The upcoming AES Convention in New York will be the occasion to kick off a series of presentations on this research that is expected to appear over the next few years. The first presentation will be focused on the design and execution of the recording process, and will take place: EB02 - Recording & Production on Thursday, October 19, 11:15 am — 12:30 pm (1E12)
EB02-3 Simultaneous Audio Capture at Multiple Sample Rates and Formats for Direct Comparison and Evaluation
Jordan Strum, ProStudioMasters - Montréal, Québec, Canada;
Richard King, McGill University - Montréal, Québec, Canada; The Centre for Interdisciplinary Research in Music Media and Technology - Montréal, Québec, Canada;
Oles Protsidym, ProStudioMasters - Montréal, Québec, Canada;
Ieronim Catanescu, McGill University - Montréal, Québec, Canada.
In order to evaluate differences among recording formats and resolutions over a variety of classical, jazz, and popular musical material, a unique collection of audio assets was recorded. Live performances were captured using a single pair of microphones, positionally adjusted for each sound source. Preamplifier outputs were routed to 11 identical recording interfaces capturing various PCM and DSD formats simultaneously with 3 analogue tape recorders, the contents of which were then transferred to the above digital formats. These assets will be used to compare differences among recording formats and resolutions using identical performances, and to provide source material for listening tests as well as further research. The design and execution of this project will be discussed.
The equipment list explains a great deal:
- 2x Sanken CO-100K "100kHz Super Wide Range Microphone”
- Spaced omni configuration, placed 80cm apart
- 12x Merging HAPI (1 as preamp using analog direct outs, 11 as A/D) with premium A/D cards
- 2x Lenovo Thinkpad T460 running Pyramix Native
- 10x Lenovo Thinkpad T61 running Pyramix Native
- Studer A80 (15 ips, 1/4”)
- Studer A80 (30 ips, 1/2”)
- Studer A810-VUK (30 ips, 1/4”)
- 2 ATR 1/4" Master Tape
- 2 ATR 1/2” Master Tape
- AKG K712 PRO reference studio headphones
This combination was used to record 18 live concerts and 5 studio sessions which featured anything from classical guitar to full symphony orchestra, chamber ensembles, jazz group, rock band, piano combined with many instruments and a soprano vocalist. By any measure, this should provide an astonishing amount of music to analyse – more than 406 hours to be precise, which is a good reason why the results will be appearing over time.
One of the technical challenges that presented itself was how to split the signal to 14 recording units simultaneously, and on the advice of Merging’s CEO, Claude Cellier, a suitable custom splitter was built by Ieronim Catanescu.
The reaction of the main participants working on this project speaks volumes:
Oles Protsidym, ProStudioMasters
“This research project has been an objective of ours for a long time, and we were thrilled when all the dots were connected for this collaboration between Merging Technologies and McGill University, our ideal partners for this project. With 1.76 TB/406 hours of high resolution audio data to analyze, we look forward to the results of this project, which should provide some answers in the domain of high-resolution audio.”
Jordan Strum, ProStudioMasters
“When we were discussing options for a recording system which would enable us to complete this research, it was immediately obvious that Merging Technologies’ products were the perfect solution, allowing us to record in all digital formats with a flexible and well-integrated hardware / software package.”
Richard King, McGill University (Winner of 14 GRAMMY Awards)
“For this collaboration between McGill University and ProStudioMasters, we were looking for top-quality microphone preamps and A/D converters to complete several rounds of high resolution audio capture. After a few tests, we were really impressed with Merging HAPI interfaces, which provided everything we needed at the highest quality. The AKD8DP input cards combine transparent analogue-to-digital conversion in both PCM and DSD formats with a great sounding, wide bandwidth preamp circuit.”
Claude Cellier, Merging Technologies
“It was an honour to be asked to participate in this research and it does vindicate our policy of covering all PCM and DSD recording formats with Pyramix. The advent of Horus and Hapi makes these the ideal front end to any recording set up and the Hapi is the perfect partner for location recording. We will be taking a keen interest in the conclusions.”