High-Resolution Audio FAQs: Part 2

Here’s the second part of the FAQs that I’ve prepared for the upcoming “Consumer Guide to High-Resolution Audio”. The first part was posted yesterday and can be read by clicking here.

6. What is Master Source Quality?

A “Master Source Quality” music file is a transfer of the best available copy of a particular track or album. For example, if the best master analog tape of a Beatles track was transferred to a 96 kHz/24-bit PCM digital file and made available to consumers, it should be referred to as “Master Source Quality” not “High-Resolution Audio”. The fidelity of today’s recording equipment is improved over the analog decks from the 1960s and offers artist, engineers, and producers the potential for greater fidelity. It is, of course, their choice to take advantage of it or not.

7. What hardware do I need to listen to High-Resolution Audio or Master Source Quality?

Consumer electronics companies have introduced new products that can play higher spec sound files. However, compact disc players use 44.1 kHz/16-bit PCM audio and thus cannot playback HRA files at 96 kHz/24-bits or higher for example.

There are new optical disc players (DVD and Blu-ray) and portable players that can play High-Resolution or Master Source Quality audio. High-end equipment makers have raised the bar with external Digital to Analog Converters (DACs) and several cell phone companies offer high-res models.

Recently, streaming services like Orastream, Tidal, and Qobuz have begun to offer higher quality music on demand. However, virtually all of the content being streamed as “high-res” is only “Master Source Quality”.

8. Where can consumers acquire High-Resolution Audio and “Master Source Quality” music?

Higher fidelity audio was introduced on competing physical disc formats back in 2000. Sony and Phillips developed the SACD format, which uses a different encoding scheme than most audio products. It’s known as DSD. Warner Brothers and Toshiba backed the DVD-Audio format, which used the same discs specs as DVD movies but added High-Resolution Audio capabilities in full 5.1 surround sound. Outside of the audiophile community these physical formats never developed a following, and with the increasing popularity of downloading and streaming, all physical formats are fading away.

The first High-Resolution Audio download site in the U.S. was launched in the fall of 2007. iTrax.com is still around today and offers real High-Resolution Audio files in stereo and 5.1 surround. Other sites like HDtracks, ProStudioMasters, HighResAudio, and PonoMusic entered the market and offer “Master Source Quality” albums from the major labels under licensing agreements. These tracks represent the best available versions of many familiar albums but they are not new recordings done in real high-res.

The era of streaming “High-Resolution Audio” is coming. There are technologies that allow better quality music to be delivered to your portable device and networked home server. Tidal and MQA are working together to deliver “Master Source Quality” audio. However, the limiting factor remains the fidelity of the original recordings, which are not real “High-Resolution Audio.

Consumers are confused and misinformed. There are logos for hardware that specify one set of requirements for hardware and a much lower set of requirements for the music content. It’s buyer beware in the search for better fidelity audio files.

9. What types of music are available in High-Resolution?

If we adhere to the definition offered at the beginning of this FAQ section, most of the “High-Resolution Audio” is classical, jazz, or acoustic. These are the typical audiophile genres.

Commercial recordings of rock, pop, urban, folk, country etc. are not being produced in high-res. And even if the engineers and producers increase the sample rate and use longer digital words while making albums, the actual fidelity of the delivered master is severely limited…the goal is not to create the best sounding records but the ones that are the loudest and will sell the most.

10. What are the future prospects for High-Resolution Audio?
HRA has not been properly explained or implemented. It is a marketing initiative developed by the music industry organizations and the major labels to derive additional profit from their existing catalogs without actually improving the fidelity of the music being streamed or downloaded. There are a few audiophile labels pushing the boundaries of audio fidelity but they don’t record celebrity artists or present popular genres to consumers.

The sites that offer High-Resolution Audio have catalogs containing about 15,000 “Master Source Quality” albums. If a site claims to have 2 million tracks, they’ve included CD rips in their offerings, which are exactly the same as the CDs that you can purchase at WalMart…except they will cost you two to three times as much.

The audiophile labels that are actually delivering real High-Resolution Audio has produced approximately 2000 titles.

High-Resolution Audio’s future is not bright. It will not expand to include mass consumers. It does not elevate the music listening experience unless you acquire real high-res recordings, play them in a high-end system, and know what to listen for.


Mark Waldrep, aka Dr. AIX, has been producing and engineering music for over 40 years. He learned electronics as a teenager from his HAM radio father while learning to play the guitar. Mark received the first doctorate in music composition from UCLA in 1986 for a "binaural" electronic music composition. Other advanced degrees include an MS in computer science, an MFA/MA in music, BM in music and a BA in art. As an engineer and producer, Mark has worked on projects for the Rolling Stones, 311, Tool, KISS, Blink 182, Blues Traveler, Britney Spears, the San Francisco Symphony, The Dover Quartet, Willie Nelson, Paul Williams, The Allman Brothers, Bad Company and many more. Dr. Waldrep has been an innovator when it comes to multimedia and music. He created the first enhanced CDs in the 90s, the first DVD-Videos released in the U.S., the first web-connected DVD, the first DVD-Audio title, the first music Blu-ray disc and the first 3D Music Album. Additionally, he launched the first High Definition Music Download site in 2007 called iTrax.com. A frequency speaker at audio events, author of numerous articles, Dr. Waldrep is currently writing a book on the production and reproduction of high-end music called, "High-End Audio: A Practical Guide to Production and Playback". The book should be completed in the fall of 2013.

14 thoughts on “High-Resolution Audio FAQs: Part 2

  • Here is my feedback on the second part

    FAQ 6
    First paragraph – second sentence
    “compact discs” should be “compact disc players”
    “, for example” could be deleted at the end of the sentence.

    FAQ 8
    First paragraph
    I think failed is both bit too strong for HRA and too weak for the rest of physical media. Possible alternative:
    “Outside of the audiophile community these physical formats never developed a following, and with the increasing popularity of downloading and streaming, all physical formats are fading away.”
    Paragraph 2
    Some of the other sites do offer some real HRA, just not very much.
    Paragraph 3
    Naxos does stream some real HRA on the classicsonlineHD site using adaptive technology. If your internet connection speed is high enough, you will get real HRA when the source is real HRA.
    Here are 2 examples of recordings available for streaming that I have measured and analyzed:
    This one is definitely HRA to 44kHz frequency.
    Dvorak Symphony No. 9 (Dallas Symphony Orchestra – Jaap van Sweden)
    The surround channels are strange on this one, but the L, R and C channels look pretty good.
    Mendelssohn and Tchaikovsky Violin Concertos ( Arabella Steinbacher – Charles Dutoit)
    The Cantate Domino is an example of less than real HRA streamed as if it were HRA.
    Paragraph 4 is right on target.

    FAQ 9
    Change “is” to “are” in the title (or change “types” to “type”)
    Change “mastered” to “master” in the second paragraph.

    FAQ 10
    There is some real HRA available. You give an estimate for Master Quality, but you don’t give any estimate for real HRA.

    • I was going to point out the same thing on 8. As written, it implies that iTrax is the only place to get real high-resolution audio. HDtracks offers some of the very same albums that are available on iTrax, and there are real high-resolution tracks available from other sources that are not on iTrax.

      Saying most of what is offered through those other sites is not real high-resolution audio, according to your definition, is fine, but saying none of it is could make this look like a marketing tool to support your businesses, rather than a genuine attempt to educate consumers. Ideally, it can do both.

      • I’ll revise the wording. My intention was to distinguish iTrax as a provider of exclusively high-resolution audio. HDtracks and others do provide high-res tracks as well, but not exclusively.

  • vjekoslav

    Dear Sir!

    I would like to say that it is obviously that materials which are not recorded in HI REZ way are not HI REZ at all, BUT, is it only to my ears or is it really some difference in sound (!) between an 16/44 and the same piece of music once resampled to, let’s say, 24/96?

    Nota bene, I didn’t say that the sound is better but different.

    Please comment.

    Vjekoslav, Karlovac, Croatia

    • You can judge for yourself. Go to the FTP site and download Mosaic in high-res and CD spec. It is very difficult to tell them apart.

  • I have one correction to my earlier comments.
    The Steinbacher Mendelssohn and Tchaikovsky violin concerto album is only available for streaming in stereo. My comments about the surround channels only apply to the multi-channel download.

  • Édouard Trépanier

    Bonjour Mark,

    You say: “High-Resolution Audio’s future is not bright. It will not expand to include mass consumers. It does not elevate the music listening experience unless you acquire real high-res recordings, play them in a high-end system, and know what to listen for.”

    I would rather say:

    One of these days, the studio equipment of the 80s will terminate its useful life. Studios will then equip themselves with High Resolution Audio capable equipment. However, the era of HRA fidelity may be pushed back several years, since most music involved companies and artists prefer the way of the “fast buck” and sell standard resolution as if it were high resolution. Since music is more subjective than picture, of a TV set for example, many consumers are happy to pay more for the « same old stuff ». The music listening experience will not be elevated to today’s possibilities unless you ask for real high-res recordings, play them in a high-end system, and know what to listen for.

    • Thanks for the comments. But most of the vintage equipment has been retired already. Yes, there are lots of studios that trade on their ability to produce that vintage sound. But regardless of the gear, most engineers, producers, and labels don’t care about sound quality. And they definitely don’t think high-resolution audio is critical. We already have the necessary equipment and expertise, but not the motivation to make HRA widespread.

  • Mark- Both of these FAQs are great.

    Question: 96 kHz/24-bit PCM or greater = High Resolution Audio. Got it!

    What is audio resolution? I get in with video resolution, more pixels = high resolution, but audio?

    96kHz means zero to 96,000 Hz of bandwidth. Sampling frequency.

    24 bit means zero to -144dB of signal to noise. Bit-depth.

    The product of Sampling Frequency bandwidth and Bit-depth signal to noise ratio is a bit-rate.


    I know that there are no pixels in audio, it makes the word “resolution” in audio almost a misnomer. I think it is really an optical definition. However we need a way to differentiate- I get that.

    What’s a better way to say resolution. Maybe Signal to Noise? Help!



    • I think one of the FAQs needs to be what is resolution as it applies to audio. You’re comments aren’t right on the mark. Sampling theory and practice is a little more complicated. A sampling rate of 96 kHz establishes certain parameters including frequency range, filter requirements, noise level, timing information and more. The same goes with word length. Using 24-bits provides additional levels to encode amplitude and establishes dynamic range, noise floor, dither requirements etc.

      Pixels and color depth are not continuously variable. They establish the resolution of images and video. The non-continuous nature of sampling audio in time define resolution in audio.

      • Mark- I’m standing by for the update to the FAQ.

        In the meantime, any textbooks that I could read that defines the state of the art on digital audio sampling theory?

        Thank you,

        • Ken Pohlmann’s book is quite good but heavy reading. The changes have been made to the FAQs online.

  • Barry Santini

    I think:

    1. Tans are an indication of health
    ‘2. Water and fertilizer fed, green lawns are desirable and I like and want them.
    3. I *think* any hi-res container for music makes it sound better, so it must be better.



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