Well the Philharmonics aren't distributed by a retailer, you would have to email Dennis to see if he's shipped any near you. Then Dennis would contact the owner and ask if they would be willing to let you into their house so that you could audition them.
Other than GTGs or shows, that's how people have been auditioning the Philharmonics, unless of course you happen to live close enough to Dennis. I'm right on the edge, Dennis is about a 4 hour drive away, but I've been thinking of making a trip down to meet him. IMO, the Philharmonics are worth a few hour drive to go audition them.
Just a thought, I'm sure you'll be happy with any of the speakers you end up with, especially since you're being thorough enough to go audition some speakers. Thats more than a lot of people do, plus you're here asking questions, so you should be golden