Amplifier bypass in 89 Carrera

[cmcfaul]

I updated the head unit (Alpine) and speakers in my 89 Carrera. The sound is just OK. I read that the old remote amp (under the pass seat) is likely to blame. Has anyone done an amp bypass? Is there anything off the shelf to easily bypass it. Did your system sound better without it?

Opinions on bypassing it or replacing it with an modern unit?

Any advice is appreciated.

Many Thanks,

Chris

89 Carrera

[mtb001]

it's not that easy to bypass or replace. I replaced amp under seat, ran new speaker wiring to doors, there are also filters in the doors depending if you have woofers, and the powered antenna will need to be wired into new head unit.

Sound may be "OK" due to lack of power to amp and did you connect wire that turns on the amp with the head unit?

[T77911S]

I doubt its the amp.

are the speakers you put in full range or do they need a cross over.
as said, if there are filters are they still in there, are they the correct crossover freq,

what are you lacking, lows, subs, hi's. is it a power issue.
are the polarities correct on everything

[cmcfaul]

Thanks for the replies. I used the adapter that came with the Alpine. Spliced in about a 12-15 wires (blue to blue - red to red - etc).

Speakers are woofer and separate tweeter in the doors and two way's in the rear (6 speakers total).

Seems to have a lot of power. 25% volume is about all the speakers can handle which leads me to believe the under seat amp is working.

Sound is just ok. Not as much bass as I would like. Not as clear as I thought a good head unit and speakers would sound like. wish there was an adapter that bypasses the external amp to compare.

Chris
89 Carrera

[wildthing]

So how is the HU connected to the amp? Regular speaker wire? You can certainly wire your speakers directly to the HU to completely bypass the amp.

Amps should be connected via RCA...

[darrin]

Lack of bass could correlate to an out of phase wiring issue -- important that all speakers be in phase with each other -- otherwise, when asked to reproduce a bass note, some will push out the diaphragm while others will pull in, canceling out the base.

Thought -- does the bass improve if the rear speakers are turned off (via fader, etc.?) -- this could suggest the rear speakers are out of phase with the fronts.

Another observation -- power doesn't necessarily = volume. One can get pretty loud with low power, but it would be distorted/fatiguing to listen to. Power minimizes distortion on louder/dynamic parts of music. On my targa, I'm running a pair of door-mounted separates directly from an old 25 watt per channel a/d/s power plate amp mounted under my passenger seat (I feed the amp with my iPhone using a bluetooth>RCA adaptor. Plenty loud and rather clear/well defined sound from it when I want it

Given my experience, I'd consider going with an amp that uses RCA (line level), not speaker level, inputs and focusing on the door speakers (I found my rear speakers didn't add much to the sound and actually messed with the soundstage) -- that way, the alpine is simply feeding the amp a low power signal and the amp's doing all the work (as it should)

[T77911S]

you need some sort of cross over for the setup you have or you at least need filters on the tweeters and sub.
the tweeters cant handle the full power and certainly don't need it.

I am not into car stereo systems so I don't really know whats out there but for best sound you should tri amp the system, that is a crossover and separate amp for each speaker.
I would imagine there are single amp units out there with all this built in.

a problem you may run into is with the full range ones in the rear.
you can run subs to the subs of course but then most crossovers are going to have a mid out and hi out. with the mid out going to the full range you will lose hi's out of those.
but like I said, I don't know whats out there for you to use. just something to consider