All About Noise Floor with Alex the Audio Scientist

We’d like to introduce you to the newest member of the ACX team, Alex the Audio Scientist. Alex has a degree in Audiobook Studies from ACX University, and he’ll be stopping by the blog from time to time to explain some key ADBLCRE-ACX_Character_Iconaspects of audiobook recording and production. So without further ado, take it away Alex!

Nice to Meet You!

Hi everyone I’m excited to share my knowledge of all things audiobooks and help you improve your ACX productions. Before today’s lesson, I hope you’ve read previous posts on this blog regarding home studio setup, because today I’ll cover a common problem with voice recording spaces: a high noise floor. Enjoy the video below, and take good notes – there’ll be a quiz afterward!

And we’re back. Ready for that quiz I mentioned? Let’s see how much you learned. Leave your answers in the comments below. The first person to get every answer correct will get a shout out in my next post!

  1. The noise floor is the ________ level of background noise in a recording, when no narration is taking place.
  2. A high noise floor in a home studio can be caused by ________, ________, ________, ________, or ________.
  3. Its best to address your noise floor issues during the ________ stage.
  4. I recommended using a ________ to remove unwanted frequencies, such as a low rumble.
  5. The appropriate frequency range to target the removal of this low rumble is usually between ________ and ________ Hz.
  6. The ACX Audio Submission Requirements call for a noise floor no higher than ________ dB RMS.

17 responses to “All About Noise Floor with Alex the Audio Scientist

  1. 1. Highest 2. Appliances, lighting, background, wiring problems, or equipment. 3.recording.4. Bandpass filter 5. 30 – 80 hz. 6. 60

  2. I appreciate what Alex is sharing here today, thank you!!!

    Sent on a Sprint Samsung Galaxy S® III

  3. There is no workable link to “the video below”! I’m not amused by your making Alex, a cartoon character, your spokesperson for important issues to producers. If he has the professional chops, who is he and what are his credentials?

    • The same thing is done for many tutorials. Companies like Google INC, Apple, Microsoft and Adobe have all used illustrations. It makes the material simpler and more connectable to people of lesser experience. It isn’t really any less professional than a screen recording where you don’t see a person at all. As a certified ACX Instructor, whether or not he has credentials, he obviously knows his stuff. Henry Ford didn’t have a degree in engineering, or any schooling past 8th grade, but did that stop him from sharing something useful? I try not to judge people by their credentials. There’s too many incredible minds without them, and too many with incredible minds polluted with pride by them.

  4. Reblogged this on RA Fischer and commented:
    Interesting article for narrators and producers

  5. Thanks & good topic & notes. Some thoughts to add: Dimmer switches and fluorescent lights also are common noise sources because they have relatively high frequency switching as do some types of newer LED lighting. Ground loops which are probably the biggest culprit if the noise is a harmonic of 50 or 60Hz – meaning that there are two pieces of equipment connected by a cable, but the electrical ground at the two equipment are different. Suggest using balanced cables (XLR) vs. RCA phono (unbalanced) cables also. Low frequency noises are over-weighted by a simple RMS floor spec. A perceptually weighted noise floor is a better measure of acceptability than the simple RMS value. -60dB at 2KHz is a lot worse than-60dB at 100Hz (which most people won’t be able to hear anyway).

  6. 3. *studio construction/setup*
    4. Might as well use a high-pass filter.
    5. Sometimes up to 100Hz; Adobe Audition’s “Kill The Mic Rumble” preset is a high-pass at 100Hz, and most people’s voices don’t go below that.

  7. When I first set up my studio, I kept getting a very-low, barely-audible hum/rumble. I found that it came from the vibration from my tower cpu in the desk cabinet transmitted to the mike stand and boom on my desk. Easily solved by placing a folded towel under each.

  8. Thank you for addressing this issue. As I learn more, these tutorials are even more helpful. Would someone please consider a video on how to reduce mouth noise while narrating? From the perspective of a new narrator attempting to produce less mouth noise as a performer, without consideration of equipment adjustment.

  9. The noise floor is the _AUDIBLE__ level of background noise in a recording, when no narration is taking place.
    A high noise floor in a home studio can be caused by _hvac_, _pc fan_, _OUTSDE NOISE__NOISY MIC_, _NOISY PRE AMP_, or __FRIDGE_____.
    Its best to address your noise floor issues during the ___RECORDING_____ stage.
    I recommended using a ___HIGH PASS FILTER_____ to remove unwanted frequencies, such as a low rumble.
    The appropriate frequency range to target the removal of this low rumble is usually between ___70_____ and ___100_____ Hz.
    The ACX Audio Submission Requirements call for a noise floor no higher than ___-60_____ dB RMS.

  10. Billy Bob Merkowitz

    Its best to address your noise floor issues during the ___Construction_____ stage.

  11. Pingback: Regarding Room Tone with Alex the Audio Scientist | Audiobook Creation Exchange Blog (ACX)

  12. The noise floor is the audible level of background noise in a recording, when no narration is taking place.
    A high noise floor in a home studio can be caused by HVAC, Computer Fans, Refrigerators, Pre-Amp, or microphone.
    Its best to address your noise floor issues during the Recording stage.
    I recommended using a High Pass Filter, (HPF) to remove unwanted frequencies, such as a low rumble.
    The appropriate frequency range to target the removal of this low rumble is usually between 70 and 100 Hz.
    The ACX Audio Submission Requirements call for a noise floor no higher than -60db dB RMS.

  13. I’ve lived and recorded in two different houses over the past 80+ productions. I’ve never had any trouble meeting the noise floor requirement, and I’ve never used a sound booth. What I have done is carefully seek out any noise I hear and eliminate it at the source. Anything that makes a noise, such as HVAC, gets shut down for the duration of each recording session. The mic is on its own stand, not on a table or desk. And so forth. I keep a “silence checklist” to make sure I remember everything that’s been guilty of letting out a sound during a session.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s