the woofer is labeled M115-8 but no such listing exists on the list of every driver ..... but there is an MI-15 bass guitar speaker whose Thiele-Small does show up on the site and is in Boxplot and WinISD. This 15" woof is a lightweight.

If I had spent 300 or 400 for each system I would have refused it as not being the 3677 but rather the 3677s (for surround). However, at $118 each, I should be able to build a kick-ass theatre main with the woofs in the 4648a-8.

The good news is that the 4648 has the 2226J woofer as advertised. So the 2 woofs from the 4648 and the 2 tweets from the 3677s, while not the exact Pi Profesional components, should turn out to be pretty good for the $450 invested.

Funny thing: the mystery component 3677 cabinet is a work of art with plastic vents, nicely done bracing and acoustic material. The much more expensive 4648 has paper vents, looks thrown together and the black paint overspray covers the damping probably reducing it's efectiveness. I wish I had a bass guitar to try on it, though!

I think I will try to get a V.P. from JBL on the phone and give him/her the liar-liar pants on fire treatment. Shameful!

Comrade Wayne, have you ever heard of the 2418H driver and 23something-something horn?

These babies have about 17.5 feet of 2x4 internal bracing on the interior panels (hey, we just lost 0.7 cu. ft.). The finish looks like a vinyl cladding to me; if it is even paint, it looks VERY NICE, even the wife thinks they look good, and we went from mahogany vintage ev enclosures to these!

Those convienient t-nut inserts on top worked perfect for attaching my altec 511 horn mounts. "Sams Time Alignment Trolley" lets you adjust the fore/aft position of the horn to optimise it per altecs practice.
If the polyurethane on the baffles ever dries, 2404H1 tweeeters on top to fill in the upper octave a bit, not really needed on most material.

We have listened to one pair at least 8 hours daily since 27 Dec, I think these were the best upgrade (for the dollars) possible for a direct radiator LF system. They rumble low enough for me, and are tuneful and articulate to the point I can identify three SEPARATE notes in bass progressions where I heard only one before.

No way would I take the two woofs from one enclosure and make two speakers, much happier with the performance of a pair per side, floor space still about the same, just taller. Sam