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?
