Going to the original post that started this thread. There seems to be quite a bit of confusion over how identical parts interact with each other (the two tweeters) in a room environment. The comment about comb filtering is a red herring. This effect can be measured in anechoic environments but it is not an audible reality in the room. If it were we would have all dumped stereo a long time ago and would be listening to mono again. The off-axis lobing effect of the tweeter and woofer is a reality in the down-axis measurement of all speakers that use a tweeter above the woofer, and does create an interesting dilemma with center-channel design because this phenomena now exists in the right and left off axis in a WTW layout. As to how big an issue this is in the real world is best determined by double blind listening tests. It is audible, especially when seated far off axis from the TV, but always surprised me as to the how slight the effect in the room is when compared to the measurements. A testament to the importance of the family of measurements as opposed to the single axis you are directly seated in. The VP150 driver layout does eliminate this issue altogether by effectively not having this particular axis no matter your seating position. The result is excellent, and it has been proved out in our double-blind listening tests. In fact it was so impressive we actually changed the VP150’s driver array to this layout mid-stream from a WTWTW layout.

Ian Colquhoun
President & Chief Engineer