Finally got to see the measurements for the Double Impact monitors. I’m a little disappointed.
https://www.stereophile.com/content/tekton-design-impact-monitor-loudspeaker-measurementsThis woofer - tweeter - woofer configuration is similar to the style named after the esteemed Joseph D’Appolito. Done well this configuration functions like a single large woofer in terms of dispersion. Less floor and ceiling bounce yield better detail at the listening position.
Interestingly, the Audiogon craze of criticizing the tweeter array for possible comb filtering is not what I’m sad about. In fact the array appears to be the least of the issues. Look at figure 4. The horizontal plots are superbly clean. Any comb filtering from the tweeter array would be displayed here, and it’s not. Those critics going nuts about the array’s poor performance can apologize for their uninformed criticism right now.
The problem is really the vertical response. It is terrible. Here we do have evidence of comb filtering! See the plot closest to the viewer in figure 5? See the regularly occurring hills and valleys completely absent from figure 4? That my friends is comb filtering. However it’s not coming from the tweeter array, but from the two widely placed woofers. There’s also a great deal of hash above 5kHz on this same plot. This makes me so very very sad.
Part of this is fixable. As Dr. D’Appolito discovered, the designer should have used a higher order crossover slope, which would have taken care of the hash above 5 kHz. However the comb filtering below this is not easily remedied. The issue has to do with how far away the two woofers are from each other. They are so far, and cut in so high that they can’t help but interfere with each other and this woofer to woofer distance is ultimately controlled by the size of the tweeter array.
Should you buy this speaker? I think you should listen to it. See how it sounds to you as you move around your listening space. If you find yourself enamored of the mid-treble resolution and detail, I would encourage you to listen to other Tekton designs that don’t attempt a D’Appolito design, because I'm afraid that the main benefit of this type of design, narrow mid-woofer dispersion, is lost. A simpler 2-way would avoid these issues and be as good at detail and resolution