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I'm trying to find on the web if there's an example of smartphone that records with low quality (which introduces lot of background noise) and an example of phone that records with good quality, maybe with the frequency response, snr and the characteristics of the ADC.

For now I have found not so much (especially on the ADC), all that I have found is old.

Can someone help me? Thanks in advance.

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You're assuming there is such a difference and that it is related to the microphone and ADC.

Background noise is not so much eliminated by the microphone or ADC. To suppress background noise, multiple microphones are used and the actual suppression is done by digital signal processing, either in software or in a DSP.

Audio ADCs are now so cheap to make on a chip that it is not worth the effort to make a lower quality version. It does not save any money so no phone manufacturer skimps on the audio ADC.

With microphones it is similar, for speech almost any cheap microphone does the job for use in a phone. For a studio recording microphone its a different story of course but then size and cost are less of an issue.

If you were able to look into the designs of smartphones you would see that they're all very similar. Even though the parts are different, the specifications for the components will be very similar.

Phone manufacturers consider their designs proprietary information and they will not easily share it so that is why it is difficult to find this information.

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  • \$\begingroup\$ Yes, I understand, I forgot to mention I'm doing a research about music recording with smartphones. You risk to have low-quality microphones, so they can cut high frequencies, reducing the audio quality. And what about the SNR? Is it really so irrelevant that all smartphones are similar? \$\endgroup\$ – rickowens Jun 23 '16 at 10:09
  • \$\begingroup\$ I think SNR will be the least of your problems. SNR is mainly determined by the FET in the electret mic. and the ADC. Most ADCs perform the same. Look at the datasheet of cheap audio ADC chips, they're mostly the same. There are 24 bit ADCs but these are too expensive for phones. Also in phones the audio recording is optimized for speech. So low and high frequencies might be attenuated. I think it is just a matter of trying it to see if the quality is good enough. If you need better quality you will need to go to products designed for audio. \$\endgroup\$ – Bimpelrekkie Jun 23 '16 at 10:15
  • \$\begingroup\$ The audio bandwidth considered adequate for human speech is about 3kHz (some might say 4kHz). Most microphones are better than this, but I would not expect an ordinary mic in a smartphone to extend beyond perhaps 10kHz at best. The same issue is usually true of low frequencies (below 300Hz). \$\endgroup\$ – Peter Smith Jun 23 '16 at 10:42

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