What on earth would you call this?? (see pic) horn, snailshell, TL???

[SkinnyBoy]

ok... there's some DISCUSSION going on between myself and the dude over there at Powered 4 Sound (ya know, the 6.5inch woofers sounding like 12inch subs)

anyway.... I am pretty sure the snailshells are horns of some type, but he denys it.... thats not the point however...

I asked him what this was: (woofer mounts where the RED line is)


and he told me it was a transmission line... hmm.. ok... strange... what are your thoughts?? and what do you think of the snail shells?? horns, TL's or some other made up term I can't remember that I'm pretty sure the guy made up on the spot... lol

here are some home made snailshells... although one person actually called it a transmission line...





so my fuzzy little friends... whats the go??

[sreten]

they are both forms of tapered resonant 1/4 wave lines.
(TL's to most people)

The 1st seems to be wasting some enclosure volume.

The second has a strange CSA profile.

sreten.

[Ropie]

I agree, they are TLs. The closed off area at the front of the section drawing could probably hold a small tweeter.

[GM]

If it has a positive taper with no constriction at its terminus, then it's technically a horn. Since this one has a low pass filter (constricted throat) in series with the driver, which also radiates into free space, it's a (low) compression loaded backhorn.

WRT the DIY pipes, it's hard to tell what the 2nd and third expansion rate is, but I would classify it as a hybrid (low) compression backhorn since it has a constricted throat, expanding first section, another constricted throat, then either two constant CSA expansions or very low positive CSA ones. Reminds me of hi-perf muffler designs.

GM

[Mudge]

They're not classic TLs or even tapered TLs. I would say due to the necking of the line they would be closer to TQWTs than classic TLs.

[BAM]

Some Bose engineer is probably kicking himself...

Or perhaps the designer is ex-Bose

If it's a horn, it has some kind of huge compression chamber, and there is a straight taper right at the beginning of the horn but it doesn't continue for the other two segments. That third segment is a lot bigger than the second.

Since a horn is just an acoustic impedance coupler, that flared section could have some sort of coupling going on to the second segment of the pipe which then is slot-loaded by the third?

Maybe the size of that terminus thing is the same as the width that the first taper is opened to before it interfaces with the second segment of the line.

Here's a picture of a concept design I saw on the Powered4Sound message board looks really stupid. The guy (not the P4S guy but someone else) explained that it lets the sound go out but doesn't let it come back in.

[Timn8ter]

Here's a picture of a concept design I saw on the Powered4Sound message board looks really stupid. The guy (not the P4S guy but someone else) explained that it lets the sound go out but doesn't let it come back in.

So once the driver pumps all the air out a vacuum remains?

[kan3]

Originally posted by Timn8ter


So once the driver pumps all the air out a vacuum remains?

doesn't stop there, a black hole is formed and eventually sucks the box and everything in the vacinity into it

probably why you don't see to many people using them

[officeboy]

Originally posted by BAM

Here's a picture of a concept design I saw on the Powered4Sound message board looks really stupid. The guy (not the P4S guy but someone else) explained that it lets the sound go out but doesn't let it come back in.

Interesting, that looks quite a bit like a lowpass filter.

[Bricolo]

what's a CSA.