This build thread documents an MLTL cabinet build for Model 19 drivers, the Altec 416-8b, 811 horn w/802-8g. I also plan to incorporate a Heil AMT1 air motion transformer as a "super tweeter".
Discussion about this project began in this thread awhile back. The response curves of the "Model19.long" and variants are referenced there. The reason for delay on this are multiple but lets just say that life and different priorities got in the way.
For background: The foremost design goal in this build is to elevate the position of the woofer to accommodate my listening space and my belief that the woofer is placed to low in the original design. A stimulus to the build was the state of the clone cabinets I had that came with the Model 19 components, they were built with fir plywood and Formica finished baffles. They were not destroyed but given to another local Altec aficionado that has more patience and the ability to improve upon them. The MLTL alignment also provides for a lower box tuning and is in line with how I like bass presentation.
I do have a drawing done in Google Sketchup but don't know how to change the file extension to accommodate posting it up in this forum. Anybody that knows how to do this and could pass along the information, gets a big gold star.
Dimensions of the enclosure are 52 3/4" H x 21" D x 30" W. Enclosure volume is 16 1/2 cu. ft..This is basically the original Model 19 footprint with the height extended as per GM's modeling. GM also had a larger MLTL model along the same dimensions with enclosure volume of 19 cu. ft. but the additional volume of the largest enclosure doesn't offer that much more for the additional volulume so 16.5 it will be.
Note: I made a poor choice regarding materials when embarking on this, purchasing what I thought was a good grade of Birch Plywood from a local lumber superstore. Those sheetgoods had many voids and the plies were found to be of some other species. Buyer beware. I returned those sheets and am now using standard Baltic Birch, 5' x 5' sheets, 13 ply, purchased from a local hardwoods supplier and was able to check the origination of the product. These are the real deal.
I have sorted sheets at this point and will be cutting them to dimension, today. I'll try to keep this thread updated with my progress. Anyone with tips and tricks regarding the construction is invited to post up their thoughts and keep me from making any mistakes.
Thanks, again to GM for doing the modeling and consulting on this, I hope my efforts prove up to the level of his design.