Circular ribbon microphone capsule

[Khron]

How resilient / elastic are they, though?

 

[s wave]

Resilient. You can pick up a .025 micron plate with your hand (so I heard). The smallest workable aluminum ribbons are about .6 microns - that is thin and very difficult) They are flexible too. I am not sure if I can post up a link. (I don't think it is allowed?) Another idea may be just affixing a very thin aluminum foil to it - or a flattened silver wire on it.

 

[ccaudle]

Another idea may be just affixing a very thin aluminum foil

Isn't trying to affix aluminum foil to an aluminum oxide sheet a very backwards approach? If you start with aluminum foil you will end up with a thin layer of aluminum oxide attached in just a few seconds.

 

[s wave]

Resilient. You can pick up a .025 micron plate with your hand (so I heard). The smallest workable aluminum ribbons are about .6 microns - that is thin and very difficult) They are flexible too. I am not sure if I can post up a link. (I don't think it is allowed?) Another idea may be just affixing a very thin aluminum foil to it - or a flattened silver wire on it.

 

[s wave]

Isn't trying to affix aluminum foil to an aluminum oxide sheet a very backwards approach? If you start with aluminum foil you will end up with a thin layer of aluminum oxide attached in just a few seconds.

Yes it seems counter-intuitive. But one is an effect or reaction while the other is designed with just the oxide. Of course you have to make it conduct electricity. But maybe graphene can come into play - this would be cool since graphene conducts electricity (yet is 'curls up' in nano sizes) but it may open up real world solutions.

 

[s wave]

Isn't trying to affix aluminum foil to an aluminum oxide sheet a very backwards approach? If you start with aluminum foil you will end up with a thin layer of aluminum oxide attached in just a few seconds.

It is not backward when; you end up using <1 micron of Al Oxide and <1 micron of foil. The weight and mass (efficiency) should make for one high output audio signal?

 

[Paul W]

My 2 cents, and something soliloqueen alluded to : the ribbon in a ribbon mic uses the same principle as a guitar string. A thin, long piece of material tensioned between two points to create - or transduce - sound. The round diaphragm in a dynamic mic works like a loudspeaker in reverse, where a circular coil is held in place around a round magnet by a circular tensioned diaphragm. And the round diaphragm in a condenser works like a drum, where the diaphragm is concentrically tensioned around a ring to create - or transduce - sound. In all these cases, the parts that move with the sound waves are kept in place through tension, linear or concentric, in one or two dimensions.

Mics don't work like guitar strings or drum heads, though, do they? You want a condenser diaphragm's motion to be roughly pistonic or something like it with higher amplitude away from the edges (and maybe center termination). You don't want all the weird higher vibratory modes of a drumhead, where one side of the membrane is going up and down while the far side is going down and up, or the center is going up and down while a ring around that is going down and up. Those motions, if present, will mostly cancel out because parts of the diaphragm are going in opposite directions and their effects on capacitance will largely cancel.

I would guess a ribbon is the same way... what matters is its overall fore and aft motion, and if it's undulating, that's either bad or mostly irrelevant.

If you want to detect those opposed motions on a scale smaller than the diaphragm/ribbon, I'd think you'd be better off with an array of smaller sensors. Then you could detect higher frequencies at off angles, where something is going in and out while something nearby is going out and in.

 

[s wave]

I think he meant "Ribbon Microphone". Which would make it challenging in a many respects. The conducting ribbon is the first hurdle, it may be plagued by bass or proximity effect also. But crazy ideas often lead to breakthroughs in unobvious ways.