Looking in to upgrading the stereo in my S2000, but had a couple questions.

From what I've seen, the Tweeters in the doors are wired separately from the full range 6.5" driver. Also, from the information I've gathered, the roll-hoop speakers are also wired separately directly from the stock head unit. (So it seems there are 3 channels coming from the stock head unit. I don't know how accurate this is, if at all.

Anyhow, my question is, if I upgrade my head unit (Aftermarket) and replace the door speakers with another full range or Coax speaker 6.5" speaker, will the stock tweeter still be powered? Basically, I'm wondering if I went with coax speakers in the doors, will I have 4 tweeters?

Anyone know where I can find a wiring diagram of the stock radio harness?

 

The stock tweeters on Honda/Acura, [excluding Bose] are wired in parallel with the front speakers, a cap is installed in series, [pos.(+) lead] as a X-over for the tweeter.

The stock HU like all stereos has a 2 "channels" [left and right] divided into a left and right front and a left and right rear.

Yes you would have 2 sets of tweeters if you installed a set of coax in the front, [and did not remove or disconnect the stock tweeter] not necessarily a good thing.

Try this, if there is nothing wrong with the stock speakers, replace the HU, you will be very surprized at how good the stock speakers can sound when they have more power, [watts] driving them, you can always replace the speakers if your not happy with thesound. 94

 

Thanks for the info fcm. I was planning on doing the headunit & speakers at once... but maybe I will upgrade 1 step at a time so I can hear the difference.

Now I just need to choose which headunit...

 

Keep in mind the source, [HU] is the most important piece of a cars audio system, how the system sounds and what kind of control you have will depend on the HU, so take your time picking the HU, make sure it has the features you want now and possibly in the future when/if you upgrade the system.

Like I said, you will be surprised at how good the stock speakers will sound.

Hint...

If you plan on using the HUs internal amp, "beef up" the power and ground to the HU.

The stock power and ground, [in stock radio harness] was not designed to supply the current needed by aftermarket "high power" HUs.

Run a fused 12ga power lead from the batt. to behind the HU, connect the HUs 12V constant, [yellow] to it, leave the HUs ground connected to the stock radio harness ground but add a 12ga chassis to chassis ground, [from chassis of HU to cars chassis (dash sub-frame)] this will insure HU gets the current needed whe HU volume is turned up.
Don't forget to cap off, [or remove from harness adapter] the stock 12V constant to prevent it from shorting out. 94

 

agree with fcm totaly.

Alpine makes great headunits, I love mine. my stock speakers were pretty much done and they still sounded very good.