Did you demo the ribbon tweeter and dome tweeter? I've read the ribbon has a vertical dispersion restriction. When sitting for critical listening the ribbon is the way to go I'm convinced. But if I was up in loft above the room in which these new speakers sit, or meandering about the lower level in the open floorplan, would I notice a drop off in HF? I'm thinking not, but have to ask.
I own the dome tweeter version, but I have heard both. To my ears, the difference is subtle. When I was able to directly compare them, the ribbon tweeter version was just a bit cleaner sounding. But I am still happy with what I have. Whether it is worth the extra cost is up to you.
The talk of limited vertical dispersion of the ribbon tweeters, at least for those ribbon tweets used by Salk, is exaggerated, in my opinion. I would not worry about that.
With any MTM speaker, when the listener stands so that his ears are above the upper midwoofer (and, of course, also above the tweeter), there is a noticeable drop in upper midrange frequencies. This is not caused by the tweeter's limited vertical dispersion. The crossover frequency in the ST is about 2600 Hz, which is higher than most people realize. What they are hearing is cancellation between the two midwoofers.
If you sit with your ears at tweeter level, both midwoofers are the same distance to your ears. There is no cancellation between them. If you stand up, the upper midwoof is closer and the lower midwoof is farther away from your ears. At some frequency, depending on the relative distances, the signals from the two midwoofs will cancel, resulting in altered sound balance. I think this is what people are hearing, but mistakenly attribute it to the tweeter.
Again, I think this effect, although real, is not a problem. Just to describe it in words, makes it seem worse than it really is. It makes the speakers sound a bit warmer, but not unpleasant. I often listen while walking around doing other things. It does not make Frank Sinatra sound like Barry Manilow
!
I've also seen Salk do front ports instead of standard rear ports in his STs to accommodate users (but that look was not for me, since the grill did not go low enough to cover the port), and for my placement I think a rear port will result in far less sound optimization (not so much crossed over at 80hZ perhaps, but in direct stereo mode with speakers going full range, I think it might).????
I have done direct comparisons of my STs placed over 1 foot away from the wall behind them and placed as close as possible to that wall. There was absolutely no problem with bass sound in any of those positions. The ST designer, and others, have confirmed this. I keep mine about 8-10" away from the wall.
I think this is a non-problem for speakers with a transmission line type bass alignment. They do not suffer from the same problems as most ported bass speakers. Again, words do not suffice - if you haven't heard a speaker with that design, you owe it to yourself to hear it. Once you hear them, you will understand better. Before owning STs, I had only known sealed or ported bass, and wouldn't have believed there was something else that (in my opinion) is better sounding.
Salk is a custom builder. If you want grills to cover front-mounted ports, he will do that - for a price
. But I think the standard rear ports are fine for nearly all situations.
You are welcome to come hear my STs. If you can bring your M22s, it would be a very interesting comparison. Dennis Murphy, about 15 miles away from me, can demo the ribbon ST for you, if you want to hear them.
