Shure used to make a mic that went inside of an accordion. Do you still make it? If not, what do you recommend?
The mic you refer to is the 99B94 crystal element. It had a high impedance, unbalanced output.
The 99B94 was designed to be mounted inside of an accordion. One model it was used in was the "Electronic Accordion" made by Duca Brothers of Milwaukee, Wisconsin. Shure stopped making this element in the early 1960's. See photos below.
Please read on:
Miking an accordion for amplification is a mystery to most players. The article below briefly explains microphone selection and placement as both will influence the sound of your amplified accordion.
An accordion radiates a different timbre in every direction and each accordion surface produces a distinct timbre. By adjusting the mic position relative to the accordion, tonal balance can be dramatically altered. An accordion is designed to sound best at a distance, i.e. two or more feet away. It is "at a distance" that the numerous sounds radiating from the accordion surfaces combine into a pleasing composite. A microphone placed "at a distance" tends to pick up a well-balanced tone quality. In contrast, a mic placed very close to the accordion tends to emphasize the surface that the microphone is near. Therefore, the sound from a closely placed mic will not be representative of the accordion as a whole. Keeping the above in mind, here are fundamentals to observe when miking a accordion:
When using a mic on a floor stand, Shure suggests a condenser unidirectional microphone with a flat (neutral) frequency response, such as the PG81, SM137 or KSM137. A unidirectional mic boosts the bass progressively as it is placed closer to the accordion. This is proximity effect. When miking less than one foot away, be aware of this effect. Premium condenser mics often have a switch to reduce proximity effect.
For initial mic positioning, close one ear with a finger while someone plays your accordion. Listen with your other ear. Move around until you find a spot that sounds good. Try the mic there. To minimize feedback, place the microphone as close as possible to the accordion. But remember that miking too close will color the accordion's timbre.
When amplifying your accordion, you may encounter feedback. In these cases, position the mic very close to the loudest part of the accordion. Then experiment with mic choice, loudspeaker location, and equalization to obtain your desired timbre and sound level.
Instead of a microphone on a floor stand, some players wear a miniature lapel mic to pick up the accordion, such as the MC50 or MX183. Experiment with different placements, for example: on the shirt collar; on the breast pocket; or on eyeglasses near the ear.
Placing a microphone inside of an accordion is very tricky. First, there is mechanical noise inside of the accordion that is not heard outside. Placing a microphone inside will pick up this noise. Second, physically mounting a microphone to the accordion's internal structure will greatly increase the amount of vibration noise picked up by the mic. [To prove this to yourself, place a live microphone on a table surface and knock on the table. Listen to the amount of low frequency noise. Now lift the mic one inch above the table and knock again. Notice the reduction of vibration noise when the mic is not touching the vibrating table surface.] Third, an internal mic will be closer to some reeds than other reeds. Therefore, an internal mic will inevitably pick up some notes louder than others. Always keep in mind that a difference of only one inch can make a tremendous difference in what the mic picks up. In general, Shure does not recommend mounting a microphone inside of an accordion.
Remember, there is no one perfect way to mike a accordion as there is no single ideal mic to use. Like playing, it is part science and part art. Choose and place the mic to get the sound you want. Experiment and listen!