This is my Rumble 40 v4.
Yeah, there’s a v4, but you have to build it yourself. Stock speaker gets replaced with Eminence Basslite S2010, ports get changed to 2.00” id x 2.63” deep.
The big muddy peak of the v3 is all gone, the amp sounds great and it’s noticeably louder.
The idea came from a helpful person on Talk Bass. See here.
