This, I don't understand - and I find it more than a little concerning.
The crossover is necessary because the panel can't go down deep into the bass. That is, the crossover frequency (SHOULD?) be defined by the capabilities of the panel - nothing else.
So if the Spire uses the same panel as the Summit, then the crossover frequency should technically be the same. Right, or am I missing something?
What concerns me: Is ML intentionally limiting the potential performance by making the crossover higher than it needs to be?
Very worrying!
Amey, take a chill-pill my friend :meditate:
There are actually very good reasons why they are different. Remember, a crossover is a component of an overall system, and is part of the tuning process to ensure the most balanced presentation is delivered.
The crossover is not only limiting the frequencies to the panel, it's also managing the woofer. If the Spire woofer can play cleaner up higher than the Summit drivers, then going a bit higher on the crossover is a good thing.
Note than even with my very large Monolith panels, I still crossover at 315Hz to the woofer, as that delivers the best balance of mid-bass to panel transition while meeting my SPL goals.
The Spire’s single woofer is probably more adept at covering the mid-bass than the more massive units in the Summit, which seem more designed to go low.
A Spire should really be matched with a good sub and spared having to handle anything under 60hz. Then the higher crossover to the panel will allow the woofer to handle mid-bass much more cleanly.
My bet is a pair of spires + Depth is better than a pair of Summits alone. Partly because they will have better mid-bass performance.
Bottom line, the crossover point is as much a function of the woofers abilities as it is the panels. And it is part of the speaker voicing and balance tuning.
PS- note, none of the panels do well below 400hz. They all suffer from roll-off and from significant power compression. I.e. even if they hit 300Hz cleanly at 90dB, they will be 3 to 6dB down at 300 when doing 102dB. Never mind that any and all dipoles have rear-wave cancellation to deal with at around that frequency, so another reason not to get to wrapped up over them moving the x-over point a bit higher.
