Many of you were nice enough to explain what things like RMS, THD, and other stereo jargon meant as I looked to upgrade my fully stock system to something better. Just thought you might want to hear what my decisions led me to.

I kept the '02 stock head unit.
Added an Alpine amp, 90 watts/ channel bridged
Kicker R5Sc component speakers in the stock mounts.

Now instead of hard to hear bad quality sound I have easy to hear bad quality sound.

The distortion is huge. One reason is the bridging, which brings the THD from .08% to .3%. Another reason I assume is the stock head unit has no pre-amp outs so I am amplifying a bad signal. The third is the lack of rear speakers.

Suggestions for my next move?

 

I love the blatant honesty! It's why I read your post...

Anyway, if I were in your shoes, I believe I'd get rid of that HU and you should definitely clean up that sound quality! From there, if you can afford it, I think rear speakers help out tremendously! If you're looking for clean, distortion-free music that you can hear with the top down on the interstate, this is the way to go. If you're worried about your sound stage and all that, talk to someone more professional than me! Personally, I just want good, loud, clean tunes to crank while I'm cruisin' and I've found this setup to be a good start. Next, I'd like to do a sub, but I'm still not sure of how I want to do that... Also, I'm running my checking account dry on this car so I'm forcing myself to take a little break!

Good luck and have fun!

 

If I run the amp 4 channel (with rears) I can only run at 40 watts per channel RMS. Do you think this would be sufficient power?

 

I installed the Alpine 9813 and one of the features that I have found to be most useful (even though it is really only used 1 time and then it is set) is the BassFocus Time Delay.

It allows you to delay the sound coming from individual speakers so that it reaches your ears at the right time. I have found this to be especially beneficial since I have rear speakers that I am literally just about sitting on.

As I adjusted the delays I could hear the shifting of the music.

 

I would definatly replace the HU.

40rms/channel may not sound like a lot on paper (especially compared to infated marketing numbers) but I think you will be happier in an envelop of lower powered sound, than having high power blasting at you from just the fronts.

 

You're probably right. The bass totally fades once you hit the freeway with the top down. All you have left is blaring squeeling empty treble.

 

head unit, head unit, head unit, and head unit.


a sub would help the bass issues i'm sure, but if you're getting lots of distortion, it's almost all head unit.

rears are nice and all, but before you throw more speakers in, try an aftermarket head. you mention that adding the amp increased the volume of the distortion... adding rear speakers will just increase the distortion as well -- now you'll hear it louder and from more sources.

and the change from .08% THD to .3% THD is ludicrously low. that distortion increase isn't what you're hearing. the distortion you're hearing is the OEM CD player's crappy output sound quality... this is definitely the garbage in ---> garbage out issue that we mentioned in the past.

 

Before you go trashing the whole setup, you may want to check the gains on your amp and line level converter. If those are not set correctly, you can easily trash a signal. If it's as bad as you make it out to be, it's not because of 0.3% THD...very few people realize just how insensitive our ears are to certain types and levels of distortion.

 

[QUOTE]Originally posted by PJK3
[B]
head unit, head unit, head unit, and head unit.


a sub would help the bass issues i'm sure, but if you're getting lots of distortion, it's almost all head unit.

rears are nice and all, but before you throw more speakers in, try an aftermarket head.

 

$350 for head unit and dash controls right?

edit:

and Mac is right -- did the installer set the gains? you might want to check them...

did you use a line level converter or just go into the speaker level inputs for the amp?