Your picture of a generic driver looks like a stretched version of one i use all the time, i guess generic yields the same results from different drawers.
dave
dave
@planet10
That was one of the thing we noticed in our architectural-engineering practice as we moved from manual drafting to CAD. The tendency was for the work to take on a misleading lowest common denominator "sameness" -- from drafter to drafter and from office to office too. Everything became "AutoCAD" not "ours".
Well that's how it seemed to us old guys anyway.
That was one of the thing we noticed in our architectural-engineering practice as we moved from manual drafting to CAD. The tendency was for the work to take on a misleading lowest common denominator "sameness" -- from drafter to drafter and from office to office too. Everything became "AutoCAD" not "ours".
Well that's how it seemed to us old guys anyway.
Well, at least that's cleared up. They do look very similar; that said, generic drawings of the same basic type usually tend to.
@scott
... which is why the accusation of theft was fundamentally problematic. The justifications would have had to have been in the fine details.
Of course if a particular drawing of a driver didn't actually look like a driver then it mightn't look like any other drawing of a driver. But then at some point your illustrations might start to depend heavily on annotation. A thousand words might not need the picture at all. ;-)
... which is why the accusation of theft was fundamentally problematic. The justifications would have had to have been in the fine details.
Of course if a particular drawing of a driver didn't actually look like a driver then it mightn't look like any other drawing of a driver. But then at some point your illustrations might start to depend heavily on annotation. A thousand words might not need the picture at all. ;-)
I don't doubt it at all and I don't feel offended, I just wanted to clarify.
Where can I find your work?
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?
Well, you could check the recent patents assigned to Bose for that one. There’s a comment on it in last month’s VoiceCoil magazine too.
So in short, does it work or don't work if the drivers are all wired in parallel and are in same phase?
Interaction will be complex, i wouldnot venture a guess without modeling it, but first approximation is a line with a driver 5x as big in the middle position.
dave
dave
Depends what you mean by 'work'. At frequencies where the centre-to-centre distance between the outer two drivers is less than 1/3 (or more stringently 1/4) wavelength they should in essence act as a single source, both in terms of direct output and also what the line 'sees', the nominal centre of excitation being the centre-point of the driver array. In practice, you may have some disruption of the longitudinal eigenmode caused by the driver motor assemblies, baskets etc. -degree depending on circumstance. Above that, it's going to be more variable.
End (throat) loading a QW line provides maximum excitation of the fundamental and all relevant harmonics; as you shift the driver along the line the former is weakened to an extent, the latter more or less significantly depending on the tap location. Where the array length is significant relative to the physical pipe length, you may get some evening out of the excitation of the harmonic modes, but this is, as noted, circumstance dependent. For a mass-loaded / vented pipe where this applies, there is usually still some of the fundamental present (no surprise there) -usually insufficient to be of much value in alignment terms, though exceptions exist, with cavity resonance largely dominating. With a fully open pipe as drawn, I'd expect more of the fundamental eigenmode to remain present, though I haven't measured such a pipe & I'm going more from what you find in induction / exhaust design.
End (throat) loading a QW line provides maximum excitation of the fundamental and all relevant harmonics; as you shift the driver along the line the former is weakened to an extent, the latter more or less significantly depending on the tap location. Where the array length is significant relative to the physical pipe length, you may get some evening out of the excitation of the harmonic modes, but this is, as noted, circumstance dependent. For a mass-loaded / vented pipe where this applies, there is usually still some of the fundamental present (no surprise there) -usually insufficient to be of much value in alignment terms, though exceptions exist, with cavity resonance largely dominating. With a fully open pipe as drawn, I'd expect more of the fundamental eigenmode to remain present, though I haven't measured such a pipe & I'm going more from what you find in induction / exhaust design.
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Yes, it's a tragedy that when designing a quality vented box, a higher percentage of designers now take the trouble to analyse in advance what eigenmodes may be present, so they can be addressed, or even exploited, in the most efficient manner possible. What a terrible step backwards that has been.
As a note of purely historical fact, Harry Olson actually invented the MLTL / MLQW in the 1940s.
As a note of purely historical fact, Harry Olson actually invented the MLTL / MLQW in the 1940s.
What caught my attention is the word millennium, (period of time of a thousand years).
The dynamic loudspeaker was developed between 1920 and 1924 by Chester Rice and Edward Kellog, both General Electric engineers.
The dynamic loudspeaker was developed between 1920 and 1924 by Chester Rice and Edward Kellog, both General Electric engineers.