Hello,
Sorry to ask due to the high levels of inputs.
What mouth width and deepness and shape would have your preference for a 7.5 cm throat to load a 3" cone driver from a 800 hz electrical XO, so not a muscled compression driver, please.
I hesitate on the mouth and OS shape to marry to a 15" driver at 800 hz...
Many thanks for your thoughts here... the 3" needs spl load as it is a 87 db...
Sorry to ask due to the high levels of inputs.
What mouth width and deepness and shape would have your preference for a 7.5 cm throat to load a 3" cone driver from a 800 hz electrical XO, so not a muscled compression driver, please.
I hesitate on the mouth and OS shape to marry to a 15" driver at 800 hz...
Many thanks for your thoughts here... the 3" needs spl load as it is a 87 db...
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"loading" aside, I would expect a directly radiating 3" driver to work well on a waveguide up until about 2-3 kHz, at which time things will get messy. That's because the much lower cut-in of the HOMs will become excited by the decidedly non-flat wavefront of the driver causing a serious disruption of the response. A phase plug could extend this several more kHz, but getting to 10-20 kHz is never going to happen with a diver with such a weak force factor (86 dB.)
Thanks gentlemen for the inputs.
Loading in my simple understanding is about spl increase as directivity is the cunterpart. I understand almost nothing (or at least I think it's the opositt if I understand some few inputs : loading i a consequence of the main physical factor which is directivity given by the WG shape... two sides of same coins for my basic understanding).
The driver is the Scan Speak 10F/8424G00, sort of full range from 500/700 hz (H3 is low above 750 Hz). Btw I had also helps of another gentleman who is Joseph Crowe, but the task is harder I was thinking for my understanding... Fascinating are the horn/WG I would say 'and the bells since antic times as well which are sort of horns but that is another story). No idea of the angle degree of this cone... and cone beinga mini horn, i"m lost.
The unknown factor is if a cone that is less stif than a CD diaghpragm is keeping its linearity with a horn 'CD are less flat idea, just don't know how much important it is with the trade off... I see all of you are always talking about copression drivers from 1" to 2"... but in the case one don"t need PA spl or low wattage amp, cone or hifi dome could be an alternative - well highly imputed with tweeter domes as you know-
Thanks for this thread, really fascinating.
Loading in my simple understanding is about spl increase as directivity is the cunterpart. I understand almost nothing (or at least I think it's the opositt if I understand some few inputs : loading i a consequence of the main physical factor which is directivity given by the WG shape... two sides of same coins for my basic understanding).
The driver is the Scan Speak 10F/8424G00, sort of full range from 500/700 hz (H3 is low above 750 Hz). Btw I had also helps of another gentleman who is Joseph Crowe, but the task is harder I was thinking for my understanding... Fascinating are the horn/WG I would say 'and the bells since antic times as well which are sort of horns but that is another story). No idea of the angle degree of this cone... and cone beinga mini horn, i"m lost.
The unknown factor is if a cone that is less stif than a CD diaghpragm is keeping its linearity with a horn 'CD are less flat idea, just don't know how much important it is with the trade off... I see all of you are always talking about copression drivers from 1" to 2"... but in the case one don"t need PA spl or low wattage amp, cone or hifi dome could be an alternative - well highly imputed with tweeter domes as you know-
Thanks for this thread, really fascinating.
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Well, I once put this Peerless 2" driver into a 10" Dayton waveguide (cut-off). It was not quite what I hoped for but this was just a single random experiment, based on which I can't make any conclusions. A waveguide in general would help to unify the directivity pattern, i.e. to increase the DI at lower frequencies. That alone would be beneficial. I suppose you could use Ath calculator for this, just use 3" throat and a piston source, I'd opt for a shallow smooth waveguide and probably not OS - more like conical with a larger initial angle (just guessing). For lower frequecies this should be pretty close. The rest will be given by the details of the particular real-world diaphragm which are completely different animal to simulate and Ath can't do this. You would have to wait and measure what you get...
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.
Example of waveguide-loaded midwoofers; Genelec 1236A
Brief technical specifiations:
Sound pressure level: 130 dB
Free field system frequency response: 17 Hz – 26 kHz (-6 dB)
Accuracy of frequency response: +/- 2 dB (21 Hz – 20 kHz)
Crossovers: 400 Hz and 3.2 kHz
Drivers: 2x woofers 18 in (458 mm), 2x midrange 5 in (125 mm), tweeter 2 in (50 mm) compression driver + DCW.
Brief technical specifiations:
Sound pressure level: 130 dB
Free field system frequency response: 17 Hz – 26 kHz (-6 dB)
Accuracy of frequency response: +/- 2 dB (21 Hz – 20 kHz)
Crossovers: 400 Hz and 3.2 kHz
Drivers: 2x woofers 18 in (458 mm), 2x midrange 5 in (125 mm), tweeter 2 in (50 mm) compression driver + DCW.
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DCW™ stands for Directivity Control Waveguide Technology.
Obviously, a single large ATH4 would easily beat the polars of the 1236A, especially in the vertical plane.
Moral of the story: it's not easy to hornload vertically stacked woofers and get decent results, even more so if these are bigger than about 2".
Obviously, a single large ATH4 would easily beat the polars of the 1236A, especially in the vertical plane.
Moral of the story: it's not easy to hornload vertically stacked woofers and get decent results, even more so if these are bigger than about 2".
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The S360's polars are better, true.
Price/performance ratio, while not necessarily bad, could easily be bettered by DIY.
The woofer in the S360 is an OEM version of the PHL Audio 3002.
Here's a German review of the S360, including measurement data.
Price/performance ratio, while not necessarily bad, could easily be bettered by DIY.
The woofer in the S360 is an OEM version of the PHL Audio 3002.
Here's a German review of the S360, including measurement data.
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It's quite remarkable to observe that bmc0's big axisymmetrical waveguide + 12" woofer, don't yield (much) worse nulls around the crossover point, compared to the tiny elliptical wg + 10" woofer of the S360.
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I have been experimenting with rectangular shapes for the last few weeks, incorporating some new features, and this is the result -
Horizontal, vertical and diagonal simulations (infinite baffle) attached, 0 - 90° per 5°. I'd say this is about as good as it gets. This particular one is 422 x 364 x 135 mm, intended to be used with 18sound ND3T from about 700 Hz.
Horizontal, vertical and diagonal simulations (infinite baffle) attached, 0 - 90° per 5°. I'd say this is about as good as it gets. This particular one is 422 x 364 x 135 mm, intended to be used with 18sound ND3T from about 700 Hz.
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