Hold my beer, this morning I’ve already shopped up the following -
JBL passive x-overs - £160
Upgrade compression driver to JBL 2450SL (c£1400); Radian 950 (£2000)
Of course now you need to change the horn as these drivers won’t fit the 1" JBL 2446; so JBL match to CD above 2380/2385 (c £800-1500); Radian 850 (c £1200-1800);
Upgrade bass unit woofers -JBL 2216ND (c £1600); Acoustic Elegance TD15H (c£2000 and need bigger cabinets).
If you stuff heavier bass drivers in then you probably need to spend a few quid strengthening the existing cabinets (£200)
Add tweeter, start with JBL 2405H (c £400) then more to mount it and integrate into x-over. Obvs you can spend utter fuck loads on exotic tweeter options.
So without going anywhere near TAD or Duelund madness I can easily turn these £700 speakers into a Trigger’s broom money pit of at least £4,500 to £6,500
Any changes are a bit pointless if you ask me. I suppose the best thing would be a honking big JMLC elliptical horn plonked on top with one of the nice coax CD drivers. But anything based around more JBL parts? Meh.