Surrounder Explained

ROBSCIX · Sep 3, 2004, 11:34 PM

I found some people are unclear as to certain values in surrounder. I will explain these settings as I have come to understand them.
Speaker Mode: Set to speakers you have. e.g 2.0, 4.1, 5.1..etc.
Surround: On...Enables balancing of surround parameters.
Surround: Off...Disables surround sound.
Surround: Copy....Allow Rear front and rear channels to receive same signal.

VCenterA: The Amount of signal to the CENTER channel on a 5.1 system.
VRearA: The Amount of signal to the REAR channels.
VRearW: The Width of your REAR channels.
VRearD: The Amount of signal Delay between front and rear channels.

Use Subwoofer: Enables Discrete subwoofer output, if you have one.

Enable Bass Redirection: Enables crossover frequency adjustment for the subwoofer channel.

Split Freq: The Frequency (Hz) at which crossover starts to filter signals to subwoofer channel.

Change your settings to get best possible surround sound imaging. Use Bass Redirection and split freq to get the most natural sounding bass response. Of course you just set them to what sounds good on your system in your space to you.

Hope that helps.

**dj_stick** · Sep 4, 2004, 01:54 AM

you sound right, and yup sticky

Max M. · Sep 4, 2004, 06:19 AM

probably, you'll find following info to be useful too
(these are some details about first version of surrounder - written 25.02.03
- something may be changed since)

:

Code:

signal paths:

spk:2.1, sur:off
----------------------
L  -------> fL
R  -------> fR
fL -------> fL
fR -------> fR
sL -------> sL
sR -------> sR
sC -------> sC

spk:2.1, sur:copy
----------------------
L  -------> fL
R  -------> fR
fL -------> fL
fR -------> fR
sL -------> sL
   `------> fL
sR -------> sR
   `------> fR
sC -------> sC
   `------> fL
   `------> fR

spk:2.1, sur:on
----------------------
L  -------> fL
R  -------> fR
fL -------> fL
fR -------> fR
     ___
sL -|   |-> fL
sR -|   |-> fR
sC -|enc|-> sL
    |   |-> sR
    |___|-> sC


spk:5.1, sur:off
----------------------
L  -------> fL
R  -------> fR
fL -------> fL
fR -------> fR
sL -------> sL
sR -------> sR
sC -------> sC

spk:5.1, sur:copy
----------------------
L  -------> fL
   `------> sL
   `------> C
R  -------> fR
   `------> sR
   `------> C
fL -------> fL
fR -------> fR
sL -------> sL
sR -------> sR
sC -------> sC

spk:5.1, sur:on
----------------------
     ___
L  -|   |-> fL
R  -|   |-> fR
    |dec|-> sL
    |   |-> sR
    |___|-> sC
fL -------> fL
fR -------> fR
sL -------> sL
sR -------> sR
sC -------> sC


spk:4.1 - same as 5.1 except Center as in 2.1

---------------------------------
phisical meaning of sur controls:
----------------------------------------------------------------------------------
          |         2.1           |          4.1          |          5.1          |
----------------------------------------------------------------------------------
VCenterA  | C to fL/fR amount     | C to fL/fR amount     | L/R to C amount       |
VRearA    | sR/sR to fL/fR amount | L/R to sL/sR amount   | L/R to sL/sR amount   |
VRearW    | width of encoded rear | width of decoded rear | width of decoded rear |
VRearD    |         n/a           | delay of decoded rear | delay of decoded rear |

So.. ok, in other words:
Sur:Off  - means "What you hear is what you play"
    (e.g. "normal" mode - nothing happens with the sound except mixing L/R into fL/fR)
Sur:Copy - "You hear everything you play with all of your speakers"
    (e.g. "dummy heads" mode)
Sur:On - same as Copy with ~phase encoding/decoding applied
    (e.g. "dumb heads" mode)

Rswave2k2 · Sep 5, 2004, 01:40 PM

wow thanks for the help and the sticky.

Russ · Nov 28, 2007, 03:57 PM

Here is an updated version of Max's routing diagram. It is almost the same, except that it uses the current input/output names, and the 2.1 modes appear to be a little different. The diagram is based on the code used in Surrounder+.

Note that the diagram does not show the Bass Redirection stuff.

Code:

spk:2.1, sur:off
----------------------------
inL    -----|-> fL
in_nw  -----|

inR    -----|-> fR
in_ne  -----|

spk:2.1, sur:copy
----------------------------
inL    -----|-> fL
in_nw  -----|
in_sw  -----|
in_n   -----|

inR    -----|-> fR
in_ne  -----|
in_se  -----|
in_n   -----|


spk:2.1, sur:on
----------------------------
         ___
inL    -|   |
in_nw  -|   |-> fL 
in_ne  -|   |
in_n   -|enc|
in_sw  -|   |
in_se  -|   |-> fR 
inR    -|___|

spk:5.1, sur:off
----------------------------
inL    -----|-> fL
in_nw  -----|

inR    -----|-> fR
in_ne  -----|

in_sw  -------> sL
in_se  -------> sR
in_n   -------> Center

spk:5.1, sur:copy
----------------------------
inL    -----|-> fL
in_nw  -----|

inR    -----|-> fR
in_ne  -----|

inL    -----|-> sL
in_sw  -----|

inR    -----|-> sR
in_se  -----|

inL    -----|-> Center
inR    -----|
in_n   -----|

spk:5.1, sur:on
----------------------------
         ___
        |   |-> fL 
inL    -|   |-> fR
        |dec|-> sL
inR    -|   |-> sR
        |___|-> Center        
in_nw  -------> fL
in_ne  -------> fR
in_sw  -------> sL
in_se  -------> sR
in_n   -------> Center

LFE input/output works as follows (not including Bass Redirection stuff):

The LFE output is only used when "Use Subwoofer output" is enabled. In this case, LFE Out = LFE In, with no mixing of LFE into other channels.

If "Use Subwoofer output" is disabled:
If Surround is OFF, LFE input is not used, otherwise:
In 2.1 Speaker mode, LFE input (half) is subtracted from the resulting downmix.
In all other speaker modes, LFE input (half) is subtract from inL/inR, and the result is used for upmixing/downmixing.

Russ · Dec 2, 2007, 12:35 PM

Input/output names
-------------------

L/R are the generic left/right inputs.
Input here is upmixed according to Surrounder's settings.

N/S/W/E/NW/NE/SW/SE = Directional indicators like those found on a
compass (except 'N' is always directly in front of you).

fL/fR = Front Left/Right
sL/sR = Surround/Rear Left/Right
Center = Center (front)
LFE = LFE

6.1 Mode:
sCenter1 = Rear Center

7.1 Mode:
sCenter1 = Side Left
sCenter2 = Side Right

Code:

fL · · · · · ·  C  · · · · · · fR
·                               ·
·               N               ·
·      NW       ·       NE      ·
·         ·     ·     ·         ·
·           ·   ·   ·           ·
·             · · ·             ·
·     W · · · · + · · · · E     ·
·             · · ·             ·
·           ·   ·   ·           ·
·         ·     ·     ·         ·
·      SW       ·       SE      ·
·               S               ·
·                               ·
sL · · · · · · · · · · · · · · sR

brainless_beginner · Jan 21, 2008, 03:57 PM

Is it possible somehow to have really stereo surround? i mean left surr and right surr separately

Russ · Jan 21, 2008, 05:39 PM

I am not sure what you mean, sL and sR and separate. The only mixing between the two (IIRC) is from the rear width setting (VRearW). If you do not want any mixing, then set VRearW to 0.

brainless_beginner · Jan 22, 2008, 04:12 PM

i mean when VRearW=1 the sounds from sl and sr speakers are the same (kinda mono from both)

brainless_beginner · Jan 22, 2008, 04:18 PM

i guess it's achived by substracting L from R or vice versa resulting in

L-R=SL-SR or
R-L=SL-SR

i mean to have only SL from SL spk and SR from SR spk

Russ · Jan 22, 2008, 07:38 PM

Right, that is how width works.

i.e. (something like this)
sL = VRearD_Delayed ( (inL * VRearA) - (inR * (VRearW * VRearA)) )
sR = VRearD_Delayed ( (inR * VRearA) - (inL * (VRearW * VRearA)) )

So again, set VRearW to 0, if you do not want that behavior.

BTW: Those settings only effect upmixing/downmixing.

WxMan1 · Nov 18, 2008, 08:13 AM

Quote:

Originally Posted by ROBSCIX

[snip]

VCenterA: The Amount of signal to the CENTER channel on a 5.1 system.
VRearA: The Amount of signal to the REAR channels.
VRearW: The Width of your REAR channels.
VRearD: The Amount of signal Delay between front and rear channels.

[snip]

Not seeing these settings in Surrounder (v3541 - debug) having any affect on sL, sR, or CENTER output when doing SPEAKER TEST.

When performing SPEAKER TEST, PEAK indicates -13.6dB and -Inf output level from Surrounder+ sR / sL whether VRearW is 1 or 0; the output levels of the specific Surrounder+ sChannels are appropriate to the specific sChannel being tested. Moreover, whether VRearA is 1 or 0, SPEAKER TEST results in the same -13.6dB output levels appropriate to the sChannel being tested, albeit output signal fluctuatation can be observed in accordance to the source program from Media Player input. However, in either case, no affect can be discerned by any changes either VRearA or VRearW (either independently or concurrently).

Nevertheless, even so PEAK indicates the same -13.6dB Surrounder+ CENTER output level whether VCenterA is 0 or 1 when performing SPEAKER TEST, it does have an affect if Media Player is the source, i.e., VCenterA at 0 results in -Inf output level observed from Surrounder+ CENTER output by PEAK.

This on a CT4780 (10k1) set to 5.1 in WinXP & in Surrounder+.

POSTSCRIPT: additional testing has revealed that VRearA has only the affect of influencing VRearW. When VRearA is set to 0, then VRearW is absolutely without affect. When VRearA is some non-zero value, then VRearW has the affect of establishing the degree of mono the rear channel signal with respect to VRearA.

When VRearA is 0, the only difference betwixt the front & sChannels signal then would be with respect to the delay that VReadD imparts upon the front channel stereo signal. If, however, VRearD is 0 then the only intrinsic difference would be any difference in gain - if any - the sChannels inherently have with respect to the front stereo channels, i.e., with VRearA and VRearD set to zero the Surrdounder+ SURROUND mode is essentially set to "copy".

This affect is very easy to demonstrate by plugging in headphones into the correct "rear" speaker jack. With VRearA set to 0 the sound is essentially two-speaker stereo. However, when VRearA is increased to 1, then maximum head-phone quality sound can then be discerned with VRearW set to zero. Subsequent increases in VRearW increases a perceived magnitude of "centerness" to the sChannels; essentially a psuedo sCenter.

Max M. · Nov 18, 2008, 09:00 AM

Quote:

Not seeing these settings in Surrounder (v3541 - debug) having any affect on sL, sR, or CENTER output when doing SPEAKER TEST.

The answer is given by Russ right above:

Quote:

Those settings only effect upmixing/downmixing.

p.s.: for the rest (e.g. VRearA/VRearW/VRearD relationship) - see the table in the end of post #3 - i believe it explains that all (not counting older names for input channels it uses)

WxMan1 · Nov 18, 2008, 03:55 PM

Yeah, I get it now.

The source used for SPEAKER TEST is not appropriate for configuring surround speakers though (per the first part of my previous post).

Furthermore, the PEAK signal level was quite misleading with respect to VRearA and VRearW. This lead to my initial post.

However, the key was in that PEAK showed VCenterA did affect CENTER output from Surrounder+ with Media Playour source. It was this that caused me to listen to the sChannel from Media Player source with head-phones that I discerned what was actually happening.

Nevertheless, even with head-phones, there's no discernable difference on sChannel between VRearA 0 or 1, or VRearW 0 or 1 when the source is SPEAKER TEST.

Russ · Nov 18, 2008, 04:02 PM

Right, the speaker test audio is not subject to upmixing because it is positional audio (i.e. like 3D audio in games, etc).

Sep 3, 2004, 11:34 PM	#1
ROBSCIX DriverHeaven Senior Member Join Date: Mar 2004 Posts: 1,745 Rep Power: 0	Surrounder Explained I found some people are unclear as to certain values in surrounder. I will explain these settings as I have come to understand them. Speaker Mode: Set to speakers you have. e.g 2.0, 4.1, 5.1..etc. Surround: On...Enables balancing of surround parameters. Surround: Off...Disables surround sound. Surround: Copy....Allow Rear front and rear channels to receive same signal. VCenterA: The Amount of signal to the CENTER channel on a 5.1 system. VRearA: The Amount of signal to the REAR channels. VRearW: The Width of your REAR channels. VRearD: The Amount of signal Delay between front and rear channels. Use Subwoofer: Enables Discrete subwoofer output, if you have one. Enable Bass Redirection: Enables crossover frequency adjustment for the subwoofer channel. Split Freq: The Frequency (Hz) at which crossover starts to filter signals to subwoofer channel. Change your settings to get best possible surround sound imaging. Use Bass Redirection and split freq to get the most natural sounding bass response. Of course you just set them to what sounds good on your system in your space to you. Hope that helps. Last edited by ROBSCIX; Aug 28, 2005 at 05:30 PM.

Nov 28, 2007, 03:57 PM	#5
Russ DriverHeaven Extreme Member Join Date: Jan 2005 Posts: 4,836 Rep Power: 41	Here is an updated version of Max's routing diagram. It is almost the same, except that it uses the current input/output names, and the 2.1 modes appear to be a little different. The diagram is based on the code used in Surrounder+. Note that the diagram does not show the Bass Redirection stuff. Code: spk:2.1, sur:off ---------------------------- inL -----\|-> fL in_nw -----\| inR -----\|-> fR in_ne -----\| spk:2.1, sur:copy ---------------------------- inL -----\|-> fL in_nw -----\| in_sw -----\| in_n -----\| inR -----\|-> fR in_ne -----\| in_se -----\| in_n -----\| spk:2.1, sur:on ---------------------------- ___ inL -\| \| in_nw -\| \|-> fL in_ne -\| \| in_n -\|enc\| in_sw -\| \| in_se -\| \|-> fR inR -\|___\| spk:5.1, sur:off ---------------------------- inL -----\|-> fL in_nw -----\| inR -----\|-> fR in_ne -----\| in_sw -------> sL in_se -------> sR in_n -------> Center spk:5.1, sur:copy ---------------------------- inL -----\|-> fL in_nw -----\| inR -----\|-> fR in_ne -----\| inL -----\|-> sL in_sw -----\| inR -----\|-> sR in_se -----\| inL -----\|-> Center inR -----\| in_n -----\| spk:5.1, sur:on ---------------------------- ___ \| \|-> fL inL -\| \|-> fR \|dec\|-> sL inR -\| \|-> sR \|___\|-> Center in_nw -------> fL in_ne -------> fR in_sw -------> sL in_se -------> sR in_n -------> Center LFE input/output works as follows (not including Bass Redirection stuff): The LFE output is only used when "Use Subwoofer output" is enabled. In this case, LFE Out = LFE In, with no mixing of LFE into other channels. If "Use Subwoofer output" is disabled: If Surround is OFF, LFE input is not used, otherwise: In 2.1 Speaker mode, LFE input (half) is subtracted from the resulting downmix. In all other speaker modes, LFE input (half) is subtract from inL/inR, and the result is used for upmixing/downmixing. Last edited by Russ; Jan 15, 2008 at 10:38 PM. Reason: correction

Dec 2, 2007, 12:35 PM	#6
Russ DriverHeaven Extreme Member Join Date: Jan 2005 Posts: 4,836 Rep Power: 41	Input/output names ------------------- L/R are the generic left/right inputs. Input here is upmixed according to Surrounder's settings. N/S/W/E/NW/NE/SW/SE = Directional indicators like those found on a compass (except 'N' is always directly in front of you). fL/fR = Front Left/Right sL/sR = Surround/Rear Left/Right Center = Center (front) LFE = LFE 6.1 Mode: sCenter1 = Rear Center 7.1 Mode: sCenter1 = Side Left sCenter2 = Side Right Code: fL · · · · · · C · · · · · · fR · · · N · · NW · NE · · · · · · · · · · · · · · · · · W · · · · + · · · · E · · · · · · · · · · · · · · · · · SW · SE · · S · · · sL · · · · · · · · · · · · · · sR Last edited by Russ; Dec 2, 2007 at 11:14 PM.

Jan 22, 2008, 07:38 PM	#11
Russ DriverHeaven Extreme Member Join Date: Jan 2005 Posts: 4,836 Rep Power: 41	Right, that is how width works. i.e. (something like this) sL = VRearD_Delayed ( (inL * VRearA) - (inR * (VRearW * VRearA)) ) sR = VRearD_Delayed ( (inR * VRearA) - (inL * (VRearW * VRearA)) ) So again, set VRearW to 0, if you do not want that behavior. BTW: Those settings only effect upmixing/downmixing. Last edited by Russ; Jan 22, 2008 at 08:09 PM. Reason: typo

Nov 18, 2008, 03:55 PM	#14
WxMan1 DriverHeaven Junior Member Join Date: Dec 2007 Posts: 60 Rep Power: 16	Re: Surrounder Explained Yeah, I get it now. The source used for SPEAKER TEST is not appropriate for configuring surround speakers though (per the first part of my previous post). Furthermore, the PEAK signal level was quite misleading with respect to VRearA and VRearW. This lead to my initial post. However, the key was in that PEAK showed VCenterA did affect CENTER output from Surrounder+ with Media Playour source. It was this that caused me to listen to the sChannel from Media Player source with head-phones that I discerned what was actually happening. Nevertheless, even with head-phones, there's no discernable difference on sChannel between VRearA 0 or 1, or VRearW 0 or 1 when the source is SPEAKER TEST.

Sep 5, 2004, 01:40 PM	#4
Rswave2k2 DriverHeaven Newbie Join Date: Apr 2004 Posts: 14 Rep Power: 0	wow thanks for the help and the sticky.

Jan 21, 2008, 03:57 PM	#7
brainless_beginner DriverHeaven Junior Member Join Date: Dec 2007 Location: KAZAN Posts: 31 Rep Power: 0	Is it possible somehow to have really stereo surround? i mean left surr and right surr separately

Jan 21, 2008, 05:39 PM	#8
Russ DriverHeaven Extreme Member Join Date: Jan 2005 Posts: 4,836 Rep Power: 41	I am not sure what you mean, sL and sR and separate. The only mixing between the two (IIRC) is from the rear width setting (VRearW). If you do not want any mixing, then set VRearW to 0.

Jan 22, 2008, 04:12 PM	#9
brainless_beginner DriverHeaven Junior Member Join Date: Dec 2007 Location: KAZAN Posts: 31 Rep Power: 0	i mean when VRearW=1 the sounds from sl and sr speakers are the same (kinda mono from both)

Jan 22, 2008, 04:18 PM	#10
brainless_beginner DriverHeaven Junior Member Join Date: Dec 2007 Location: KAZAN Posts: 31 Rep Power: 0	i guess it's achived by substracting L from R or vice versa resulting in L-R=SL-SR or R-L=SL-SR i mean to have only SL from SL spk and SR from SR spk

Nov 18, 2008, 04:02 PM	#15
Russ DriverHeaven Extreme Member Join Date: Jan 2005 Posts: 4,836 Rep Power: 41	Re: Surrounder Explained Right, the speaker test audio is not subject to upmixing because it is positional audio (i.e. like 3D audio in games, etc).