Cylindrical Speakers

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Hi! Have you ever listened to any cylindrical speakers? How good they are? What are the pros and cons of speakers in such shape?

Besides those designed by Jim Rogers in the late 1970s, it seems not many cylindrical speakers in the market. The traditional box-shaped design has been dominating. I'm curious to know why.
 
Hi...

I built a pair of cylindrical transmission line speakers a number of years ago... I made them out of 10" high pressure water line (PVC)... I can't really comment regarding sound (I've not compared them with 'box' speakers of similar design)... I like their sonic characteristics, particularly their sound stage... but I'm not sure how much of this is due to the cylindrical design..

But... They where a real bugger to build... Wouldn't want to build another pair.. And there is one other issue worth mentioning.... The materials I used where incredibly heavy... the speakers weigh about 135lbs each, and this combined with their shape, makes them nearly impossible to move... There just isn't anything to grab onto... And that makes them really hard to live with...

But hey, I'm not in a hurry to trade them in....

steve
 
steve said:
wow... I didn't know that that word that starts with a 'b' and ends with an 'r' is a cuss word.... Sorry about that...
steve


It isn't. Whoever programmed the star inserter apparently leans too heavily towards being a wus.

The meaning you were trying to portray has been totally misrepresented. Your post now reads that your project gave you a six star building experience. I am quite sure this is not what you meant.

Got any pics of your plastic water main pipe speakers that you care to post?
 
I recently made a lightweight cilindrical cabinet:

http://groups.msn.com/luidsprekers/f18.msnw?action=ShowPhoto&PhotoID=305 (click next).

Inner skeleton: http://groups.msn.com/luidsprekers/preconcept.msnw?action=ShowPhoto&PhotoID=283

Benefits of cilindrical would be a smaller rimple in the frequency response and the round shape is better suited to withstand pressure (the reason why gastanks are never square or rectangular).

Thing is about most cilindrical enclosures (talking subwoofers now, hmm wrong forum?), because they 're downfiring, with the port up, it's difficult to pinpoint the position even if standing up close or crossing higher as 80 Hz (which is good). They do however ratlle the floor much more (in case of wood) which can be good (can be bad :D )

Take a look at the SVS subwoofers as well.

Wkr Johan
 
Hello Rademachers

That's a very nice design. Did you laminate mulitple sheets of 1/4" birch ply for the skin? If you did, could you please tell me what type of glue you used for the lamination.

It seems like everyone in your part of the world are born master woodworkers, very well done.

John
 
Hi..

I've previously posted a picture of the 'sewer pipe' speakers..

It's located at:
http://www.diyaudio.com/forums/attachment.php?s=&postid=340823&stamp=1078422560

it's in a reply to 'PVC for sonotube!!!!! help Experts' in the subwoofer forum...

And no, I didn't mean to implie that it was a 'terrible awful experience'... to build them, but it was a trial...

But I'm listening to them right now... and they still make me smile... and thats what really counts...

take care
 
If you did, could you please tell me what type of glue you used for the lamination.

In this case I used Fuma because of it's lightweight. I however do glue birch ply from time to time in cilindrical shapes. In all the cases (including the Fuma) I use the regular PVA wood glue (is that the same as Elmers glue?).

However you should do the proces of glue-ing a layer in several smaller steps (on this project I did 8 inches/step), or use staples or screws to fixate each step and continue right away. Always use a piece of wood to even the pressure (on the ends) over the total length of the material.

Something like this: http://www.speakerplans.com/index.php?id=vit1

Wkr Johan
 
Dear all, planning a cylindrical sub like these with a 18" driver. Front facing..

How do I calculate baffle length and rear port length/diameter to achieve a certain tuning freq ? Are there any calculators for cylindrical boxes ?

Courbe-Speakers.jpg
 
Harry Olson says no to cylinders

http://www.aes.org/aeshc/pdf/how.the.aes.began/olson_direct-radiator-loudspeaker-enclosures.pdf

When I see speaker like this I just know the designer had no idea what they are doing. They are clearly just ‘art furniture’ designers.
Harry Olson’s work on diffraction in the article to which the link above will take you to explains why.
Since it’s only a sub the diffraction issues shouldn’t apply though.

Box volume is all that matters in ported box design. Shape doesn’t. Use the T/S parameters from the speaker spec sheet in any readily available on line box calculator to get the box volume required and port size and lengths as well.
Cylinder volume is ‘area times length’.... or Pi times radius times radius times length.
 
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... possibly

Olson did great work, but his experiment used a custom 7/8" driver on a 24" dia circular baffle. This clearly caused a lot of diffraction using a high ratio of baffle to driver dia.

Linkwitz did some more tests, varying the baffle diameter, and it seems the larger the ratio the worse the diffraction. Diffraction from baffle edges He uses a cylinder in his LXMini but keeps the baffle diameters ratio small like the previous photo(s).

Vance Dickason also took Olson's work a little further and tried the driver on the side of the cylinder and found diffraction was nearly as low as a sphere or egg shape. It's in his 7th ed Loudspeaker Design Cookbook, tables on pg107, and graphs on pg111 .
 
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