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Question about combining two mic signals live.


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Good grief there's some bad info here...


Combining 2 like dynamic mics with a Y cable is not a problem (for most practical applications anyway).


Transformer combiners are not required as many dynamics (like 57's) have transformers inside them. Also, the voice coil and magnet of the capsule look just like a transformer anyway. There are some minor resonance and impedance curve effects that may alter the tone alittle bit, but pretty small stuff. You could use 150 ohm buildout resistors in the Y cable to eliminate most of this effect if it was that important.


Phase/polarity makes no difference in this case when combining, you would NOT want to reverse the polarity of one mic because the signals are different, and in fact it would be a problem because of the bleed. This suggestion is a classic misunderstanding of basic principles.


Summing a signal with a mixer or passively makes no difference with regard to phase or polarity. A mixer allows buffering of the signal and isolation between sources, higher load impedances, (make-up) gain, etc.


Doesn't matter about the length of the cables, the signal moves at the speed of light. Remember the guy here a few years ago who said he (and his clients) could tell the difference between a 25' and 50' mic cable on arrival times? Craig snuffed him good after his a-hole side emerged when presented with the fact that signal travels through a mic cable at the speed of light and there is less than 0.00001 degrees of phase shift due to the extra 25' of cable. Of course we were all wrong in his mind, but often bull{censored}ters believe their own dung.

 

 

Sheesh - no kidding. I'm glad to see you (and others) correcting some of the bad info here. You beat me to it.

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Why not a Y cable for your two mics?

 

 

You know, I don't have a really good answer for that. A combiner is only going to cost me a little bit more, and I know you said that there is no harm done by using a Y-cable, but I just feel a bit more comfortable using a combiner. Sure, it may be irrational, and unnecessary, but if I feel more comfortable with it for whatever reason, those 15 extra dollars are well spent, right? haha

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Why not a Y cable for your two mics?

 

 

Earlier, "before the crash" I suggested that relative volume control is a reason. If his on-stage levels (relative to each other) need to be adjusted, this affects what he sends to FOH and can't be changed without affecting his stage 'mix'. Amp/cab positioning could be causes for this issue to arise.

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Alright, so I realized that the mic combiner may not be the way to go. I may have to use two vastly different sized amps on stage (5 watt, and 15 watt amps), but I want the signal coming from the 5 watt amp to be way louder into the PA, but I'll need the 15 watter to be able to hear myself over the drummer. Sounds to me like I'll need a mixer of some sort. Is this even going to be possible to do this way? Run the 15 watt amp louder on stage so I have enough stage volume to be able to hear myself, but have the 5 watt amp louder through the PA since I love the tone, or is this just asking for trouble?

 

If I need a mixer of some sort, would something like this be acceptable? http://pro-audio.musiciansfriend.com/product/ART-ProMIX-Mixer?sku=180626

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