HD-Audio Challenge II – Extended

The “stay-at-home” orders that exist in most of the states in this country and other in countries and the notice that the HD-Audio Challenge II is nearing the end have resulted in a flood of request and submissions. I received over 1700 requests for the files and 327 people have completed the survey and submitted their results. It’s very gratifying that so many people have shared so much of their time to participate in this project. Thanks to everyone.

If you’re desperate to know how you did, I will respond with personal emails. Just send me a request and I’ll let you know how you did. I know that many of your have been patiently waiting since last fall. Others have taken to analyzing the files to determine how you fared.

It could be prejudicial to say too much about the results. But I would like to share some of the responses that were included in the submission form. Yes, I have read every comment.

Here are a few of my favorites:

I tried very hard to find a difference on what I would consider a standard affordable setup. In all cases I could not find any evidence that persuaded me in either direction. The outcome honestly does not surprise me but does help me confirm what I have started to believe in recent years. If I had to make a statement after this exercise I would say that at a minimum the CD redbook format does remove any detail from the production and certainly does not take away any enjoyment of the recording compared to high res.

I would like to thank you for putting together the high res challenge and for sharing your work. I greatly appreciated the production quality of the recordings which is something I rarely get to hear (seems most of the music I listen to the production quality was not a priority and recorded during the ramp up and peak of the loudness wars).

And this from a 42 year old who scored 60%:

I’m not sure how many of my answers are correct but I would like to share my experience in deciding if the track is hires. When it’s hires, the sound seems to go deeper in my ear. l get this tickling sensation that’s very satisfying. When I switch to the non-hires version, I miss that feeling… it’s like part of my ear is not being stimulated. I also notice a very subtle muffling of the sound with cd res especially as Ive gained experience comparing the 2 versions. Hires also feels more like you’re surrounded by the sound and CD res sounds more like the sound is in front of you.

I know that my JH13ciem’s frequency spectrum doesn’t fall under hires audio earphones but I still hear a difference. Do you recommend that I purchase earphones that are labeled hires or it wouldn’t matter much?

Thanks for all you do and for always standing your ground on the truth about hires audio.

This 68-year old was sure about the last track, but he was incorrect:

The last track, LS, has a huge soundstage and the X version was very easy to pick out as the HD. I’d be shocked if I got that one wrong. On the other hand, the first track, MCQ, was hard. I thought classical, stringed instruments would make it easier, but the recording seems close miked and I could not hear much difference in the air and ambience. I made a pick anyway based on smoothness, but it’s possible I was fooling myself.

This is another take from a confident participant (he scored 45%):

I’m very surprised by what I heard. Previously I only thought there was a distinct sound difference between DSD and the PCM conversions of the same track, I didn’t really imagine there were such noticeable differences on PCM frequency cutoffs above 48khz. In day-to-day you don’t play 2 versions of the same song so it’s not something you’d notice, however the hi-res versions are generally more emotive and satisfying to listen to. I agree with the statement “like you are right there as they play”, you lose that sense of being aware it’s a recording being played back. My point is I totally wasnt expecting to hear differences (based on your articles and general position) , but having heard them I know why I prefer hi-res music… it is more “present”.

And finally:

I kept notes of the tracks I thought were the higher resolution but in reality I couldn’t tell a difference. I would be lying if I answered the survey saying I could confidently tell the difference between the two. I’m bummed because I really thought I could at least tell a little difference, I guess this will save me future $$ as all the tracks sounded fantastic and meet my needs.

I’ll leave the files up for any new participants for another month. I’d love to get 500 submissions, so sit back and enjoy the process. Thanks again.

A Music and Audio User Guide 30% OFF Special Continues

In these challenging times, all of us are being asked to sacrifice and find ways we can help others. I have talked to a few of my musician friends over the past couple of weeks. They are really struggling because ALL their gigs have been cancelled or delayed. Guitarist Dorian Michael, a very close friend and artist on AIX Records, was here recently and told me that he’s taking on students and teaching via FaceTime instead of traveling up and down the west coast doing concerts as he had planned. And who knows how long this situation will last?

So I encourage you to support the artists on my label by buying a disc or asking for a music download (more on that in a moment). I will extend the AIX30Percent coupon until the “stay at home” orders are lifted.

In addition, I’m discounting paperback copies of my book Music and Audio: A User Guide To Better Sound by 30% for the same duration. Use the coupon code MAAG30Percent during checkout. Note that this applies only to the paperback version. But anyone that purchases the paperback will get the eBook in PDF format as well.

I will donate 25% of the sales receipts to an as yet to be determined GoFundMe campaign in support of struggling musicians.


I’m in the process of relaunching iTrax.com, the digital music download site that I first launched in 2007. I’ve cloned the AIX Records site and am modifying the entire catalog to allow for WAV and FLAC downloads in several different mixing options. Not everything is working yet…but I if you want to take look, feel free. I’d love to get some feedback on the layout, product table, etc.


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.

3 thoughts on “HD-Audio Challenge II – Extended

  • Thanks Mark. Certainly it is fun to read ‘confident’ comments from people who scored approximately no better than random guessing.

    And on that point, it is worth remembering that, even if no-one can tell the difference at all and everyone is guessing, you will get scores ranging from 0% to 100%.

    Therefore if an individual gets a high personal score on their return, and you tell them the score, they are almost *certainly* going to misinterpret it!

    After all, let’s say your instructions were to not listen to any music, but instead to fill in the forms by tossing a coin for every choice. You will still get scores ranging from 0% to 100%. So what does it mean that someone scored 100%? Absolutely nothing! They won’t deduce that they are a super coin tosser. I hope!

    So, I just want to remind readers that their personal scores mean nothing at all. Sorry! The only thing that has any meaning is the overall statistical analysis of the total population, and whether it varies meaningfully from a coin-tossing result by an infinite population.

    • Thanks Grant. Yes, this is mass numbers game.

    • Greetings Sir. Would it be too much trouble to get access to the music files so that I may analyze them. Just for fun of course. Thanks.


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