# Two Microphones



## edmedmoped (Sep 26, 2009)

I do a 'webshow' with some friends from school. One of the biggest problems is that there's three or four of us in the room, and one microphone.

I was looking for something that would let us plug two mics in (one XLR to 6.3mm and one 3.5mm to 6.3mm). SO what I need is something that will do this:

6.3mm + 6.3mm -> USB

I thought about this, but it looks as if you have to select which one you want to use/can't use both at the same time.

We don't have a huge budget as we're relying on donations and profits from merchandise. Try to keep it around the same price as the thing above if you make a suggestion!

Cheers, and sorry if it's a bit naughty posting this on a technical theatre forum .


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## mstaylor (Sep 26, 2009)

You can go to a music store or Radio Shack and they will have ready made twofers and adapters to do what you want. The quality may or may be affected, hard to tell without seeing what you have.


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## BillESC (Sep 26, 2009)

What you need is a small mic mixer.

Go to Phonic.com and look at the AM 220 and AM 440. Both are under a hundred USD and will give you the flexibility to balance the mics.


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## mstaylor (Sep 26, 2009)

Bill's way is better, I was looking a next to nothing solution.


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## rwhealey (Sep 27, 2009)

I've seen that tiny Behringer 4 channel mixer on craigslist for $25.

I'm sure you can find something used. You might have to get/make some adapters though, and that will drive up the cost.


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## edmedmoped (Sep 27, 2009)

Thanks guys.

Would it work if i got one with 1 input and plugged the two mics into a 2 female -> 1 male thing?

EDMEDIT: I'm going to go for this:
http://www.soundslive.co.uk/product~name~Phonic-AM440~ID~9997.asp


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## Chris15 (Sep 27, 2009)

There are a small handful of situations when it is acceptable to use a Y combiner, ie. 2 female to a single male.

If you have to ask, then it's not one of those times. You will lose individual control of the mics not to mention that in some cases you can damage the mics because of impedance mismatching.


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## 00AVD (Sep 27, 2009)

You'll never damage a dynamic mic by impedance mis-matching. One may drown the other out, but that's about the worst that can happen.


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## Chris15 (Sep 27, 2009)

No but anything with an active output can be, because mic 2's output presents a low impedance and Mic 1 tries to drive that and can't cope. The opposite happens also and basically it can get nasty.

We've discussed this before, go look at the Rane Note here: Why Not Wye?


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## edmedmoped (Sep 27, 2009)

Ah alright.


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## 00AVD (Sep 27, 2009)

I'm guessing the OP has dynamic mics by the situation being discussed. I doubt even condenser mics would be damaged in any "Y" connection.

Now, mixer and other outputs are a different kettle of fish.


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## edmedmoped (Sep 27, 2009)

^ correct.


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## museav (Sep 27, 2009)

00AVD said:


> You'll never damage a dynamic mic by impedance mis-matching. One may drown the other out, but that's about the worst that can happen.


If nothing else you can 'damage' the response and the resulting mix.


00AVD said:


> I'm guessing the OP has dynamic mics by the situation being discussed. I doubt even condenser mics would be damaged in any "Y" connection.


But it could damage the mixer, the lower resulting source impedance and greater current requirements from the input seeing two mics in parallel could easily exceed the phantom power capabilities of the input.

Paralleling mic inputs where only one input at a time is used is an accepted practice in some situations, paralleling mics is generally not. Ignoring any other potential issues, you have no control of the mix and the levels and response for each mic will be dependent upon the characteristics of the other mic and the console input. Especially since you apparently have two different mics, I would look for a better solution.


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## 00AVD (Sep 27, 2009)

museav said:


> But it could damage the mixer, the lower resulting source impedance and greater current requirements from the input seeing two mics in parallel could easily exceed the phantom power capabilities of the input.



The phantom supply voltage is current limited (< 10mA usually) by the series resistors (often 6800 Ohms with a 48V supply) in the mixer and should be able to take a short to ground if correctly implemented.

This is also assuming a condenser mic, which I'm fairly sure the OP doesn't have. Balanced dynamic mics would have no effect on the phantom power anyway.


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## MillburyAuditorium (Sep 27, 2009)

How about a small sound board? You would just need to find a wire that goes from dual 1/4 inch to USB. This way you could have some live sound aswell, if you web show is live.

I use this for my little setup in my basement, $60, two mic inputs and two other audio inputs, although you can still use them for mics, if they are 1/4 inch. XENYX 802

Or if you want four mic inputs, this one is $120, also has solo buttons etc.
XENYX 1204FX


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## museav (Sep 27, 2009)

00AVD said:


> The phantom supply voltage is current limited (< 10mA usually) by the series resistors (often 6800 Ohms with a 48V supply) in the mixer and should be able to take a short to ground if correctly implemented.


That is not necessarily true for all mixers and unless you know that it is valid it is probably better to not assume it or try it. I just don't want anyone getting the impression that "Y"ing two mics of any type to one input is a generally suggested or accepted approach, it is not, however it is an option in specific situations.


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## edmedmoped (Sep 28, 2009)

MillburyAuditorium said:


> How about a small sound board? You would just need to find a wire that goes from dual 1/4 inch to USB. This way you could have some live sound aswell, if you web show is live.
> 
> I use this for my little setup in my basement, $60, two mic inputs and two other audio inputs, although you can still use them for mics, if they are 1/4 inch. XENYX 802
> 
> ...


Yeah that's kinda what I'm going for now .

It is live as well.


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## howlingwolf487 (Sep 30, 2009)

How about this little guy? Seems like it would fit the bill perfectly! Cost from GC Online: $79.00USD. Or, if you want more functionality for later...look at this offering from Peavey.


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## edmedmoped (Sep 30, 2009)

No worries guys, I've gone and bought this: Manufacturers | AM 440 | Non-powered Mixers | Mixers | 4 Mic/Line 4 Stereo Input Compact Mixer

Found it really cheap too.


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## edmedmoped (Oct 10, 2009)

I have a problem...

I have my SM-58 plugged in to the mixer (XLR to 1/4") and that works fine.

I have two other cheap mics which are 3.5mm with two black lines. They work fine when plugged into the computer but don't work at all when plugged into the mixer with a 3.5mm to 1/4" adaptor.

I've tried an adaptor thing with two black lines and that didn't work so I tried one with one black line and that didn't work either.

I'm confused.


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## mstaylor (Oct 10, 2009)

Try and see if you have a mic type and number. You may have a condenser mic that requires phantom power.


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## edmedmoped (Oct 10, 2009)

:neutral: One's a cheap clip mic and the other's a cheap long mic. I don't have any condensers.


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## mstaylor (Oct 10, 2009)

Just a thought.


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## museav (Oct 11, 2009)

edmedmoped said:


> I have my SM-58 plugged in to the mixer (XLR to 1/4") and that works fine.


Why the XLR to 1/4"? The 1/4" inputs on the mixer are intended for line level signals, the XLR inputs are for mics. So just use a standard male XLR to female XLR mic cable and plug into the XLR input.


edmedmoped said:


> I have two other cheap mics which are 3.5mm with two black lines. They work fine when plugged into the computer but don't work at all when plugged into the mixer with a 3.5mm to 1/4" adaptor.
> 
> I've tried an adaptor thing with two black lines and that didn't work so I tried one with one black line and that didn't work either.


I'm guessing that the "two black lines" is a TRS connector and the "one black line" is a TS connector. Are the two mics in question computer mics? Computer mics are usually wired as unbalanced audio and DC power with the tip for signal +, ring for +5VDC and sleeve as shared ground. Computer mics are intended to work with sound card mic connections and are not directly compatible with standard audio connections. It is likely possible to construct a circuit to allow you to use computer mics with the mixer but given the audio quality of typical computer mics, the cost and effort of building such a circuit and the cost of some entry level audio mics, it's probably not worth it. You could hook a computer mic and the mixer output to your sound card and use the PC mixer software to mix the sound card's computer mic input and the sound card's line input, giving you two mics. Or you could simply get an entry level audio mic or two and connect them to the mixer with mic cables.


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## edmedmoped (Oct 11, 2009)

Oh cool.

They are computer mics, and the reason I'm using xlr to 1/4" is because I have that lead and it worked so I couldn't be bothered to buy an xlr lead.


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## Soxred93 (Oct 11, 2009)

edmedmoped said:


> the reason I'm using xlr to 1/4" is because I have that lead and it worked so I couldn't be bothered to buy an xlr lead.



Be aware that Mic In and Line In are NOT INTERCHANGABLE. They may have a standard pinout, and many places use them, but the two have very different levels. Line In is designed for stuff like guitars, keyboards, basses, instruments which send a high, line-level signal through the cable. Mic In is designed for micrphones, which have a low signal level. This is why they need a preamp if going into a line in spot. 

It would be a lot more cost efficient to buy XLR cables than a preamp...


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