Hi Toby

JBL describes the 4625B as having an internal volume of 4 1/2 cubic feet, which is best size for bass guitar. But, if you are going to use the E140 for guitar and not bass guitar than maybe you should be looking for something like a Fender Showman or Dual Showman cab. If I remember the dimensions right, the Fender Showman cabs should have an internal volume of only about 2 1/2 to 3 cubic feet per driver. Now, I am not sure if the Fender Showmans came with D130F or D140F speakers. But, it could be possible to adjust the port tuning if necessary.

Baron030