hissing on podcast mic

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Level 1

12 points

hissing on podcast mic

I have x2 podcast kit with the Mivo PC-M6 mics (budget ones for my school as I am a media teacher), but whenever I use them them in garageband they seem to be very low in sound and I get a lot of background hissing. Naturally I have tried all the settings to boost recording volume but this just makes the hissing louder. I mam using a Rode AI Micro to connect the two mics to my macbook pro M1.

I have tried recording through rode connect and garageband and the hissing remains. I have tried different leads and the hissing remains.

However, if I try just recording via my macbook internal mic on garageband there is no hissing; I also tried with a Rode shotgun mic and no hissing was present (although that also picked up lots of background environment sounds).

Any suggestions about how I can use these mics without the hissing and why the recording volume is so very low. E.g; when I plug x1 pc-m6 and x1 rode shotgun mic into the same Rode AI Micro and have the same settings (using garageband) the rode mic is MUCH louder, and only the rode mic appears to produce visual soundwaves (the pc-m6 does produce sound as I can hear it on export, but again only with lots of hissing.

The mics manual say PLEASE NOTE: These microphones require +48V Phantom Power to operate.

Any help?

MacBook Pro 13″, macOS 13.0

Posted on Jun 11, 2024 6:27 AM

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Answer 1

Jun 11, 2024 7:23 AM in response to KippMajors78

Do you mean Movo PC-M6? These are condenser (capacitor) mics and require an operating voltage to work: this is supplied along the input line from the mixer (hence 'phantom' power since it isn't a separate lead). Your Rode A1 Micro does not supply this: their info says:

'You can plug virtually any microphone that has a 3.5mm output into the AI-Micro. This includes RØDE VideoMics, lavaliers, wireless systems like the Wireless GO, and stereo microphones that do not require plug-in power.'

These mics will not work with your mixer. Indeed I'm surprised you got any output at all. You need to use moving-coil mics which generate their own output power.

A moving-coil mic has a coil attached to the diaphram which when vibrated moves within the field of a surrounding magnet, thus producing a varying voltage.

A capacitor mic places a voltage across two close together plates, thus forming a capacitor: vibrations vary the distance between the plates causing variations in the capacitance which produces voltage fluctuations.

Moving-coil mics can be good quality but have natural resonances which can be smoothed out bny verious design means. Capacitor mics have a smoother frequency response and are very sensitive but are more expensive and not as robust to rough handling.

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