I would like to perform some measurements of the microphones (i.e. frequency response, SNR, etc.). First and best option would be to use the Anechoic Chamber- obviously this is not an option because of access and price. Another way would be to perform measurements in quiet room and then window the Impulse Response. Unfortunately this will limit lower frequency of my measurement - obviously I do not want that. I believe that the best way to do that is by using small Anechoic Box and putting speaker and microphones in it. Prices of such are very high, therefore is there any good way of creating one? Maybe someone already did it. Mostly I am curious with:
- what kind of absorbent to use inside
- what to use as the skeleton (maybe some kind of server cabinet?)
- how to insulate it in a best way from outside noise
I would be thankful for any help. Regards.
Copied from comment so everyone could see:
Indeed I thought about performing measurements in open field or in a duct (as proposed in IEC 60268-4). Of course doing outdoor recordings in the UK city is rather complicated, therefore I immediately dropped this idea. Although sequential averaging of IR's from sweep-sine measurement is doable.
I've been also thinking about this "duct" solution, but there is no information regarding it's specification. I suspect it is more like impedance tube, but probably it is not enough to make it on your own. Hence I've chosen to go for the Anechoic Box.