Need help for microphone - For IOT kind of project

[sudhirbhosale]

Hi I am working on proof of concept where need to use small microphone (mainly to capture audio from tele-conference meetings not to be used for any music purpose) .

One of my friend gave me mic (pl see attached pic). Shocked to hear that price is just 10 rupees .
I used that in my model, did the job but not upto the mark. Now in order to refine the design, need following inform from FM friends
1. Are there any brands for such types of mic
2. Are there any types based on range, sensitivity
3. Speaker has parameters which help to finalize specific model i.e. RMS Fs, freq range. Does mic have such design parameters
4. Any best mic available upto price range of couple of hundreds
5. Online store specially for mic where I can find big range

Thanks

 

[tcpip]

The mic you've sent a photo of seems very similar to the Panasonic WM60/61 mic capsules I've used for several years for speaker measurements. Siegfried Linkwitz has discussed that capsule in detail. It has a wide FR range with a nearly flat response, which makes it very good for SPL measurements without calibration. It's available from Digikey at about $2 each.

I don't know whether you're using this model. I only said it looks similar to your photo. Maybe all mic capsules look similar.

Mics have a lot of parameters, like SPL range (how loud can it record), self-noise, and frequency range. The polar pattern of its sensitivity is also very important, which determines how its response changes off-axis. This is usually shown in a graph.

For the kind of application you're describing, I'd blindly use the Panasonic capsules I mentioned. They're excellent for general-purpose recording and have been studied extensively by the DIY community.

Hope this helps.

 

[sudhirbhosale]

The mic you've sent a photo of seems very similar to the Panasonic WM60/61 mic capsules I've used for several years for speaker measurements.

Thanks lot.
Some questions:
Do they ship to India? If yes then how many days. Any seller from India?
I also came across noise cancelling mic at element14. But are those Omnidirectional? Since I am going to use for human voice then Omnidirectional+ noise cancelling would be good. So are noise cancelling mic Omnidirectional?
Are there any other design implications?

 

[tcpip]

The Panasonic capsules are available from Digikey. And Digikey ships anywhere in the world.

About noise cancelling mics, I can't comment. I don't even understand the term "noise cancelling mic". In my very limited understanding, a noise cancelling system, not mic, will use 2 or more ordinary mics. One mic will be directional and pick up the main signal, and others will pick up ambient noise. Then, signal processing circuits will attempt to remove the noise from the main signal. I can't see how just a mic will do all this.

 

[keith_correa]

The Panasonic WM60/61 went obsolete I think in 2011/12.

You should be able to get what you need at: JLI Electronics. Mail Brad at BConfer [AT] jlielectronics.com and ask him for recommendations. They sell Panasonic replacement mics too.

 

[tcpip]

The Panasonic WM60/61 went obsolete I think in 2011/12... .

Yes. But if you search on Digikey, you'll get excellent substitutes from other brands, with SPL curves and other tech data, at similar prices.

 

[sudhirbhosale]

Thanks lot tcpip and keith_correa

Another source I found is element14.com. They have many mic with data sheet and technical specs but from many unknown brands. Sharing this as input might be helpful for other readers.
Thanks

 

[keith_correa]

Thanks lot tcpip and keith_correa

Another source I found is element14.com. They have many mic with data sheet and technical specs but from many unknown brands. Sharing this as input might be helpful for other readers.
Thanks

element14.com is B2B. For B2C you need to buy from Kits 'n' Spares

 

[sudhirbhosale]

About noise cancelling mics, I can't comment. I don't even understand the term "noise cancelling mic". In my very limited understanding, a noise cancelling system, not mic, will use 2 or more ordinary mics. One mic will be directional and pick up the main signal, and others will pick up ambient noise. Then, signal processing circuits will attempt to remove the noise from the main signal. I can't see how just a mic will do all this.

Thanks tcpip
I found noise cancelling mic here : http://in.element14.com/pro-signal/abm-710-rc/microphone-solder-pad/dp/1736567
ABM-710-RC - 4mm Noise Cancelling Electret Condenser Microphone (Solder Pads)
Sharing for reference.

 

[tcpip]

I found noise cancelling mic here:
ABM-710-RC - 4mm Noise Cancelling Electret Condenser Microphone (Solder Pads).

I read the one-page technical documentation. This is just a mic, not an active noise cancelling system. They claim that the directivity of the mic is noise cancelling. This probably just means that it has a narrow polar pattern of sensitivity, so signals coming from off-axis will be attenuated compared to direct on-axis signals. Calling this "noise cancelling" is the manufacturer's attempt at being creative, I feel.