Thanks Nick. Yes that's what i was asking about. Why the different placement of the drivers in different models. I'm no sound engineer, and I have no idea why the tweeters, mids, and woofers are placed the way they are in a cabinet. I had assumed that with the VP-180 they had engineered the 'Ultimate' center channel, but then came out with a smaller Vp-160 model. When I first bought my 150 a few years ago,it was recommended that it be paired with the M60/80's so I thought it was the be all end all of center channel engineering for the Axiom line. Of course there is always going to be R&D and things change. By the reviews on the VP-180, there sounds like there is a definite change in the sound compared to the VP-150. So much so that I think I'll more than likely bite the bullet and buy it over the Klipsch RF-64ii. So naturally when I heard that they were coming out with the 160, I wanted to know why the over/under configuration as opposed to the inline placement like the others. After reading 20 pages over at the VP-160 thread (my eyes are drying out) it seems different people have different opinions about how the drivers should be placed and I just wanted to know Axioms taking this approach and how it affects the sound.
The number of drivers in the VP160 were made to match the M60's, and they are both supposed to have the same crossover and cabinet volume. But, since there was only one midrange and one tweeter, this gave them the ability to put the tweeter over the midrange which is supposed to give much better off-axis listening. Meaning that it will sound almost the same at an off axis seat in comparison to the center seat.
The VP180 was designed to have the same number of drivers as the M80's, same crossover and cabinet volume. It is not really feasible to put the tweeters over the two midrange drivers in the VP180, since it would be too tall. So, they had to have all of the drivers in a horizontal line (a compromise). Now the VP180 should be a very good match to the M80's sitting right on axis. But, off axis there will be lobing issues where it doesn't sound the same as in the center seat.
I don't think that you can say that one of the centers is the "ultimate" or "flagship" center channel speaker since they are different designs. The VP180 is matched to go with the M80's perfectly (for a horizontally designed speaker) and the VP160 is designed to go with the M60's perfectly (for a horizontally designed speaker). But, as mentioned above the centers will match well with both the M80's and M60's. The VP180 will have more output. The VP160 will do better for seats that are off axis. This is the big point for me. Even though I have M22's right now and will probably eventually upgrade to M80's, I would prefer the VP160, so that off axis seats don't have the lobing issues. So my first upgrade will probably be replacing my VP150 with a VP160.
