Below is a quick look at the near field response curves for the UFW-15 Big Block upgrade (red), the UFW-12 Amp Modification upgrade (blue), and a measurement of a stock UFW-12 as delivered from AV123 (green): You can immediately see the much smoother response above 25Hz, and the much more gradual roll off below 25Hz allowing for much more real and perceived VLF energy in most any room. In more common size rooms you will get the added benefit of useful response into the teens. What you can't see is the much better overload characteristics, which make both of the upgrade kits much more fun with soundtracks like War of the Worlds or Master & Commander. I very much look forward to the thoughts of the first few taking advantage of the amp only upgrade given how much easier the upgrade task is in terms of simply removing, shipping and replacing the amplifier. Kevin and I even have some original UFW-12 cabinets in decent shape from AV123(obtained prior to closing) which Kevin will offer with the updated components. Feel free to tell your friends.
Seaton Sound, Inc. firstname.lastname@example.org 773-290-8436