Put a pair of 4" diameter, 9" pipes in each of the cabs today (actually, more like 10"). I kept the bottom venting, as it was physically easier to implement in an afternoon, is easily reversible, and I have reservations about chopping up a vintage piece unless I have to. The venting did clean up a lot of problems, and they do go very, very deep. BUT:They have turned into "punchless wonders". The wife described it as "wrapping them in foam rubber". I also had to pad the 2420 down quite a bit more.
Where should I go from here? Progressively shorter pipes 'til some life comes back? Thanks.
Follow Ups: