I found a pair of 4625 cabs on eBay and loaded them with Sub 1500's. The results are surprisingly good, since I don't believe the tuning is optimal. Perhaps you guys will run the numbers for me?
Allegedly, the boxes are 4 cu.ft. The interior dimensions calculate to 4.3 cu.ft., but deducting for the bracing, ports, and speaker volume, 4.0 net seems about right, at least for the E-140's that came in these. Sub 1500 is a little bigger, it would appear.
The ports, a pair in each, are 4" X 5-1/4" deep from the face. Somewhere in the literature, I believe I saw the factory tuning was to 40 Hz. I was going to plug the ports, but I'm not so sure now.
In any case, the bass is tight, low, clean, and effortless. I'm running them on a Mackie M-1400i, with the sub filter set at 63 Hz. If I crank the full 300 W into each that amp will deliver, it's clear the cabinets aren't made of thick enough material, but that's WAY more bass than I need here.
I ran them overnight with the local "boosted bass" FM station playing to break them in. Big difference when I got up this morning. These babies throb oh so nicely now.