My car came with an aftermarket stereo head unit, and as far as i can tell, a cheap one at that. the speakers are factory, i think there's a factory amp somewhere too.

when i play stereo loudly, the sound breaks up violently. if i tune out the bass, it still happens with the high notes.

i went to a local two-bit stereo shop and they couldn' identify the culprit. their best bet was a blown speaker causing some kind of interference.

anybody have any suggestions on the culprit?

 

It probably is not wired up correctly. The factory amp is in the trunk in front of the battery. Should be mounted on a black metal bracket. If you use the stock amplifier, as far as I am aware you need to convert the radio into a low pass signal (non amplified, such as RCA outputs) If it is wired up using the headunits amplified outputs it will sound like crap when turned up.

 

Exactly...so you either need to bypass the amp and use the head unit amp...or use an adapter to run a line level signal to the porsche amp in the trunk. Or best of all is buy a decent amp (the porsche one sucks) and have it installed bypassing both the head unit amp and porsche amp and using that amp to drive the speakers.

 

It is an impedance or voltage mismatch between the head unit and factory amp. This causes the condition you are describing.
+1 for newports' suggestion, change the amp or use the head unit to drive the speakers direct. You can do the line-level converters but it is not guaranteed that it will sound good.

Overall, it really depends on what type of sound you are after. IMO a new head unit and separate amp would be the best choice for a start if you want to drop the $. Plan on changing speakers shortly thereafter though

Oh, and be sure to take your car to a stereo shop that know's what the !*#k they are doing. sounds like some real knuckleheads at that shop you went to...

 

car has a boston acoustic crossover in there too. does this change your collective advice?

car does have the factory amp in the front. the stereo is a "high power" stereo, so, yes it is internally amplified.

nowadays, even cheap stereos all pretty much come with high power, mp3, and removable face. so for me, no need to change the head unit, because even though it's cheap, it still has the featurs i need.

any money spent will be used for repairing existing equipment. not upgrading.

 

newport996, am i better off bypassing the factory amp and using the stereo's high power feature, or bypassing the stereo in favor of the factory amp?

 

I have an alpine head unit with high power output. I bypassed the factory amp and the stock speakers sound amazing after tuning the built in crossover and equalizer.

 

I think you would be better off bypassing the factory amp.....BUT it depends on the head unit...what brand/model is it? The Porsche unit is not the greatest 40x4 I think or 60x4 at best....

 

I bet the rms wattage is something like 10 watts.

 

alright...the heAD UNIT'S a panasonic cq-c1303u. i will bypass the facory amp and try out just the head unit. should i upgrade from this head unit?
http://www.crutchfield.com/S-X21LfU5...300&I=133C1303

 

If it were me? YES....If I wanted something fairly simple, yet looked stock and sounded great, get a Nakamichi CD500. Then I would NOT get an amp...the Nak should be clean enough to drive the speakers nicely.

 

Heres a link for a NAC Bruce for specs. I listened to the cd 400 series with quart speakers and 800 wt amp and it was pretty good. My issue was with NAC is that I am not sure how long they are going to be in NAmerica and some of there earlier issues with disc skipping issues scared me away if servicing is a required maybe the 500 model is better. I am putting my sys together also and it is exhausting. Not sure what you are listening to the most radio, cd's mp3 etc, but I have figured one thing out is that I listen to just the radio most of the time in town so HD is a must for me. good luck

http://www.techronics.com/index.cfm?...roduct_ID=3575