Hi Duke, congrats on a great show (RMAF)! What are the specs on these bad boys? DB of Eff, 3db down points etc.
I don't have exact specs on the low end, and this isn't a technology that we can model with accuracy yet. Still too young. I think the bass response sort of approximates a low-Q sealed box, as far as having a gradual rolloff, but we're able to use higher efficiency woofers than would be suitable for a sealed box. I'd probably claim ballpark lower 40's/upper 30's, but we played a pipe organ recording that someone brought and, once we turned the volume up a bit, it made the room shudder. We played part of a kodo drum track and the exhibitor two doors down came into the room to track down the rumble that had permeated his room, at first he thought his subwoofer amp was dying a nasty death and trying to take its woofer with it. So there is more happening way down low than my claim implies, but the low end isn't apparent until something like that comes along.
The calculated efficiency, based on the woofers' Thiele/Small parameters, is in the 96 dB ballpark. But the characteristic of the vortex enclosure that causes its efficiency to increase a bit as more power is applied results in a somewhat higher "real world" efficiency. We probably get an extra 3 dB or so once the vortex generators get hit with some power.
Not one, but two new designs unveiled?
Youvguys are killing me.
'Bout killed me too! I hope to never do that again - two new designs at one show, that is.
I didn't give out much in advance on the MVW speaker because frankly I wasn't confident enough in my ability to get it up to audio show level performance. We had a few hurdles to overcome along the way - it has enormous potential, and in some ways corresponding challenges, given the attention to detail that is called for in the home audio market.
In my opinion, a good home audio speaker has to do two things: First, it has to do something so well that you can close your eyes and suspend disbelief and get lost in the music. That something can be timbre, imaging, impact, coherence, clarity, sense of immersion, whatever. Doesn't have to do them all, but has to nail at least one of them. And then (this is the hard part), the speaker has to NOT turn around and do something so wrong that it spoils that illusion. So my primary job is detecting, identifying, engaging, and functionally destroying audibly significant colorations and distortions.
I've done some work in the prosound world in bass guitar cabs, and in a live sound setting the bar is not nearly as high as far as minimizing coloration. A little coloration isn't going to spoil the illusion because there is no "illusion" - it's reality that you're experiencing, and a little coloration is just part of it. Not that this is anything new of course, but beating a prosound-type speaker into home audio smoothness can be a challenge. I believe that I have done so with waveguide-style horns, and now my job is to do so with this new type of enclosures. Fortunately I'm able to work closely with the inventors, who come up with amazing outside-the-box approaches to help me do my job. It's like I'm struggling to think in freshman algebra, and they're thinking in differential equations without even being aware of it.
Fascinating. A few questions. Is the mid-high cab separate from the bass cab? Do the mid drivers also benefit from the MVW technology? How do you address the cancellation caused by the cross-firing mids? Any plans for single bass, single mid, tweeter, cab?
Yes, the mid-high box is just sitting atop the woofer box, connected only by wires. The crossover is in the base, at the bottom of the wooferbox - the inside of the enclosure itself is too busy for me to shoehorn the crossover into it.
The mid drivers are indeed also loaded by manipulated vortex waveguide enclosures. They cover roughly 220 Hz to 8 kHz, so a lot is asked of them.
As to how the design addresses the cancellation caused by the horizontally-spaced cross-firing mids, I don't fully understand. I have worked with splayed arrays in the past (mostly with fullrange drivers), toed both inward and outward, and always felt they had poor clarity and only so-so radiation pattern.
That being said, the toe-in does prevent a strong on-axis hot-spot. Then we have the output of the mids encapsulated by the vortex, to the left and to the right. The vortex energy, particularly the lower-frequency vortex energy if I understand correctly, acts as a carrier wave
and so you have propagation of the shorter-wavelength mids and highs that is guided more by the vortex than by the physical dimensions of the drivers themselves.
I have experimented with several other, smaller configurations, and will continue to do so. Most have not had side-by-side drivers, but I find no degradation of the horizontal dispersion from using a side-by-side driver format with this technology. I know, this is all goes against everything you and I both know about loudspeaker design, so I don't expect you to take it at face value, but just be open to the possibility that there is something going on that is outside the norm.
This is all like weird science fiction, so let me offer an analogy: Suppose we lived in a world where Helmholtz resonance had not yet been discovered. We have two types of speaker enclosures: Sealed boxes, and open baffle dipoles. Along comes this idiot who cuts a small hole in his sealed box and claims that the result is more powerful bass, when we all know good and well that a hole in a sealed box turns in into a poorly designed dipole, so we know
the result is going to be less bass. And we would be wrong.
So I don't ask you to go so far as to believe
any of what I'm saying - just be open to the possibility
. I'm in a fortunate position at the moment - my and Jim Romeyn's "conventional" (relatively speaking) Dream Maker LCS system was deemed a success by many who heard it, so that gives me a little credibility. I'd like to cash in on some of that credibiliy by saying that I wouldn't be actively engaged with the Manipulated Vortex Waveguide if I didn't believe that it was doing something special.