Saw something strange and want opinions? (1 Viewer)

[Dustin B]

I was in an A&B Sound the other day and some sales people where demoing some PSB equipment for a couple, turning the volume way up for a while then down for a while and way up again. It was in a closed demo room that had a glass window in the door (it went down for a while well I was looking in the window and the oldest sales guy asked of it sounded better). I wasn't there for very long so I just took a quick look in the room and didn't bother going in to ask questions.
They had two sets of PSB Image 6T towers setup. One pair normally (a good distance from the front and side walls in the rectangular room) and the other pair turned upside down sitting on top of the first pair. Couldn't see if there was a second sub, but there was what looked like an Image Subsonic 6 right beside one of the tower pairs.
I have no idea how the sub/subs where wired in (ie using their crossovers or just from the LFE of the receiver) or how they were powering both sets of towers.
My question is what would this accomplish. Could stacking the towers improve the sound or would it be a detrimant and why?

 

[Brandon B]

Sounds like it would be detrimental, since the layout of the drivers in a speaker is done with dispersion, cancellation and lobing in mind, and putting a second set of drivers right above it emitting the same signals is going to cause all sorts of interference, constructive and destructive. Wave goodbye to your flat frequency response.
But it would be louder, I guess.
BB

 

[Chu Gai]

did you ever go back and ask them what they were doing? btw, did the people buy anything?

 

[Dustin B]

Don't know, didn't have time. I looked in, saw what was going on. Thought, are they nutz, wanted so bad to go in and ask a bunch of questions and then make them look like idiots (although I don't think I have a good enough vocabulary or a good enough understanding to have properly explained why the second speaker would trash the frequency response, was just pretty sure from my understanding of the subject that it wasn't a good idea). But I didn't have time and didn't think I would have been received that well even if I did. Brandon said more or less what I was thinking, but has a better vocabulary for explaining it than I.
I also wonder if they managed to mark up the tops of both speakers, that would just be icing on the cake to their stupidity

I find it scary sometimes how little research people do when making major purchases.

 

[Hank Frankenberg]

I don't know the driver layout on those speakers, but if it's tweeter on top, then one or two larger drivers, maybe they were trying to create an impromptu "M-T-M" layout OR maybe they were trying to impress a customer with their "expertise". Hey, maybe they made a two-pair sale!

 

[Dustin B]

The 6T is a 2 1/2 way tower (or is it three way, I haven't quite figured the distiction out yet). Has a tweeter crossed over at 2500hz to a ported 6.5" cone that is crossed over at 500hz to two ported 6.5" cones. So on the front in a straight line from top to bottom there is a tweeter, cone, port, cone, port, cone, port.
If they made a two pair sale I think the screwed up. Instead of the two 6T they could have made more money offering the Stratus Silver with a pair of powerful seperate amp. Would have sounded better to