Help diagnosing car stereo problem

[Ag NSX]

I'm having a problem with my car stereo in my other car and I'd like some opinions on what could be wrong before I begin to take things apart.

One night while listening to the radio it went silent. CD, Tape, FM, everything was silent but the radio face plate was still on and all functions working.

The next day, the stereo worked (CD, tape, FM), but my left rear speaker had no sound and the left front speaker had a raspy sound. Right speakers were fine.

A day later, the left front speaker sounded fine and left rear was still out. Right speakers were fine.

Even another day later, speakers in the same shape. However, when I turn the volume up (5 out of 10 scale) all 3 speakers begin to sound raspy, especially on bass.

At first, I thought I had a short and blew all my speakers, then I thought maybe my wiring harness was loose causing some speakers to work intermittently. Now, I'm thinking that my radio amp is bad which is why at med-high volumes my sound is distorted.

On top of all this, my CD changer stopped changing CD's also!

 

[SNDSOUL]

Is this a factory system or aftermarket? Do you have an external amp or just radio power? You are right in thinking it has something to do with the amp section.Is there a chance that something got wet? Just shooting in the dark.

 

[Ag NSX]

It is an aftermarket head unit only. The head unit connects directly to the speakers and cd changer. My speakers are aftermarket components too.

There's no chance anything got wet. The speakers just went out that first day while I was driving.

 

[nsxxtreme]

If the headunit connects directly to the speakers what powers them. Head unit?

 

[fangtl]

Originally posted by Ag NSX:
One night while listening to the radio it went silent. CD, Tape, FM, everything was silent but the radio face plate was still on and all functions working.

Signs of a bad internal amp. Did you hear any noises before or after your system went silent?

The next day, the stereo worked (CD, tape, FM), but my left rear speaker had no sound and the left front speaker had a raspy sound. Right speakers were fine.

Signs of a bad internal amp, bad speaker connections, and bad speakers.

A day later, the left front speaker sounded fine and left rear was still out. Right speakers were fine.

From you previous description, this is another sign of a bad internal amp, or a bad speaker connection (I doubt it's the latter because radio harnesses are not prone to fail).

Even another day later, speakers in the same shape. However, when I turn the volume up (5 out of 10 scale) all 3 speakers begin to sound raspy, especially on bass.

"Raspy" as in the speakers are raspy or the music is raspy? If the music is raspy it has something to do with the source, if the speaker is raspy, in all likeluhood it's the speaker.

At first, I thought I had a short and blew all my speakers, then I thought maybe my wiring harness was loose causing some speakers to work intermittently. Now, I'm thinking that my radio amp is bad which is why at med-high volumes my sound is distorted.

I am guessing a bad source amp, but it's a good idea to check the conditions of the speaker(s) also. A bad fuse would have diabled your system completely.

On top of all this, my CD changer stopped changing CD's also!

When it rains, it pours.

 

[Ag NSX]

Thanks guys, it sounds like I need to replace the head unit. Probably a good time to put in a DVD/MP3 and LCD screen

!

One question, on regular head units, are the individual speakers powered by 1 amp or 4 separates? I guess I can't figure out why only the left rear speaker would be totally dead if its powered by 1 amp. I hope I don't need to replace speakers too!

The 'raspy' sound sounds sort of like an amp clipping combined with a distorted speaker (like when you turn up the bass too high). It's not due to source because when I turn the volume down it sounds fine.

BTW, it's an Alpine head unit and 6 CD changer and Fosgate speakers.

[This message has been edited by Ag NSX (edited 20 December 2002).]

 

[fangtl]

One question, on regular head units, are the individual speakers powered by 1 amp or 4 separates? I guess I can't figure out why only the left rear speaker would be totally dead if its powered by 1 amp. I hope I don't need to replace speakers too!

It's an 1 amp 4 channel source.

The 'raspy' sound sounds sort of like an amp clipping combined with a distorted speaker (like when you turn up the bass too high). It's not due to source because when I turn the volume down it sounds fine.

Now I definitely think it's the source. See, your head unit uses one power supply to run everything, internal amp - speakers - Tuner - CD player - transport, everything. whereas, an outboard amp uses one power supply for one thing. Thus, when you are pounding away, the source is overdriving/overclipping and sending a clip signal to your speakers. Your speaker, being Rockfords, should be able to take way more power than the head can ever supply, and should not be the reason for your trouble. What you should really be doing is get an external amplifier rather than another source unit. JM2C