OMG, nice Sunn rig! Which reminds me - I totally forgot to post mine. But before we get to that, I don't think anything can replace one of these beauts - nothing will compete with those MArshall rigfs without having to sacrifice bottom like the larger Sunns. 120 watts is a serious understatement (especially if ss vs tube rectified) - my 1200s (same amp + trem and verb) pushes 200 watt speakers to the limits of their comfort zone. There was a 2000s on reverb for US999 that I was considering because the price was too damn good, but I hesitated cause that's a lot of cash for me to drop on what is essentially a spare,and someone else grabbed it.
Anyway:
Finished my guitar/bass dual use rig. That Riviera (Pepco stencil brand) 4x12 (actually rather well built for a budget cab of that vintage - not chipboard) has been loaded with 2 each JBL D120f and EV Force 12 and lined/stuffed with that insulation made from recycled jeans. I am thinking I need to swap out the JBLs, because the cab is now too heavy for me to lift (I put recessed corner castors on one side for tilt and roll, but stairs etc - why it's on the bottom in the pic.... in use I wouldn’t stack them like this at all).
The other cab is me old badgeless Musicman 115RH (actually very similar to the Sunn 2x15s the 2000s came with, or more aptly the 1x15s the smaller bass heads of the same era did, which are also reflex horns) with an EV speaker in it. I would love to replace it with a 1x15 Sunn but they didn't make very many in this width and we rarely get Sunn cabs up this way (there's one in Montreal I was going to get my little brother who lives there now to grab for me, but it looks like it's one of the skinnier ones for the 200s, 190b and 300b heads).
The cabs mate really well, for either G or B and gives some tonal choice depending on which I decide to run. For gigging (not 6 bangin in any group currently) I'll probably only use the 15, but the 4x12 really worked out nice for bass I just don't want to move it. With guitar it covers anything from doom metal girth to shoegaze noise fx abusing sparkle. The top end isn't icepicky at all (I was a bit concerned; have had JBLs before), but actually pretty sweet - I suspect due to being well complemented by the EVs. For bass it gives the dynamics and cut you don't get from a 15 alone, and solo, a cool grungy 60s Brit bass tone; Scott would approve.
Currently in the jam space I have it set up stereo, one cab on either side of the drummer and that is gonna be really neat for some live-off-the-floor recording.