On June 6, 2010 seven members of the recording web forum Gearslutz got together to test the audible difference between several converters. This VIDEO shows how the session was recorded. All of us had to learn Ben Arthur's song "Tonight" on the spot and get all the way through in one take. So please forgive the minor gaffs. Rhythm acoustic guitar and vocal by Ben Arthur. Lead acoustic guitar by John Guth. Cello by Ethan Winer. Percussion by Ed Dzubak.

Gear used: Michael Joly MJE-K47H microphone, into a Grace 101 "Ribbon version" preamp, split to a Lavry Blue converter and an M-Audio Delta 66 sound card. Both converters recorded at 24 bits, 44.1 KHz. The Lavry was recorded directly into a multi-track project in Pro Tools, and the Delta tracks were recorded separately into Sound Forge then aligned manually afterward as closely as possible in SONAR Producer version 8.

To include a consumer grade sound card in the test, the Delta converter files were also recorded out of the Delta 66 into a $25 SoundBlaster X-Fi sound card at 16 bits, and the SoundBlaster files were also manually aligned in SONAR. So there are three mixes total - two are "first captures" from the microphone, and the third is a re-recorded version degraded by an extra pass through the Delta's D/A and the SoundBlaster's A/D sections. Besides testing converters using "first capture" versus re-recording from a CD or analog tape, this song also tests "stacking" because some people claim that converter deficiencies don't show up until several tracks are combined. I disproved "stacking" in my AES Audio Myths video (section starts at 28:28), but some people still believe in stacking anyway.

All of the tracks were aligned starting at the beginning of the tune, so nulling the mix files to identify differences quickly fails because of clock drift due to using different converters. Note that the cello track was impossible to align perfectly because there were no transients to zero in on, and because the cello is very soft in Ben's original mix that was used as the alignment reference. But the point of posting these mix files is for people to listen to them and judge based on how they sound, versus trying to null them!

Here are links to the three 24-bit mix files (each about 50 MB):

MixA.wav
MixB.wav
MixC.wav

Your challenge is to identify which files were recorded through each of the three converters, then email me your answers (see below). Although this converter test was described at the Gearslutz audio forum where people posted their guesses, the file name letters were changed before posting the files here.

The Pro Tools mix was made using only volume and pan settings, with no plug-ins, to simplify porting the mix from Pro Tools to SONAR. Those settings are:

Rhythm Acoustic Guitar: Volume 0, Pan 40 Percent Left
Lead Acoustic Guitar: Volume 0, Pan 40 Percent Right
Vocal: Volume 0, Pan 0
Cello: Volume -10.1, Pan 0
Percussion: Volume -13.2, Pan 0
Master Bus Volume at +8.3

After you email me your answers from my Home Page I'll send you the correct identities, and also send a link to the original Pro Tools and SONAR session files. Please do not send your choices by PM through Facebook or YouTube. I need replies by email to organize them efficiently.

Ethan Winer has been an audio engineer and professional musician for more than 45 years, and is co-owner of RealTraps where he designs acoustic treatment products for recording studios and home listening rooms. Ethan's Cello Rondo music video has received more than 1.8 Million views on YouTube and other web sites, and his book The Audio Expert published by Focal Press is available at amazon.com and his own web site.

Entire contents of this web site Copyright © 1997- by Ethan Winer. All rights reserved.