Constructing the Stereo Bar
Preparing the base plate
Here is a template for the stereo bar base plate. Save it to disk and then print it out full size. Tape it to the front of the cover plate and with a hammer and nail tap guide marks for the center of the 4 holes. Also mark the flat top where you will cut the piece off using a saber saw with a metal blade or a hacksaw.
Cut off the top piece and then drill the three small holes with the 1/8" bit. The two large 5/8" holes are made by first drilling two smaller 5/16 holes for guides and then using the 5/8" flatblade to enlarge them (of course if you have a 5/8" regular drill bit, use that). Here's a picture:
Note that you will probably only be able to use 2 of the three 1/8" holes, It all depends on how you prepare the third mic clip but it's better to drill all three so you won't have to go back.
After the holes are drilled and the edge cut off, clean any ragged edges with a file and go over the whole thing with some 150 - 220 grit sandpaper.
Here's the finished base plate (kinda makes you want to whistle the X-Files theme, doesn't it?). If you don't feel comfortable working with metal, take it to your local auto machine shop. It shouldn't take them more than 10 minutes.
Preparing the microphone stand adaptor
Cut the third mike stand adaptor where the dotted line is in figure 1. You'll want to file the top flat so the the base plate sits solid. You 'll end up with something resembling figure 2.
Below is how the adaptor mounts to the base plate. Hold it together and put a nail thru the small holes on the top plate and make some marks on the center of the adaptor where the screws will go. Drill some 1/16" holes where the marks are. Now you can temporarily screw the base to the adaptor to make sure the screw holes align. They do? good, take the screws out. Mix up some epoxy and coat the flat surfaces of the stand adaptor with it and then screw the base plate to the adaptor again. Wipe up the excess epoxy (rubbing alcohol is a good solvent for JB-Weld while it's still wet)
On the left is the view from underneath. Be sure stand adaptor is not too close to the large holes. This one seems a bit close so I may have to cut an angle off the corner on each side (we'll see). On the right is the top view. Besides the two small screws, I was able to get a third larger screw in the slot at the end, if you stand adaptor is hefty enough for this third screw then use it
Installing and aligning the 2 clamp-on microphone holders
This is a 110 degree angle . Download it and print it out full size, you will need it for the next step. After you have printed the templet. cut along the 2 straight lines and keep the part with "110 Deg" on it.
Until now, nothing was very critical but the alignment of the mic holders is the most important part of the project and must be done properly. Below is a side view of the mic holders with a cut-away to show how the threaded pipe fits. Notice that one microphone will sit higher than the other so they can overlap at the rear and maintain the required angle and spacing.
Put epoxy on all the threads marked with a star (above). The idea is that once everything is in place and the epoxy is dry it will stay that way. Nothing is adjustable except the adaptor where the base plate attaches to a mic stand. The epoxy has a long drying time so you will have plenty of time to align the 110 deg angles. Start with the mic holder on the left. Epoxy about 1/4" of the threads, screw one ring about 1/4" up the pipe, put the pipe thru the plate and then tighten the bottom ring against the plate with a pliers until it is tight. Epoxy the top threads and screw the mic holder down until you get the .5" distance from the bottom of the holder to the plate. Epoxy the threads of the other threaded pipe about half way down and screw the remaining ring about half way up the pipe. Put the epoxied part of the pipe thru the plate and screw the other mic clip onto the pipe tight but still nudgeable.. Here's what ya got, one more step and your're finished.
Put a dowell or other fairly long and straight object ( I had some drumsticks handy) in each holder and take the 110deg paper template you cut out and align the sticks (and mic holders) to the 110 deg angle. Now you can tighten down the rings. Recheck the angle, when it's tight and right, remove the dowels and put the contraption aside so the epoxy can dry overnight.
The next day you can apply the two clips that will hold the mic cords to the rear of the stereo bar. They come with some self sticking stuff that varies in quality. Finally, adjust the mic holders to a 90deg angle and tighten the holder screw down solid (for clarity only one mic holder is shown below). Hey, you're all done!
Put your mics in the holders and move them backwards or forward until the distance between the capsules is about 17mm. The mics will be clamped pretty close to the front. I marked my 451's so I don't have to measure every time I setup.
That's it. Have fun and enjoy the stereo.
This article copyright 1998, Frank Vuotto, Taos Amp