After the sucess of my modified Cambridge R50 transmission line bass cabinets, I was hankering after building a transmission line midrange unit. I had in the interim partnered the R50's with a pair of Fostex 123E full rabge drivers in a bass port enclosure allied to a pair of supplimentary KEF tweeters. I came across a design for 'Zigmahornets' on the net which used Fostex 103E full range drivers, and after doing a bit more checking decided to try this design scaled up to fit the larger full range drivers. The design is a 1/4 wave straight transmission line and in the plans I found wasnt damped in any way with long hair wooll - just a simple damping pad on the rear baffle behind the driver. Id worked out that one sheet of 18mm mdf would complete the build so quite a cheap test build ahead.
The pic above shows the simple design/construction of the cabinet, with the damping pad in place. I couldnt leave it like that so as is usual with me it out with the 15mm dowel to act as bracing and 'fix' the long hair wool damping material.
Here is a pic of the wool in place
Here is a pic of the 'finished' speaker
Sound wise Im pleased...a much better sound stage then with the ported cabs.....let other judge this better during the bake off this weekend