Teton monitors from Wavetouch Audio - A Must Hear

Hi Randyhat,

"The thing is, if you depend upon word of mouth
internet reviews to get the word out about your product you
have to be prepared for negative comments".

Agreed. It's not hard for me to feel that, if I were Alex, I
would've at least tried to handle that differently...even if
I thought Ctsooner was lying (which I don't). In that
instance I think it just would've made good business sense
to me. I don't think Alex necessarily always gets an A+ for
his business skills or his current level of understanding
how the American way works...or even always his engineering
explanations, for that matter. But, as much as I can
sympathize with Ctsooner (and have with him on this point
before), I can also do so with Alex otherwise, at least up
to a point. English just isn't his first language, plain and
simple. But, being that the company is basically just him on
the payroll (I think he farms out the CNC cabinet cuts), I
don't imagine he can realistically hire anybody to help him
with the language barrier without ultimately running the
risk of losing control of his company. And in truth I can
sympathize that he may feel he simply has no other choice,
as a result, but to try to fly his company by the seat of
his pants, like he does. At least he seems to have the
courage to take that much on the chin, so far. And, like you
suggest above, it might be too early for him to be
advertising by means other than forums. But, in my view, I
just can't help but feel that this business with Ctsooner,
anyway, has damaged his reputation. That to me is
unfortunate. But, if nothing else, I'm sincerely hoping Alex
will come to understand and appreciate our heritage of the
American sense of fair play as the rest of us generally
enjoy.

BTW, I do have a pair of GT's. I find they really are
uniquely amazing. And I'm also fully convinced they are the
last speakers I will ever need to own, FWIW.

Regards. John

I bought a pair of Grand Tetons in June of 2015 and during break in I was liking what I was hearing. There was some lack of clarity in the upper mids/lower highs and, despite my having to break in new amps at the same time, was confident the mild harshness would settle out after break--in and that it was really just the amps that needed more break-in time.

But, as the weeks went by I realized that this problem was in fact here to stay - a flaw - and not in the amps as I’d hoped, but in the speaker’s design. After a while I tracked it down to the type of tweeter used.

These are the Dayton AMT2-4 https://www.parts-express.com/dayton-audio-amt2-4-air-motion-transformer-tweeter-4-ohm--275-092

After some time I decided, rather than returning the speakers to Alex (a nice guy btw), to try my hand at a little exploratory surgery since I could get another pair of these tweeters at PE and it might help me to understand what the true nature of the problem was and whether or not it might be something I could fix.

I dissected the tweeter and removed its diaphragm assembly from the magnet structure and housing. I don’t have any pics to show you at this point, but I eventually uncovered the flaw in the design. Turns out, however, that it’s a rather interesting flaw IMO and one I find to actually be very telling on what it is exactly that the GT’s were envisioned to do, which I will get to later on.

The Dayton diaphragm though, I learned, uses Kapton as the "former" (physical support) for the mylar pleats that produce the sound from the signal. Kapton has a few advantages, it’s lightweight yet rigid and not expensive. However, the problem I found here is that Kapton is not acoustically transparent. This needs to be the case for an AMT type tweeter since the diaphragm’s operation is always going to be dipolar regardless of whether the rear output is designed to be let out into the room or it is to be enclosed in an absorbent, rear chamber. What I found was that the Kapton former, despite any minor efforts Dayton had allowed for to prevent or reduce this, actually sings like a canary - it is actually quite resonant, and I was able to confirm in fact that it adds noise to the music that was not at all part of the original signal...a distortion by definition.

So, I looked for what might be better ways than what Dayton had done to see if the Kapton former could be damped. Since the Daytons here are used as monopoles and I didn’t have to worry here about allowing for a rear output. I tried some neutral-cure silicone applied to the back of the former and spread it down into the grooves of the pleats with a paper business card to see how much resonance control this offered. This would not take up any extra room inside the tweeter once it was reassembled.

This actually worked pretty well...although not perfectly. About 90-95% of the lack of clarity went away, but I could still tell that a trace of it remained. However, when I did this, much of the (artificial/exaggerated) sense of spaciousness went away.

The only other conceivable negative of the GT’s performance I ever encountered with them was in the stage presentation. It seemed to have a somewhat ’football’ shape to it - the area around the drivers seemed to have a slightly ’pinched’ perspective, with staging that tends to ’hunker down’ at the left and right edges and that grows taller and more fully developed as you moved toward center stage. No change in placement I found could ever completely get rid of it.

But, as you recall I said above that the choice of these particular tweeters were to me very telling of how these speakers came to be and what they were meant to do. First, I noticed that the distortion characteristic of the tweeters is rather unusual. Typical driver resonances tend to express themselves as ’zones’ or ’peakiness’ over the entire response of the driver. Very annoying to hear really. But, this was not the case here. Looking at the Dayton AMT’s from top down, I found that from 20k Hz down to around 10k Hz or so there is virtually zero resonance in the Kapton former in these tweeters. So micro-detail remains intact.

But, from around 10k Hz and below the resonance seems to begin to kick in, in a nice, gradual, forgiving slope that seems to plateau somewhere around 4-6k Hz or so and then continues very smoothly all the way down through the crossover zone...so, unlike most tweeter resonances that create false or exaggerated/muffled vowel or consonant sounds, the resonance here is so unusually extended, uniform and smooth that it does not offer us the usual cues that we’re used to hearing that would alert us to a potential problem. Btw, the crossover point for the GT’s is 3k Hz.

This unusually smooth resonance over such a broad portion of the driver’s range has a number of effects on the sound And on the this overall speaker design. First, it seems to exaggerate the sense of space of the venue of the recording. Suddenly, recordings of spacious venues are a renewed treat. This is perhaps instantly what most people hearing them for the first time are reacting to so positively.

The other main thing that people hearing these speakers are likely reacting to is the fact that these speakers image like crazy. Much of that is in Alex’s use of the horns, which I could confirm by simply removing them (easy to do in just 2 or 3 minutes) and listening again. The horn for the tweeter does amplify a bit the sheer incisiveness in 10k-20k Hz range and does it rather beautifully. But the horns also work synergistically with the spacious quality being injected below 10k Hz. So much so, that I now understand what Alex was doing when he settled on this particular tweeter to use in his horned designs. His chief critic whose ears he needed to please, according to Alex himself in his own literature?? His wife! A non-audiophile music lover. So Alex has, in my estimation, really designed a rather terrific speaker for music lovers everywhere, rather than for audiophiles per se. Nothing wrong with that certainly, it’s just that for my money I’m looking for something that offers the clarity that I know is possible and does not rely on, in the course of it’s design, adding something to the sound that was not part of the original signal.

I have not yet brought up this idea to Alex, but I would hope that he might consider making a design for audiophiles in the future that would use a different tweeter. The Aurum Cantus AST tweeters, like the 25120’s, have superb clarity and don’t use Kapton formers. It would mean having to design a new horn for them, but I’m finding it’s a snap when choosing appropriate sized quater-round wood trim...like the kind you use on your floors against the baseboard in your home, only the specialty kind found online that is a little larger. I think if Alex followed through along those lines he’d Really have something there!

I have moved on from the GT’s (while forgetting none of the lessons, good and bad, that I learned from them) and after discovering Danny Ritchie’s "Wedgie" design have decided to DIY my own version of them - but incorporating horns into my design. Not finished yet, but everything is very promising so far.

The stock GT’s are stunningly dynamic for their size and in my fairly large, open room were down about 3 or 4 dB at 40 Hz. I just needed to solve the clarity problem and straighten out the left-to-right stage a bit more.

Regards,
John

But in case I did not make the connection clear in the above, the Kapton former's resonance is what is responsible for both the sense of spaciousness And also the lack of clarity in the upper mids and most of the highs...(except for the top end). Unfortunately for Alex's current designs that use these Dayton tweeters, you can't have the increased spaciousness without necessarily also having the lack of clarity at the same time.