[Arny Krueger]

"Barkingspyder" wrote in message
...

Are there any advantages other than a smaller foot print for
cylindrical subwoofers?

Potentially low cost and easier assembly, particularly if the cylinder is
based on Sonotube.

Do they require damping material in the
same way a box would?

Yes.

I'm considering a DIY project and would be curious as to the science
on this topic. Are there the same problems with vibrations inside
the enclosure, or does the cylinder reduce or make them a non-issue?

Two types of vibrations

(1) Vibrations of the air
(2) Vibrations of the enclosure

(1) Is based on enclosure volume, driver characteristics, stuffing, and are
the same given the same volume, driver, etc.
(2) Is based on the stiffness of the enclosure.

I see a lot of the sonotube desgins have the driver at one end and he
port at the other. Does it make any difference if they are are at
the same end of the tube assuming a large enough diameter?

Not unless the enclosure is itself a signficiant portion of a 1/4 wavelength
at the port tuning frequency.

I am considering a 143 L EBS alignment with both the port and the
driver at the bottom. The tube would be 20" in diameter and a 4"
port. I am not married to these dimensions but I thought there
would be a higher WAF if the thing looked less like a water heater.

What driver?

I've never heard of a 143 L EBS alignement and can find no online references
to it.