I can only imagine the three tweeters in the Aurelia Cerica above do act as one larger diaphragm driving their waveguide. That probably allows a considerably lower crossover at high SPLs.
Sounds reasonable. Reminded me of JBL VT4886 which uses four midranges and two tweeters in a waveguide.
http://www.jblpro.com/BackOffice/ProductAttachments/JBL_VT4886_v3.pdf
I still don't understand why one might use more than one tweeter.
We have the technology to use a single compression driver to hit well over 120dB from a few kHz and up.
They're not small, granted, but I'd still expect them to integrate much better than a few domes all interfering with each other.
Chris
We have the technology to use a single compression driver to hit well over 120dB from a few kHz and up.
They're not small, granted, but I'd still expect them to integrate much better than a few domes all interfering with each other.
Chris
Well, I certainly agree. My latest project uses a radial horn in an MTM arrangement. The speaker above does use a waveguide, which may help integrate the three dome tweeters, but some lobing at very high frequencies is almost inevitable.
Flagship model has to stand out visually. Customers can see that they are paying for something more than hypothetically better sound.
Using 2 neodymium tweeters of same type, which can be
mounted closely together, you have double displacement
volume:
That could make you go lower about 1/2 octave,
using 4 tweeters you can go lower 1 Octave,
as you need 4 times the displacement volume
per octave.
(given the tweeter's spec's allow it ...)
No one forces you to use all the tweeters to
the upper end, you can lowpass a subset of them.
The point is, that the drivers are mounted closely,
and there is a valid concept applied how the drivers
are used at higher freqencies.
Using a pair of conventional dome tweeters with
a large faceplate each and a distance far more
than one membrane diameter inbetween, does not seem
very elegant acoustically, i have to agree.
But using arrays of smaller drivers is a valid way to go ...
This model also makes use from arrays of smaller
drivers:
http://www.mcintoshlabs.com/Assets/Images/Products/XR100/XL_XR100_1.jpg
mounted closely together, you have double displacement
volume:
That could make you go lower about 1/2 octave,
using 4 tweeters you can go lower 1 Octave,
as you need 4 times the displacement volume
per octave.
(given the tweeter's spec's allow it ...)
No one forces you to use all the tweeters to
the upper end, you can lowpass a subset of them.
The point is, that the drivers are mounted closely,
and there is a valid concept applied how the drivers
are used at higher freqencies.
Using a pair of conventional dome tweeters with
a large faceplate each and a distance far more
than one membrane diameter inbetween, does not seem
very elegant acoustically, i have to agree.
But using arrays of smaller drivers is a valid way to go ...
This model also makes use from arrays of smaller
drivers:
http://www.mcintoshlabs.com/Assets/Images/Products/XR100/XL_XR100_1.jpg
Last edited:
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Joined 2009
I have considered using a 'helper' tweeter with a 1st order low pass to extend the crossover point lower. Didn't get to do it yet so I don't know how well it will work.
I would not run 2 tweeters full range. Even if it sounds great I will be seeing lobes in my head. The Keele array does something very unique where the wavefront is unified through clever design.
but consider almost everything that are not by the book to cause problems
and especially when it comes to the crossover, like 'adding a bit here and there'
its really a no go, mostly
and especially when it comes to the crossover, like 'adding a bit here and there'
its really a no go, mostly
This is one of the most interesting discussions I have read. 🙂
I have LIKED D'Appolito type arrays ever since I heard the excellent Wharfedale E70:
This 1979 speaker had tremendous midrange presence, even if it's not strictly D'Appolito.
Here's the answers to some of our questions from 6moons audio reviews: Aurelia Cerica
The Aurelia Cerica, BTW, is my favoured series wired solution that has good impedance at the expense of high SPL or loudness per volt. I hadn't thought about the way a single tweeter falls off at 6dB, whereas the twin woofers fall off at 3dB. 😎
I have LIKED D'Appolito type arrays ever since I heard the excellent Wharfedale E70:
An externally hosted image should be here but it was not working when we last tested it.
This 1979 speaker had tremendous midrange presence, even if it's not strictly D'Appolito.
Here's the answers to some of our questions from 6moons audio reviews: Aurelia Cerica
The Aurelia Cerica, BTW, is my favoured series wired solution that has good impedance at the expense of high SPL or loudness per volt. I hadn't thought about the way a single tweeter falls off at 6dB, whereas the twin woofers fall off at 3dB. 😎
Tweeters mostly come in low power versions especially in regards to disco/band applications. To get around this they are used in multiples.
My disco speakers have 4 per speaker cabinet.
My disco speakers have 4 per speaker cabinet.
Ah well, this IS interesting. We now know why the Gryphon Mojo, which is a Steen Duelund inspired design might be rather good:
Cylindrical tweeter...😎
An externally hosted image should be here but it was not working when we last tested it.
Cylindrical tweeter...😎
I have also been puzzled by this. I noticed that those speakers that have two tweeters (and/or two midranges) sound very incohesive. Probably due to an increase of lobing.
Those Adams sound anything but incohesive. It should be noted though that they use a single tweeter and the two flanking AMT's are used for upper midrange so really it's an MTM.
A 3 tweeter arrangement was used by some to meet THX vertical dispersion restrictions at the time. Fleetwood Mac's Rumours 5.1 mix was done with a setup like that…the name of the speaker company is on the tip of my tongue, argh! Up in the San Fernando Valley of L.A., my brain keeps saying "Morel" but of course not, maybe sounds like it. M&K I think! 3 tweeters vertically stacked NEXT to a woofer. Acoustically, UGH, you think-but at the mixing console sweet spot, in that sound-treated studio, it sounded fabulous. Any lobing etc would not affect the mix location.
"Cylindrical tweeter...
"
Gryphon Mojo has a single conventional AMT pleated diaphragm planar rectangular tweeter.
Duelund Company resistors are used.
Crossover is regular LR4 acoustic at 2000Hz
Don't be fooled by some marketing phrases 😉
Gryphon Mojo has a single conventional AMT pleated diaphragm planar rectangular tweeter.
Duelund Company resistors are used.
Crossover is regular LR4 acoustic at 2000Hz
Don't be fooled by some marketing phrases 😉
Attachments
I wonder why we never see any published measurements from such "no compromise" speakers. 🙄"Cylindrical tweeter..."
Gryphon Mojo has a single conventional AMT pleated diaphragm planar rectangular tweeter.
Duelund Company resistors are used.
Crossover is regular LR4 acoustic at 2000Hz
Don't be fooled by some marketing phrases 😉
A lot of talk with great words, but nothing serious to support it. Thank you God for someone like Don Keele.
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