Recording Levels

I’m recording voice on a single mic (Bluebird) and an M-Track Plus ii interface. The level can be controlled from both the M-Track and Audacity. There seems to be a significant difference in audio quality with different settings on each level control–even if the resulting wave form is about the same, e.g. peaks at -4db. Does that make sense? The worst seems to be when Audacity level is at 100%. Using this interface, what should I set the Audacity level at? Thanks


It’s usually better to leave the digital setting (Audacity) at 100% and adjust the analog level (M-Track). But of course, do whatever sounds best. :wink:

If the level is too high, you’ll get [u]clipping[/u] (distorted squared-off waves).

If the analog or acoustic level is too low, you’ll degrade the signal-to-noise ratio. The noise will become more noticeable, and if you later boost the level (digitally, or analog), you’ll boost the noise along with the signal. The digital level is not so critical as long as you have a good analog signal-to-noise ratio. Pros typically record at -12 to -18dB (at 24-bit resolution).

With digital recording, clipping happens when you try to push your ADC (analog-to-digital converter) over 0dBFS. The ADC is built-into the M-Track. So if you are clipping, the digital data it’s already clipped by the time Audacity sees it, so reducing Audacity’s recording level won’t help.

Analog circuits can also clip if you exceed the voltage limits. This shouldn’t be a problem with the M-Track, since it’s all designed to work together and the built-in preamp should have more headroom than the ADC.

You can also clip the electronics in a condenser mic with very-loud sounds, such as sticking the mic in front of a guitar amp or a kick drum.

The BlueBird is a mic with a very high output (27 mV/Pa). It is quite capable of clipping the M-Audio M-track, fi if you breathe into it. If that is the case, you need a plop filter.

Unfortunately, neither the mic nor the preamp have pads.

If the clipping is in the analog domain, you’ll need external XLR attenuators. Like these:

Which M-track BTW. There are several… And the flat black model has only rudimentary meters. M-audio doesn’t even bother to specify input sensitivity or gain for these interfaces.

But I’d still guess the gain setting is too high. Try and adjust that before venturing into other avenues.

Thanks! It’s an M-Track Plus ii. I’m not showing any clipping on the waveform. But if the Audacity level is at 100% (and the M-Track level turned down a bit) it almost sounds like clipping is occurring even tho the waveforms look fine.

That’s the opposite of what I (and DVDdoug) would expect.
Could you post a couple of short audio sample in WAV format to illustrate the differences with different settings. Just a few seconds for each sample will be adequate. See here for how to post an audio sample to the forum:

There seems to be a significant difference in audio quality with different settings on each level control-

I don’t think this is a “normal” noise/overload volume problem. You should not be able to tell if you do simple volume changes. They should be completely transparent until you reach way too loud or way too soft. You can get those odd symptoms if you left Windows conferencing and voice processing running by accident.

Windows can have other processors as well. Do you leave Skype running in the background waiting for a call?


No, nothing is running on this computer except for Audacity. I will do some tests and post some files. Thanks