Interpreting mic sensitivity numbers

[JPS]

I would like to get a better understanding of what the mic sensitivity data can tell me about a microphone when I want to use it for a particular purpose. Maybe a link or a discussion. I am aware that the sensitivity number is the amount of current generated by a mic on a standard test. So, I would assume the higher the amount of current generated the more sensitive the mic and the better for recording low sound sources. Am I close?

For example, I noticed the Soundelux U99 has a mic sensitivity of 21mV/Pa, while the Soundelux U195 is 14mV/Pa. The AKG C 414 B-XLS is 23 mV/Pa. So, of these mics, the C414 would be the most sensitive to low sounds?

Also, is there an inverse relationship between the mic sensivity and the SPL? More sensitive means less SPL.

 

[mshilarious]

I would like to get a better understanding of what the mic sensitivity data can tell me about a microphone when I want to use it for a particular purpose. Maybe a link or a discussion.

http://www.shure.com/support/technotes/app-sensitive.html

I am aware that the sensitivity number is the amount of current generated by a mic on a standard test. So, I would assume the higher the amount of current generated the more sensitive the mic and the better for recording low sound sources. Am I close?

Yes, close. But just because a mic is sensitive doesn't automatically make it ideal for a given source that just happens to be quiet. Maybe a less sensitive mic placed closer would be better.

For example, I noticed the Soundelux U99 has a mic sensitivity of 21mV/Pa, while the Soundelux U195 is 14mV/Pa. The AKG C 414 B-XLS is 23 mV/Pa. So, of these mics, the C414 would be the most sensitive to low sounds?

Not just low sounds, but any sound, loud or soft, at the tested frequency. However the AKG and U99 are less than 1dB difference, so you won't be making a selection between the two based on sensitivity.

Also, is there an inverse relationship between the mic sensivity and the SPL? More sensitive means less SPL.

You might notice some correlation but it isn't very strong. However since max SPL is a function of distortion, using a mic's pad will increase max SPL and of course reduce sensitivity, so from that point of view it's true.

 

[JPS]

Thanks. I saw that Shure link on an earlier thread, but I felt it really didn't explain much about how sensitivity relates to microphone use or what makes microphones more sensitive. I would just like to explore this topic a little deeper and I have several questions on the issue. Like:

-What are the elements in microphone design that make for sensitivity?

-When would sensitivity become a criteria for selecting one microphone over another?

-Can we infer any other important information from the sensitivity number?

-I have noticed that SD condensers generally have lower sensitivity ratings. Is there a cause for this?