KVR Audio

arkmabat · Post by **arkmabat** » Mon Jun 22, 2015 9:40 pm

I don't get how they work exactly

whyterabbyt · Post by **whyterabbyt** » Mon Jun 22, 2015 9:45 pm

Piezos turn vibration into voltage; unlike regular mic elements, they're not moved by air pressure. Hence they only pick up the transmission of vibration through solid objects, not through air.

arkmabat · Post by **arkmabat** » Mon Jun 22, 2015 9:58 pm

So it wouldn't pick up the sound of the inside of the mattress if I put it on it?

whyterabbyt · Post by **whyterabbyt** » Mon Jun 22, 2015 10:05 pm

arkmabat wrote:So it wouldn't pick up the sound of the inside of the mattress if I put it on it?

Not quite sure what you mean by 'sound of the inside of the mattress'. Any vibrations that pass through the physical structure of the mattress body and have enough energy should get picked up by the piezo. Matresses, though are quite soft, so a lot of what's transmitted wont travel far because it'll be absorbed.

In contrast, though, you can scream, yell, and turn your stereo up to 11 etc while you're hitting the mattress, and none of that will be picked up by the piezo.

arkmabat · Post by **arkmabat** » Mon Jun 22, 2015 10:16 pm

When my ear is on the mattress and I can hear the inside. Like when the doctor listens to heartbeats with a stethoscope.

arkmabat · Post by **arkmabat** » Mon Jun 22, 2015 10:20 pm

You can hear the springs and it's like a natural low pass filter.

whyterabbyt · Post by **whyterabbyt** » Mon Jun 22, 2015 10:21 pm

arkmabat wrote:When my ear is on the mattress and I can hear the inside. Like when the doctor listens to heartbeats with a stethoscope.

If its a physical vibration inside the mattress, maybe, unless the mattress itself absorbs it all.

Stethoscopes, though, are acoustic.

lofty · Post by **lofty** » Mon Jun 22, 2015 10:27 pm

arkmabat · Post by **arkmabat** » Tue Jun 23, 2015 3:43 am

I've recorded underwater in my bathtub with a condom over a $10 mic. Works well. This is a similar sound with the low pass and all but I don't know how to record it. When I was a kid I thought it was the perfect bassdrum sound though.

arkmabat · Post by **arkmabat** » Mon Jul 20, 2015 5:10 am

Am I the only one who puts my ear to the mattress and bangs on the side? It's a deep, resonating, thud. I'm trying to capture it.

deastman · Post by **deastman** » Mon Jul 20, 2015 6:49 am

arkmabat wrote:Am I the only one who puts my ear to the mattress and bangs on the side? It's a deep, resonating, thud. I'm trying to capture it.

I do that too. I'm not sure if a piezo is the best way to capture that, but its worth a try... they're cheap.

Otherwise, you just need a sensitive mic to capture the sound. You could try making your own stethoscope recorder...
http://advan.physiology.org/content/36/4/360

Can a piezo mic pick up the sound of my ear on a mattress while drumming on it?