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

Showing 25 responses by 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.
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.   
Sean,

So if you asked your friend about the DI's already knowing pertinent details as I've mentioned why are you wasting our time with this nonsense.

Have you actually listened to these speakers or are you just trying to convince yourself they are not for you.

Just wandering,I go where my ears lead me and really don't care about specs at the end of the day.But I still can't help not measure and test sometimes just to back up what I hear.

Kenny.
Hi Kenny, since you are being blunt, I will reciprocate. I didn't blindly trust the pertinent details that you've mentioned so I went to my expert to verify those details. He had a different explanation for the tweeter array and comb filtering, which I posted. If you feel like this thread is a waste of your time, then of course don't follow it.     
Can you help us better understand how your expert friend is testing and measuring the DI speaker? I am sure he must have a pair to take measurements of. Did he actually precisely measure all the details he is talking about? I assume he has the crossovers in hand and knows the precise workings and design of it.
Grannyring - I am not a speaker designer nor an engineer. My source knows the tweeter used as well as the spacing of the tweeters and box. It appears that he is using math to calculate the comb filtering. If someone can explain why there would be no comb filtering or how he solved that particular problem, I would love to hear.
Agreed , it’s great to ask questions about any product and that’s what these forums are for However the OP is really not asking a question but throwing the statement out here based on nothing really There is a difference.

It is a negative comment and not a question. So now the rest of us are asking him to back up his comment. It is his comment as he chose to use quotes from a friend of his.
Just to clarify, these are not the comments of a friend. I reached out to a well known speaker reviewer and this was his response. He is one of those reviewers who is into measurements. His response put me into a hold pattern on whether or not I should purchase these speakers and I felt like the information was worth sharing and discussing.
I see the DI's as just getting started. Already there are upgraded crossovers and caps. There also appears to be quite a bit of room to upgrade the woofers and tweeters to higher end, such as from Seas or Dynaudio. And to solve any phase or comb filtering issues, DSP can be offered. Lots of potential. I love the efficiency. 
You can get away with cheaper speakers in a design like this because they aren't being pushed like they would be in a 2 way design and individual drivers aren't being asked to produce a really wide frequency range. This is not to say that there aren't better sounding off the shelf drivers available. Eventually I expect a DI reference line with top shelf drivers and a DSP option. 
It will be interesting to see if he allows current DI owners to swap in the Scanspeak drivers or if he goes with a trade up program. If he does used prices should remain strong as folks won't have a need to sell to upgrade. 
The Tekton Brilliance was reviewed today. Same price as the DI. It's smaller and doesn't play as low, but the price is the same. Why have 2 floor standers at the same price? My guess is that the Brilliance is geared more towards 2 channel in a medium room and the DI is more geared towards larger rooms and home theater. 

http://www.enjoythemusic.com/magazine/equipment/0817/Tekton_Design_Brilliance_Loudspeaker_Review.htm
I think that this thread has been very helpful. Tekton is a lot like ZU Audio. Very unique designs that are well reviewed and award winning. Having said that, there are flaws and warts in every design. Not every speaker is right for every application so I think it's okay for folks to have concerns before they buy a product without hearing it first. Otherwise, this becomes the Church of Tekton. ;-)
I believe that if there is a return situation, Tekton eats the send shipping cost since it was "free." There is more risk buying internet direct but the reward is if you like the speaker, you can save quite a bit. The guy who started the DI monitor thread originally really liked them, but then returned them due to being too forward for his taste and there being a "hole" in the center image with his specific room setup. I think that the moral of the story is that no speaker can meet everyone's tastes. The DI might not be ideal for those midrange junkies that like a laid back sound (harbeth ls3/5a) but might be perfect for home theater and music that has slam. 
@seanheis1 you mention the DI’s might not be ideal for midrange junkies and that they are for movies and music with slam.
I suggest that you read again what I said. It was a Harbeth owner who found them too forward for his taste and had a challenge with the center image in his specific room. I hear the same thing a lot with the KEF LS50. Folks loving them at first and then eventually tiring over the forward image. We all have different tastes, rooms, and gear so I expect folks' mileage to vary and I like to hear folk's experiences, good or bad so thanks for sharing yours.    
I've explained the 7 tweeter array in many threads including the beginning posts in this thread
It is a fascinating read, but with all due respect, where did you get that information? 
This was a good response from another thread on the Tekton phenomena. 

shadorne5,843 posts08-23-2017 9:13am@stfoth

I suspect your reservations (BS meter) are worth following. Why not wait and see how Tekton fairs over time.

When Zu took guitar cabinet speakers from Eminence and then made a full range speaker by claiming small mods to these designs can work full range (instead of what they were designed for) there was a huge buzz. Zu was the darling of these forums. As a musician I know how little the drivers for guitar cabinets cost and how the designs have more in common with PA than high fidelity but for sure I can see how these high sensitivity drivers are ideal for tubes as most guitar amp heads are tube driven. So my background knowledge raised alarm bells but I recognized that Zu had some advantages with tubes.

I recommend to wait. There is always a buzz when there is something completely new especially an unconventional approach (7 tweeters!). I read somewhere that the DI sounds like a panel but with much higher sensitivity. This seems to be what they bring to the table and it makes sense that comb filtering from a large star pattern of tweeters is going to sound more like a panel than a conventional design with one tweeter.

So my guess, not having heard them, is that they will sound like a panel but with a high sensitivity that allows them to be driven by a modest tube amplifier. Like Zu I see this as fulfilling a niche for those who like modest tubes but are looking for something more dynamic than is typically available in audiophile soeaker designs which tend to subscribe to low distortion and full range flat frequency response and even dispersion (the kind of things Stereophile's Atkinson would focus on).


What I don't get is why Tekton is withholding the  frequency response graph of their speakers, so prospective customers can see how the speakers compare with their own, or with other brands.  
Zu Audio did the same thing as far as not releasing measurements. When reviewers started to release the measurements and they weren't favorable, folks who value objective measurements turned on Zu and began smearing their name.

If John Atkinson of Stereophile were to release poor measurements, then the Tekton's would be the high SPL equivalent of a Zu product. Some folks would feel duped while others would say that their ears are all that matters.    
So one thing can be certainly said, those speakers will color the sound, and change the music from what the artist intended.
This is not necessarily a bad thing as one can argue that hifi is getting things better than the original recording. Of course that's a preference. 

It's common for some hifi brands to voice a rising response from 2-7k to give the speaker it's over detailed sound. The "I'm hearing things in the recording that I've never heard before" is a clue that you are listening to boosted speakers. A dip in the presence zone from 7-8k helps the speakers "disappear."

IMO, this is part of the fun of hifi. If we wanted super accurate speakers, we would be talking about our Genelec Studio monitors, which were probably used in the studio by the recording engineers. But these speakers are no fun to listen to...no extra sparkles, dips, or sweetness.

At the end of the day, the recording engineers go home and listen to the sweet lies of their hifi systems.  

Well, well, well. It looks like comb filtering might not be a problem...it may just be the secret sauce!!!

If you are familiar with panels then you will know the sound of comb filtering. If you use a flanger or reverb on a guitar you will be familiar with the effect too.

It is hard to describe but comb filtering makes the sound seem to come from a wall of sound rather than a defined point and of course this would only happen in the upper treble with the Teckton DI design. It gives a bigger Soundstage. Large ribbons do this too.

Here is a demo - notice how the sound shrinks as comb filtering is removed (microphones close) and how it feels expansive (microphones apart). These effects are on recordings already but a speaker that naturally does this will add a bit of this characteristic to all music played through them.

https://m.youtube.com/watch?v=6JK721OpLko

It is hard to judge but the distance of about 9 inches separation on the video is the sort of enhancement you might expect with the DI. It is a very pleasant enhancement and no surprises it is used a lot in music production!

Here is another example of how comb filtering effects drum sounds (in this case the sound is bouncing off the ceiling and combining with the direct sound to produce a comb filter) In fact any two devices recording the same sound or producing the same sound will produce these effects if they are physically separated a greater distance than the audio wavelengths concerned)

https://m.youtube.com/watch?v=4qgmY8jIGi0


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shadorne5,855 posts08-27-2017 6:42pmMore examples of comb filtering - hopefully you now know what to listen for - it is certainly not always a bad sound - quite often it is desirable in pop/rock and electronic music. The faux stereo effect is perhaps the most impressive demo on the link below

https://m.youtube.com/watch?v=Zic2eNbxNmY


Mr. Eric, I have actually said very little. I have posted the opinions of others, who are much smarter than myself...they don't have the innate knowledge of your loudspeakers like you do...but they understand the math and physics stuff and don't appear to have any conflicts of interest. 

My definition of hifi is improving the original recording. If that means tubes, vinyl, multibit DAC, or a bit of comb filtering to get that feeling of being there in the presence of the music, then in my book that's a good thing. 

There are a lot more speakers that I want to listen to before making a decision, but yours are by far the most interesting and I like the custom colors. 
Me too, so I asked a smart person what they thought and this is what they said: 

"Yikes, patents can be dreamy but this one is pretty out there.
The invention is predicated on (a) the relationship of transducer moving mass versus whatever is resonating in the instrument and (b) harmonics not being accurately reproducible in a traditional dynamic loudspeaker.

re a: String instruments and loudspeakers are damped entirely differently, it's not just moving mass. What does this say about brass instruments that don't have a moving mass?

re b: a dedicated "low-mass" driver specifically for overtones sounds novel. It sounds like the inventor wants to solve IMD but creating an overtone crossover capable of separating the orders of harmonics is likely impossible. Instead, a 4-way (or greater) network can be employed to push the overtones up an octave to the next driver anyways.
btw, Eric Alexander, the author of this patent is the designer for Tekton."

1. Internet Direct

2. Basic Cabinets

3. Lower cost drivers

4. Word of mouth advertisement 

5. Profitable upgrade options 

6. Clever engineering 
So, in this environment, Eric must offer a "budget" equivalent to high-end products at a fraction of the cost -- to attract new buyers who want the best but cannot (or will not) pay $30k.

I agree and I think that Tekton should be considered along with Magnepan, Spatial Audio, Ohm, Zu? and Vandersteen because all of these companies do something DIFFERENT and compete with speakers that are much more expensive when it comes to sound reproduction.  
I'm thinking that this is coming from Mr. Eric. It's not mentioned in patent or website as far as I could see. This would be an impressive accomplishment for a passive speaker. 
It seems to be coming from kdude66. The first two posts in this thread give the crossover details and coaxial explanation.  
Speaking of speculation, the coaxial effect isn't even mentioned by the speaker designer.