Hi, everyone!
If this should be moved to the Microphone forums, please move it there.
I am working on a broken Avantone CR-14 ribbon mic with four totally rusted (almost entirely into brown powder) magnets and dual ribbons.
They are plated metric magnets measuring 30mm long, 4mm wide, and 4mm thick.
These are just unusual enough to make things difficult. The US-based magnet suppliers that sell in quantities of 1 for reasonable prices all seem to use inches for the dimensions, but these metric sizes aren't close enough to any of the common Imperial sizes.
The closest would be 1.125in long, 0.125in wide, 0.125in thick, but this size is not available. Also, the nearest available sizes in length are either 1.0in long or 1.25in long, not 1.125in. The thicknesses of 0.125in are smaller than the 4mm, meaning there will be noticeably more space between the magnets.
I could physically fit the closest-sized magnets into the truss, but it's practically guaranteed that the response of the microphone will be noticeably different from the originals, due to the wider gap, lower mass, and too-long or too-short lengths.
Does anyone know of a metric supplier of small quantities of plated neodymium N42 block magnets in 30mm x 4mm x 4mm that is based in the US or has reasonable shipping to the US (probably from China)?
Also, if I MUST buy Imperial sized magnets because there are no metric suppliers that serve the USA, which of these is better:
a) too long length of 1.25in instead of 30mm OR too short length of 1.0in instead of 30mm?
b) too wide width of 0.25in instead of 0.125in? (This question is somewhat moot since 0.125in wide block magnets are not available in the lengths I would consider.)
c) On the thickness, I have no choice but to go with 0.125in because two 0.25in magnets would have almost no room for a ribbon in between given the size of the truss, and two 0.0625in magnets would have a super-wide gap. In thickness, I would love to buy the exact thickness of 4.0mm.
I'm thinking that too long and too wide is better in both cases for mic sensitivity and frequency response, but I have no idea whether this is correct.
Thanks in advance!
If this should be moved to the Microphone forums, please move it there.
I am working on a broken Avantone CR-14 ribbon mic with four totally rusted (almost entirely into brown powder) magnets and dual ribbons.
They are plated metric magnets measuring 30mm long, 4mm wide, and 4mm thick.
These are just unusual enough to make things difficult. The US-based magnet suppliers that sell in quantities of 1 for reasonable prices all seem to use inches for the dimensions, but these metric sizes aren't close enough to any of the common Imperial sizes.
The closest would be 1.125in long, 0.125in wide, 0.125in thick, but this size is not available. Also, the nearest available sizes in length are either 1.0in long or 1.25in long, not 1.125in. The thicknesses of 0.125in are smaller than the 4mm, meaning there will be noticeably more space between the magnets.
I could physically fit the closest-sized magnets into the truss, but it's practically guaranteed that the response of the microphone will be noticeably different from the originals, due to the wider gap, lower mass, and too-long or too-short lengths.
Does anyone know of a metric supplier of small quantities of plated neodymium N42 block magnets in 30mm x 4mm x 4mm that is based in the US or has reasonable shipping to the US (probably from China)?
Also, if I MUST buy Imperial sized magnets because there are no metric suppliers that serve the USA, which of these is better:
a) too long length of 1.25in instead of 30mm OR too short length of 1.0in instead of 30mm?
b) too wide width of 0.25in instead of 0.125in? (This question is somewhat moot since 0.125in wide block magnets are not available in the lengths I would consider.)
c) On the thickness, I have no choice but to go with 0.125in because two 0.25in magnets would have almost no room for a ribbon in between given the size of the truss, and two 0.0625in magnets would have a super-wide gap. In thickness, I would love to buy the exact thickness of 4.0mm.
I'm thinking that too long and too wide is better in both cases for mic sensitivity and frequency response, but I have no idea whether this is correct.
Thanks in advance!
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