I posted this in the amps forum, but this is probably a better place. And, as a happy owner of a new Rumble, please make me a Rumble Club member.
I used an Ampeg SVT with the 8x10, or two 1x15 JBL E140s for many years. I think it's the best bass amp ever made. It's semi retired now (like me), and my main rig is a SVT 3 PRO and BSE 410HLF cab. I play bar gigs in a blues band, and I love this rig. But, that 4x10 must weigh close to 100 lbs, and I've been wanting to try a combo. I got the Rumble 500 combo and the 2x10 ext cab based on the reviews I've been reading here on the forum.
I took my new Rumble 500 and the 2x10 ext cab to a bar gig last Saturday. I put them side by side. My main player is a Fender Aerodyne Jazz. I was able to quickly dial in a nice fat tone. This thing puts out a huge, punchy, sound. I unplugged the ext cab, and played half the night without it. I really didn't need it for this gig, but I think it will be nice to have, and it brings out the amp's full potential. I wanted to try stacking the cabs, but I didn't get around to it. It's been many years since I used an amp without tubes. The "vintage" tone button seems to add some warmth and bit of compression.
It's amazing that a 36.5 lb combo can put out this kind of sound. The 2x10 is actually noticeably heavier than the combo, which is kind of strange. The guys in my band use vintage Fender amps, and the Rumble's looks fit right it.
If this thing is reliable, I think I'm going to be very happy with it.