MATRIX vs DISCRETE

When creating a surround sound recording, this question comes up:
Do I use matrix or discrete?
This chart will help make the decision:

ITEMADVANTAGESDISADVANTAGES
Matrix Works with all two-channel stereo media
Media are in general use
Players are readily available
Uses less bandwidth
Stereo compatibility
Use of Involve's Surround Master decoders increases separation
Reduced channel separation
Limited mono compatibility
Can have the cogging problem
Discrete Full separation between channels Requires special media and players
Players and decoders are relatively rare
Finding players that can play your format is even harder
Needs a lot more bandwidth
Must mix or matrix down to play on 2-channel player or on mono
Has the cogging problem if not prevented with special techniques
Regular
Matrix
RM
Works with all two-channel stereo media
Media are in general use
Best for stereo play
Anyone can play it
Compatible: HD, DQ, EV4, QS, DS, DPLI, DPLII, SM(QS)
Passive decoders are available and work
Uses less bandwidth
Stereo compatibility
Reduced channel separation
Limited mono compatibility - center back disappears
Can have the cogging problem
Phase
Matrix
PM
Works with all two-channel stereo media
Media are in general use
Includes SQ matrix and variants
Compatible: SQ, SQB, EVU
Anyone can play it
Uses less bandwidth
Stereo compatibility
Reduced channel separation
Limited mono compatibility - center back disappears
Can have the cogging problem
Not compatible with RM list (above)
Not very compatible with ambience pickups
Hafler
Diamond
HD
Matrix
Works with all two-channel stereo media
Media are in general use
Best for stereo play
Anyone can play it
Compatible: HD, DQ, EV4, QS, DS, DPLI, DPLII, SM(QS)
Passive decoders are available and work
Uses less bandwidth
Stereo compatibility
Does not have the cogging problem
Cheapest system
Limited mono compatibility - center back disappears
Reduced channel separation
ITEMADVANTAGESDISADVANTAGES
Denon
UMX/BMX
UM
Matrix
Works with all two-channel stereo media
Media are in general use
Anyone can play it
Uses less bandwidth
Stereo compatibility
Stereo image is distorted
Reduced channel separation
Not compatible with other matrix systems
Very limited availability of recordings
BBC
Matrix H
UM
And Ambisonic
Works with all two-channel stereo media
Media are in general use
Anyone can play it
Passive decoders are available and work
Uses less bandwidth
Stereo compatibility
Limited Stereo compatibility - Image without decoder distorted
Reduced channel separation
Not compatible with other matrix systems
Very limited availability of recordings
JVC/RCA
CD-4
CD
Discrete
Full channel separation Limited to phonograph records
Special pickup, stylus, and demodulator needed
A fussy system that fails if not set up perfectly
Records can wear out quickly
Dust on record makes loud crashing sounds
Limited availability of recordings
Jet 8
Quad 8-track
Q8
Discrete
Full channel separation Limited to Q8 8-track cartridge players (rare)
Stereo player cannot play Q8 cartridge
Tapes can wear out quickly
Limited availability of recordings
Limited availability of blank tape
Quad Reel
4-track reel
Q4
Discrete
Full channel separation
Recorder can be used as studio multitrack.
Limited to 4-track quad reel players (rare)
Stereo player cannot play Q4 tape
Limited availability of recordings
Limited availability of blank tape
ITEMADVANTAGESDISADVANTAGES
Surrfield
Matrix
SF
Special mic system
Works with all two-channel stereo media
Media are in general use
Best for stereo play
Anyone can play it
Compatible: HD, DQ, EV4, QS, DS, DPLI, DPLII, SM(QS)
Passive decoders are available and work
Uses less bandwidth
Stereo compatibility
Mono compatibility
Headphone compatible binaural
Does not have the cogging problem
Reduced channel separation
Not fully compatible with panpot mixing, but can be used with it
Stereo plus
Ambience mics
AP
Works with all two-channel stereo media
Media are in general use
Best for stereo play
Anyone can play it
Compatible: HD, DQ, EV4, QS, DS, DPLI, DPLII, SM(QS)
Creates a full sphere of sound around the listener
Uses less bandwidth
Stereo compatibility
Mono compatibility
Headphone compatible
Reduced channel separation
Not fully compatible with panpot mixing, but can be used with it
Can have the cogging problem
Dolby
Surround
DS
Matrix
Works with all two-channel stereo media
Media are in general use
Best for stereo play
Anyone can play it
Compatible: HD, DQ, EV4, QS, DS, DPLI, DPLII, SM(QS)
Uses less bandwidth
Stereo compatibility
Does not have the cogging problem
Limited mono compatibility - center back disappears
Reduced channel separation
Not compatible with Dolby Digital or Dolby Atmos
Dolby
Digital
5.1
Discrete
Full separation between channels
DVD version usually has Dolby Surround on stereo tracks
Requires special media and players
Players and decoders are relatively rare
Finding players that can play your format is even harder
Needs a lot more bandwidth
Must mix or matrix down to play on 2-channel player or on mono
Has the cogging problem if not prevented
Not compatible with Dolby Surround or any other matrix system
ITEMADVANTAGESDISADVANTAGES
Dolby
Atmos
7.1.4
Discrete
Full separation between channels Requires special media and players
Players and decoders are relatively rare
Finding players that can play your format is even harder
Creates a hemispherical sound field around the listener
Needs a lot more bandwidth
Must mix or matrix down to play on 2-channel player or on mono
Has the cogging problem if not prevented
Not compatible with Dolby Surround or any other matrix system
Spherfield
Matrix
SR
Special 3D mic system
Works with all two-channel stereo media
Media are in general use
Best for stereo play
Anyone can play it
Compatible: HD, DQ, EV4, QS, DS, DPLI, DPLII, SM(QS)
Creates a spherical sound field around the listener
Uses less bandwidth
Stereo compatibility
Mono compatibility
Does not have the cogging problem
Reduced channel separation
Not fully compatible with panpot mixing, but can be used with it
Spheround
Matrix
SR
3D matrix system
Works with all two-channel stereo media
Media are in general use
Best for stereo play
Anyone can play it
Compatible: HD, DQ, EV4, QS, DS, DPLI, DPLII, SM(QS)
Creates a spherical sound field around the listener
Uses less bandwidth
Stereo compatibility
Mono compatibility
Does not have the cogging problem
Reduced channel separation
Not fully compatible with panpot mixing, but can be used with it
SQ Spheround
Matrix
QR
3D matrix system
using SQ instead of QS
Works with all two-channel stereo media
Media are in general use
Anyone can play it
Compatible: EU, SQ SM(SQ)
Creates a spherical sound field around the listener
Uses less bandwidth
Stereo compatibility
Mono compatibility
Reduced channel separation
Not fully compatible with panpot mixing, but can be used with it
Unequal channel separations