This was completed over a period of about a week, off an on work. These are the first headphones I have really modified. I have done a detachable cable mod to my Sennheiser HD280 Pro, but nothing else. These were a fun project, and the end results were amazing. The sound stage is nicer, the highs are not as ear piercing, and there was virtually no effect on bass (though it was VERY SLIGHTLY dampened). I have a pair of SR-60's that sound nearly the same as these SR-80's did when they came out of the box, so I have something to compare it to!
I read through the first 87 pages of the Grado mods thread, getting ideas from several people. I still need to finish reading though it though!
The first thing I did was make a custom headband with padding. I used my Bernina 830 Record to do the stitching. While not perfect, much more comfortable than the original vinyl thing it was shipped with!
I wanted wood cups, they just really make the headphones pop, and give them some atheistic complement to their sound quality. Very pleasing to the eye.
So, I went to the local woodcraft store and found two pieces of wood that were good for first time experimenting. 5x6x2" blocks of Padauk and Zapote. For these, I am using the Padauk, as I like it's sheen of red.
Using my dad's ShopSmith at their house, we (my dad and I) set up the lathe together. This is the ShopSmith in "lathe mode". The chuck to the right is actually drill chuck from a Craftsman standing drill press we have. It was the only way we could figure out how to bore out the wood for the sound chamber. On the right, the left is the drive with a lathing disc, which the wood was screwed on to to secure it. The Shopsmith can be turned upright to be used as a drill press as well, so the head actually has a lever on it to move it in or out.
To bore out the sound chambers, we simply pushed the wood (which was spinning on the disc) into the forstner bit on the drill chuck to the right. It actually worked out extremely well! Everything stayed center and cut very cleanly!
One of the cups ended up with some chips where the ear pad rests, but nothing the pads or the distancers wouldn't hide.
These are the cups after being cut, ends formed, sanded and drilled for wire and yoke holes. Not to shabby!
Next up were the distancers, which also serve as the holder for the ear pads. Killing two birds with one stone here! :)
To keep the distancers from being oversized (too deep), but still have enough groove for the ear pads to sit without deformation, we sandwhiched a narrower ring of the padauk between two larger rings of oak. The thinnest Home Depot carries is 1/4", however this is still to big! So we used the board planner to plane the 1/8" oak down to 3.5mm (as low as the planner would go).
These are the Padauk rings we lathed out of left over material from the cups.
Once the oak was thin enough, we sandwhiched the oak (after cutting it to shorted sections) between some 3/8" pine of the same size, and clamped it into the drill press vice. This kept us from getting really jagged edges once we started to drill through the oak.
Starting with the inside chamber, we bored out the center hole with a forstner bit in the drill press, going through the top layer of pine, down just until it made contact with the bottom layer of pine.
Next we swapped out the forstner bit for a hole saw (again in the drill press). This cut out the discs of oak, giving us the rings we need to sandwhich the padauk between.
After removing them from the hole saw, we were gifted with these!
Here is a sneak peek at what's to come of them.... :)
Because they were still to large at one end, and wouldn't fit into the cup, we had to improvise for a way to shrink the outside diameter uniformly. We came up with this!
It's a sanding drum which is slightly larger than the inside diameter of the oak ring(s). The rings were pushed onto the drum snug as far as they would go. At 800 RPM they didn't budge, even when they made contact with the palm sander with 80 grit paper on it!
Here is what we got when finished:
And, all assembled:
Back to cup assembly, I cut out some mesh from a $2.00 mail filer I got at walmart. It serves it's purpose well!
Here are all of the parts to the new cups, on display:
Next everything was lacqured, to bring out some of the grain and color of the padauk. I love the dark red!
Edited by PintoDave - 11/24/12 at 1:07am