The Genus Behind Wide Baffles

[twinter]

More links for wide baffle speaker articles from Troels Gravensen:

Poor Man'

http://www.troelsgravesen.dk/PMS-EXCEL.htm

 

[Boden]

If one looks at the transfer function of a typical conventional, say 8 wide, 12 "high baffle 2 way, with a 7" midwoofer crossing over at 2kHz, you can see that the transfer starts to roll off at approx 500 Hz @6 dB/Oct electrical off and then at 2Khz second 6 dB/Oct comes in, amounting to 12 dB/oct electric from 2kHz upwards. That is all.

The12dB/Oct electric combined with woofer intrinsic roll off, usually amounts to 18 or 24 dB/Oct acoustic woofer roll off.

 

[planet10]

Warning: Zombie thread

Compensating for that requires reducing efficiency above the step.

Note that compensating for the 2∏ to 4∏ transition to bring the on-axis flat elevates the lower part of the spectrum wrt the room response.

BSC is a compromise.

A wide baffle which acoustically merges with the wall behind has neither of those 2 problems — but as always it will also bring compromises.

Elipsa wide baffle speakers

These were inspired by Ellipsa, we even just call them the Eipses

And i note that the link to Troels in the thread that got me here, has much the same polygonal shape the above started out as… but Chris decided to make those a proper curve. Troeals beat us by over a decade (but i had never seen his project).

dave

 

[WhiteDragon]

Still love those speakers planet10
The in process build shot,
is such a cool picture.

 

[picowallspeaker]

BSC is a compromise

I think most builders of small, narrow 2-ways use BSC compensation via bumped up woofer inductors as you noted

Dave, once you stop considering just one driver...
The efficiency factor when BSC related in a multi way is just a matter of Watt so volume on the preamp

 

[planet10]

Not sure of your meaning pico.

dave