Inconsistent bass levels and engine whine

[Grunkille]

Hello everyone


I have been having consistent issues with my car audio, and hope someone can help with resolving my issues.


​I have a 2018 Kia Picanto with stock radio with a PAC Locpro Hi-Low converter. Infinity Kappas in the front and JBL GTO's in the back running off of a Rockford Fosgate P4004 amp. I also have a secondary 130AH AGM battery installed in the boot.

Problem 1:


I had a new DD712 sub with 3000w RMS @ 1ohm amplifier installed. At the installation shop I was advised that my Stock radio is not providing enough power, as they turn the amp almost full without the sub performing optimally(the midbass is also lacking). I was then advised to install either a crossover in the back, or an EQ.


I then got an EQ from a friend which I wired up, and initially sounded great(could push more bass and adjust the midbass). However, the bass at is completely inconsistent, but always at the same place in a track. At one place in a song the bass is almost 0, and in the next place its turned up to 100. I then went and purchased a new different brand EQ thinking the one from my friend might be faulty, but I am still experiencing the exact same inconsistent bass in tracks. Without the EQ I did not have this problem, everything was just at a much lower level.



Could it be that the Hi-Low converter are causing issues with each other? What are my options if this is the case? Replacing the stock headunit might be difficult due to costs in my country and the weird protruding look of the stock radio.



Problem 2:

I am experiencing constant engine whine on my speakers, which I cannot get rid of. Ive changed RCA cables, moved power cables around, the PAC converter has a ground loop isolator also built in that does not make a difference if the wire is connected or not. I have heard that connecting 2 Hi-Low converters at the same time can resolve the problem, but I have no idea to do that.



Any concrete answers that can point me in the direction of experiencing my car audio to the fullest would be greatly appreciated.

[BigAl205]

Did they set the gains on the PAC LOC?

https://catalog.pac-audio.com/index...._attachment=35

[Justin Zazzi]

Problem 1 sounds like it might be a loose connection somewhere, or a potentiometer (knob) that needs cleaning. This seems to match the pattern of "only a problem with the new EQ which is louder" because louder might be causing the loose thing to misbehave.

To troubleshoot, you can try reducing the number of parts in the system until the problem goes away. For example, can you get an aux cable and plug your phone directly into the subwoofer amplifier? If you do, can you play it loud and see if the problem is still there? If the problem is still there, then your have an issue somewhere between your phone and the speaker. If the problem is not there, try adding one more piece of equipment back in like connecting the equalizer, but still use your phone as a source. Check if the problem returns. And so on.

For problem 2 whining, I'm not much help sorry.

[Grunkille]

Thank you all for your responses.

The LOC was adjusted, multiple times to try and remediate the problem.

I actually connected a phone with a RCA-Audio jack cable to the EQ yesterday. Bass levels are INSANELY higher than through the radio and LOC, but as can be expected its not great quality.

Multiple shops in my area has now also advised me that the engine whine could be due to the radio/LOC connection.

Ultimately I think my best bet would be to change out my radio with something proper to get rid of the LOC and EQ.