So my boy has an 04 Volvo and has been having an issue that we can not figure out. I will try to keep this short and to the point.
The issue: When listening to the radio his bass will knock pretty good then will cut down a few DBs, its very noticable. If I had to guess it would be like a 48 and drop to like a 40. We dont loose all bass but the output goes down dramatically. The highs are not affected, bass only.
Troubleshooting that has been done:
Old amps had this problem...replaced the amp...still have the problem
Old HU had this problem...replaced the HU...still have the problem
Bypassed his Epic 160 (RCA directly to the amp)...still have the problem
New RCA from HU to sub amp...still have the problem
Voltage is reading a steady 14v
Pulled subs, checked coils and rewired...still have the problem
Checked amp ground, its a good solid ground. Bolt has no lock tight or any other compound on it prohibiting a good connection. Painted surface has been sanded smoot to bare metal.
Checked ground at the amp...removed it and reinstalled it...its in there tight.
Power is tight at amp, fuse and battery.
We are at a total loss here. He has an Epic 160 and a crossover inline before the sub amp but we have bypassed them both and still have the same issue so I have ruled them out. We swapped the HU for a brand new one that was identical and still no change...same with the sub amp and RCAs. I just have no clue where to start.
Also this problem just started out of the blue, there were no changes to the audio system when it started acting up. It had been installed for a long time before this problem occurred.
Any help would be great..we just need more minds working on this because we are all out of suggestions.