Dual/Triple tuning TL/Horn: bad idea?

[racingpht]

My own efforts analysing similar arrangements indicate that even when you balance the amount of energy into each duct, the output combines in a fairly chaotic way. The problem is that you have to take phase into consideration as well as amplitude. For example, if you have ducts resonant at 30 Hz and 50 Hz, you might expect to get a resultant response with peaks at 30 and 50 Hz. But the output of the "50 Hz" duct at 30 Hz might be out of phase with the "30 Hz" duct, resulting in partial cancellation of the 30 Hz.

That's why I said in the first thread, the lowest resonance frequency of each pipe should be reasonably close.

To be more specific, the reason I said the TLs should be turned within one octave is that, in (my) theory, the phase difference of the TLs will stay within 90 degrees, hence no cancellation will happen in the lowest tuning frequency.

 

[picowallspeaker]

GM mentioned it: it's not you that decides where the air flow goes, nor how it'll behave.
Trial & error with a solid scientific approach might reveal if the theory is wrong or valid.

 

[Scottmoose]

Either way, to my mind, it's to an extent making life somewhat harder than it needs to be. Double-tuning can work -hm who sometimes posts here has a number of plans for sale using double-tuned horns, either with one or two drivers, that seem to be well regarded. And it's been played with for simple Voigt pipes for a number of years.

Still interesting though.

 

[Soldermizer]

Re-reading this thread has been educational: I am considering something similar but it would be a case of two or more independent transmission lines, each with its own driver. Of course the sound will combine but only outside the boxes 🙂