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moray james 18th January 2007 04:23 AM

Freddi here are some newer patents...
Hey Freddy here are some that you may find interesting. The good ideas stick around and get used. Hope there is some additional ideas for this old idea. When an idea gets patented as many times as this one i think that it's a safe bet it's a good one.

US # 4,722,418
US # 5,056,616
US #6,628,799

Ron E 19th January 2007 12:29 AM

Here's some more:

Keld 19th January 2007 04:46 PM

another site, unfortunally not updated since August:

freddi 20th January 2007 01:30 AM

not much new thinking re-hashing the R-J - one patten looks bad -- do make ok reflex and port sums with driver

cat exerciser is exciting

18" R-J syle vented - got 4 - 2 this size 2 larger - low q low mass 18 are ok things

this 6.2CF box with 0.25/103g 18 played pretty well adn its vent didn't chuff like what might happen in one of those patents

moray james 20th January 2007 01:39 AM

50 years later....
still making people think and still works. Would bear further investigation to see if a model could be worked out. Would seem to be a cross between a reflex vent and a aperiodic vent (as a result of the high friction. Would seem to have the best features of each. Regards Moray James.

freddi 20th January 2007 04:05 AM

hey Moray -- my RJ's aperture came from a 1953 diy article where builder even employed de-Q-ing holes through the front and sub baffle ! IIRC didn't have a lot of chamber volume - speaker was 18 and baffle made of good old asbestos.


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