Ribbon Mic Question

[Dave S.]

I'm using a ribbon mic to record brass instruments. I'm wondering why so much more of the wave is below the center line than above? This is creating some problems for me in my mix.
Dave

 

[wheelema]

Dave,

Would you be so kind as to provide the make and model of the mic, and the make and model of the preamp? Also, what piece of gear/software are you looking at?

 

[Dave S.]

Sure:
Mic: Royer R-122
Pre: Omni-IO
Software: Cool Edit Pro 1.2a

Also attached is a picture of a wave that illustrates my question.

Thanks.

Dave

 

[crazydoc]

Does Cool Edit have a mechanism for adjusting the DC offset voltage? That looks like the problem.

 

[Dave S.]

That's what I originally thought too. But, the baseline is right in the middle. Also, when I record the same signal through another mic (a condenser) it's fine. That's what made me think it's something inherent in ribbon mics.
Dave

 

[DJL]

Hey Dave, shoot Harvey Grest a PM... he love's helping with these type of questions. http://www.homerecording.com/bbs/member.php?action=getinfo&userid=7767

 

[Harvey Gerst]

Click on "Transform", then cliclk on "Invert". Looks like the mic is wired incorrectly and the polarity is reversed.

 

[chessrock]

If you invert it, then it will just be the same thing, only upside-down. I get that kind of wave when I apply too much EQ on something. It's actually fairly common. It's definitely a phase/polarity thing, but it's one of those rare audio mysteries that no one seems to have a clear answer to. Or at least I have yet to hear one that is commonly agreed on.

 

[Marik]

I had exactly the same problem using my ribbons. I would think that the problem is in time delay and phase shift of the signal between front and rear of the ribbon itself. With frequency increase, when the wavelength approaches the lehgth of the path between front and rear, one side of the waveform gets partially canceled. The best person to talk about it would be David Royer himself, I guess. I would be also very interested to know what's that.

 

[Harvey Gerst]

With the possible exception of synths and samplers, very few actual instruments (or voices) produce exactly symetrical waves that are even in amplitude, both in the positive and negative cycle of the wave form. Most people are accustomed to seeing primarily positive energy waveforms, but negative is not unheard of either.

As I said earlier, invert the waveform and see if it sounds better. If it doesn't, just live with it as is - it's no big deal.

 

[chessrock]

With the possible exception of synths and samplers, very few actual instruments (or voices) produce exactly symetrical waves that are even in amplitude, both in the positive and negative cycle of the wave form. Most people are accustomed to seeing primarily positive energy waveforms, but negative is not unheard of either.

That's really interesting. Thanks for the info, Harvey.

I think I tend to see the negative kind when there are various forms of distortion added -- i.e. tube amps, etc. Even from using too much funky EQ.

 

[Dave S.]

Thanks for all the replies. As chessrock said, when I invert it, I get the same thing only upside down.
Harvey, when you say “few actual instruments (or voices) produce exactly symetrical waves that are even in amplitude, both in the positive and negative cycle of the wave form” I can understand that. However, if I record the same instruments, in the same positions, with my condenser I get a pretty symmetrical pattern. Not at all like the pattern with the ribbon.
There is no EQ on these tracks.
The reason it is kind of a big deal to me is that I’m mixing other parts, some recorded direct in and some with a condenser that all have a more symmetrical pattern. I can’t get the levels right without doing a submix of the ribbon tracks, letting them clip, and then mixing that with the others.
I did try using the page on the Royer web site to contact them about this but have not, as yet received a reply.
Dave

 

[spankenstein]

The reason it is kind of a big deal to me is that I’m mixing other parts, some recorded direct in and some with a condenser that all have a more symmetrical pattern. I can’t get the levels right without doing a submix of the ribbon tracks, letting them clip, and then mixing that with the others.

Why not bring the level of everyhting else down giving you more headroom on the tracks in question?