rear speakers low power factory amp? Help! Options

[joy_zze]

I have a
1999 Celica with 4 6.5" speakers and the little
tweeter in the door. I am pretty sure there is only
one factory amp in the console. For some mysterious
reason, the rear speakers are only getting about 1/4
the power of the front speakers, and very little bass.
I replaced all 6.5 inch speakers with JL audio, and
replaced the head unit with a pioneer mp3 player.
Still, the problem persists. I have double checked the
head unit installation, and all seems to be fine. Is
it possible the factory amp only partially crapped out
on the rear speakers? If so, what should i replace it
with? I don't need anything fancy. The front 4
speakers sound great. I'd just like the rear speakers
to sound as good. Should I (could I) just bypass it? Any help/hints you could offer would
be greatly appreciated, as I am getting quite
frustrated! Thank you in advance, Joy

[shid]

Uhm, did you even LOOK at the power requirements of the JL speakers? The factory amp puts out 6 watts of power. You're trying to power speakers that require a minimum of 25 WITHOUT another amp.Who sold you those JLs and told you they'd work with your amp?

Even if you got the stock amp out of there, you'd still need an aftermarket amp to power those speakers, they'd distort at the lowest volume.

[joy_zze]

Thank you for your reply, Shid. However, if you'll read my post carefully, you'll notice, that I had the problem before I changed the speakers to the JLs. I was having the problem with the factory speakers as well. Do you have any other ideas?

[shid]

you'll have to follow my advice anyway. Yes, it is possible that the rear speaker outputs on the stock amp died.

To fix that problem, or the problem of simply underpowering the speakers is the same thing however, and the specifics dont matter.

You need to rip out the stock amp, and buy a decent 4 channel amp rated to give out the HUGE amount of power the JLs need. This isn't going to be cheap. And then you take the preouts from the head unit (I assume it has some) to the amp.

Bypassing the stock amplifier will still not have enough power to power the new speakers- it would have been for the stockers tho, you need an aftermarket amp for those.

I do love JL tho.

[joy_zze]

Also, my Dad suggested that the problem might lie with the front speakers having a crossover to separate the sound to the tweeters, and no crossover in the back. If that were the case, I would think that other 6g owners with this setup might be experiencing a similar problem. Could this be a design flaw? Would the crossover be included in the factory amp, or is it beyond the amp in the door somewhere. If I removed the factory amp, and didn't replace it with an aftermarket amp, would I lose the front crossover? Thanks a lot, Joy BWT, congrats to all you 6Gers out there. I think they ruined the Celica design aesthetically with the 7th generation -- at least for those of us looking for a little class. I could have bought a new 7th Generation, but I opted for a used 99 with low milage instead.

[shid]

the crossover isn't the problem. The factory amp does have one (sends low frequencies to the back) but that can't be the problem.

If you removed the factory amp, you're lose the built in crossover of the back vs front speakers, but you wouldn't lose the front door crossover- as thats a seperate piece.

But I'm really not lying when I tell you that removing the stock amp might make the back speakers equal volume to the front, it's still not going to be a workable system without an aftermarket amp

[Andason]

Ditch the factory. I can guide you through the install if you need help.

I use the decks amp

[joy_zze]

Thanks Andason!!! I would love help with an install!! I have a Pioneer DEH-P7600MP head unit that says it has 50W x 4. I believe the speakers I have are 50-75 watts per channel, so I might see if I can squeak by without an amp first. I've already torn apart my dash -- so I know how to do that. I just need a wiring diagram from the amp out to the head unit. I don't suppose anyone makes a wiring harness for that so they?? Feel free to contact me at Z_I_L_C_H@yahoo.com. Thanks!!

[shid]

Joy, your head unit; if rated at 50Wx4; produces only 25W RMS- the 50W rating is PEAK power. You cannot power your JLs with the stock amp, or the head unit.

I'm sorry if this isn't the info you want to hear, but it's true.

[Andason]

[joy_zze]

Well, I can always try it without an amp, and if it sucks, I can go buy one!!! I just need them to be reasonably loud, not loud enough to shake the glasses in my neighbors cubboard!

[shid]

Andason, we both run Alpine speakers off our equal RMS head units. All of our head units output 25W RMS- which is above the minimum of the Alpine Type S speakers minimum RMS. It is NOT above the minimum of the JL speakers, and JL does not overrate their speakers like Sony.

Joy, the problem isn't that they're not gonna be loud, its that they're going to distort at extremly low volumes becuase the speakers need more power to reproduce even moderate volume. THats what recommend power means- the power needed to make the speakers move.

This post has been edited by shid: Jun 26, 2004 - 10:05 PM

[Andason]

[Andason]

[shid]

*gives Shawn his NAWZ pills*

EDIT: Andason, 50x4 is peak power, NOT RMS. If he looks at his manual, he will find the reading for RMS its true of every head unit, they advertise the peak power, not the RMS

This post has been edited by shid: Jun 26, 2004 - 10:08 PM

[joy_zze]

I read that there are blue connectors under the amp that are easily visible unless you are looking at them. Is this what you are referring to, and not the in and out connectors on the left side of the amp. I was in there poking around today, but I didn't see the blue connectors, but then I wasn't looking for them.

[shid]

Crutchfield's webpage:

http://www.crutchfield.com/S-ytzM0inzQQl/c...r+DEH%2DP7600MP

[joy_zze]

BTW, I appreciate the help of both of you. But it can't hurt to try it first without an amp right? . . Before I crank out the bucks. I will keep an ear out for the distortion you mentioned Shid, and definately get an amp if it sounds bad. What would you recommend (high end - low end)?

[shid]

I'm only trying to save you time and frustration- that, and if you DONT notice anything wrong you might just let it go.. and be stuck with an inferior JL audio install (and JL is so awesome, I feel it needs to be done right)- so some day 2 years down the line you might get that 4 channel amp and suddenly go: OMG I LIVED WITH THAT FOR 2 yearsA?!

I'd recommend 75w x 4 channel amp, ask around for good brands, but you could just buy a JL one and get the best combination of the speakers and the amp. Be ready to spend at least 1 dollar per w of power (so thats 300 dollars) for an actual quality amp- but beware of amps that are just overpriced (RF amps)

[Andason]

50x4 rms r0x0rZ