diy sub trap

Hello, how do I calculate the tuned core in sub trap like this http://www.asc-home-theater.com/subtrap-flyer.pdf

please update your profile with your location. as far as "tuning" it? it looks like they have created some Helmholtz resonator around an inner tube trap. it says it patented technology so presumably you can research the patent number where it explains how it works. you might just consider purchasing one as the fastest way to obtaining one.

Yes, but I wonder how they can patent Helmholtz Resonator :shock: . I will replace "their" patent with Helmholtz Panel Resonator.

just my observation on the cut away... it could be an amplitude grating design :roll: but for accuracy, i suggest reading the patent filing which should explain how it works... a review: http://www.asc-hifi.com/widescreen-subtrap-review.pdf 1985-U.S. Patent Number: 4,548,292 'Reflective Acoustical Damping Device for Rooms' (TubeTrap) http://www.freepatentsonline.com/pdfb/d ... 548292.pdf

thank you, gullfo