Hochschule für Musik Winterthur Zürich

VST Ambisonic Tools

B-dec High resolution First Order Ambisonic B-format decoder

Original code by Ambrose Field

For use in Nuendo 1.5 and above.

Usage:

B-dec is a 64-bit double precision ambisonics decoder optimised for sound quality and large listening spaces. The decoding method reflects this means by not processing the signal inappropriately: there are no shelf filters in this design. Instead, the decoding method is a clean signal path, in-phase decode.

Usage is very simple: just select the decoding arrangement with the slider. The following layouts are available:

• Cube (with height)
• Square - horizontal
• Rectangle - narrower and longer than square
• Hexagon with speakers in the stereo locations
• Octagon with speakers in the stereo locations
• Octagon with speakers at compass points
• Decode to stereo
• Decode to mono

How:

B-dec is designed to be used as part of the master effects section. It will install istelf as a 'surround effect' in Nuendo. Make sure you have sufficient hardware output channels available to run the process, and that you have set-up and activitated in "Master Outpus" sufficient output channels. B-dec does not worry about the speaker layout specified in Steinberg's box, as this does not currently use the height (Z) information.

Speaker Layouts:

Loudspeakers routings (and their corresponding Nuendo outputs) are numbered as follows;

Layout	CH1	CH2	CH3	CH4	CH5	CH6	CH7	CH8
cube	LFD	RFD	RBD	LBD	LFU	RFU	RBU	LBU
square	LF	RF	RB	LB
rectangle	LF	RF	RB	LB
hex	LF	L	LB	RB	R	RF
octo1	F	LF	L	LB	B	RB	R	RF
octo2	LF1	LF2	LB1	LB2	RB1	RB2	RF1	RF2
stereo	LF	RF
mono	F	F

Blank spaces indicate no output.

Users should beware of possible confusion with Nuendo's labelling of channels as L,R,Ls,Rs etc. The specific Nuendo Master Setup you choose has no effect, so long as enough channels are available. As can be seen below, an unmatched number of outputs will not be rejected

The mono layout provides the same signal to the front two speakers.

Speaker layouts are selectable via the Nuendo Automation system.

Inputs:

Make sure your B-format siganl is in W, X, Y, Z (1,2,3,4) format. Currently (as of April 2002) Nuendo does not offer a multichannel file input option so any B Format recordings have to be provided as two stereo files feeding separate input channels. Configure Nuendo so that these two channels feed the Decoder on these busses. BPan connects itself correctly automatically.

Installation:

PC Windows

Simply drop the B-dec.dll file into any plugin folder currently active in Nuendo.

Macintosh

Bdec must be placed into the plugin folder currently active in Nuendo.