the noise floor lowered to -60 dB only when I activated the mic’s bass cut filter.
Many home recording systems generate tons of subaudible noise, based, I suppose, on the theory that it’s expensive to fix, nobody can hear it and in most cases, it doesn’t make any difference anyway.
It does if you’re trying to pass ACX. ACX apparently uses unlimited noise measurements (Z Weighing) which responds to acoustical energy in the performance whether you can hear it or not.
We had a significant fuss whether or not to include a High Pass Filter as part of the Audiobook Mastering Suite. We did on the theory that it did more good for technical compliance than voice problems it caused.
So even if you left the high pass filter off in your audio equipment, if you follow the mastering suite, we do the same thing in the first step.
“Low Rolloff” and “High Pass” are the same thing.
Having a rumble filter is perfectly valid. There are such filters on many sound mixers and interfaces. Most of the voices you hear in Hollywood movies have been through such a filter.
There’s a festival of different ways to miss noise conformance. The legacy mic preamp internal noise (Hiss. FFFFF) is joined by computer fan noise, lighting or other home appliance noise, sub audible “rumble noise” and the much more exotic Yeti Curse.
And it’s all made much worse by home style microphones delivering lower volume by design. Generally, only high volume overload and clipping distortion will cause you to send the microphone back.
Most trash is introduced when the sound is still analog. Once you digitise it into ones and zeros, it’s relatively immune to misbehavior.
Nobody wrote you can’t have more than one problem. A majority of home user failures are noise,
Post a sample of the work. We can give you a good idea of what’s gone wrong and how to fix it.
http://www.kozco.com/tech/audacity/TestClip/Record_A_Clip.html
Do Not Process Anything. Leave the filter off. Record it, export it and post it on the forum.
Koz