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New MMT from Dennis Murphy with SOTA drivers!

Beave

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... That’s my work ethic and I don’t believe it’s unreasonable so I cannot help but feel slightly unsettled to find out details about Dennis’ design from a public forum....

What details about Dennis' design have been posted? From my reading of the thread, he hasn't even started his design.
 

CDMC

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There are a lot more technical aspects that should be considered when working with this driver, therefore, I believe a discussion beforehand [in private] would have made a lot of sense so that when the project like this is done and ready to go, everyone involved walks away knowing that the final outcome couldn’t have been executed any better. I think that we can agree upon.

Hello, pot, this is kettle!!! Perhaps you should have reached out to Dennis before posting and making yourself look really bad. The impression you have left is one that if I were a speaker manufacture, I would question if I wanted to do business with you.
 

arya-audio

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Hello, pot, this is kettle!!! Perhaps you should have reached out to Dennis before posting and making yourself look really bad. The impression you have left is one that if I were a speaker manufacture, I would question if I wanted to do business with you.

It's interesting that a few days ago I didn’t even know that someone called Dennis Murphy is involved in this project. Now I am being told in a public forum that I should have reached to him. Very interesting turn of events. I’m sorry CDMC but before you start judging maybe you should get your facts straight.
 

SerpensCaput

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I had no part in the design of the cabinet or driver placement. Given the complexities of implementing this driver optimally, I'm surprised you didn't at least ask Jim a few questions or give him some pointers rather than simply shipping the drivers to him.

I think it's a fair point about the acoustic center, in part because I asked just that after I saw this wild tweeter demo'ed in Munich last year. I am no professional loudspeaker builder but seeing, for example, Wilson Audio going to all those lengths to time-align their drivers, it certainly seemed obvious that it should be considered unless you want it to bite you in the ass. (No) pun intended ;)
 

leeroy 85032

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It's interesting that a few days ago I didn’t even know that someone called Dennis Murphy is involved in this project. Now I am being told in a public forum that I should have reached to him. Very interesting turn of events. I’m sorry CDMC but before you start judging maybe you should get your facts straight.
be advised .. although Dennis Murphy isn't a household name .. in the world of passive crossover design in particular and speakers as a hobby in general,*and this is a speaker hobby forum*.. Dennis is the equivalent of Lou Gehrig in baseball ..
 

KaiserSoze

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It's interesting that a few days ago I didn’t even know that someone called Dennis Murphy is involved in this project. Now I am being told in a public forum that I should have reached to him. Very interesting turn of events. I’m sorry CDMC but before you start judging maybe you should get your facts straight.

I think this would be a good point to allow the posts of the past couple of days to fade into oblivion and hope for something more productive going forward. There's nothing you can do to stop people from making fun of how the driver looks. It is unfortunate that the looks are off-putting, because even at a glance it is apparent that a great deal of engineering has gone into it. This is quite apparent, and I wish there were some way to show that off without getting the reaction that we saw. It is what it is, as the saying goes. What I find lamentable, though, is that I think that you and Dennis working together cooperatively would likely produce something better than either of you would produce alone. You obviously understand the special needs of the driver. Dennis is obviously very skilled at passive crossover design. He will most likely prove that it is possible to do something with this driver that hasn't previously been done, revealing its unique advantages in a way that hasn't previously been done. This forum provides a way for two people to have private conversations. Perhaps you should use it to initiate a private conversation with Dennis.
 

MZKM

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I think it's a fair point about the acoustic center, in part because I asked just that after I saw this wild tweeter demo'ed in Munich last year. I am no professional loudspeaker builder but seeing, for example, Wilson Audio going to all those lengths to time-align their drivers, it certainly seemed obvious that it should be considered unless you want it to bite you in the ass. (No) pun intended ;)
Unless severe, isn’t phase alignment much more important than time alignment?
If it’s was such a huge deal, most tweeters would be placed behind the woofers in an offset cabinet, and one of my speakers do just that:
iTATS9gzS6Hb9rvdi6CuzDrPQZXMbhDLZA-00VDoa3Br1gqqYYI7DNPV5IfbLvccNH8NuUxg_UEXSGXZV7qisOM


And I wouldn’t bring up Wilson to illustrate the importance of time alignment.


Back to this tweeter, I did find it odd that this expensive, supposedly amazing driver doesn't have full measurements, Christensen's webste has this though:
1624b465a938990fbc76af1b543c9f9c


but then I saw that email saying they are taking it slow, so I guess they don't want to be inundated with emails. But, while I hope it is amazing, when the only other products the company has are RCA interconnects at ~$650 for a 2m pair, and ~$900 for a quad set of damping feet, I would not expected it (though if I understand, this was designed by someone else, and Arya Labs picked up the design and developed it).
 
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andreasmaaan

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Unless severe, isn’t phase alignment much more important than time alignment?

The two are not really separable. If the drivers aren't time-aligned, they will never be completely (acoustically) phase-aligned either, although asymmetrical crossover slopes can compensate for misalignment to some extent. Ironically, time alignment is less important in the only speaker you have which is time-aligned (since the MTM layout greatly reduces the effects of time-misalignment in the summed amplitude response).
 

MZKM

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The two are not really separable. If the drivers aren't time-aligned, they will never be completely (acoustically) phase-aligned either, although asymmetrical crossover slopes can compensate for misalignment to some extent. Ironically, time alignment is less important in the only speaker you have which is time-aligned (since the MTM layout greatly reduces the effects of time-misalignment in the summed amplitude response).
Out of all the measurements on Stereophile of speakers with a great step response (looks like a right triangle), I don't recall a single one actually have a good FR. Whereas of course one can find measurements of speakers with great FR but can see the tweeter leading the woofer in the step response.

And, I'll join you half way saying I certainly think the tweeter looks cool. Not so such I would want one personally though.
 

andreasmaaan

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Whereas of course one can find measurements of speakers with great FR but can see the tweeter leading the woofer in the step response.

It depends what you mean by "leading". If the speaker is time-aligned, the step of the woofer and tweeter will begin at the same time, i.e. neither will lead the other, strictly speaking. However (and this is oversimplifying it a bit by assuming it's a conventional LR or Butterworth XO) if the order of the crossover is greater than 6dB/octave, at a casual glance the step of the tweeter may nevertheless appear to "lead" the woofer because it has a shorter duration. Such speakers are still "phase coherent" in my book, although others may quibble with this definition.

In other cases, the drivers may not be time-aligned in the first place. A reasonably flat summed response on the design axis may nevertheless be achieved by introducing some asymmetry into the crossover slopes. Or in other cases, the drivers may be made to sum to flat(ish) on axis but exhibit an asymmetrical lobing pattern (or a combination of the above). So it is certainly possible for non-time aligned drivers to produce a flat(ish) summed amplitude response on a chosen design axis. Alternatively, MTM configurations allow for significantly more tolerance to time misalignment due to the complex summing of the vertically arrayed mid/woofer pair with the tweeter. So in such speakers it will be easier to achieve a flat(ish) on-axis response even if there is significant time misalignment between the mid/woofer pair and the tweeter in the middle of it.
 

MZKM

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To implement the AirBlade driver correctly you need to take its acoustic center into consideration. In an active design, this can be done through adjusting the time delay of the crossover. In a passive design however, that you probably will be using, it has to be done by (physical) lateral alignment. If the driver is sticking out of the baffle, as you mentioned it, what I read from that is that the cabinet you are working on has all the drivers mounted to the same flat baffle, which, despite your unquestionable talent in crossover design, will result in time misalignment that cannot be addressed with a passive crossover.

From your Instagram, and it looks passive:
http://instagr.am/p/B7RF42yprp8/ Cool to see it using Purifi woofers too, so at least @Dennis Murphy is not alone in trying to see what’s the best combo out there.
I still wouldn’t own a pair of speakers using Purifi woofers without a grille, as they look like they melted in a fire, yet I doubt a non acoustically disruptive grille is possible with the tweeter sticking out (unless individual woofer grilles like on my Wharfedale Jade towers).
 
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ace_xp2

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At this point given the businesses responses as provided here, if this thing shows at all comparable measurements to alternatives, I'll happily buy the alternatives. And if it is truly incredible, I'll buy the inevitable knock offs.
 
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D

Dennis Murphy

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I think it's a fair point about the acoustic center, in part because I asked just that after I saw this wild tweeter demo'ed in Munich last year. I am no professional loudspeaker builder but seeing, for example, Wilson Audio going to all those lengths to time-align their drivers, it certainly seemed obvious that it should be considered unless you want it to bite you in the ass. (No) pun intended ;)
Well, you had the advantage of actually seeing the Airblade. I really didn't know what the cabinet and driver positions were going to look like until I got the cabinet. It's pretty obvious that there should have been better communications between the folks at Airblade and Jim before the cabinet was built, but that can all be remedied with some new mdf sawdust. Onward.
 

phoenixdogfan

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How about a cardioid design using these tweeters and the purifi woofers with the Purifi amp modules. See if it can be priced under $10k.
 
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Dennis Murphy

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From your Instagram, and it looks passive:
http://instagr.am/p/B7RF42yprp8/ Cool to see it using Purifi woofers too, so at least @Dennis Murphy is not alone in trying to see what’s the best combo out there.
I still wouldn’t own a pair of speakers using Purifi woofers without a grille, as they look like they melted in a fire, yet I doubt a non acoustically disruptive grille is possible with the tweeter sticking out (unless individual woofer grilles like on my Wharfedale Jade towers).
From your Instagram, and it looks passive:
http://instagr.am/p/B7RF42yprp8/ Cool to see it using Purifi woofers too, so at least @Dennis Murphy is not alone in trying to see what’s the best combo out there.
I still wouldn’t own a pair of speakers using Purifi woofers without a grille, as they look like they melted in a fire, yet I doubt a non acoustically disruptive grille is possible with the tweeter sticking out (unless individual woofer grilles like on my Wharfedale Jade towers).

Hmmm Looks familiar. But it may be powered. Just to set the record straight, could @arya-audio please tell us whether there has been a passive implementation of this tweeter?
 

CDMC

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It's interesting that a few days ago I didn’t even know that someone called Dennis Murphy is involved in this project. Now I am being told in a public forum that I should have reached to him. Very interesting turn of events. I’m sorry CDMC but before you start judging maybe you should get your facts straight.

I have the facts straight. You came, saw and posted very publicly without bothering to reach out to the person whose post you claim offended you. The record is clear. Perhaps you should go back and look at it. Perhaps you might consider the optics of your approach.
 

KaiserSoze

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...But, while I hope it is amazing, when the only other products the company has are RCA interconnects at ~$650 for a 2m pair, and ~$900 for a quad set of damping feet ...

Much as I am bothered by overpriced interconnects and damping feet, I do not think that any of that ought to be brought up in this thread. The reason I feel this way is that this driver is something new and special. We want to know what its merits are, and what potential drawbacks it might have. Some admin created this thread expressly for discussion of this speaker under development, using this novel tweeter. The thread was created for this express purpose. Let us avoid giving Arya-audio any further justification for the indignation he has already expressed.
 

MZKM

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Much as I am bothered by overpriced interconnects and damping feet, I do not think that any of that ought to be brought up in this thread. The reason I feel this way is that this driver is something new and special. We want to know what its merits are, and what potential drawbacks it might have. Some admin created this thread expressly for discussion of this speaker under development, using this novel tweeter. The thread was created for this express purpose. Let us avoid giving Arya-audio any further justification for the indignation he has already expressed.
I was just pointing out that it was odd for a company who was only selling those to now also selling a unique, maybe SOTA tweeter; but then I saw that the initial design came from elsewhere.

Would love to see how it actually performs, but looking at those measurements I linked to, if they are close to the final product, does not inspire confidence, as it’s using 20dB intervals on a 100dB axis with 1/6th smoothing and it still isn‘t that smooth.

For reference, here is the semi-recently measured Dynaudio LYD 5 using the same chart scale as the measurements for the AirBlade, and this is with the native 1/20 smoothing:
chart.png
 
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