Factory B&O Audio Signal and Max Volume

[LAX-DAD]

Wanted to share what I found with the factory B&O sound system before tearing it out. I'm not a professional just enjoy playing in the garage with toys and with my son on our vehicles. There have been many posts about the audio system in our Bronco's from speaker swaps to full systems but nothing about the audio signal from the B&O dsp feeding the speakers.

I set up my laptop, DM-RTA along with my SMD DD1+ to see what I could measure from the audio signal. For those not familiar with these items, the Audiocontrol DM-RTA a great tool for tuning, measuring and troubleshooting while the SMD DD1+ by D'Amore is a clipping indicator. While the DM-RTA has an oscilloscope for measuring maximum volume or system clipping I found it easier and quicker in this setup to use the DD1+. Keep in mind I measured the electrical signal feeding the speaker, I did not mic and measure the output of the speaker. For each speaker location I played 'pink noise' and measured the signal with wire probes to the speaker wires.

Subwoofer signal

Rear pod speakers

Dash Speakers

Kick Panel

Here are all the signals averaged

For measuring maximum volume, on the subwoofer I played a 40hz test tone. The sub signal volume was clean up to 23 (5.8volts) at 24 on the signal clipped. For the kick panel, dash and rear speakers we played a 1khz test tone. For all three locations the audio signal did not clip all the way to 30 (9volts) on the volume/display. The B&O wiring schematic does show a 'clip detect' circuit not sure if this is why I couldn't get the signal to distort, maybe someone more knowledgeable can elaborate.

If there is something I missed please let me know.

Sponsored

 

[Alfa]

Thanks for posting this. Super interesting to see how they are shaping the signal at the different speaker locations. Might be good data in selecting replacement speakers