spiraling out of control

[brucegseidner]

I have tried using the web page interpreter option to make sense of Japanese spiral horn sites. Are there known sources for the spiral inserts?

I have not seen much discussion of these horns before stumbling upon them earlier this evening. They are fascinating.

Has anyone played with these designs?

http://www3.ocn.ne.jp/~hanbei/eng-intro.html

http://tokyo.cool.ne.jp/pomme2/spiral.htm

[Geek]

Originally posted by brucegseidner

http://tokyo.cool.ne.jp/pomme2/spiral.htm

We heard this one in 2006 @ the RAW Acoustics get together with a FR125. It rocked!

The young fellow made his out of ABS pipe and chopped extension cord for the spiral.

Cheers!

[Bob Brines]

Hmmmmm.

These look to be either MLTL's or acoustic labyrinths depending on how they are terminated. Geez, I built a pair of these with alternating internal plates for 4" RX drivers back in the '70's. This is also the principle behind Lynn Olsen's "Arial's".

Bob

[brucegseidner]

I did find some links here subsequent to posting this and several of you have been quite patient as this model is "discovered" anew every couple years on this listserv.

It is another arrow in the quiver. More tools and variations. It is particularly interesting to see it used in one unit following a bass reflex loaded driver chamber.

I do wish I could get better results translating these Japanese pages. The colors and graphics are wild.

[human.bin]

i tried the 250 BG, think this was the name, the tall floorstander for the fostex 206. without woodworking tools, it was not easy to get it perfectly done, so i used some special glue to fill the odd millimeters left by some spiral flare. it was not difficult, but it was quite heavy, and certainly harder than a quarterwave cabinet would be.

btw i did it using an adudio nirvana super 8", at the time (and so do i now) i had really little understanding of driver T/S parameters, so i tought the design for the 206 would work... well it didn't, it was a total mess up. very noticeable dips in the response. bass was sometime there, powerfull and extended, better than the CSA 'monitor' cabinet i did before. but sometimes it wasn't there at all... also the high-mids, and highs where even harsher than before, and equalization was needed.

it was obviously my fault, and probabibly the space behind the driver was just too small. so i can't give any judice.

but for what i've read around, the big advantage of this kind of cabinet should be no need for bsc, while another guy here on the forum built them for the fostex 206 and he wrote there was no bass until he drop spl down by bsc... and he was directly comparing to the solo206...

also on this forum someone reported of a spiral horn design with a jordan. compared to a fostex in an onken cabinet he reported something like: jordan is the best driver, but onken is the best enclouse... what does it mean i don't understand, but it's worth a search. also on diyparadise (the site the charlize come from i think) they used to sell a modded spiral horn design, the tubular type, with a jordan, and talked of it as horn-like sound.

then it is only my understanding, and i never found satysfing direct comparison to understand if the high and mids are someway deteriorated by this kind of enclosure while trying to push the bass response so far from driver intended capabilities...

also an italian small speaker maker maclemethorn used to sell kits with small drivers, and said they where top class design for them, then again what he was comparing to i don't know...

hope this helps a little. my idea is that on a small driver it's certainly worth a try. but it is only if you have something good to compare them too, and already know what to expect from the driver in terms of mid/high reproduction.

hope this helps.