Dave A Posted June 17, 2018 Share Posted June 17, 2018 Looking at a set of MWM plans the other day got me to thinking about why did Klipsch limit the depth to less than 48" which was the width of a standard sheet of plywood. I had no idea what percentage of these were for theaters where space was a problem and how many ended up in places where outdoors or in big arena settings space would not be a problem. So they made a decision based on space restrictions I figure. My thought was what if one designed this around a 5' x 5' sheet of Baltic Birch and I did so using the same exterior dimensions at the front and back. This meant that the horn would be 60" deep and still 67.75" wide leaving two small sections to be added on to complete the shape. I had no good way of doing so at that time but modeled it that way and then also modeled it for the 60" wide sheet which would cut off some of the front width. In the mean time since Claude was kind enough to send me the set of drawings for the MWM I figured he would like to see what I was thinking of doing. He ended up providing technical assistance to interpret the results of what I proposed to do and validated that the idea had merit and added to it with suggesting adding back chamber space which improved it. He also came up with the Super MWM moniker so we have the Super Heresy and Super MWM's to play with. There are three iterations of this. One as shown below. One with the back center triangular guide like the La Scala with the addition of two corner pieces also. Then finally one that can be made without adding to the sides of the 60" wide sheet. If anyone is interested I can provide line drawings of all three. Now in regards to adding onto the length of a piece of plywood here is a way to easily and securely do it. http://www.rockler.com/finger-joint-router-bit#turnto-reviews-content Some comments from Claude regarding these. "6 db down at 32 Hz. -10 at 30 Hz. so yes, it's definitely usable. Had a higher peak 38 Hz. and a dip between it and 100 Hz. until I opened up the space in the triangle. The it flattened out like a pancake. You got the final version. I even tried other woofers, but the K33 is the winner. I think a Crites woofer would do just as well or better." Regarding the idea of using 60" wide instead of adding wood to get to the 67.75" wide. Considering the above mentioned way of finger splicing wood I do not intend to build just 60" wide ones for myself. " It's volume is more important than the small percentage of mouth area it adds with the taper. Also, the Crites woofer models the same way with about 1/3 of a db more output at 400 Hz. BTW this horn is way more flat magnitude response than the Khorn, Jube, or LaScala ever were." Really like these double MWM bins and the idea I can go lower like this greatly interests me and these will be the first speakers I actually build. Maybe if I actually get to the Klipsch gathering next spring I will bring a set to listen to. 2 Quote Link to comment Share on other sites More sharing options...
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