These bottom knobs/tone knobs gradually go bad. This has happened before, and I blame it on the gig bag.
Notice the hole in the chrome plate. That’s not an input-jack, Jack! That’s where the top of the mid range tone knob should be.
This is what it should meow like.
I pulled it out moments before a performance.  I am really lucky there’s still a good solid connection. Yes, I literally pulled the knob out because it was popping in and out loudly, and actually disrupting the connection.  I didn’t know this was possible. I was just trying to do something different with the knob during sound check. I’m also lucky I was able to insert the knob and Control the peace inside.
Obviously, I turned it up all the way. High mid-range bass is good. I can deal with that until I get it fixed. 

How is this possible? Not sure, makes me think the hardware is premium. Maybe one of the differences between a $1000 instrument and a $500 or less instrument.
This GIF from previos post was inspred by this revelation.
Videos coming soon.
I haven’t showed any performance footage with this tone knob removed. Losing the toe knob is a recent 2026 phenomenon. Videos coming soon. 
The tone knob eating gigbag.
Lots of gear in the front pocket seemed to make things worse. I once owned a bass gig bag made by Warwick and I never had issues. 
This gig bag is made by Momo. Overall, it’s great I like many of the other features. The front should have a handle, but this is missing on most gig bags. I’ve had it a long time and I’ve added various clips to hold onto. I always try to keep the next straight and reduce pressure near the top of the bag. 
If the front of the bag opened up more, the base knobs wouldn’t slide against the inside of the bag. This sliding pressure is what gradually flexes, pushes down on, ruins the fighters/tone knobs. Crunchy/popping tone knobs amplified over a venus PA system can be really, really, really bad. 
