I've owned a pair of Q2's since they first came out, love them a lot, but regret that I didn't pop for the QLS. The attached file contains a CAD drawing of a QLS derived from the photo in the Infinity brochure. I would very much appreciate someone who owns a QLS verifying the various dimensions. I have been bitten with the speaker building bug and am contemplating creating a QLS look-alike (Watkins woofers, but everything else new). I've seen the QLS and Q2 hybrids folks have created, so they give me some confidence that this is do-able. Saw the amp thread, and for the record I push my Q2's with an Adcom 5802. Previously used a Bryston 4B and before that a Dynaco 400 (which surely dates me!). None of them have had any issues with the Watkins. In the drawing, the woofer, mid-bass coupler, dome mid-range and tweeter diagrams were all derived from direct measurements on my Q2's (and I have CAD drawings of them as well).