Universal bass knob causing noise from subs.

[whoopdeedoo]

Been trying to figure this out for 3 weeks or so. I switched out my CAB amp for a Smart 5 and I can't have a bass knob connected with interference. I changed nothing about the system other than the amp. I've tried my main knob and also my backup, both of which worked fine with my last 2 amps. Whenever I have a knob connected in line with the RCAs I get constant noise through the subs. Even with no music playing or if I turn off my sub option at the headunit.

I've checked all my grounds, tried multiple different RCAs, I set my gain with my DD1 and checked it with my Oscope. I tried wrapping wire around the RCAs at the headunit and on the bass knob. I even borrowed a friends Smart 5 Bass version and it did it also. The only thing that's worked was a ground loop isolator but with that connected my DD1 was sensing distortion constantly regardless of gain and other settings so I disconnected the isolator.

For the life of me I can't figure this out. I hate using the headunits sub option to adjust bass. Any ideas?

[CstrokerV]

Might just be the smart 5 doesn’t like the bass knob throw your old amp back in see what happens

[whoopdeedoo]

1 hour ago, CstrokerV said:

Might just be the smart 5 doesn’t like the bass knob throw your old amp back in see what happens

I sold it when I bought this one. Have to try and track down a half-bridge to test. Didn't have an issue with my other amps but these full bridges are causing problems. I know other people running the Smart 3 with a universal knob not having problems. My car doesn't like em apparently.