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In the Forum: Audio For Dummies ™
In the Thread: It is possible to eliminate some forms of gross side band distortions
Post Subject: Engineers are very cautious types, just like me when I design power transformersPosted by Bud on: 7/13/2005

Please, have some fun. First download the white paper to see what the patent artists came up with. It is essentially correct but not to scale.

Note that it requires 18 offset sets of blocks around the periphery of a cone. About two degrees of space should be left between the top of the top row of blocks and the glue flange of the surround. If there is no glue flange, leave 1 degree of space to the edge of the cone. One block here is composed of two spaces filled with paint with one open space between.

Use the polar coordinate graph paper to guide your work. Find an old divider from some ancient mechanical drawing set (the pivoted, two armed thing with needles in both arms). Use this to transfer diameter of inner edge of surround glue flange to polar paper. Make the diameter smaller by 4 rings and then draw out the pattern on the graph paper using the meridian lines to control your block length. Cut carefully  around the outside of the outer ring of blocks and if you have alternated your blocks in two rings with 10 degrees devoted to every block you will have 36 blocks, in two rings of 18, in each ring. Place this circle in the cone, center is well and you should have enough room to draw two rings of blocks on the cone, between the guide circle and the surround glue flange or edge of cone.

The inner ring of blocks can be reduced by one. Means two rings on the cone, with the bottom ring right in the joint of cone and center dome and a third ring up the side of the dome, the correct distance.

The rings are to be equivalent to one degree apart and one degree thick so each  block has a 1 X 10 ratio, with the portions 1X2, 1X1 & 1X2. Treat POC cheap cones for a while. For a hoot find some closed back headphones that are blown. Remove the driver and cut the baffle plate to accept a small 1 12" or 2 " PM speaker and treat that. Will sound very close to Stax Electrostatic headphones.

You will need to place a dot of paint in the center of the dome of any speaker and it helps to put a six element set of blocks around this dot. For even more termination and to remove the occasional spike of high frequencies, take a round tooth pick, cut off the end to the start of the taper, dip it in to Elmer's White Glue and place a nipple, in the center, at the top of the dome. This will help almost all dome and cone with dome drivers by the way, just by itself.

Another thing to try is to treat a cone in open air in front of you with music from some cheap radio clip lead attached to the terminals. AS you finish the last few dots in the ring the sound will "pop up" in a very holographic image, with surprising width and specificity to the sound field.

When you have some cones to abuse and a speedball lettering set from A0 to A5 and all of the other stuff I can walk you through the details ... what!? you thought this was detailed enough already?!!!! hah... saving grace is you do not need to be very precise with your pen work for it to work just fine.

Bud

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