Can I wire two mono microphones to a 3,5mm stereo jack?

[Arne Jensen]

Hello,
My mum is looking for a mic for her podcast and since I have 2 mono microphones (Uher m534) and she is doing the podcast with a partner I thought
it might be neat to use them together via stereo jack so there is a slight stereo effect. Her laptop only has one mic input so it would be convenient if it worked. Is this possible or will it result in a pop noise , possibly some smoke and followed by silence ?
Thanks for your help!
Arne

 

[TNT]

Sure - join the ground form each mic into one and hook this up to the input ground and then use the + from each mic to go to + left and + right input respectively.

These are Dynamic mics so no power involved.

Happy podding! (I think it will work... 🙂)

//

 

[teologean]

It is possible, however you will no longer have balanced connection so be sure you have a mic preamp that is stereo and not mono balanced (if it is a balanced mono preamp it will flip polarity of the right channel and then sum both channels together) or that your mics output at line level, and so you should be able to use a line level minijack which are much more commonly set up as a stereo pair. And keep in mind if each intervenant speaks into their mic it will be a heavy stereo effect as each mic is hard panned. From my podcasting experience no stereo at all or a really minuscule amount is best.

Hope it helps and good luck with your project !

 

[steveu]

It depends on the computer. Many do not have a stereo mic input. The "right channel" contact, the ring is used for DC bias instead, and the tip contact is a mono mic input (L+R). I would use a 35mm to RCA cable and test if both channels connect, to find out how your computer is wired. Also possible is 4 wire 35mm jack but that is usually used with headphone jacks, ie mic, ground, right, left.

 

[rayma]

If the laptop mic input is mono, which is likely, there's no stereo effect with two mics.
Since your mics are cardioid, you could use them both into a simple mixer, which then connects to the laptop,
so each person has their own mic.

 

[Pano]

Ditto what was said above. Laptops usually don't have stereo mic inputs, just mono. You could wire the two mics together into that mono input, but you won't have any individual control. And the mic input on a laptop normally has 2.5V DC on it, to power the mic. Your dynamic mics won't like that.

 

[rayma]

Really, the laptop mic input can have 2.5VDC?
That's enough reason to get a small mixer, which will have a blocking capacitor.
Or you could easily build a passive mixer with three resistors, a capacitor, and three connectors.

 

[Arne Jensen]

Thank you very much! I had never thought that the mic input is mono but I guess it makes sense.
So if I choose to use one mic inly can I connect the signal wire to L & R + of the 3,5mm jack or does the laptop automatically
record the mono signal to both channels?

 

[Arne Jensen]

@rayma : do you have a schematic of the mixer?

 

[rayma]

You'll have to read your laptop manual about that. The mic output could either go to one channel, or both.

This should work for your two identical dynamic mics. A small plastic or metal box would be ok.

 

[TNT]

What is your laptop?

//

 

[rayma]

Some laptops auto detect an external mic based on its resistance.
That may be why the mic jack is DC coupled.

 

[Arne Jensen]

Hi, thanks for the schematic, all parts are available in my electronics workshop aka kitchen🙂
I'll have to ask my mum for the model nr but I think it's an HP. I assume I can find it's detailed specs
on HP's webpage?
Thanks a lot so far! you really helped me while google didnt find me an answer... once again this site is an indispensable resource!