POW-r Algorithms

Twelve years ago, some friends and I got together with the intent of developing the most musically neutral and dynamically accurate audio bit length reduction algorithms. As we completed the code, many of the audio industry’s golden-eared engineers and producers reviewed our work favorably. We soon after became the world’s #1 software for audio bit length reduction.

The software is called POW-r, which is an acronym for “psychoacoustically optimized word-length reduction.” Most professional audio recording today uses DAWs, PC-based “digital audio workstations.” ¬†Digitized audio is stored in software bit chunks called “words.” Most DAWs today default to 24-bit word lengths (although internal processing may be twice that or more). Each bit represents a 6dB change in “audio voltage.” More bits equals higher acoustic dynamic range. A higher dynamic range equates to more realistic sound reproduction.

The common CD stores digital audio in 16-bit word lengths. And this is the problem: when transferring native 24-bit audio from the DAW onto a 16-bit CD, we lose 8-bits, or 48dB!

What does 48dB sound like? It’s the difference between normal conversation (65dB) and a live rock concert (115dB), or the difference between a softly played piano (75dB) and a forte symphony orchestra (120dB). How do you get the full impact of a 24-bit studio recording (potentially 144dB*) onto a CD which can only represent 96dB?

Enter the unique software algorithms called POW-r. Our code was created in the real world of symphony orchestras, of which I have engineered hundreds of recordings. We tested numerous iterations of the software in real-world acoustics, carefully comparing musical results until we found optimal subjective performance.

Today, POW-r remains the world’s #1 word-length-reduction solution, both for CD and MP3 bit preparation. Most of the top DAW companies license POW-r (Apple Logic, Avid ProTools, Cakewalk Sonar, Magix Samplitude and Sequoia, Ableton Live, Pyramix, and many others). It’s been estimated that POW-r is now used on over 400 million CDs and downloads annually.

(* in practice, studio recordings rarely achieve 144dB dynamic range, and home playback systems can rarely offer much more than 110dB, if that. What’s worse, most music today is played back into ear buds, with a dynamic range rarely exceeding 90dB, and that assumes a very quiet environment and high quality playback source.)


Leave a Reply

Your email address will not be published. Required fields are marked *