DIY Woody Grado/Symphones Magnums - A build diary
Sep 29, 2012 at 2:15 PM Post #76 of 128
Quote:
 
I remember seeing those when you posted before, they look really nice.  Not sure if i want mine to go as dark as that though, after spending some time with them i almost want an 'invisible' finish, kinda like them just as they are tbh.

wax!

only on the outside though
 
Sep 29, 2012 at 4:37 PM Post #77 of 128
I remember seeing those when you posted before, they look really nice.  Not sure if i want mine to go as dark as that though, after spending some time with them i almost want an 'invisible' finish, kinda like them just as they are tbh.


Probably best to avoid an oil-based finish and go with a natural stain to bring out the grain and then finish with a light poly-based finish for protection. No need to oil after that.

Again, all wood is different. Even within species. So, a test sample is always a good idea if at all possible.
 
Oct 6, 2012 at 9:55 AM Post #78 of 128
Not sure that this really justifies an update, but i've been trying out a test finish on an off cut and am fairly happy with the results.  Went with dewaxed shellac in the end, although i don't want a supershiny finish so i'm using a satin laquer.
 
 

 
Depending on the angle and amount of light it changes colour quite dramatically, but then so do my RS1s...
 
 

 
And up against the unfinished wood for comparison...


 
Oct 6, 2012 at 3:41 PM Post #80 of 128
Interesting, although i would hope that the outside of the can would have minimal impact on the sound, and at most the inside will get a coat or two of shellac...
 
Oct 6, 2012 at 9:43 PM Post #82 of 128
I think the finish combination is excellent. Very rich and dimensional. The grain has lot's of pop and depth. A very pleasing combination.

Unlike a guitar or violin body, the wood here is not serving as a resonating surface. Or at least I would not think that would be a desirable characteristic.

In a guitar or violin, the wood chamber is integral to the production and amplification of the sound made of the strings resonating against the bridge. In a headphone, the cup should not contribute any audible resonant effects or at least strive to minimize those effects in a controlled and predictable way. Perhaps best controlled with the appropriate driver and associated response characteristic.
 
Oct 7, 2012 at 3:58 AM Post #83 of 128
grados have very little by way of mechanical damping, most i've seen on the inside was a lump of black tack on the back of the driver with an obvious thumb print on it (accurately measured of course), I think its part of the reason people say they work best with current sources. I would think the wood and chamber will absolutely have an impact on the sound
 
Oct 7, 2012 at 10:37 AM Post #84 of 128
I would think the wood and chamber will absolutely have an impact on the sound


No doubt.

My particular curiosity is the effect of a lacquered vice un-lacquered surface on the resonances of a wooden chamber built especially to minimize (or at least somewhat control) resonances.

In violin construction, there is a very much pronounced (and hotly debated) effect on cavity resonance due to finishing, indeed, some say it is what gives a Stradivarius it's particular tonal characteristic. But in the case of a violin, the whole point of the body is to provide a tuned, resonating, amplifying chamber for the strings against the bridge.

I would have thought the circular shape and thickness of a wooden headphone cup would work to minimize resonance while also providing a visually pleasing and easy to work with material.
 
Oct 9, 2012 at 2:42 PM Post #85 of 128
Well, the nice postman put 2 large jiffy bags through my letterbox today, one containing 3 metres of mogami 2893 and a neutrik plug (ordered a month ago but out of stock) and the other some assorted heatshrink (ordered yesterday lunch time from http://www.heatshrink-online.co.uk/ - highly recommended if you're in the uk and need any).
 

 
After a little cutting, soldering, fiddling and heating, a cable is made...
 

 
I was planning on trying to use a heat shrink end cap to make the Y split by punching a couple of holes in it, but i couldn't get them big enough or neat enough for my liking to thread the individual sides through, so i resorted to regular adhesive lined heatshrink, 8mm 4:1 if anyone is that interested.  The cable north of the split has clear 2.4mm 2:1 heatshrink, which was only just large enough to comfortably thread the two wires through.  I also got some black of the same size and shrink ratio, but the clear stuff felt more flexible before shrinking so i went with that.
 
Close up of the split...
 

 
For now i've hard wired it in, since i'll need to make the cable entry hole bigger to accommodate the SMC connector, and i want to do that on a pillar drill, which will have to wait till i go into the workshop next.
 

 
I'm quite impressed by the neutrik plug, nice and solid.  What you can't see here is the innards, which has a bit that grips the cable as you screw the end in, so the solder joints are isolated from movement of the cable.
 

 
Nov 8, 2012 at 4:44 PM Post #87 of 128
These look great and inspired me to buy a wood lathe. I started a thread to try and get a few pointers from the experts.
 
http://www.head-fi.org/t/635202/first-attempt-at-grado-cups
 
 
Dec 1, 2012 at 12:05 AM Post #88 of 128
rav, fyi, that first wood is indeed purple heart and the 2nd doesn't look like any mahogany i've used. I'd guess khaya if pressed, it's a diff family from mahog I velieve and is harder as well. Could be a good choice however regardless. As you found, the purpleheart is super dense and tough to work, burns easy unless your tools are razor sharp. Any sound differences you notice? I'd predict the purple is a bit more strident?  Try making a set of the 2nd wood at 1 1/8" head to toe, you may find the sound more natural. Have fun and keep on truckin'
 
http://www.mcilvain.com/hardwoods/african-mahogany/
 
Dec 1, 2012 at 10:41 AM Post #89 of 128
It's been a while since i listened to the purple set, but my first impression when i put the drivers in the browns was that they (the brown) were brighter (like the difference between flats and bowls brighter, but without doing an a/b i can't back that up).  I think i prefer the sound of the purple from memory, and i do plan on making another set, and also putting the drivers back in while i do the finish on the bown so i can have another listen with fresh ears.  Trouble is that it's got really cold just recently so working in an open ended workshop with no heating has lost its appeal slightly...
 
I asked an acquaintance of mine who restores antique furnature and he wondered if it might be a type of cherry wood.  It really sands well, like super smooth at 600 grit, where the brown still feels a little rough, although the direction of the grain might be a factor there as well.  The brown wood has a very similar grain pattern (the little cross grain pores to be exact) to one of my sets of RS1s, so i'm quite confident that it is mahogany of some sort, the shop i got it from said it was (although i didn't ask for any providence or anything).  It's dense, but nowhere near as dense as the purple.
 

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