The Gough Enclosure

[freddi]

an old friend brought this up (as he'd like to build one for either Stephens 80FR or University 6201) and someone might have fun looking and modeling what's happening - perhaps its good for B20? (--anyone here familiar with this cabinet?) To me it looks like a ~constant cross-section t-line - but the lid coming down might get it into some TH territory (?)

Popular Science - Google Books

[planet10]

Yes, looks like an upffiring straight TL with an adjustable reflector.

dave

[freddi]

hi planet10 - for modeling purposes, what's your estimate for its path length? - why might it have openings on the "top" and sides"? how does that affect the model? (I didn't read to see how far the lid goes)

a typical & perhaps timeless (so far) argument from that article - note it even gives a 1/2 octave more top :^)

[Keriwena]

Would that work like a 1/4 wavelength line loaded by a 1/2 wavelength line?

[Mosquito]

Funny and interesting
A completely no math, no T&S paramenter concern project.
Directly from the "witchcraft and sorceress" speaker baffles era
Some perplexity though about lid vibration issues, lack of data about the needed lid and baffle angles, and the triangular pieces both side of baffle, possibly causing reflection issues.

[Poindexter]

I hate to rain on the communal parade here, but the expectation of getting 15Hz bass from a 8" driver in that box is pure fantasy. Looks like the f/4 path length there is about 60-70Hz, best.

P

[Mosquito]

Yes, most probably, but, for many of us, 60/70 hz at reference level, plus a moderate gradual roll off, is enough to enjoy music program material in home environments.

[freddi]

using GM's estimate for path length, it looks like this half-space (with no damping materials) in Hornresp with a Stephens 80FR
(I think he used the given dims as internal)