Neither could I, once I found my Bullock!

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 Full Thread

Topic - down-facing woofer and port , 2" or more gap, effect on bass extension? - Timbo in Oz 20:36:47 06/12/12 (12)

RE: down-facing woofer and port , 2" or more gap, effect on bass extension? - Vic D 08:08:45 06/14/12 (0)

Just better room loading and a wee bit of boundary reinforcement - Kloss 07:52:28 06/14/12 (0)

No one knows? - Timbo in Oz 16:01:02 06/13/12 (7)

RE: No one knows? - Scholl 05:57:26 06/17/12 (1)

aha and Hmmm! IF I had the encl, in a circular baffle matching the paver then the compression might be better? - Timbo in Oz 18:08:25 06/17/12 (0)

If the right combination of tuning, distance from floor and FB existed, it could happen, but - Edp 07:32:21 06/14/12 (0)

I looked in Bullock, Beranek, and Marshall Leach and couldn't find anything. - andy_c 16:07:47 06/13/12 (3)

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)

RE: down-facing woofer and port , 2" or more gap, effect on bass extension? - fstein 12:39:11 06/13/12 (1)

effect on bass extension? Specifications were given because I already have the spkrs. - Timbo in Oz 15:58:06 06/13/12 (0)

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)

Neither could I, once I found my Bullock!

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