“Maximizing Your Bit Count”

Have you ever noticed how digital recordings sound richer/fuller/better when the peak level surpasses -6db? This is due to the fact that the bit count itself is describing more featured instrument/voice, than background noise or silence.

Here is a brief breakdown of digital recording options, how they affect the quality of the final recording, and how you can maximize your bit count for better sounding digital recordings:

Digital recordings have several options to choose from, all of which affect file size and quality of recording.

To begin with, you must choose a “File Type”…typical options are:

– WAV
– AIFF
– Broadcast WAV
– MP3

Note: Several others are available, but we will focus on these types, as they are the most prevalent in the world of professional audio.

File type is the first point at which a choice of file size vs quality must be taken (.wav, aiff, Broadcast wav are all larger files than mp3, but deliver considerably higher sonic quality).

Beyond file type, you must choose a “Sample Rate”…typical options are:

– 44.1 KHz

– 48 KHz

– 88 KHz

– 96 KHz

Note: Again, there are several other options, but we will focus on the most prevalent sample rates used in professional audio.

The choice of sample rate determines how many times per second a “picture” of an audio waveform is taken (ie: 44,100 times per second for 44.1 KHz). The more times you sample a waveform, the more defined the representation of the waveform, the better the recording sounds. Intuitively, the more samples, the larger the file. This is the second point at which a choice of file size vs quality must be taken.

Finally you must choose a “Bit Rate” to describe each sample within the sample rate…typical options are:

• 8 Bit
• 16 Bit
• 24 Bit

Note: Again there are several other options, but we will focus on the most prevalent Bit Rates used in professional audio.

The choice of “Bit Rate” determines how many descriptors are used within the “Bit Word” (ie: 16 Bit means 16 bits of information describing each sample). Intuitively, a longer Bit Rate makes for a larger file size, more defined description, and a better sounding recording. This is the last point at which a choice of file size vs quality must be taken.

Recordings within this digital framework are then affected by the material present at the microphone, or the mix output. The bit count can only effectively describe the material it sees…up to a maximum of 0db (once you exceed 0db, you run into digital distortion…not pretty to listen to). So, if your levels are above -6db, and at or below 0db, the “Bit Word” will be describing more of your intended material than noise floor or anything else. More defined description is why recordings sound richer/fuller/better when the peak level surpasses -6db.  This is what is called “Maximizing Your Bit Count”.

I encourage you to maximize your own bit count, regardless of the file type/sample rate/ bit rate you are using. If you can find that sweet spot, you won’t be disappointed!

As a side note, the majority of the public are now choosing smaller file size over quality… which is why the mp3 has become so prevalent in today’s recorded material. As someone who is passionate about audio, this is highly disappointing, and I am hopeful there will be a movement to higher quality files now that transfer rates and storage capacities can accommodate them.

As well, the Broadcast Standard for Television is lacking, as it doesn’t allow for maximizing your bit count. With a standard of  -20db VU … it requires peaks not exceed -8db. The choice of such a low standard was made for safety reasons to avoid programs from exceeding 0db, and thus creating digital distortion. There is a better solution than this … hire a professional audio engineer.  They are trained and educated in how to create mixes that approach 0db, retain perceived dynamic range, avoid digital distortion, and maximize the program’s bit count.

I am hopeful these standards will change.

If you have any thoughts on this posting, or on any of the “Audio Insights”, please contact me…I look forward to hearing from you!

Passionate about the craft of audio,

Brad Belcher