Ribbon Mics, Backsides, and fliping phases

bkkornaker

bkkornaker

www.bryankmusic.com
Ok, i don understand really why someone has to flip the phase on thieir preamp when recording using the backside of a Ribbon mic. I understand that the backside is the reverse polarity of the ribbon (yadda yadda yadda), but why then flip the phase on the mic preamp? why cant you just use the backside of the mic, and not flip anything and let it be what it is?

Only reason i ask is cause recently got a CAD trion 7000, and when i first got it i really didnt know much about it or ribbon mics in general. So i tested it by doing some spoken word stuff, and recorded it.....then decided to try the same on the backside of the mic, and noticed it seems clearer and a tad bit louder?

also, if i were to use the back side of the mic, and flip the phase, would it not sound just like the front side? then what would be the point in doing that?

can someone share some thoughts on this subject?
 
bkkornaker said:
Ok, i don understand really why someone has to flip the phase on thieir preamp when recording using the backside of a Ribbon mic. I understand that the backside is the reverse polarity of the ribbon (yadda yadda yadda), but why then flip the phase on the mic preamp? why cant you just use the backside of the mic, and not flip anything and let it be what it is?

Only reason i ask is cause recently got a CAD trion 7000, and when i first got it i really didnt know much about it or ribbon mics in general. So i tested it by doing some spoken word stuff, and recorded it.....then decided to try the same on the backside of the mic, and noticed it seems clearer and a tad bit louder?

also, if i were to use the back side of the mic, and flip the phase, would it not sound just like the front side? then what would be the point in doing that?

can someone share some thoughts on this subject?
Click to expand...

I think you only need to flip the phase if you are recording the same source with 2 mics. If you are just recording using the back side of a ribbon mic I see no reason to switch phase.
 
Here's what I know about it...

I use a pair of ribbon mics in a Mid/Side stereo recording arrangement. One of 'em points right at the source--that's the mid. The other mic (a figure 8, by the way--with front and back pickup like yours) is perpendicular to the Mid mic. That's the side.

I duplicate the side track, invert the phase of that duped track, and pan one hard left and one hard right. Those two tracks now operate as the "side" info in a cool stereo set up--in conjunction with the mid mic. Turn the sides down, the stereo field narrows, turn 'em up, and the stereo field gets wider.

In this case inverting the phase means that if the two side tracked are panned to the center, they completely disappear. That's why this was such a popular technique when mono was still more prevalent--it would still sound good when summed to mono.

I don't know if any of this has anything to do with how you're using your ribbon mic--but that's the only situation in which I flip the phase on my ribbon mic.
 
right.....everything you guys mention makes sense...

everything ive researched on the net made it sound like you should flip the phase when using the backside, even if your not using multiple mics.

which is why i am so confused as to why do that when using the mic by itself.
 
bkkornaker said:
right.....everything you guys mention makes sense...

everything ive researched on the net made it sound like you should flip the phase when using the backside, even if your not using multiple mics.

which is why i am so confused as to why do that when using the mic by itself.
Click to expand...

Because real-world sounds (at least the transient portions thereof) aren't identical on both halves of the waveform. If you mic a drum, for example, the hit goes outwards towards the mic first, and the volume on the next part of the cycle is significantly weaker. Same goes for plosives.

Whether the human ear can distinguish phase or not is a question open for debate. Some studies pretty clearly say yes, while others say no. My experience is that yes, there is a definite perceived difference in the sound of non-continuous waveforms (e.g. transients) when phase reversed, though how much of that is caused by nonlinearity in the speaker design is left as an exercise for the reader. :)
 
bkkornaker said:
right.....everything you guys mention makes sense...

everything ive researched on the net made it sound like you should flip the phase when using the backside, even if your not using multiple mics.

which is why i am so confused as to why do that when using the mic by itself.
Click to expand...
Ribbon mics themselves aren't necessarily symmetrical. As a result, many ribbon mics do, indeed, sound distinctly different on the two sides of the mic. In fact, some manufacturers tout this as a benefit. (Two mics in one! ;))

So you may find that you prefer to use the back of the mic on some sources. If so, and especially if you have other mics open that may pick up the same source, then it's a good idea to reverse the polarity on the ribbon so that it is in sync with the other mics in the room.

If there are no other open mics, then the only concern would be the absolute polarity, which (as dgatwood points out) may be important for some sources.

In any event, to go back to your original question, flipping the polarity may not give the same result as physically reversing the mic.
 
Even if you aren't reording with two mics at once, what if you are doing something like layering tracks? You are still better off to reverse the polarity to keep things in proper relationship. I guess a better question is why not reverse the polarity?
 
ok, so lets say im recording 4 guitar rhythm tracks. 2 panned left, 2 panned right.

If i use this ribbon mic by itself and record each take/track at a time.....are you saying to flip the phase at my mic preamp, when recording 2 out of the 4 takes?

why?

i think im growing more confused with this now.....

i still dont know why one should even flip the phase on the mic preamp when using a single ribbon mic by itself to begin with....useing either front or backside of the ribbon mic.....it just doesnt make sense...
 
bkkornaker said:
are you saying to flip the phase at my mic preamp, when recording 2 out of the 4 takes?
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No.
If you are only using one mic per take you never have to worry about phase.

A mic can only be out of phase in relation to another mic. If you are only using one mic at a time there is no way it can be out of phase whether you are using the front, back or side.
 
xstatic said:
Even if you aren't reording with two mics at once, what if you are doing something like layering tracks? You are still better off to reverse the polarity to keep things in proper relationship. I guess a better question is why not reverse the polarity?
Click to expand...

Wouldn't reversing the polarity take to take actually have more of chance of screwing up phase than just leaving it?

I'm having trouble understanding why you would do that.
 
bkkornaker said:
...i still dont know why one should even flip the phase on the mic preamp when using a single ribbon mic by itself to begin with....useing either front or backside of the ribbon mic.....it just doesnt make sense...
Click to expand...

I wouldn't...
 
xstatic said:
Even if you aren't reording with two mics at once, what if you are doing something like layering tracks? You are still better off to reverse the polarity to keep things in proper relationship. I guess a better question is why not reverse the polarity?
Click to expand...

I don't see why this would be a good thing. When adding a layer, it's an entirely new track, I've never heard of reversing polarity of a new track like that just because it's 'safer'.
 
The549 said:
I don't see why this would be a good thing. When adding a layer, it's an entirely new track, I've never heard of reversing polarity of a new track like that just because it's 'safer'.
Click to expand...
I don't think "safety" has anything to do with it.

Some people believe that absolute polarity is important. In other words, if the first pulse from a drum hit is a compression, they think that it is important that the same is true of the first pulse that comes from the speaker when that sound is reproduced. I don't necessarily accept that position, but that's the viewpoint that would argue in favor of carefully maintaining polarity on a ribbon mic - even when it is the only one in use.

If absolute polarity doesn't matter to you, then the only time you need to worry about polarity is when multiple mics are capturing the same source.
 
Gilliland said:
I don't think "safety" has anything to do with it.

Some people believe that absolute polarity is important. In other words, if the first pulse from a drum hit is a compression, they think that it is important that the same is true of the first pulse that comes from the speaker when that sound is reproduced. I don't necessarily accept that position, but that's the viewpoint that would argue in favor of carefully maintaining polarity on a ribbon mic - even when it is the only one in use.

If absolute polarity doesn't matter to you, then the only time you need to worry about polarity is when multiple mics are capturing the same source.
Click to expand...

Ah, well then I'll look that subject up.
 
bkkornaker said:
..Only reason i ask is cause recently got a CAD trion 7000, and when i first got it i really didnt know much about it or ribbon mics in general. So i tested it by doing some spoken word stuff, and recorded it.....then decided to try the same on the backside of the mic, and noticed it seems clearer and a tad bit louder?
Click to expand...
If that happened to be your own voice in headphones then yes- it mixes diffetently with what you hear through your head. A good thing to check when you doing vocals, one flip will usually sound beter than the other in the phones.
 
MarshallLaw6278 said:
not true about the one mic not having to worry about phase. you can get reflections off of walls/floors etc. that will cause phase issues
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Yeah but then they gave us the 3:1 rule which when you apply the 'why' portion to the possible reflections -you're back in the ball park and good to go. :)

Welcome to the site there too. lots of fun round here. :D
 
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