Tekton Double Impact & Comb Filtering


Like many of you, I have been pondering purchasing these speakers but am very curious about the unusual tweeter array. I asked the smartest speaker person that I know (he is a student of Sean Olive) about the design and below is what he had to say.   

"In theory it could work, but the driver spacing means that the crossover point would need to be very low.
He is using the SB acoustics tweeter which is 72mm in diameter, center to center on the outside opposing drivers is around 5.7 inches, which is about 2400Hz. This means that combing would stop between 1/4 to 1/2 of the wavelength (between 1200-600Hz) is where the outside tweeters should start playing nice with each other.
Since he is not using low enough crossover points he has created a comb filtering monster. Now while it's not the great point source that was promised, it's no worse than most line arrays and the combing will average itself out given enough listening distance.

The MTM spacing on the other hand is ridiculous. Hopefully he is cutting the top end off on one of those midrange drivers to avoid combing."

seanheis1
Sean,

There is some confusion in how the DI's are configured related to crossover points and the "unusual" driver configuration maybe this will help give a better understanding.

Even though these are tweeter transducers the six of them that form the circle, based on what frequencies they handle, radiate acoustically as if they were one six inch mid-range driver.  The transducer in the middle is being used as a tweeter and handles the high end frequencies up to 30Khz.  So, acoustically you have a six inch mid-range driver with a coaxial mounted tweeter which means it functions as a single point source.  Now, by Eric figuring out how to make this work you get all the advantages of a coaxial driver, however the mid-range array weighs close to nothing leading to blazing speed/dynamics/micro-details compared to a regular six inch driver, regardless of what materials it is made out of it cannot be as light in weight.  Yet, you still get not only remarkable transit response, but great control because each driver is small and well behaved.  The closet you could come to this regarding weight/control would be a ribbon or AMT which cannot be used as a coaxial design as a single point source.  Brilliant on his part!

The more I listen to the DI's regarding mid-range and high frequencies they easily rival any panel design/ribbon/AMT I have had in my system and surpass them in low end extension/dynamics and overall macro-dynamics,micro-dynamics and brings out realistic nuances from the music.Truly a magical sounding speaker at any price.


You end up with a speaker that has very good pin point sound stage and vertical dispersion that equals or rivals many speakers that are in a much higher price range.

The only negative I can find overall is the lack of appearance but I did buy a black metallic painted finish and I can easily live with this minor shortcoming in appearance the sound I get more than makes up for this.

Kenny.
  If not mistaken Mcintosh uses a similar looking approach.The tweeters in the DI are very inexpensive,assuming to keep cost down but until I see a break down of what this speaker does,,,
Personally I would avoid any line array design unless listened to  from a relatively far listening distance in a fairly large room.  Even then I am a fan of fewer drivers not more.
Sean,

There is some confusion in how the DI's are configured related to crossover points and the "unusual" driver configuration maybe this will help give a better understanding.
Hi Kenny, thanks for that explanation. It was actually the same explanation that I used when I asked him the original question about the line array and comb filtering. He responded with his own numbers that are in the first post of this thread.   
According to the many posters on this site who’ve actually  listened to the Double Impacts they are unanimous in confirming their superb sound quality. It seems although this speaker has an uncommon driver array ( relatively speaking) the designer knew precisely what he wanted to achieve. Based on owner feedback he certainly has in resounding fashion .
Charles