Mmm,knowing what I do I just might build my own someday,no great hurry though.
Kenny.
Kenny.
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."
"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."
362 responses Add your response
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Missioncoonery, if I may make a friendly suggestion: When you begin a post by quoting from a post someone else made earlier in the thread, please provide some indication that the quote is a quote. Either by simply using quotation marks, "like this," or better yet ... ... like this, which can be done by highlighting/dragging through the text you are quoting in the box in which you are composing your response, and then clicking the button just above the box which contains a " symbol.Thanks. Regards, -- Al P.S: Thanks to Soundscience for the informative post. Makes sense to me! |
Kdude66: Yes, you are right about the large room and classical feeds with dynamic changes that could generate very disruptive bursts. As a classical musician, I sit in front of a large piano every day and once took the time to measure its decibel level. Loud passages are around 95 db at the keyboard side. But they do not sound as loud as 95 db of recorded music because there is no distortion/noise. As I know most of you recognize, the less noise in your system, the more you can listen to louder and louder feeds. AND, Kdude, everyone should read your second post at the start of this thread. It is the clearest explanation I have seen yet explaining Eric's minimum mass theory. Congrats! |
craigl59, Very nice analogy of basic driver costs that effects the bottom line that all speaker designers and manufacturers must factor in. Just for clarification for the other readers,I believe you told me that your room is very large and you enjoy large scale highly dynamic classical music and you listen at loud levels hence the spare drivers already purchased as backups just in case. Kenny. |
Hi Guys, I would like to help clear the air on comb filter effects and line arrays. The math that describes comb filters really comes from antenna theory and while speakers are acoustic antennas they don't behave the same as an antenna for radio waves. In Leo Beranek's Text book for MIT on acoustics, he talks about how the air molecules between the drivers if they are close together vibrate in sympathy with the drivers. The consequence of this is that there really isn't any comb filtering at least on a vertical or horizontal line array if the drivers are close enough together. The first time I heard the Pipe Dreams at CES I knew something about the comb filter idea for line arrays was not right. I have built 2 different line array speakers and never got any comb filtering on either pair. I didn't discover Beranek's book until after I built them but Beranek's explanation matches |
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. |
Speaking of math and the oft-stated "cheap speakers" in the DIs... Have been using the DIs for three months and after two, decided to purchase some backup speakers for those unfortunate blowups that might occur. So, I checked carefully on the Internet and purchased the exact same speakers Eric uses at the best available price -- but just a few, of course. The SB Acoustics ring tweeters are the most expensive at $57 apiece, the midrange at about $50 and the woofer at about $40. So, you add them all up and the best price for the 22 drivers in two speakers is right at $1158 -- this is 39% of the speaker cost. Now those of you who keep touting the "cheap speakers" line, tell me another premium speaker that spends 39% of its retail cost on the speakers. Does Wilson's Sasha (say, $28k) contain speakers in it that cost $11,000? BTW, if you actually examine the DI speakers as I have, they are well made. But, then, so many of the posts deal with theory, speculation, manipulation, and dogma. When I purchased the DIs I made the decision on the basis of the large number of owners who uniformly expressed delight with the sound. Guess what? We're all still doing that. |
Charles, I actually deleted that post from embarrassment for not mentioning kdude66(Kenny C). Like you he’s a wealth of knowledge. I’ve had the pleasure of speaking with him several times and his knowledge base is mind blowing.Thanks to both of you and grannyring and mapman and most everyone else on the thread. There is a wealth of experience and knowledge on this thread. |
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missioncoonery, why the sour grapes man? The guy answered the question you asked. He bought something he liked but wanted to make it better. We all do that to everything we buy, to the extent our abilities allow. I bought a brand new Harley and the first thing I did was change the intake and the exhaust to make it "better". What am I missing here? |
So doing the math...$3000 for the DIs...$300 for ungraded version..$500 for paint..$260ish for new woofers,I undersrand you bought flawed finish but if one was to order them today ,basically 4 grand...Why did you stay with eminence,was it simple because of a direct size fit..have to say I consider them, well junk..Did you think about trying better drivers or did you want to stay in a price range.Its appearing to me these speakers are a project DYI,I've upgraded speakers before but normally vintage stuff like caps etc,never something new |
This DIY guy says your the Man! Love reading what you did and you have now worked me up into DIY frenzy. I must do something else to my current speakers😊 I have found the types of improvements you outlined above will improve the sound of any and all speakers. Builders must build to a certain price point and we all get that. Now i I must smell some solder..... |
They did sound great right out of the shipping boxes,but I haven't owned a speaker yet that I did'nt mod and get better sound. Even though I did buy a upgraded pair of Di's from Eric,I have upgraded farther with even better caps,inductors and resistors and some wiring. I started with the crossover on the woofers, The heavy duty Jantzen coil is fine I didn't change it but I did change the single cap and got rid off the sand cast resistor,I don't like that type,I think they can be noisy.From day one when I got the speakers I didn't like cosmetically the blue colored woofers with my black metallic paint so I changed to the Eminence beta which gave me black cones the stock ones are the alpha's with blue cones.The physical size including depth are the same but the specs are slightly different.The beta's are 2 to 3 db more efficient in their specs of the driver in free air and they give me better bass and dynamics at very low volume levels and they equal or are slightly better defined bass at higher volumes.I also biwire mine with a single run of western electric 10ga wire that solders directly in the crossover,and I use the same wire to the woofers.The beta woofers cost 60.00 a piece from us speaker.I hear just better defined bass maybe tighter and does measure 2 to 3 db down at 20hz in room. Now that's the easy stuff,I took a look at the crossover for the tweeters and mids and decided to change all caps,resistors,and coils to better parts IMO but I did'nt change any wiring,It's ok and would be a lot of work. Even though my speakers sounded very good once broken in I couldn't leave them alone because I knew I could make them sound better,I basically gained overall smoothness and a tiny bit of clarity without hurting the magical midrange that these speakers have by design. I wouldn't honestly recommend that everybody that owns a upgraded pair of Di's would want to incur the expense and time involved for the noticeable but modest gains in sound. Basically what I'm saying It's a lot of work and it took me 2 whole days to do mine. Take the time and remove a couple of tweeters and maybe the lwr mid and look at the crossover and you will have to decide if you want to tackle it. One option might be just to change the little bypass cap on the tweeters input to better quality. Any more questions, Kenny. |
I know the DI speaker quite well, Just curious, if the DI sound so great why all the changes..changing out all the woofers and upgrading completely the crossovers.What didn't you like,missing or want to hear ,and what drivers did you go with |
kalali, The efficiency comes from the combination of, Drivers used crossover design cabinet internal volume 4 ohm impedance And a touch of designer brilliance IMO. They do sound simply wonderful in my system,the best sound I've ever owned and rivals many super high end systems that I've heard. I guess that is why you can see I'm so passionate about them. I sent you a pm a few days ago,I don't know if you got it. Kenny. |
kalali, When I purchased my pair they had a set on their specials page that were ready to ship the same day.I got a upgraded black metallic paint finish,they were reduced slightly because of 2 super tiny flaws in the paint,you have to be within 6 inches to see them.I understand from others that the average wait is 3 to 4 weeks including shipping time,but that may vary depending on finish ordered. Onhwy61, The upgrades are explained in detail if you view the double impact speaker from the drop down that is located in the full tower section. Now I know Tekton doesn't have the best website and needs more info maybe that will get better in time. Kenny. |
@onhwy61 : The upgrades offered are listed at the tail end of the Specifications Section on the Double Impact page. There is a link at the end of the upgrade descriptor that will take you to this page: http://www.tektondesign.com/upgrades.html In short:
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Please, if you aren't serious about purchasing from him and are just looking for rocks to throw, don't call him. We, who await upgrades or shipments would rather have him working on our stuff. But if you're actually making a decision to buy, he will happily satisfy your need for information. Thank you! |
Probably not, When I first called Eric I had read a little about the DI's and I put together a list of questions for him and that included detailed exact crossover points,So I could get a better understanding of the unusual and different design of this speaker. He answered every one of my questions and after getting my DI's, I have confirmed that every detail that he told me is spot one. When I read his patent that he has several times I found that to be kinda Vague and generic,so I really won't comment on that,Honestly don't really care. Kenny. |
grannyring, +1 on everything you have said in your previous post. The current audio market is very slow and is generally a buyers market not a sellers. I watch certain categories of components on audiogon like a hawk and really good stuff at decent used prices aren't selling.I see this pattern on a daily basis and I'm sure you do as well. Kenny. |
Mission, we disagree. I am very happy you have had good fortune buying and selling. Be thankful. For the record, you don’t have near the experience as I and many others selling gear. Just look at our feedback. The current market is slow, very slow, and chances are very strong you will not make money on your buying and selling today. Perhaps you are an Audiogon sage of sorts with better selling skills then us common Aphiles. Perhaps a little luck on your few transactions also played a role. |
Taking a chance on my DI's worked out really good in my favor,I threw away boxes and packing at the end of the first week. I realize 3k is 3k but what about the other chance I took with 8k in buying the Linear tube audio gear that I pair with my DI's. What about the 9k I have invested in 3 Dac's that I own taking the chance again. I have no dealers in my state other than HT gear and I have no interest in most of those products. This is why I greatly appreciate these threads and other sites as a starting point to gain valuable info from actual users,It's priceless IMO. I greatly respect these threads and I always try my best to give solid advice which I can backup from actually listening and or owning a product and I can generally backup what I hear with actual in room measurements and experience.I always try to do best in real information and not speculation. I know the DI speaker quite well, I have upgraded every part in the crossovers except the coil on the woofers. I know every crossover point from testing and confirming the points with the crossover design. I have upgraded all 4 10 inch woofers to a better match for me. I will only publish on any thread,a certain amount of info related to any products specs or measurements and this is out of Respect for the designers and builders of the products. Kenny. |
Grannyring and schw06, I agree with your comments/ take on this as well. If I were really interested in a speaker I’d welcome the opportunity to hear it in my system. What better way to assess them could there possibly be? What is a superior scenario to a home audition? Yes you will incur some expense with shipping if you decide to return them, this is acceptable to me given other alternatives. Listening at a ďealer showroom is helpful but this isn’t "your" system. Is the expectation there should be zero out of pocket cost and the manufacturer just absorbs everything? That makes little sense to me. Many speaker manufacturers don’t publish crossover point figures. If it’s that important for you to know call or email the builder. Even if this information is readily available you would still not know what the speaker sounds like. Home audition when possible is the best method for judging an audio product. Tekton willingly offers this vital option. Charles |
I've never paid a 40% markup,if you do find another dealer.I've never met an online only dealer that will come to my home and help with setup.I've never met an online dealer that will allow me to bring my amp or what ever gear in and hook it up.I've never met an online only dealer help me with issues if something goes a miss...on and on.I like to support a local stereo shop if they have great customer service .True,every one is different.....Now, if I buy a pair of speakers for 7k on the used market most likely Im getting speakers that are over 20 grand new . I know what these speakers sound like as I've done my research and listening. When selling i'm recouping my money,that's why we buy used.Ive never lost money buying used as a matter of fact Ive always made money after listening to them for a couple years.I hate to say it but for me your arguments don't hold water.....but thats just me.Having said that if Tekton had dealer support ,I could actually listen to them and liked what I heard,sure id be a player. |
Interesting how we all view a situation differently. To me being able to audition a speaker in my home with my electronics without having to pay the dealer 40% markup and sales tax is a win. In my opinion the risk is less than guessing if I may like a speaker in my listening space after hearing it somewhere else with foreign electronics, source, and music. If you don't end up loving that choice you are quickly out 50% of your purchase price and then have to take the cost and effort to sell and ship them (and hope Fedex/UPS doesn't damage them). The Tekton/Spatial/Vinnie Rossie model makes the most sense to me...Everyone is different. |
