connecting USB to radio, output is distorted in aftermarket stereo system
OK, so my installer & I had been going crazy trying to figure out how I was blowing speakers. In the system: DMH-1500NEX head unit, JL Audio XD700/5v2 for 2 pair of ADCS622's, C5 1000.1 sub for a cadence US12D4. The phone is connected to the head unit via USB, using Android Auto as the interface. In over 30 years, I had not blown any subs (always made sure I matched well the subs & amps) New car, new system (installed this August 2019) 1st sub blew a couple days after break in period (always give a solid week + of slowly raising peak volume to break the subs in) and not maxing music. Replaced, rebreakin new sub, a month later, pushing louder...sub 2 goes down. Now, we bench the system (meaning we test each component to see where we are getting distorion from.) tested each source & found distortion from the phone (source for playing music with google, pandora & spotify). At 1st we lowered "Media" volume to midway (before the "Listeining to loud music" warning) I had to make a concerted effort to make sure I always checked the level before attaching to the car. One week before Thanksgiving, playing the stereo loud (but still not enough to get radio added distortion) the last sub has blown. At the shop, he used my phone to tune the system & it is not even CLOSE to loud any more (to not damage any more equipment) which makes me NOT happy. We noticed that with the phone connected, didnt matter if we raised or lowered the media volume because the output seems to be set. There was NO change in loudness raising or lowering it on the phone. I have not been able to find any one else who has had this issue. The installer uses Apple, tested with apple drove the system harder than I ever do & could not reproduce the issue. I am NOT changing to apple, but am running out of patience.
1. am I the ONLY this is happening to? (I know I dont have a stock system, but that aspect has been checked, rechecked & checked again)
2. ANY possible solutions? (and please dont say get an apple)
3. Is there a means by which to be able to communicate with engineering or someone who ACTUALLY knows the details of the output on the C to USB.