VA Stereo Transferability Testing
As a key aspect of this type of surround encoded audio is that it is done with only 2-channel PCM waveforms, this testing session will investigate whether this is digital dependent or whether it is compatible and able to be reproduced over analogue stereo tape. The purpose of this is to understand whether the encoded audio on reproduction should be consistent regardless of 2-channel playback medium, to understand whether playback speed has any effect to the encoded audio’s spatial properties, as well as to demonstrate that the spatial and binaural cue properties are fundamental to the waveform with no additional decoding / processing / playback setup requirements.
Utilising a demo recording of multi-tracks within a VAS from the previous initial implementation session - “VA TestSession - MultiChannel Medium Size VAS” - the recording was sent to a Tascam 414 over 2 mono channels that are hard panned LR. This was then recorded to cassette tape, where through monitoring it is confirmed that the spatialisation and externalisation properties of the recording were still present both during recording and on playback of the tape recording. This was then rerecorded into Logic Pro X, available below, where the audio could then be finally assessed.
Once completed through this to tape / off tape recording, the audio has still maintained the original encoded properties of spatialisation and directionality from the listeners perspective, this confirms that the compatibility and transferability of additionally encoded signal information is not dependant on digital only playback mediums as well as that it is not exclusive to any one type of storage format between analogue or digital. Slowing down the recording as well revealed that the ITDs present within the HRTF localisation and reflection cues maintain distinction and do not break down from alteration. I had anticipated that there may be issues with ITDs behaving in such a way that the exocentricity or localisation may be lost or altered in such a way to distort the original encodings, however this did not occur and the audio maintains its virtual acoustic properties and holographic panoramic stereo image. With slowing audio imparting only a subtle added depth which does highlight its versatility and creative use. This could lead to some creative applications, timewarped audio over tape leads to some distinct timbres and aesthetics of classic analogue sounds which could be used in tandem with the VA spatial qualities for interesting retro futuristic audio aesthetics.
Below are the off tape recordings, the mixed speed demo starts at the original playback speed, and is slowed at 0:20 / sped up at 0:40 :
VA 414 Mixed Speeds.wav https://drive.google.com/file/d/1ZWVoibsrT3ArPaiIXxsm8P_kcO6pVqbz/view?usp=share_link
VA 414 Slowed.wav https://drive.google.com/file/d/1OjSuyTIl6_7hcP5GpBZbnUWTrpN1AM1P/view?usp=share_link
