I picked up a pair of the new Ampeg SVT 12HE cabs in March. They are ported, single 12" cabs with a HF horn, constructed from 13 ply baltic birch and are 8 ohms/300 watts RMS. I generally use a (classic series) SVT 410HE + 15E or (vintage) SVT 810 cab & like a lot of you, I have been looking to downsize. My first gig with the SVT 12HE cabs was a tiny little... well... bar. No stage, limited PA. Not the type of place I am used to playing at anymore, but it was a cool place non the less. I had just picked up the cabs that day & had not even opened the box until I was inside the club, but I had heard the cabs at winter NAMM so I had a pretty good idea of what to expect. I used the pair of the SVT 12HE cabs with zero PA support & a borrowed Peavey 300 watt head (with a BDDI on the front end). The setup carried the room. It did not produce bowel shaking low end, but that was not needed in that room anyway. But the mids were growly Ampeg all the way. I actually had to turn down at one point because I was overpowering the guitar. Again, these were not ear blistering volume levels (well not for me, anyway, maybe for you), but we have a hard hitting drummer and loud guitar, so it was pretty d@mn loud. Since the cabs are ported, I find myself backing off the amp's low end more than with my 410 cab, which is fine. the 12 HE still has nice low end, but you need to control it with the amp so it is not boomy. I next played a decent sized club with a good PA. This time I had a bit more power into the cabs and they held their own for stage volume. I loved the growly mids, but I was wanting a little more low end depth. Last night I played this new club for the first time. Its holds a few hundred people & has a decent sized stage so I decided to try something different. I used one SVT 12HE and one SVT 15E. Man, those cabs sounded awesome together! The combination was big in all the right places. It was a pretty loud/bassy stage so & had to keep the volume down, roll off the low end & let PA do most of the work to carry the bass out to the front. Otherwise all you could hear was bass directly in the front of the stage - mind you it sounded really good- but just too loud. But when I backed off on the amp and it went through the mains, it was heaven. HUGE tone. I used an old Ampeg SS 150H guitar head last night which is a bit less than 300 watts at 4 ohms & it wasnt even maxed. I do like the SS 150H for bass, but the cabs are what sealed the deal on this setup. I regularly would use my SVT 410HE +15E with the SS 150H & I actually like the 12HE + 15E tone (and size) even better! good stuff. I had 3 other bands booked last night, they all used my rig & they all sounded fantastic through it. At the end of the night the sound guy complimented me on how good my "old tube amp" sounded. I laughed out loud. Not a tube inside that head Its the cabs baby! I am very familiar with the room I playing tonight & i will use a bigger power amp and carry the room more with the bass rig, using the PA for a little extra support. I have pushed my Stewart World 1.2 into the 12HE + 15E in my studio, the cabs didnt even flinch. It was that "punch you in the chest and rumble your nuts" kind of power. My ears would have exploded before I damaged the cabs running too much power. I am confident the bass is gonna sound bad @ss tonight with the Stewie 1.2, SVT 12HE + Svt 15E. I will use my sansamp BDDI so it will sound just like a vintage SVT. My impressions so far is the cabs sound very "Ampeggy". Nice mid growl, nice low end, but not a ton of low end. I will try "just" my pair or 12HE's a few more times, but I believe the 12HE + 15E is the best combination for me so far. I play in a loud Thrash Metal band, so a single 12HE or pair may be plenty for less agressive music. For the record, the tone I like is the sound of a cranked vintage SVT through an 810. I have recently loaded some Eminence Delta 12 LFAs into a cheapo 212 cab that actually sounds pretty good (the Delta 12LFAs are some SERIOUS bass speakers IMO. very deep, very mid growly, the more you push them, the better they sound. perfect for Ampeg). I am going to swap out the cheap horn for an ampeg horn/L-Pad and end up with a 4 ohm 212 cab. Once this is together, I will pair it with my two 12HE cabs and see what that produces. But I have a feeling I may eventually dump that 212 and just getting another 15E to mate with my second 12HE. We'll see how that goes. These are my impressions so far. I still need to try these cabs with my vintage SVT so I will update as I use them more. But so far - I highly recommend the SVT 12HE cabs for that mid-growly Ampeg tone in a powerful lightweight package.