In Reply to: I looked in Bullock, Beranek, and Marshall Leach and couldn't find anything. posted by andy_c on June 13, 2012 at 16:07:47:
Andy,
It is a DIY project a 3-way column with two bass enclosures, BUT ... the enclosures were OEM'd, concrete spheres. ?*
The ports (PVC plumbers pipe) are cemented in, so all I can do is turn one pair over (on the blocks I have made) onto a 24inch round paver and measure how deep they go.
If I decided to tune the down-facing pair lower I'd not be going any lower than 2/3rds the Fs of 38hz = 27Hz. A right-angle bend to fit over the back end of the port is a snap. How low will depend on what effect the acoustic loading has. May not have to retune.
* the second matching pair of spheres? one of each will sit on top of a down-facing sphere. ???? Cut-down basketball hoops on an adjustable column on rollers, and gravity will hold them in place, plus a small ball of blutak.
The third smaller sphere on top running from ~400-6kHz will be mounted in the same way. Moving them will be doable, as will be working on them.
Warmest
Tim Bailey
Skeptical Measurer & Audio Scrounger
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Follow Ups
- Neither could I, once I found my Bullock! - Timbo in Oz 16:29:18 06/13/12 (2)
- Concrete spheres? Holy moly! - andy_c 16:39:14 06/13/12 (1)
- When I'm happy, yes I'll report - Timbo in Oz 17:08:10 06/13/12 (0)