Size and shape of infinite baffle

[paulspencer]

it's not only the low frequencies that come around the baffle though, pushing the low frequency diploe rolloff down below the audio range is fine, but above that you still have higher frequency back waves bouncing around the room interacting with the front wave. Assuming it's a round baffle (as using a single number for D does) you get a comb filtered high frequency response, and still figure of 8 radiation pattern right?

I don't see much point in arguing the merits of a true infinite baffle vs one with an fequal at 20 Hz, since the latter is not practical to fit into a room which is of a size that benefits most from OB.

If you wanted to discuss a practical OB vs IB, then you would have to consider things like polar and power response, directivity and room response, excitation of room modes, imaging and room treatment, SPL requirements, driver choices, room modes ........ it would be a very in depth discussion. The ideal would probably be a combination of the two, with OB being the winner from 40 - 200 Hz, IB below that and for the treble. The midrange would be the most likely range of contention over which is better. Those prefering IB midrange would perhaps use a waveguide for the treble and select a larger mid driver to get some pattern control.

For a dedicated room, I'd be interested in a Linkwitz Phoenix main panel with 4 x SS 10" added to the main panels like in the Beethoven, and dipole woofer array either side, with an IB sub operating below 40 Hz.

 

[poptart]

Fair enough. I just don't see any reason to try and connect infinite baffle and open baffle, an infinite baffle is much more like a giant box speaker than a giant OB. The argument would be irrelevant to the original poster's question too since his design has a small open baffle for the mid+tweet on top of a box, Bazzilla style, nothing to do with large dipoles or infinite baffles.

 

[j.burtt]

Thank You.