Hi Dave,
I was wondering if you've heard or played with dipole speakers?
I finally got to hear the Linkwitz Orions the other day and was very impressed.  I have no idea how the Orions compare to your 1801s, but I noticed that the driver complement has a lot of similarities--which made me wonder if you'd ever tried out a dipole configuration with them.
SL uses the Excel W22 instead of the W18, and the T25CF002 tweeter rather than the OW1.  Unfortunately I haven't ever heard an OW1, but you and many others seem quite smitten with them and they're an awful lot more cost-effective than the T25CF002.  So with existing parts you've already got on hand you've got a great basis for serious dipole speakers, especially with the addition of one or two of those 10" drivers you mentioned in a different discussion here.
In case any overly sensitive types are reading this (an unfortunate trend on AC recently 

), I'm not implying that dipoles sound better a priori.  I'm just curious if Dave has either tried it out, or would be interested in doing so. 

 Dayne