Open-Baffle Subs – “Subwoofer Origami”

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Yes. You can't pack two 12" woofers any smaller.

attachment.php


Surely the output of such topology is Dipole??
 
Not as pretty as the one above due to only being a test box. Drivers are JBL GT5-15: GT5-15 | 15? single voice coil subwoofer | JBL US

wckqxuQh.jpg


Except at the extreme LFs, distortion is only ok...(taken at 1M).

ExBW2U1h.jpg


On axis.

EPQq5S5.jpg


90 deg.

By5XUVl.jpg


180 deg.

GUiIaCr.jpg


Only looks usable up to 100-125hz, which should be fine as the mid I have in mind is an AE TD-15M.

What intrigues me is the spider venting is exposed on the outside. I may cover it with another layer of ply on the outside just to see what happens to the response. It may help with LF extension, but it also may make the dipole peak worse, no?
 
The issue I see with that (and other 'slot loaded') is the difference between front and rear output.
If you compare a "ripole" with Nelson Pass' "SLOB", it is evident where the symmetry is - and where not.
If you notch the front output quarterwave, what happens to the back output ?
In a ripole you have the same notch/quarterwave situation in front and back. After all the cone can't move in different ways on its front and back side.
If smooth dipole radiation is desired then the front and back output needs to be as symmetrical as possible.
What is wrong with a subwoofer construction if the radiation pattern tends a little bit to cardioid?
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.