I know this is not the right place for this thread- but, since it is the only part of this site that deals with physical pick-ups, I thought it would be the best place to start.
I was wondering if anyone here was knowledgeable about contact microphones. I've been wanting to record sounds with contact microphones and play them back through the same surface on which they were recorded. For instance: with a contact mic, record the sound of rain on a sheet of glass or window, and then, with some sort of contact speaker, play the sound back through the glass.
My intuitive feeling is that this could create a very convincing illusion of the original sound, as the material used for recording and playback are identical.
Does anyone have any thoughts on this? Is a "contact speaker" something which arleady exists? Could a contact mic double as a contact speaker? If not, how might one construct a contact speaker?"
I apologize for cluttering the forum with non-phono related posts, but I thought some people here might be able to help.
Sonic Impact makes a "contact" speaker. It will turn any surface into a speaker of variable quality. Other companies make similar products with more or less success. Most are aimed at the HT market where adding visceral impact is exciting to some people.
I don't see that a microphone in contact with the item recorded would be any better than a microphone palced in close proximity to the object recorded; assuming, of course, you wanted a recording that was that closely mic'd. Let's say you wanted to record a tuba. What advantage would a "contact" microphone have over a plain ol' condensor mic placed a few inches from the mouth of the tuba? What you hear is the entire instrument responding. It would be impossible for the tuba-mic to make the tuba respond as if someone where forcing air through the entire instrument by blowing in one end. Even harder would be the ability of the mic to discriminate between near and far sounds on a surface like a window pane, and that differentiation is what your ear perceives. You can buy pressure zone mics which sit very close to the flat surface of the recording venue in order to minimize phase effects and I would choose something on that order if I wanted to record the sound of rain hitting a window pane.