Need help using EM258 for headphone frequency measurement

[LegendDark]

Hello, I would like to use 2 EM258 mics 1 inserted in each ear to measure the frequency response for my headphones, this will be used to measure the effect of different ear-pads on my headphone to be able to tweak the ear-pads, other than the mics I know I would need some way to connect both microphones to my PC, I have seen some posts mentioning an audio interface but they seem to require having the interface + 3.5mm to XLR adapter, is there any budget solution to this problem?

 

[staticV3]

A Rode AI Micro, or any field recorder with 3.5mm Mic input (e.g. Olympus LS-10)

 

[LegendDark]

A Rode AI Micro, or any field recorder with 3.5mm Mic input (e.g. Olympus LS-10)

any option that cost less than $50?

 

[DVDdoug]

The easiest thing would be to record left & right separately, or just measure one side and assume the other side is the same.

The mic input on a laptop or soundcard is usually mono but not always. If you have a laptop with a combo mic-headphone jack the mic input is mono.

You can probably find a USB soundcard with a stereo mic input. But sometimes the specs are unclear or misleading... Sometimes they'll say "7.1 channel" when there's obviously only one stereo headphone output.

Then, since you aren't using a stereo mic you'd need an adapter to split left & right. I don't know if you can find a 3.5mm adapter like that but you can get adapters with a (stereo) TRS plug split-out to two separate left & right RCA connectors. Then you could add two RCA-to 3.5mm (mono) TS socket adapters.

Of course there are audio interfaces with 2 (or more) mic inputs but they are not compatible with "computer mics". Computer mics are unbalanced, and electret condensers require 5V. Stage/studio mics are balanced with XLR connectors and studio condensers run from 48V phantom power. A simple 3.5mm to XLR adapter won't work.

 

[LegendDark]

The easiest thing would be to record left & right separately, or just measure one side and assume the other side is the same.

The mic input on a laptop or soundcard is usually mono but not always. If you have a laptop with a combo mic-headphone jack the mic input is mono.

You can probably find a USB soundcard with a stereo mic input. But sometimes the specs are unclear or misleading... Sometimes they'll say "7.1 channel" when there's obviously only one stereo headphone output.

Then, since you aren't using a stereo mic you'd need an adapter to split left & right. I don't know if you can find a 3.5mm adapter like that but you can get adapters with a (stereo) TRS plug split-out to two separate left & right RCA connectors. Then you could add two RCA-to 3.5mm (mono) TS socket adapters.

Of course there are audio interfaces with 2 (or more) mic inputs but they are not compatible with "computer mics". Computer mics are unbalanced, and electret condensers require 5V. Stage/studio mics are balanced with XLR connectors and studio condensers run from 48V phantom power. A simple 3.5mm to XLR adapter won't work.

so lets say I get a sound card with stereo mic input, then I would wire the 2 mics with the same ground going to the TRS 3.5mm jack and have the tip + the ring to each mic correct?