I posted this in my thread on setting levels and other questions but I thought it might be good to post for anyone who might be using the HD HK head unit. I hope someone can confirm or deny these findings...

Well I was all ready to button the fairing up this AM as I got the rear speakers set-up yesterday and set their levels by ear. But I was thinking about what my son had said about having an O-scope (he is an Electrical Engineer student) so I waited for him to get up. THAT was brutal!
Good thing I did because his scope will accept the input voltages generated by the head unit, the line level convertor, and the amps (Soundstream Picasso Nano and RF 300x2).
We hooked it up and played a 1000hz test tune I had recorded for a DMM test but never used. Heres what we found.....

The HK head unit volume level began to show clipping after 13 bars on the volume! This was 2 or three bars LOWER than what I had used to set everything by ear! My boy said it was an odd clipping signal as it was on the backside of the wave. Not the entire top of the wave hacked off!!??
So we decided that 13 bars was my max level on the HK head unit and then set the line level convertor to 4.5 volts out and balanced L & R pots. I was shooting for 5 volts out but for some reason his range was only 4.7 or 4.8. And then we set the Picassos outs, also with the scope, and then we set the RF's gain.
It was very interesting to watch the O-scope climb and finally show clipping. And the amps clipping signal, BTW, was more like the tops and bottom of the wave was hacked off. The amp gains were also pretty touchy so we played for a good amount of time.
Well, I found this technique pretty easy and am REALLY happy now that I waited to get confirmation on my ear-settings vs. O-scope settings. And finding the head units limitation was a lucky stroke!
I wonder if all the HD HK's are this way!!??

 

It would be interesting to see the scope output.....

 

https://www.hdforums.com/forum/11567540-post17.html

 

Danke...