Originally Posted by lalakersfan34 /forum/post/16897254
Actually, the new PB10-NSD has a slightly higher tuning than the old PB10 due to the fact that the port is larger and the enclosure is the same size (I believe I've seen a rep state the new PB10-NSD is tuned around ~21-22hz). However, I'd doubt the 1-2hz difference in tuning makes a very perceptible difference in performance.
That said, as you mentioned the new PB10-NSD has a larger port which gives better output and less compression near tuning than the older PB10 - likely a more tangible benefit than 1-2hz more extension, or else SVS wouldn't have chosen to redesign the PB10 this way. It also has a fully featured amplifier with multiple connection options and slightly more power. The driver is also new and should be a slight upgrade over the older NSD woofer (if I had to guess I'd say it's probably a bit more linear and has lower distortion in the 50hz and up range).
Overall, the new PB10-NSD is a better subwoofer than the old PB10. I couldn't see SVS going backwards and raising the price. A used PB10 in the $350-$375 range is likely a better bargain in terms of price/performance, but if I were in the market I'd probably get a new one.