The study that I mentioned previously happened today. I packed up a bunch of donated equipment and headed to the other side of the San Diego Freeway to help set up and view a session or two of the study. The basic idea is to survey typical listeners of all ages, backgrounds, and musical interests about their knowledge of high-resolution audio. After a few basic questions about their own listening habits and musical preferences, they had the chance to audition portions of three tracks of mine in both MP3 (256 kbps) and the original 96 kHz/24-bit PCM formats.
The hardware was graciously provided by Sony and Teac and consisted of a UD-501 DAC connected via XLR balanced cables to an AX-501 integrated amplifier and then to a couple of $239 Sony SS-CS3 tower speakers. The system was billed as a setup that an average consumer could afford. Lest you doubt that this gear could actually reach the JAS definition of Hi-Res Audio, the super tweeters on the speakers spec to around 40-50 kHz.
The Teac gear is also capable equipment. The AX-501 says its frequency response is down 5 dB at 60 kHz and has a S/N ratio of 100 dB. The UD-501 DAC has all of the PCM and a couple of DSD rates including 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz, 192 kHz, 352.8 kHz, 384 kHz and DSD at 2.8/5.6 MHz. It also supports word lengths of 16/24/32-bits. The signal to noise ratio is 115 dB and frequency range extends from 5 Hz – 80 kHz (-3dB). Teac should start using the Hi-Res Audio logo…this gear seems to meet the specs.
During a planning phone call it was decided that the researcher would play a track at reduced resolution or high-resolution…followed by the other file (switching the resolution, obviously). I don’t believe this is the best way to “hear” the differences between samples so I rigged up my Pro Tools rig with both stereo audio files playing simultaneously with the ability to seamlessly switch between them on the fly. Playing the files one at a time requires great sonic memory and doesn’t allow for instant comparison of the same section of the tunes. I was ready but for resource reasons…they choose to play my 96 kHz/24-bit PCM WAV files on a PC using the Teac software playback software through a standard USB cable (borrowed from a printer in the facility).
The organizers also strongly suggested that the participants be able to listen to the files through headphones, which presented other problems. The guy from Sony brought a Samson C-que 8 multiple headphone box. I plugged it in and took a listen through a set of Sony’s new Hi-Res MDR-10R headphones (they do carry the logo!). The phones specs read 5-40 kHz. I played the “Mosaic” by Laurence Juber, which won the CEA “Demmy Award” back in 2002 for the “Best High Resolution Audio” track. Both the gentleman from Teac and I agreed that the Samson box was incapable of delivering high-resolution audio or even marginal quality audio. In fact, the sound was horrendous.
Luckily, I cam prepared with a Rane headphones splitter…nothing of ultimate audiophile quality, but it was clean and available.
The AIX Records sound files were randomly identified as Selection_1_A or Selection_1_B. Both the MP3 version and the High-Resolution version were played back at 96 kHz/24-bits. I converted the MP3 using Sonic Studios’ Process converter back to 96/24 so that I could use them in the same PT session AND so that the display on the front of the DAC would read 96/24 PCM in both cases.
As a trial run, one of the staff people from the facility came in to the space and listened intently to the “Mosaic” track. His eyes widened as he listened…I could tell he was thoroughly entranced. As he left the room, he came over to me and said, “I can actually hear the fingers of the percussionist tapping on the congas. The details of the sound are amazing.”
I didn’t have the heart to tell him he had been listening to the MP3 file.
I’m still looking to raise the $3700 needed to fund a booth at the 2015 International CES. I’ve received some very generous contributions but still need to raise additional funds (I’ve received about $2500 so far). Please consider contributing any amount. I write these posts everyday in the hopes that readers will benefit from my network, knowledge and experience. I hope you consider them worth a few dollars. You can get additional information at my post of December 2, 2014. Thanks.