 4-ohm, FWIW. So perhaps there's a different signal coming from the amp between the fronts and rears.

TheOtherEric

Check the impedance of the speakers from their spec sheets. BTW, impedance is the same as resistance, we just call it impedance because it's a function of frequency. If your rears are higher than fronts, that could explain it. Then there's the issue of sensitivity that Jeff raises, and that could be it too.

Edit: beat me to it. Probably a sensitivity thing, unless you possibly crossed the wiring.

bart1

Out of phase means you have the + and - switched on one of the rears. They will cancel one another if so.

I hate to say go buy an amp but that is probably the coorect fix. Do you have a multimeter you can check the impedance of the factory speakers with? ( <--- This is a stupid suggestion, I wasn't thinking)

NP993

If they're out of phase, they wouldn't work at all, right?

I agree that an amp is probably the solution. Or is there any way to add an impedance regulator to the rear speaker wires?