I recorded the audio from my band's gig this weekend. The mixer/PA (Allen & Heath) can record the audio from each channel as a WAV directly to a USB attached device. The image is the graph of two of the channels, the sax player (top) and the trombone player (bottom). Both use mics that clip to the bell and both were wired directly to the mixer. I don't know what brands they used, although I know the trombonist's mic requires phantom power (I assume the sax player as well, but I'm not sure.) What would cause the asymmetry in the signal of the trombone player?
\$\begingroup\$
\$\endgroup\$
4
-
\$\begingroup\$ Is there any possibility that it's getting a constant positive bias from the increase in pressure due to the wind from the instrument during a note? Do you reckon there could be DC coupling from the mic through the mixer channel? It's unlikely for a phantom powered mic,. I reckon. \$\endgroup\$– TransistorCommented Sep 16 at 18:05
-
\$\begingroup\$ A trombone signal envelope is sometimes asymmetrical. Have you tried looking up examples? \$\endgroup\$– Andy akaCommented Sep 16 at 19:18
-
\$\begingroup\$ does it sound distorted? \$\endgroup\$– jsotolaCommented Sep 17 at 2:23
-
\$\begingroup\$ That is quite normal for brass. See this article: soundonsound.com/sound-advice/… \$\endgroup\$– ex4Commented Sep 18 at 18:45
Add a comment
|
1 Answer
\$\begingroup\$
\$\endgroup\$
1
Guesses only are possible without having the used mics, desk and recorder. My two best guesses: 1) The mic is an electret which has poor battery or phantom feed. Or 2) the sound pressure was too high for linear operation of the internal preamp of the mic.
Other possibilities: bad mic channel circuits somewhere between the mixer input and the digital output. But if the sound is perfect (the right amount of distortion can in some cases be also perfect) do nothing except try to remember for the future how the recording system was set up.
If the sound is bad you may be able to perform a proper fault finding procedure by swapping things between channels. You, of course, must have the used equipment in your hands. Otherwise you have only guesses.
-
\$\begingroup\$ was guessing a mis-biased electret mic too. \$\endgroup\$ Commented Sep 16 at 19:24