OEM tweeter wiring on UK Yaris

[Paul Evans]

And in case anyone else wants to know, I have now answered my own question, via a circuit diagram from a "usually reliable source".
In a 2009 UK Yaris with the 6 speaker setup (2 front, 2 back and 2 tweeters) the front door speakers and the front tweeters on each side are wired in parallel. The wiring seems to go from the HU to the tweeters on each side and then down into the doors.

This means -
- that the tweeters at least must have a cap mounted on each tweeter to roll off the low frequencies
- that the front door speakers may have a choke mounted on the back to filter out the high frequencies (different part number to the normal 4 door speakers)
- that putting component speakers with crossovers into such a system is going to be tricky using the existing wiring!

Not rushing into action now, having a bit of a think!

Paul

[TOLMACH]

Originally Posted by Paul Evans

And in case anyone else wants to know, I have now answered my own question, via a circuit diagram from a "usually reliable source".
In a 2009 UK Yaris with the 6 speaker setup (2 front, 2 back and 2 tweeters) the front door speakers and the front tweeters on each side are wired in parallel. The wiring seems to go from the HU to the tweeters on each side and then down into the doors.

This means -
- that the tweeters at least must have a cap mounted on each tweeter to roll off the low frequencies
- that the front door speakers may have a choke mounted on the back to filter out the high frequencies (different part number to the normal 4 door speakers)
- that putting component speakers with crossovers into such a system is going to be tricky using the existing wiring!

Not rushing into action now, having a bit of a think!

Paul

Not sure about yaris.. with couple of my previous toytas, tweeter was crossed exactly in a way you describe.. 1st order filter.. tiny (inappropriate type) capacitor.. and woofer working in the full-range mode.. you can use similar crossover type to replace the tweeter using the capacitor of appropriate value.. you might also need to attennuate your new tweeter (quality tweeter is likely to have higher sensitivity) using resistance or L-pad (if you are using a resistance in series the crossover point will shift downward.. keep this in mind.. L-pad is a bit more predictable).. the problem with 1st order filters is that most likely you would have to experiment with different caps.. like 4.7 / 5.6, etc.. to find the one that serves the task best depending on tweeter location and orientation/angling.

IMO opinion replacing the tweeters might be a good idea (stock tweeters usually suck) keeping the OEM door woofers - they are of a good quality.. you might as well need to build the custom podium for tweeters (lots of examples how this is done can be found here on YW) or place them somewhere on the dash (some tweeters come with nice looking mounting hardware/podium)

if you want to continue with this project you might want to read some on-line stuff on filter types - (not a rocket science)

http://www.the12volt.com/caraudio/cross.asp#hp
calculator (you want something like 3500 or 4000 hz as your crossover point)
http://www.the12volt.com/caraudio/crosscalc.asp

good store for parts
decent tweeter (lots of other stuff to consider)
http://www.madisoundspeakerstore.com...weeter-4-ohms/

capacitors.. bennic - inexpensive but quality stuff (you have to buy several values.. like 4.7 / 5.6/ 3.9 each one is 2-4 bucks.. of course you need them in pairs - one for each channel)

http://www.madisoundspeakerstore.com...-poly-5.6-mfd/

you re also gonna need some resistors (you can use cheap stuff like this)
http://www.madisoundspeakerstore.com/resistors/