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Hi
I bought a U195 a couple of weeks ago, and it sounds fine, although I haven't used it for any critical recordings yet. I was just curious/concerned about the audio waveform of recordings made with this mic.
The waveform produced by my other mics display almost mirror image amplitude readings either side of the zero amplitude point, (the line running through the centre of the graph) but my Soundelux waveform weaves either side of the zero point like a snake. Sometimes spending up to .25 seconds in the upper (positive area) or lower sections. Is this a phase problem? It sounds OK, but do you know if this is normal? I don't want to use this mic on anything until I know it's not going to do weird things in a mix.

Comments

anonymous Tue, 05/04/2004 - 11:13

What you describe is called "DC offset". I don´t really know the scientific/theoretical side of it well enough to be the man to explain it, but that´s most likely what it is. Most softwares have a "remove DC-offset"-function that fixes it. I´ve experienced this with a SM57 sometime. As long as it sounds fine I don´t think you need to worry. Anyone know how to explain this phenomenon, I´d like to know aswell.

sdevino Tue, 05/04/2004 - 13:56

It may not be DC offset. Some non-linear distortons (like what you would see if you look at the waveform of a recorded saxophone) appear to be more above the 0 point than below or vica versa.

If you look closely though you may find the there is a wide but not very high amplitude signal in one half and a narrow but higher amplitude peak in the other. If you calculated the area under each of these curves they would be very close to equal. So while the peak voltage is different, the RMS voltage is the same.

If you do not track what I am talking about you need either more math or more electronics education.

On the other hand it could be DC offset :)

Steve

JeffreyMajeau Tue, 05/04/2004 - 17:45

Monitor your mix in mono and you'll have your answer :P. If it sounds correct, then the waveform display isn't that critical. Remember, we used to do this gig with no CRT screen, using our ears. Instead of pointing at a transient we used our ears to find 'em and then marked w/grease pencil. :P. I'm just being a smartass...