On Fri, Dec 27, 2024 at 08:01 PM, Richard Lee wrote:
On Fri, Dec 27, 2024 at 10:59 AM, <soundwichartist@...> wrote:
I've measured up to 40k on the electret mics that i'm using, which is very nice. but I want more.
How do you measure mikes up to 40kHz?
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I too would be interested to learn how soundwichartist makes the appropriate measurements.....?
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I have found that measuring the detailed ultrasonic response of mic caspules is not an easy task, without access to some serious scientific equipment.
The published ultrasonic responses for cheap capsules - like Knowles MEMs and electrets - show a pretty erratic response (See Knowles App note here: )? ?
Even the expensive Sanken? CO-100k model mentioned earlier has a very non-linear HF response (see here: ).
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I've found applying the ultrasonic output from a suitable generator directly to a piezo audio 'tweeter' - like this one: ? - can give a rough idea of the ultrasonic response of a capsule......
Sadly of course the linearity of that type of transducer at ulrasonic frequencies introduces another unknown to the proceedings!
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The published ultrasonic response for the Knowles MEMs capsules can be quite useful.
I find a complex response curve like that easier to correct digitally - in post - than it would be trying to build an accurate hardware analogue filter to compensate.
