[7keys]

  Hi everyone. About a year ago I purchased some mahogany cups and magnum v5 drivers from turbulent labs, as well as some nice cable from toxic cables, and set about modding my grados (sr80s). Since then I've been thinking about the mahogany cups and would love to spend some time making my own cups, as a friend of mine has his own lathe.
 
I've read so much information on this forum about cups and how different woods give the headphones a different sound. I'd really like to delve a little deeper with regards to what the cups actually do, and it would be great to hear some opinions. When I say "what they actually do", I mean technically what they do, how they physically work. The cup is open at the back, so the aim is to let sound waves/ pressure waves emanating from the rear of the driver escape rather than rebound off a closed back and cause issues.
 
So the drum of the cups shouldn't allow any waves that are meant to escape bounce around and reverberate instead, so longer cups might cause problems. In fact as well as a shorter cup length, perhaps non-parallel walls would be beneficial (eg slightly conical, widening as they get further from the driver, thus funnelling waves outwards). The finish on the inside of the cups should simply be smooth to allow the pressure waves to escape without issue.
 
With regular speaker housings the goal seems to be all about dampening. Are wooden cups used exclusively for dampening purposes? To quote What Hifi's review of the ps1000s, "The combination of [a mahogany inner core with an alloy outer-casing] self-damps to give the revised unit a solid low-resonance base to work from.
Mahogany is a tone wood though, which is likely to resonate when exposed to sound waves. But that's not what dampening is all about. Some of the other good tone woods are spruce, cedar, maple and rosewood, all with different levels of warmth (or otherwise brightness).
So with the use of wood, is the goal actually to add a little warmth to the sound by transmitting vibrations physically from the driver to the wood (by the driver being tightly fitted to the cup), thus allowing the wood to react to those vibrations and impart its own tonal additions? If pure dampening were in order then a tone wood wouldn't be that useful.
 
People have been talking on the forum about different woods, and have seemed in general to lean towards the much harder woods such as cocobolo, ebony, zebrawood, mahogany, but the theories always seem to be about the density and hardness, not about how well regarded they are as a tone wood (or indeed the opposite, how well they dampen).
 
I'd love to hear some opinions and gain a little more understanding of this subject, and if you know of any other interesting pieces of literature then I'd love to be pointed in their direction.
 
As a cheeky addition, maybe people just choose whatever wood looks the most beautiful when polished nicely?

Check out the The Great Grado Experiment (4 tonewoods tested thread where we are testing tonewoods. We have four up for test right now and after Christmas we'll be adding some exotics. I'd like to have members test these tone-woods side by side.

 

[JonnyW]

Heya everyone, thanks for your suggestions and comments. I'm about to check out The Great Grado Experiment, which looks really interesting - Walnut seems to come out of it highly regarded in the first review, which is good because woods seem harder to come by in England than in the USA, but walnut is common enough compared to the more exotic woods. I'll take a look to see if Limba's available anywhere over here.
 
I had seen the first page of the thread by the lostMIDrange, but hadn't quite realised until now what an epic quest it was, and having just read it through it's really fascinating. I reckon he's got better ears than me, I can't believe I'd be able to recognise such subtle differences as he can.
 
The consensus does seem to be that the woods are used for their tonal properties rather than dampening, therefore thelostMIDrange's findings about wall thickness and overall length are well worth taking note of.
 
Spruce is one of the most popular tonewoods used in guitars, however I haven't come across its use in cups. I haven't checked but I'd imagine its relatively cheap to purchase so would make a good experiment. Maple is also used extensively though and that didn't do so well in the first set of reviews in The Great Grado Experiment, which was surprising. Maybe traditional guitar woods aren't necessarily quite right for cups.

 

[7keys]

 Maple is also used extensively though and that didn't do so well in the first set of reviews in The Great Grado Experiment, which was surprising. Maybe traditional guitar woods aren't necessarily quite right for cups.

The Maple used in the Great Grado experiment is soft Maple and not Hard Maple, although some say you can use either one Hard Maple is my favorite tone wood so far. But I haven't tried the ones in the test yet.

 

[austonia]

.

 

[hoagster]

  Heya everyone, thanks for your suggestions and comments. I'm about to check out The Great Grado Experiment, which looks really interesting - Walnut seems to come out of it highly regarded in the first review, which is good because woods seem harder to come by in England than in the USA, but walnut is common enough compared to the more exotic woods. I'll take a look to see if Limba's available anywhere over here.
 

Try exotic hardwoods uk ltd. I bought some sonokeling from them recently. They sell 6" * 6" * 2" blocks of various woods which is enough to make 2 sets of cups.
 
I think limba is known as afara in the uk (according to wikipedia anyway). Woods are known by different names in different parts of the world so it's always worth checking.

 

[Levictus]

In the US, Limba is also called Korina especially within guitar making circles

 

[kopral 21]

my last indian rosewood wood cup..

 

[austonia]

  my last indian rosewood wood cup..
 

 
wow. fantastic looking cups. would be an easy sell if you could make more (i'm in!) 

 

[wolfetan44]

 

  my last indian rosewood wood cup..
 

 
wow. fantastic looking cups. would be an easy sell if you could make more (i'm in!) 

He lives in Indonesia!

 

[austonia]

.

 

[wolfetan44]

 

  He lives in Indonesia!

 
that's ok, in modern days, you can ship (almost) anything, anywhere! and shipping costs are pretty darn reasonable. 

Oh, thought it would be a lot!

 

[austonia]

  Oh, thought it would be a lot!

 
I'm sure it can be, but for small / medium size things it can be pretty cheap. for instance:
 
bought an O2+ODAC from Australia recently, and the shipping cost was $14 to USA. That's like 9,000 miles. woh!

 

[JoeDoe]

So, a few weeks ago I purchased some B-stock/blemished cups from Vibro Labs for $40 a pair. Honestly when I bought em, I wasn't expecting to be able to do much with them as I don't have any woodworking tools and very little experience outside of woodying Grados using pre-made cups. Really just wanted something I could experiment with.
 
Finally finished with em today.

 
They're the same mahogany used for Turbulent Labs, stained with a red mahogany finish with two coats of Poly. Started like this:
 

 
Had to finish cutting, sanding, and finishing them myself. Since I bought 3 pairs originally, let's just say there's quite a pile of sawdust in the shed...
 
Unfortunately one of the pairs cracked as I was installing the drivers w/ foam liner. Not a deal-breaker as functionally, they're still fine, but a little disheartening nonetheless. Luckily all of these guys were destined to be Xmas gifts and the recipients aren't the nitpicking type. One of em is actually an amateur carpenter...
 

 
Just thought I'd share. 

 

[kopral 21]

   
I'm sure it can be, but for small / medium size things it can be pretty cheap. for instance:
 
bought an O2+ODAC from Australia recently, and the shipping cost was $14 to USA. That's like 9,000 miles. woh!
 

if i sold my cup for $35-$50 and shipping $14-$20 i think that shipping cost for me to much expensive..

 

[kopral 21]

sr325i + borneo tiger / borneo rosewood wood cup. not 100% finished