Meeting Topic: 3D Sound for Personal Entertainment Devices
Moderator Name: Kerry J Haps
Speaker Name: Robert B. Schulein and Dan Mapes-Riordan
Meeting Location: Niles, IL, USA
The September 25, 2013, meeting of the Chicago AES Section was held at Shure Incorporated, located in Niles, Illinois. About forty audio enthusiasts (members, non-members, and several UIC students) attended the presentation in the S.N. Shure Theater, listened to demos using wireless headphones, and then rotated through three table stations that were set up in the lobby to compare listening over pairs of headphones versus loudspeakers.
Bob Schulein started his presentation by giving an overview of 3D audio. In a 'quest for realism' we want to have the impression that sound can come from anywhere. We often find what is missing is having more sensory inputs or a spatial reality. Trends in 3D audio are emphasizing headphone listening which provides a 3D-enhanced listening experience with (only) two speakers. It's not surprising that the consumer electronics industry is always active in creating more exciting ways to provide an enveloping auditory experience. In this quest, at times it appears that offerings are 'solutions looking for problems to solve.'
Wireless headsets were distributed to the audience which enabled our group to listen to and compare various demos that Mr. Schulein queued using different consumer product offerings such as Dolby Headphone, DTS Headphone X, Jawbone's 'Jambox', Longcat, Fraunhofer's 'Nexus 7 Cingo', and ImmersAV. A consensus from the group was that it was relatively easy to identify and locate each independent channel (in the channel-demos) but it became more difficult to distinguish between the 3D-processed versus stereo demos when listening to movie or music content.
Dan Mapes-Riordan presented an overview of his work on how cross-talk-cancellation (CTC) affects listening over loudspeakers. There are past and present efforts attempting to use CTC to convert binaural content created for headphones so it can be played over loudspeakers which provide more playback opportunities and offer stabile frontal imaging. Although many are still looking...he believes that there is no single analytical solution that provides optimum CTC (where the CTC audio is indistinguishable from the original audio). ImmersAV has found that stereo pair loudspeaker placement at +/- 30 degrees is the best positioning (or at the very least, a good starting point). By using a custom EQ and 256 point filters, they have confirmed that 20dB CTC is achievable. Also, avoiding reflective surfaces and having good room absorption is a given.
Once we were able to thank each of our presenters with a Certificate of Appreciation and honorary AES mug, we convened to the lobby to listen to each of the three loudspeaker vs. headphone setups: Genelec powered near-field monitors + headphones with iPad video; M-Audio powered near-field monitors + headphones with iPad video; and small powered 'mini speakers' + headphones with iPhone video.
The Chicago AES Section would like to extend a special thanks to Robert B. Schulein and Dan Mapes-Riordan for their respective presentations, for setting up and providing the wireless and wired demos, and for their efforts in striving for (and providing) an improved listening experience.
Written By: Ken Platz