Voigt pipe as a TQWT

[Keriwena]

Forgive me for not finding this by searching as I'm sure it must have been considered at some time....

What's the advantage of the stuffed triangular peak of a Voigt pipe? What do you lose by cutting it off and just having a more typical TQWT?

[planet10]

I usually use Voigt & TQWT interchangably.

You question then becomes what is the difference between S0 = 0 vrs S0>0

Depends on the line, and the driver. When i was consulting with Scott on Demetri & Mileva, line length was extended (with the same taper) such taht S0 became 0 with no appreciable effect (except making the box easier to build)

dave

[Keriwena]

You're a mind-reader, Dave!

Yep, my next question is, what is the difference between S0 = 0 and S0>0 ?

[planet10]

Scott or Greg?

dave

[GM]

SO = 0 = infinite (Dc) band-width (BW) throat in theory, but it has a tiny incompressible air boundary area in reality, so the effective throat area frequency is way up above our hearing limit, ergo any larger area progressively lowers the pipe's throat frequency with increasing area, i.e. its high frequency limit.

Ideally then, a pipe horn such as a BIB or Voigt pipe would be designed using horn theory, but few, if any have been. As already noted though, increasing stuffing at the peak of a SO = 0 pipe acts as an acoustically larger throat plus typically yields superior damping to a damped larger throat area and easier to build if folded, so is what I prefer.

GM

[Keriwena]

Oh, duh! Never mind.....

I forgot they flared in different directions.