Well, I've been planning my HT for a couple years now. Originally it was going to be a Tritrix setup all around with an RSS315HF sub. I purchased all the Tritrix kits to build everything, built a sealed center channel (bare MDF), ported RSS315 (bare MDF), and then procrastinated for the longest time. I changed my mind and decided to go with a Stentorian front sound stage (L/C/R) and Tritrix MTM surrounds. Around Christmas time I finally purchased parts to build the Stentorians and started making dust after the first of the year. It's been a LONG, SLOW process, but I wanted to take my time and make sure everything was just right. So, here's my first build thread for the L/R mains:
I picked the Stentorians mainly because of the combination of small footprint and high sensitivity. Plus, I think anyone will admit the Stentorians just plain look cool . I added my own twist to the design by going with curved sides on the cabinets. I kept the baffle width, driver spacing, and volume per driver the same as Curts original design. Instead of using window braces between each pair of drivers, I opted to make them all solid. I wanted the cabinets to be as solid as possible and was afraid window braces would give during the clamping process of building up the curved sides.
Because the cabinets are so skinny and deep and I wanted the sides to be perpendicular at the front edge, I used an elliptical curve instead of circular. Since I knew what the height of each section would be, I drew up some cross-sectional views of the elliptical curves and integrated to find the cross-sectional area I needed to acheive the proper volume. After I knew exactly what elliptical curve I wanted, I drew up some 2-D plans in AutoCAD and some 3-D models in Sketchup to make sure everything lined up the way I was hoping it would.
After being satisfied with the way things were going to look, I printed off the 2-D pattern for the braces. I can only print letter or legal pages, but the pattern wouldn't fit on one page, so I put a 1" square grid on the pattern and printed it on two pages. I then used the grid to align the two pages. Using Loctite spray adhesive, I applied the pattern to a piece of 3/4" plywood. This is the light spray adhesive which allows repositioning, but also sticks well. I like to spray both surfaces with a fairly liberal amount and let them tack up before sticking them together. After applying the paper to the plywood, I use the bandsaw to rough cut it and the disc/belt sander to smooth out the edges and finish off my pattern piece.
Next, I traced my pattern piece onto 3/4" MDF (14 times) and again used the bandsaw to rough cut each piece. With each piece rough cut, I screw the pattern piece to the MDF and use a flush trim bit to accurately produce 14 copies of each other.
The "frame" for each cabinet consists of a front, a rear, 7 braces (one cut short that goes directly behind the tweeter), and one false back to go behind the MTM section. Everything is made from 3/4" MDF except for the "fronts". The fronts are made from 1/2" MDF. A 3/4" baffle will be glued to the front later, resulting in a 1-1/4" total thickness to mount all the drivers. The sides will then have 6 layers of 1/8" HDF.
The elliptical curve is perpendicular to the front baffle, so 90 degree edges are standard on the front pieces. Using the 2-D CAD drawings, I determined the angle of the back pieces. These came in at 68 degrees. Here are the stack of braces, fronts and backs:
I cut the 3/4" baffles (1/2" over-sized) and centered them on the 1/2" front pieces. I marked the center of each driver location and drilled the 1/8" holes for the circle jig through both boards at the same time.
I then cut 1/4" dadoes in the front and back pieces for the braces to fit into. This greatly eased assembly so I didn't have to worry about the braces sliding all over the place during clamp-up.
I picked the Stentorians mainly because of the combination of small footprint and high sensitivity. Plus, I think anyone will admit the Stentorians just plain look cool . I added my own twist to the design by going with curved sides on the cabinets. I kept the baffle width, driver spacing, and volume per driver the same as Curts original design. Instead of using window braces between each pair of drivers, I opted to make them all solid. I wanted the cabinets to be as solid as possible and was afraid window braces would give during the clamping process of building up the curved sides.
Because the cabinets are so skinny and deep and I wanted the sides to be perpendicular at the front edge, I used an elliptical curve instead of circular. Since I knew what the height of each section would be, I drew up some cross-sectional views of the elliptical curves and integrated to find the cross-sectional area I needed to acheive the proper volume. After I knew exactly what elliptical curve I wanted, I drew up some 2-D plans in AutoCAD and some 3-D models in Sketchup to make sure everything lined up the way I was hoping it would.
After being satisfied with the way things were going to look, I printed off the 2-D pattern for the braces. I can only print letter or legal pages, but the pattern wouldn't fit on one page, so I put a 1" square grid on the pattern and printed it on two pages. I then used the grid to align the two pages. Using Loctite spray adhesive, I applied the pattern to a piece of 3/4" plywood. This is the light spray adhesive which allows repositioning, but also sticks well. I like to spray both surfaces with a fairly liberal amount and let them tack up before sticking them together. After applying the paper to the plywood, I use the bandsaw to rough cut it and the disc/belt sander to smooth out the edges and finish off my pattern piece.
Next, I traced my pattern piece onto 3/4" MDF (14 times) and again used the bandsaw to rough cut each piece. With each piece rough cut, I screw the pattern piece to the MDF and use a flush trim bit to accurately produce 14 copies of each other.
The "frame" for each cabinet consists of a front, a rear, 7 braces (one cut short that goes directly behind the tweeter), and one false back to go behind the MTM section. Everything is made from 3/4" MDF except for the "fronts". The fronts are made from 1/2" MDF. A 3/4" baffle will be glued to the front later, resulting in a 1-1/4" total thickness to mount all the drivers. The sides will then have 6 layers of 1/8" HDF.
The elliptical curve is perpendicular to the front baffle, so 90 degree edges are standard on the front pieces. Using the 2-D CAD drawings, I determined the angle of the back pieces. These came in at 68 degrees. Here are the stack of braces, fronts and backs:
I cut the 3/4" baffles (1/2" over-sized) and centered them on the 1/2" front pieces. I marked the center of each driver location and drilled the 1/8" holes for the circle jig through both boards at the same time.
I then cut 1/4" dadoes in the front and back pieces for the braces to fit into. This greatly eased assembly so I didn't have to worry about the braces sliding all over the place during clamp-up.
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