tl;dr
What are the parameters of the speakers mounted in the doors of C5's X7 non-hifi audio system (impedance, power output)?
complete story:
I am making a complete audio-system rebuild of my C5 X7 Saloon, though I want it to look as OEM as possible. I swapped the RD4 with RT6 head-unit and hooked it up via custom harness. Front channel outputs are connected to Pioneer DSP that levels/fixes the sound.
The issue is that the DSP I'm using can only process two channels: front left and right. The signal is then pushed to an amplifier that drives all 7 speakers throughout the car (four in the doors, two under the windshield, one sub-woofer in the trunk).
In order to preserve audible parking assistance from the rear sensors I had to wire new cables going from the head-unit all the way to the back-shelf (bypassing the DSP) where I installed OEM tweeters that I removed from underneath the windshield. I thought those speakers would do the "beeps" just fine, though it turns out that they just can't handle them - I believe that the beeps frequency is way lower than the tweeter drivers can produce, thus the parking assistance is nearly inaudible. I hooked up the speaker that I took out from the door instead and it works really well. I measured that those beeps are around 800 Hz (using iPhone app). But those in-door factory speakers are too big to fit under the back-shelf nicely - they protrude too much into the trunk, plus I would have to drill some holes in the shelf to mount them. Also they suffer from not having any enclosure - playing music makes distorted sounds if playing loud, near the radio's max volume. I need new speakers, as small as possible to clearly play 800 Hz tone, easy on the radio. So then the question is: What are the parameters of the speakers mounted in the doors of C5's X7 non-hifi audio system (impedance, power output)?
Cheers!