Folded horn cabs?

[greenboy]

Alex, would you please format that for easier browser reading and post it in the Waterfalls thread? Definitely pertinent to what I've been wanting to impart.

 

[Crockettnj]

The backs of the speakers have output too. And they are firing into the horn.

Right, but I thought (erroneously I guess) that when the back of the speaker fires into a horn its a transmission line, and if the front fires into it it is a standard horn.

Come to think of it, I am remembering that the Tline depends upon how the backwave is tuned. I need to go read more.

 

[alexclaber]

A true transmission line is a quarter-wave resonator, so it's tuned to one particular frequency and then overtones are dampened through stuffing, very different to how a true horn works. However, I have a suspicion that with all shorter horns (i.e. <1 wavelength long) there is a degree of 1/4 wave resonance going on as well as horn-loading.

Clever thing about the PJB 16H is that the high throat ratio means that driver excursion is minimised as much as possible so the front wave won't have much bottom at all as it isn't coupled with a high impedance air load like the back wave.

Alex

 

[bgavin]

The non-infinite horn is simply a variable quarter-wave resonator.

I was curious about the high compression ratio in the 16H. I've not seen anything published about it, so I can't tell what the compression ratio is.

 

[billfitzmaurice]

However, I have a suspicion that with all shorter horns (i.e. <1 wavelength long) there is a degree of 1/4 wave resonance going on as well as horn-loading.

Horns are quarter-wavelength devices. They differ from TLines in that they apply gain broadband, not just at the quarter wavelength frequency.

Clever thing about the PJB 16H is that the high throat ratio means that driver excursion is minimised as much as possible so the front wave won't have much bottom at all as it isn't coupled with a high impedance air load like the back wave.

There's nothing about the PJB that differs from other rear-loaders save the use of multiple drivers, which as Bruce pointed out will result in massive combfiltering if the vertical driver lines to either side of the center line are not properly low-passed.

 

[Shawn Norton]

That must have been the worst thing Fender ever made but it summed up the problem in those days which low power handling by the speakers.
I restored this one recently, stripped down the quality of construction was a joke

View attachment 1398442

Sunn produced a similar design, a V type angled front baffle and EAW has subwoofers designed as such. The only real benefit is reduced frontal area which is useful in larger arrays. In a bass cabinet you seem to reducing the enclosure volume to no real benefit. Looks cool I guess and you standout from the crowd. A bit awkward to mic up in a live situation unless you remove the grill.

 

[bgavin]

Ugh.