What's the science behind my folded horn?

[Mr. Foxen]

So why does it take a distance before it makes sound instead of blows air (is it a wavelength or half a wavelength, seems like around 20 feet from the cab, but I dunno how far inside it counts as). And how is it so direction even in the low end. Some dude is trying to tell me the easily observable phenomena of this throw is scientifically impossible, I figure he is clueless. As am I, which is why I'm asking.

[Bill Fitzmaurice]

[quote name='Mr. Foxen' post='380864' date='Jan 14 2009, 06:57 PM']So why does it take a distance before it makes sound instead of blows air[/quote]
It doesn't. The reason you can't hear low frequencies close to the cab is !00% the result of boundary cancellation, mainly off the ceiling, that doesn't exist further away. That's explained here:
[url="http://www.padrick.net/LiveSound/CancellationMode.htm"]http://www.padrick.net/LiveSound/CancellationMode.htm[/url]
You can't hear midrange anywhere because the geometry of the cab filters midrange out. Very few folded horns are capable of being used alone with a good result. It would seem yours is not one of them.
[quote]Some dude is trying to tell me the easily observable phenomena of this throw is scientifically impossible, I figure he is clueless.[/quote]He's quite correct. The phenomena is easily observable, or audible to be more exact. The explanation, for the layman at least, not so much.

[Mr. Foxen]

For the purposes of those charts, is the speaker at the mouth of the horn, or is their fun with horn length as the speaker is inside? And for micing, is cramming a mic inside it going to give me a poor representation of the sound of the cab, but a less coloured one? Micing it has been a the main pain with it, mostly due to sound engineer unfamiliarity with it, been using sansamp DI instead. The sticking your head inside it to see what the mic will hear didn't give a spectacular result.

[Bill Fitzmaurice]

[quote name='Mr. Foxen' post='380910' date='Jan 14 2009, 08:06 PM']For the purposes of those charts, is the speaker at the mouth of the horn, or is their fun with horn length as the speaker is inside? And for micing, is cramming a mic inside it going to give me a poor representation of the sound of the cab, but a less coloured one? Micing it has been a the main pain with it, mostly due to sound engineer unfamiliarity with it, been using sansamp DI instead. The sticking your head inside it to see what the mic will hear didn't give a spectacular result.[/quote]
The horn mouth is the radiating plane. I can't comment further without seeing the cab.

[Mr. Foxen]

It's a clone af the Acoustic 36x:


much like:


Jaco got plenty of mid in his sound, something special about those?

[Bill Fitzmaurice]

[quote name='Mr. Foxen' post='381501' date='Jan 15 2009, 12:02 PM']It's a clone af the Acoustic 36x:


much like:


Jaco got plenty of mid in his sound, something special about those?[/quote]
That's a variation of the 1970s JBL Keele W bin, which is described by inventor Don Keele as [i][b]A medium-throw "W” folded horn providing uniform response from 55 Hz to 400 Hz [/b][/i]Just like a modern subwoofer It never should have been used alone, but should have been be paired with a 1x10 atop it. Jaco's tone was mainly the product of his fretless, and he boosted his treble to full and pulled the bass EQ down to make the best of the response shortcomings of his Acoustics.

[Mr. Foxen]

Interesting, I've been turning down the bass on the eq and boosting the mids as my bass puts out a lot of low anyway, and the sansamp scoops mids when I kick it in. The head with it is matching and works pretty well as a guitar head, so guessing that has some treble boost going on on its own, it does have a treble input also, best doom guitar sound was patching between them.