Patent link?
Right, should be so resonant that in theory sums as a center tapped single driver with the driver area relative to the pipe's net volume [Vb], basic harmonics setting its frequency response, so ideally would set the summed driver's acoustic center at a proper TL offset for best overall performance.
Based solely on the B0$3 WAC's 2:1 CR, guessing a good way to create a powerful, yet relatively tiny sub TL using powerful [low Qt] drivers.
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It's right.
And in the last millennium Leonardo Da Vinci had modeled his acoustic cabinet, to this day there is controversy if it was BR or sealed, since the original plans are not preserved.
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It seems that the Inquisition forced him to renounce them and destroy them ..... or was it Galileo Galilei? I can't remember everything that happened in the last millennium, excuse me !
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DTQWT-mkIII
It is identical to the TQWT of Troels .....
There seems to be a point at which a transmission line and a Quarter Wave Horn come together, so what is their true identity ?
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My mistake, I must have enlarged that sketch. There are several speakers in there, and they radiate to both sides of the internal baffle, I suppose the advantage is efficiency, but the disadvantage is construction. Rara avis.
Did the BOSE boys decide Tapped Horns are Transmission Lines, or did Tom Danley decide Transmission Lines are Tapped Horns?
"Acoustic Horn Assembly", or "Tuned Acoustical Device" patents 2,765,864 and 3,047,090 covered those 65 and 59 years ago, but only bothered with a single driver 😉
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They are all quarter-wave lines. Traditional TLs were but a small subset. Now the word can loosely be used for large swaths of quarter-wave space (MArtinNKing, and to a lessor extent George Augspurper). There is sort of a loosey goosey divide between “TLs” and “horns”. Most BLHs are actually acting as TLs down low, and the Voigt is both a horn and a TL, they can all be modeled with the same quarter-wave modeler.
dave
The VoiceCoil review of this one was great. I particularly liked the comment “quarter-wave air columns are *discovered* approximately every decade since the mid-1900s”.
I haven’t seen this one make it into a product yet, as far as I can tell. But there are a few other Bose-assigned patents from the past 5 years or so that come close to Synergy-like approximations too.
Imitation is the sincerest form of flattery and all that 🙂
What's up with the highs / mids on that Bose patent?
I can't imagine lying on the floor to be able to perceive them 😀 , since all the FR from those speakers radiates through the mouth towards the floor.
I guess the answer will be to add a tweeter, but where? And how would the integration between the highs and mid-highs be? There will be a hole there. I really don't see any advantage to that design, as it looks.
I can't imagine lying on the floor to be able to perceive them 😀 , since all the FR from those speakers radiates through the mouth towards the floor.
I guess the answer will be to add a tweeter, but where? And how would the integration between the highs and mid-highs be? There will be a hole there. I really don't see any advantage to that design, as it looks.
Dunno, though have noticed over time that B0$3 tends to lay claim to any expired speaker patents for [potential] profit's sake.
Me n' Freddi asked him about some old patents back at the beginning, showing him several long gone patents plus a design of which I built out of curiosity back when I was just starting to get serious about pipe/horn design theory beyond just stuffing to 'taste' whatever big enough pipe to fit the driver was available for the taking [Jensen Transflex: Home page2] and his response was he wasn't aware of any of them IIRC and that the Jensen was too different? didn't qualify? [can't remember his exact response].
Then there's the interesting '60s Paraline I'd of tried had I known about it: https://www.diyaudio.com/forums/full-range/221532-rex-baldocks-paraline-speakers.html#post3203014
What highs? I mean its published response [Fig. 6] is of a ~30-150 Hz 'sub' woofer.
Well, to answer my own question, I tried putting four 12" drivers like that in a tube that has an inside diameter of 23 inches / 58 cm, to accommodate the drivers in straight line it was 51 inches / 130 cm long and just like in my picture I left one end open.I also have a question. Let's say there is a one driver in a tube, that still works, but what happens if the whole tube length is full of drivers?
...aand it didn't really work, only in some narrow frequencies a bit. I realized if the drives are all along the tube length, it's not good. I think they would need to be located all in the closed end and rest of the tube should be just the tube. Also since I had such a big diameter tube, it would need to be at least over double the length compared to what I had now, so let's say 3 meters long would have worked fine.