Well Joe, what did you mean by upgrading? I upgraded my 25-31PC with the new woofer and the replacement 300-watt amp. Or were you trying to ask about going from one model to another?
So, did the driver upgrade provide any noticeable improvement to your system? Is that upgrade the ISD one? What exactly does the amp upgrade entail... how many watts did the old amp provide?
I think if you're going for a discount SVS, just get a B-stock. It'll save you a lot of time and hassle since they have their discounted UPS shipping + $50 off. When I got my 20-39 PC+ used, I ended up saving like $100-$125 off MSRP. So that's like $50-$75 off B-stock not counting the extra shipping that might have been incurred from shipping at a retail counter vs a company.
Glenn, The new driver did seem to be louder than the original one(which was still good.) The original amp was a 190watt, the new one is a 300watt. The new driver is required if you are going to upgrade the amp. Yes, it is the ISD driver.
Sorry, they're not mine, they're ScottCarr's.......just a link to the seller. I believe he's getting a PB2-Ultra to replace those. I gotta let the guy answer himself.....lol.