Bigger BIBs AGAIN

[jamikl]

Last night I had another look at a magazine article which was an interview with Dr. Edgar about horns etc. He mentioned at that time that he was about to do or try a cheaper version with a central lower bass horn flanked by two higher, maybe 80 Hz up horn and mid and high horns. I have not visited his sIte so don't know if it was ever done. Set me to thinking about BIGGER BIBs though. Big BIB for the centre, to 70 - 80 Hz horns up to about 250 - 300 Hz and then round tractrix with two of the smaller Fostex units. How does this sound? What would be a good candidate at not too high a cost for the 80Hz horn? Are there like to be problems with delays through the different length horn paths. If the BIB is central, sideways maybe, and the other bass horn well separated this should go a little way to evening the paths to the listener maybe? Look forward to any ideas.
jamikl

[freddi]

a 15" driver (to keep horn length reasonable) with low mass, low inductance, low Qts, and reasonably high fs.

Below is my example of Dr. Bruce Edgar's old system 100 horn outdoors in half-space with JBL 2220H.

The 100Hz horn had an 80 square inch throat (10" high by 8" wide), m= ~0.55 expansion, ~20.5" by 20.5" mouth with about 20.5" from mouth to throat plate. Note the JBL's ~2Khz peak still shows. In-room sensitivity might have been around 108dB in the middle of its passband. One could build such a horn with a trapezoid piece to hold the two flat plates which in turn hold slats to form this expansion. (see Dr. Edgar's midhorn article download at Volvotreter's site) A conic midbass horn might work well too but I've not had the pleasure of hearing/building one.

100Hz hypex straight horn
http://img426.imageshack.us/my.php?i...00onoffpj5.jpg

PV FH1 (~like La Scala) in same spot outdoors for comparison
http://home.earthlink.net/~buddhaboy2/FH.jpg

For center woofer you might look at Volvotreter's Edgar download section for the 1/8 size 40hz Monolith horn article with plans which is ~flat to 40hz with a driver having Qts ~0.26, fs = 26Hz and mms about 110g.

I'd like to know about the bigger BIB too. Walt at Speakerstore.com has plans for a tower which may be related to Danley's tapped horn but Walt provided no data so ....

http://www.speakerstore.nl/index.php?l=nl&pg=11&c=61

[jamikl]

Thanks for the response Freddi. I was thinking about something like the La Scala for the 80Hz upwards horn and then make my own tractrix horns using perhaps papier mache initially. Are there any plans for DIY horns similar to La Scala. I have seen sites that say that such plans are coming but nothing has turned up. I know that La Scala types have been used successfully with Oris horns.
jamikl

[freddi]

Hi Jamikl - go over to the Klipsch technical and modification forums and ask for links to La Scala and Belle plans. There was one tread on the Belle which included nice plans and detailed progression of build. Also one might consider a vented version per DJK. Dana Moore (D-Man) has a horn-plan like that but its probably too tall for a large tractrix on top.

Best,
Freddy