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Tekton DI Monitors

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-measurements

This 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 
erik_squires
erik_squires OP
16,016 posts
 
@teajay - On the other hand the woofer to array crossover seems rather high, around 1-2 kHz, so we can’t call the outer ring mid-woofers either.

Point is, why bother with a W - (something) - W array if you are not going to get the benefits?

Yeah, this is one major reason I throw Stereophile reviews in the trash. Bad rooms they refuse to do anything about, or failure to listen to manufacturer's requirements before auditioning. Their measurements are credible though, so worth looking at, especially when they completely dispute their review. :) 
erik_squires OP
16,016 posts
 
Based on the impedance charts, I'm guessing the woofers cross over at around 1kHz when (based on spacing) they should have been crossed around 300 Hz.  Alternatively, the designer could have done an (array) - WW design, eliminating the comb filtering altogether and providing similar output. 

In case it's not clear, one reason I wanted to talk about this design and measurements is that it clearly illustrates comb filtering while at the same time proving the tweeter array doesn't have any. It's pretty ironic to me. :) 

Best,

Erik 
corelli
969 posts
 
roberjerman,
I'm sure you speakers are better than mine and I'm glad you are able to fully enjoy them while walking about the room.
Me, I'd never seriously listen to ANY speaker that way--yours included.


teajay
1,687 posts
 
To address seanhies1 "pet peeve",

Here's the speakers that have been in the same system for review that the the DI Monitors were compared to: Role Audio Enterprise Speaker 4K, Lawrence Audio Violin SE Speaker $8,500, Lawrence Audio Mandolin $5,500, NSMT Super PSM Monitor Speaker 5K.  These are all wonderful music makers that I gave high ratings to and enjoyed having them in my home.  However, the much less expensive DI Monitor was at least there equal and out preformed them on certain sonic parameters.

erik_squires,

Part of the magic of both the DI Monitor and the DI's is that the circle array with the tweeter in the middle functions as a single point co-axial driver that virtually weights nothing so it presents with horn like dynamics and yet has the speed/transparency of a planar design.  So, in my experience with this speaker you get all the benefits with out short-comings.  I hear no muddling of the mid-range band and the upper bass foundation, along with taut powerful lower bass extension, is excellent.


erik_squires OP
16,016 posts
 
@teajay - 

I understand the theory of the tweeter array and I think it's very interesting. 

What I meant was, the DI monitor's quasi-D'Appolito design leaves things to be desired. If those woofers were closer together you'd get even more of the array benefits. But to your own ears be true! 

Best,

Erik
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