As to the SVSound PB or PC12-NSD specifically, what you've got in that sub is basically the least expensive sub that genuinely plays flat right down to 20Hz - and more important than that, IMO - it STAYS flat down to 20Hz even as you increase the volume! There are less expensive subs that technically hit 20Hz output. But it's basically only at lower volume levels. As you increase the volume with those subs, the 20Hz output doesn't really get any louder. It gets "stuck", or the sub starts to put out crazy high distortion trying to produce the signal. The PB/PC12-NSD is pretty much the least expensive sub to have no compromise in its output. It plays flat. It plays right down to 20Hz. And it stays flat - even when you up the volume
It's also worth noting that the price includes shipping. That's important. There are other great subs that can also hit 20Hz, like the Outlaw LFM-1 EX or the HSU VTF-3 MK4. Those subs are less expensive than the PB12-NSD by about $100, but then there's shipping on top of that of about $70-$100, so the price ends up basically equal.
So where the PB/PC12-NSD has one nice advantage over the other subs that basically cost the same once you include shipping - it's the new "Sledge" amps that SVSound is using, and more importantly, the fantastic engineering that has gone into them. What you get is a sub that is "unbreakable". Basically, those "Sledge" amps have limiters, compressors and filters that prevent the sub from ever playing louder than is safe for the sub or that will cause crazy high distortion. Crank the volume as loud as you want! If you go beyond what the PB/PC12-NSD can actually play, it will simply play as loud as it possibly can, but will politely refuse to play any louder

When you plan to move to a larger space in the future, this can be a great "safety net".
It's unlikely you would make the LFM-1 EX or VTF-3 MK4 ever bottom out, get into crazy distortion or generally "run out of steam" in room that would be considered a "normal" size. But these days, houses all have these "great rooms" or wide open basements, where the volume of air is enormous! A sub doesn't know that only a portion of that open area is considered the "theater" or the "TV area". It just tries to pressurize the entire space! So even tremendously capable subs like the Outlaw and HSU can be pushed past their limits in such environments. The PB/PC12-NSD might not be able to play as loud as you would like in a huge, open space. But it will never bottom out, never output crazy high distortion, and never be in any danger of damaging itself. So it is definitely a sub that can go with you into ANY room, which is nice
In your current apartment, there is zero question that the PB/PC12-NSD will have all the output you could ever want and more. In fact, you are very likely going to have a fair amount of "room gain", which basically just means that the lowest bass from around 30Hz on down gets amplified because the bass is "bouncing" around your walls. As such, you might want to add some form of EQ so that you can keep that really low stuff under control. You can get quite a big boost on the low end in a smaller room - and the PB/PC12-NSD has plenty of output down there! So some form of EQ is likely to help you out in your current room.
The other issue you're very likely to have is bothering your neighbors, unfortunately. Sound is just vibration. The air vibrates to carry sound. The box of the subwoofer also physically vibrates when it plays.
When the sound reaches your walls, floor and ceiling, they start to vibrate. And those surfaces are connected to the structure of your building - so that starts to vibrate too! Now the sound is structure-borne and can be conducted VERY well to the rest of the building. So now your neighbors' walls, floors and ceilings are going to vibrate, which means they can hear your noise.
Bass sound waves have more energy than higher frequencies, so they are the hardest to stop. They've got the energy to vibrate your walls and start the whole process. But worse than that, when your subwoofer is sitting directly on the floor, its physical shaking is in direct contact with the floor, and that starts the floor vibrating even more easily! The floor is connected to the walls, which are connected to the ceiling, so now your sub is shaking the whole building. And if you think concrete is inert - think again! Concrete is quite massive and dense, so it takes more energy to get it moving. But concrete DOES move and it does transmit sound. It is far from inert, so having your sub vibrating on top of concrete doesn't mean you're going to avoid the structure-borne sound transmission.
So this is where decoupling comes in. If you're building your own theater in a house that you own, you want to decouple your wall, ceiling and floor surfaces so that the vibrations never get into the structure of your house in the first place! But in an apartment, it's highly unlikely that you're going to be tearing down drywall and constructing decoupled walls
So there's nothing you can do about the bass that travels through the air, reaches your walls and starts them vibrating. You're stuck with that, unfortunately. But you CAN do something about the vibrating subwoofer box that's sitting directly on the floor and making your floor vibrate through direct contact! You can decouple your subwoofer from the floor - and believe me, this can help quite a bit - regardless of whether your building is wood, steel or concrete.
For pre-made decoupling products, you can use the Auralex SubDude, GRAMMA or Great GRAMMA isolation risers. They are about $50. You can get them at Amazon or Sweetwater.com
Those three are all the same thing, just different sizes. The riser doesn't have to be larger than the bottom of your subwoofer's box - you can use a smaller sized riser and just sit your subwoofer on top of it. The only time you need a riser that's the same size or larger is when you have a downward-firing driver and some "feet" on the bottom of the sub to raise the bottom off of the ground. One example would be the Outlaw LFM-1 EX, which has its driver and ports on the bottom, so you'd need the larger Great GRAMMA for that sub. The PB12-NSD though can use the smaller, less expensive GRAMMA, and the PC12-NSD cylinder version will fit nicely on the smallest SubDude version.
edesignaudio.com also has pre-made decoupling risers around the same price range.
You can also make your own if you like. Just get an MDF platform. Maybe wrap it in some durable carpet. And use some foam on the bottom that is stiff enough to not totally compress under the weight of the subwoofer, but also squishy enough to have some give so that it makes for a good shock absorber.
If you already have a really thick carpet pad, that can also be a good physical decoupler already. So not everybody needs to buy or make a riser. But a sub like the PB12-NSD is pretty heavy and can crush a lot of typical carpet pads, so a riser is never a bad idea
Finally, I'll just answer: is the PB12-NSD worth $769?
Yes.
It includes shipping in that price. It plays right down to 20Hz and STAYS flat as you up the volume. It is unbreakable. It most certainly has enough output to "rock your world" in your current apartment. And while there are some very, very good subs that are maybe $20 or $30 cheaper after you factor in shipping, there is no sub that is less expensive that is
better than the PB12-NSD.
If you can afford it, I'd say get it! You won't be disappointed and it will easily travel with you to a larger room in the future. And don't overlook the PC12-NSD cylinder version as an option. It's a great way to save floor space standing up, and you can also put the cylinder on its side, which makes it easy to tuck behind a couch or along the edge of a room somewhere. $20 cheaper too
Just pray for your neighbors
