Steinberg Nuendo 4 Plug In Reference Manual

							41
The included effect plug-ins
Reverb plug-ins
This section contains descriptions of the plug-ins in the 
“Reverb” category.
RoomWorks
RoomWorks is a highly adjustable reverb plug-in for creat-
ing realistic room ambience and reverb effects in stereo 
and surround formats. The CPU usage is adjustable to fit 
the needs of any system. From short room reflections to 
cavern-sized reverb, this plug-in delivers high quality re-
verberation. RoomWorks has the following parameters:
Parameter Description
Low Freq Frequency at which the low shelving filter takes effect.
High Freq Frequency at which the high shelving filter takes effect. 
Both the high and low filters EQ the input signal prior to 
reverb processing.
Low Gain The amount of boost or cut for the low shelving filter.
High Gain The amount of boost or cut for the high shelving filter.
Pre-Delay The amount of time before the onset of reverb. This al-
lows you to simulate larger spaces by increasing the time 
it takes for first reflections to reach the listener.
Reverb Time Reverb Time in milliseconds.
Size This alters the delays times of early reflections to simulate 
larger or smaller spaces.
Diffusion This affects the character of the reverb tail. Higher diffu-
sion is smoother while less diffusion can be clearer. This 
emulates changing the types of surfaces in a room (brick 
vs. carpet for instance).
Width This controls the width of the stereo image. At 100 %, 
you get full stereo reverb. At 0 %, the reverb is all in 
mono.
Variation Pressing this button will generate a new version of the 
same reverb program using altered reflection patterns. 
This is helpful when certain sounds are causing odd ring-
ing or undesirable results. Creating a new variation will of-
ten solve these issues. There are 1000 possible variations.
Hold Pressing this button freezes the reverb buffer in an infinite 
loop (yellow circle around button). You can create some 
interesting pad sounds using this feature.
Low Range This determines the frequency below which low damping 
will occur.
High Range This determines the frequency above which high fre-
quency damping will occur.
Low Damping  The amount of damping applied to the low frequencies. 
At 100 %, no damping occurs. Values lower than 100 % 
increase the amount of damping, reducing low frequen-
cies over time. Values above 100 % have the opposite ef-
fect.
High Damping This affects the decay time of high frequencies. Normal 
room reverb decays quicker in the high and low fre-
quency range than in the midrange. Lowering the damp-
ing percentage will cause high frequencies to decay 
quicker. Damping percentage values above 100 % will 
cause high frequencies to decay longer than the 
midrange.
Amount This determines how much effect the envelope attack 
and release controls have on the reverb itself. Lower 
numbers have a more subtle effect while higher numbers 
sound more drastic.
Attack The envelope settings in RoomWorks control how the re-
verb will follow the dynamics of the input signal in a fash-
ion similar to a noise gate or downward expander. Attack 
determines how long in milliseconds it takes for the re-
verb to reach full volume after a signal peak. This is similar 
to a predelay but the reverb is ramping up instead of 
starting all at once.
Release The release determines how long after a signal peak the 
reverb can be heard before being cut off, similar to a 
gate’s release time.
Mix Determines the blend of dry (unprocessed) signal to wet 
(processed) signal. When using RoomWorks inserted in 
an FX channel, you will most likely want to set this to 
100 % or use the Send button.
Wet only This button defeats the mix parameter, setting the effect 
to 100 % wet or affected signal. This button should nor-
mally be pressed when RoomWorks is being used as a 
send effect inserted on an FX or group channel.
Distance This control is only available for surround configurations. 
With this parameter you can control where the virtual lis-
tening position is within the room. Positive values position 
the listener closer to the front of the room and negative 
values place the listener towards the rear of the room.
Rotate This button is only available for surround configurations. 
When active, the perspective of the room is shifted 90°.
Balance This control is only available for surround configurations. 
Balance controls the relative levels between the forward 
and rear speakers. Positive values favor the front speak-
ers and negative values favor the rear speakers. Note that 
when the Rotate option is activated, these relationships 
will shift 90°. Parameter Description 
						

							42
The included effect plug-ins
ÖNote that the options in the Surround section on the far 
right of the RoomWorks panel are available only when us-
ing the plug-in as an insert for a surround-enabled track.
RoomWorks SE
RoomWorks SE is a “lite” version of the RoomWorks re-
verb plug-in. This plug-in delivers high quality reverberation, 
but has fewer parameters and is less CPU demanding than 
the full version. RoomWorks SE has the following parame-
ters:
Efficiency This unique control determines how much of the CPU is 
used for RoomWorks. The lower the percentage of effi-
ciency, the more CPU resources will be used. This will 
yield a higher quality reverb than higher percentage set-
tings. Interesting effects can be created with very high 
Efficiency settings (>90 %). Experiment for yourself.
Export This button determines if during audio export Room-
Works will use the maximum CPU power for the highest 
quality reverb or not. You may wish to keep a higher effi-
ciency setting for a desired effect during export. If you 
want the highest quality reverb during export make sure 
this is selected (yellow circle around button).
Parameter Description
Pre-Delay The amount of time before the onset of reverb. This al-
lows you to simulate larger spaces by increasing the time 
it takes for first reflections to reach the listener.
Reverb Time Reverb Time in seconds.
Diffusion This affects the character of the reverb tail. Higher diffu-
sion is smoother while less diffusion can be clearer. This 
emulates changing the types of surfaces in a room (brick 
vs. carpet for instance).
High Damping 
AmountThis affects the decay time of high frequencies. Normal 
room reverb decays quicker in the high and low frequency 
range than in the midrange. Lowering the damping per-
centage will cause high frequencies to decay quicker. 
Damping percentage values above 100 % will cause high 
frequencies to decay longer than the midrange. Parameter DescriptionLow Damping 
AmountThe amount of damping applied to the low frequencies. At 
100 %, no damping occurs. Values lower than 100 % in-
crease the amount of damping, reducing low frequencies 
over time. Values above 100 % have the opposite effect.
Mix Determines the blend of dry (unprocessed) signal to wet 
(processed) signal. When using RoomWorks SE inserted 
in an FX channel, you will most likely want to set this to 
100 % or use the Send button. Parameter Description 
						

							43
The included effect plug-ins
Spatial plug-ins
This section contains descriptions of the plug-ins in the 
“Spatial” category.
MonoToStereo
This effect will turn a mono signal into a “pseudo-stereo” 
signal. The plug-in must be inserted on a stereo track 
playing a mono file to work.
The parameters are as follows:
StereoEnhancer
This plug-in will expand the stereo width of (stereo) audio 
material. It cannot be used with mono files.
The parameters are as follows:
Parameter Description
Width This controls the width or depth of the stereo enhance-
ment. Turn clockwise to increase the enhancement.
Delay This parameter increases the amount of differences be-
tween the left and right channels to further increase the 
stereo effect.
Color This parameter also generates differences between the 
channels to increase the stereo effect.
Mono This switches the output to mono, to check for possible 
unwanted coloring of the sound which sometimes can 
occur when creating an artificial stereo image.
Parameter Description
Width This controls the width or depth of the stereo enhance-
ment. Turn clockwise to increase the enhancement.
Delay This parameter increases the amount of differences be-
tween the left and right channels to further increase the 
stereo effect.
Color This parameter also generates differences between the 
channels to increase the stereo enhancement.
Mono This switches the output to mono, to check for possible 
unwanted coloring of the sound which sometimes can 
occur when enhancing the stereo image. 
						

							44
The included effect plug-ins
Surround plug-ins 
This section describes the plug-ins in the “Surround” cat-
egory.
Matrix Decoder
The Matrix Decoder reverses the Encoder process per-
formed by the Matrix Encoder (see above). It is used for 
monitoring how an encoded mix will sound when played 
back on a Pro Logic compatible system. When an en-
coded mix is played back via the decoder, the Lt/Rt chan-
nels are again converted to four outputs (LRCS).
Setting up
Create an output bus with the “LRCS” speaker arrange-
ment, in the VST Connections window, and route it to the 
physical outputs on your audio hardware.
This is if you want to make a four-channel surround mix. If you want to make 
a five-channel mix, see “Using the Matrix Encoder with the 5.0 surround 
format” on page 45.
The Encoder should be placed in the first “post fader” in-
sert slot (#7) for the output bus, followed by the Decoder.
Using the Matrix Encoder/Decoder
1.Set up the mix roughly the way you want it.
Use the Surround Panner to place channels in the Surround mix, or assign 
channels to the individual LRCS outputs.
2.Activate the Matrix Encoder.
What you now hear is the encoded stereo mix, the way it will sound when 
played back on a normal stereo reproducer. If you open the Matrix En-
coder control panel you can adjust the Gain of the Lt/Rt output by using 
the fader.
3.Activate the Matrix Decoder, open the control panel 
and click on the Steering “On” button.
Now you can hear how the mix will be reproduced in surround on a Pro 
Logic compatible system. 
The “Steering” display shows a ball within the LRCS 
axis. The position of this ball indicates the dominant direc-
tion of the mix, sometimes referred to as the “dominance 
vector”. Part of the processing that is applied, for various 
technical reasons, results in the dominant channel being 
enhanced and the non-dominant channels being reduced 
in gain.
4.By switching the Matrix Decoder “Bypass” button on 
and off, you can compare the decoded mix with the en-
coded stereo mix, and make adjustments in the Mixer as 
necessary.
The main goal is to produce a mix that sounds good in both the encoded 
and the decoded version. If you wish to compare the encoded or de-
coded mix with the unprocessed mix, you should switch off both the Ma-
trix Encoder and the Decoder.
5.When you are satisfied with the result, Bypass the Ma-
trix Decoder, or remove it from its effect slot.
!This manual does not attempt to explain the full 
background on how Pro Logic works, but focuses on 
how you can use the Matrix Encoder/Decoder to 
produce a mix that is compatible with this standard.
!The encoding/decoding process will produce signif-
icant signal loss compared to the unprocessed mix. 
This is normal, and does not indicate that something 
isn’t working properly. You can however, with careful 
tweaking of the mix decrease the signal degradation 
to a much more acceptable level. You have to adjust 
levels and other settings before the Matrix Encoder, 
neither the encoder or decoder can “control” the mix 
in any way. 
						

							45
The included effect plug-ins
6.Connect a master recording device to the stereo mix 
output and perform a mixdown as usual.
The resulting encoded stereo mix will now be compatible with common 
home systems that use the Pro Logic standard.
Using the Matrix Encoder with the 5.0 surround format
There are situations when you may want to mix for several 
Surround formats. For example, you might need to mix the 
same material for 5.1 and one for LRCS.
5.1 is similar to LRCS. Omitting the LFE channel is easy, 
but more of a problem is that LRCS only has one Surround 
Channel whereas 5.1 has two.
For this reason there are two Surround Channels in the Ma-
trix Encoder, making a total of 5 Channels. This is meant to 
be used in conjunction with the 5.0 surround format. Pro-
ceed as follows.
1.Create your mix for 5.1.
2.Create an output bus with the “5.0” speaker arrange-
ment, in the VST Connections window, and route it to the 
physical outputs on your audio hardware.
3.Run the mix through the Matrix Encoder.
Now, the two Surround channels will first be merged to-
gether to make the mix compatible with LRCS. Then the 
four resulting signals will be encoded as usual. This will 
require much fewer adjustment when moving between 5.1 
and LRCS.
Using the Matrix Decoder with the 5.0 surround format
The Matrix Decoder also has five channels. This is for similar 
reasons. Normally two surround speakers are used even 
when playing back LRCS. The two speakers then simply 
use the same material. The Matrix decoder simulates this by 
delivering the Surround channel to two outputs. This allows 
you to move between formats and listening situations with 
less repatching of speaker channels.
Matrix Encoder
The Matrix Encoder is intended for Pro Logic compatible 
encoding of multichannel files. This is a process where a 4 
channel Surround mix is “packed” into two channels for 
broadcasting or distribution on video tape, for example. 
The Matrix Encoder takes four separate inputs; left, right, 
center, and surround (LRCS), and creates two final out-
puts, left-total and right-total (Lt and Rt). 
						

							46
The included effect plug-ins
Mix6To2 
The Mix6To2 effect allows you to control the levels of up to 
six surround channels, and to mix these down to a stereo 
output. The pop-up menu contains a number of speaker ar-
rangement presets that correspond to some default sur-
round formats. The Mix6To2 lets you quickly mix down your 
surround mix format to stereo, and to include parts of the 
surround channels in the resulting mix.
Note that Mix6To2 does not simulate a surround mix or 
add any psycho-acoustical artifacts to the resulting output 
– it is simply a mixer. Also note that the Mix6To 2 should 
be placed in one of the post fader insert effect slots for the 
output bus.
Each of the surround channels has the following parame-
ters:
 Two volume faders that govern the levels of the surround bus 
to the left and right side of the (master) bus.
 A Link button that links the two volume faders.
 Two Invert buttons allow you to invert the phase of the left and 
right side of the surround bus.
The Master bus has the following parameters:
 A Link button that links the two Master faders.
 A Normalize button. If activated, the mixed output will be nor-
malized, i.e. the output level will automatically be adjusted so 
that the loudest signal is as loud as possible without clipping.
Mix8To2
The Mix8To2 effect allows you to control the levels of up to 
eight surround channels, and to mix these down to a stereo 
output. The pop-up menu contains a number of speaker ar-
rangement presets that correspond to some default sur-
round formats. The Mix8To2 allows you to quickly mix down 
your surround mix format to stereo, and to include parts of 
the surround channels in the resulting mix.
Note that the Mix8To2 does not simulate a surround mix 
or add any psycho-acoustical artifacts to the resulting out-
put – it is simply a mixer.
Also note that the Mix8To 2 should be placed in one of 
the post fader insert effect slots for the output bus.
Each of the surround channels have the following parame-
ters:
 Two volume faders that govern the levels of the surround bus 
to the left and right side of the (master) bus.
 A Link button that links the two volume faders.
 Two Invert buttons allow you to invert the phase of the left and 
right side of the surround bus.
The Master bus has the following parameters:
 A Link button that links the two Master faders.
 A Normalize button that will normalize the mixed output if acti-
vated.
Normalize is a function for controlling the overall loudness 
of the output. When this is activated, the level of the mixed 
output will be boosted to exactly 0 dB. 
						

							47
The included effect plug-ins
Mixconvert
The Mixconvert plug-in is similar to the Mix6To2 plug-in in 
that it is used to quickly convert a multichannel mix into 
another format that uses less channels when used as in-
sert (for example converting a 5.1 surround mix to a stereo 
mix). Mixconvert can convert surround mixes into other 
surround formats such as mixing a 7.1 Cinema surround 
format down to a 5.1 home theater format.
There are several obvious applications for this:
 Auditioning what an automatically generated downmix will 
sound like at the customer’s location.
 Quickly generating an additional mix that uses a different num-
ber of channels or a different speaker configuration.
 Outputting several mix configurations simultaneously in vari-
ous surround formats for broadcast purposes.
Users can use presets with standard upmix/downmix set-
ups for specific configurations. It is possible to save up to 
64 user-defined presets for each input/output configura-
tion.
Mixconvert is unique as a plug-in since it is used automat-
ically by Nuendo in certain situations (like SurroundPan-
ner). Nuendo will substitute Mixconvert for the panner in 
either the main channel or in the aux send panner position 
when an upmix or a downmix is needed. These are the 
possible scenarios:
 Whenever a multichannel audio track (more than three audio 
paths), group channel or FX channel is routed to an output 
bus or group channel with a different number of audio paths 
(e.g. 5.1 to stereo), a Mixconvert plug-in will be inserted in 
place of the panner in that channel.
 Whenever a multichannel audio track, group channel, FX 
channel or Output bus has an aux send that is routed to a 
Group channel or Output bus with a different number of audio 
paths, a Mixconvert plug-in will be inserted in place of the aux 
send’s panner.
Indicates that Mixconvert is 
inserted in place of the panner.
Indicates that Mixconvert 
is inserted in the aux 
send panner position. 
						

							48
The included effect plug-ins
Interface
Overview
The plug-in’s interface has three different sections. On the 
left you find the input Configuration display with all para-
meters that directly affect the input configuration. In the 
middle section the level parameters for the upmix/down-
mix are displayed. Above this, the preset controls can be 
found. On the right the output configuration is displayed 
with all parameters that affect the output configuration. 
Additionally, on the far left there is a gain fader.
The following sections explain all controls in detail. Note 
that when you move the mouse pointer over a control, a 
tooltip is displayed at the bottom of the MixConvert win-
dow.
Global Gain fader
Gain depends on the input signal, the number of loud-
speakers and a number of downmix parameters (see 
“Level” on page 50). You can use this fader to globally 
adjust gain by ±12 dB for all channels.
Max Output Level
This field shows the maximum output level. The LED dis-
play on the right hand side of the field indicates whether 
this maximum level is above 0 dB (clipping). Click the LED 
to reset the value field and the indicator.
Input Configuration
The Input Configuration is determined by the channel 
width of the track, group or output bus Mixconvert is in-
serted in. 
Output Configuration
The Output Configuration can only be modified when 
used as an insert effect. When Nuendo automatically re-
places the panner by Mixconvert, the Output configuration 
is determined by the destination of the channel or aux 
send. When used as an insert effect, the Output configu-
ration can be changed either directly in the pop-up menu 
above the Output Configuration display or indirectly by 
loading a preset.
Faders for Surround, Center and LFE
These faders control the levels for the surround channels, 
front center channel and LFE channel in the upmix/down-
mix. The surround channels cannot be modified individu-
ally. For center and surround channels, the level can be 
changed between -× and +6 dB. For the LFE channel it 
can be changed between -× and +10 dB, since in some 
mixes the LFE channel may be attenuated by 10 dB (see 
“LFE channel” on page 50). The names Surround, Center 
and LFE refer to the corresponding channels in the Input 
Configuration.
Solo and Mute buttons
Using the Solo and Mute buttons (on the left of the Input 
Configuration and the right of the Downmix Configuration 
sections) you can mute or solo all front or surround chan-
nels simultaneously (see “Solo mode” on page 50).
Soloing or muting individual speakers
If you want to solo or mute a single loudspeaker in the Input 
Configuration or Output Configuration displays, you can 
click on it. Simply clicking will solo the channel. When you 
hold down the [Alt]/[Option] key while clicking, the channel 
will be muted. Holding down the [Ctrl]/[Command] key 
while clicking will also mute all channels currently in solo 
mode. Clicking again (without a modifier key) will reset the 
channel. 
						

							49
The included effect plug-ins
Phase shift
You can shift the phase of the front left/right channels and 
the surround left/right channels in steps of 90°. Clicking 
the button once will increase the phase by a further 90°. 
You can reset the phase value by right-clicking (Win-
dows) or [Ctrl]-clicking (Mac) on the button.
Phase shifting can be used for various purposes. In a 
downmix from 2 channels to 1 channel it may be useful to 
introduce a 90° phase shift on one channel to avoid level 
increases in the downmix signal (caused by frequencies 
present in both channels). Also, phase shifts can be used 
to create “virtual” reverberation by cancelling all center in-
formation, leaving the resulting ambience.
Toggling between parameter sets
You can use the Memory, Toggle and Clear buttons to 
toggle between two different sets of downmix parameters, 
for direct comparison. Click the Memory button to write all 
current parameters to the temporary parameter buffer. 
This buffer is cleared when clicking the Clear button. Us-
ing the Toggle button, you can switch between the buff-
ered parameter set and the (changed) current parameter 
set. Note that here the Output Configuration is not a pa-
rameter, but must be identical for both parameter sets.
Modifying the width
The front and back Width controls are used to set the 
width of the audible panorama. At minimal width (0 %) the 
panorama is very narrow. In most cases, the default set-
ting will be 50 %. The 50 % setting results in unaltered sig-
nals. Values above 50 % will create an artificial widening 
of the panorama; similar to phase shifting. You should be 
careful when modifying the panorama width when you 
want to generate matrixed downmixes. Drag the Width controls (the colored lines at the top and 
bottom of the input Configuration display) to set the width. 
You can also click on the name of the control to open a 
pop-up menu from which you can select set values (0 %, 
25 %, 50 % and 100 %).
Loading and saving presets
Full presets are only available for Mixconvert when it is used 
as an insert effect. When Nuendo automatically places Mix-
convert in place of a panner, the preset menu displays only 
presets for the current input/output configurations.
Presets are selected and managed at the top of the mid-
dle section of the plug-in interface. The name of the cur-
rently selected preset is displayed in the text field. Click 
the symbol next to the text field to open a pop-up menu 
from which you can select a different preset. Which pre-
sets are available from this pop-up menu depends on the 
downmix options available for the current input configura-
tion. You save a new set of parameters by entering a new 
name in the text field and selecting Save Preset from the 
pop-up menu that appears when you click the Save but-
ton. You can save up to 64 presets for every input/output 
configuration. To delete a user preset, select Delete Pre-
set from the Save pop-up menu. Note that the factory-de-
fined presets cannot be deleted.
!As a general rule, you should be careful when using 
phase shifts, as they might have negative repercus-
sions on the frequency spectrum and the level of the 
downmix. Also, when you generate matrixed down-
mixes, you should avoid introducing additional phase 
shifts, since these would prevent the decoding of the 
mix for different speaker configurations.
!Any signals that are equally in either the surround 
channels or the main left and right channels will be 
completely out of phase (180°) when the width pa-
rameter is set to 100 %. This will cause those signals 
to be completely cancelled when played over a mono 
system, such as AM radio broadcast or mono televi-
sion. Always check for mono compatibility with mixes 
that are to be broadcast. 
						

							50
The included effect plug-ins
General Notes
Level
The volume of the downmixed signal can be different from 
the volume of the original mix. There are several reasons for 
this:
 The input signals must be scaled to avoid clipping.
 The number of speakers used influences the overall volume.
 The level of the downmixed signal depends on the correlation 
of all added signals, which is why phase shifting can influence 
the volume level.
LFE channel
The LFE channel is automatically filtered using a low-pass 
filter. The cutoff frequency of this low-pass filter is 120 Hz, 
the filter slope is 12 dB/Oct. An LFE channel present in 
the input configuration, but not present in the output con-
figuration, is mixed evenly to the front-left and front-right 
channels since it is assumed that these will be the chan-
nels using the speakers with the widest frequency range.
Keyboard shortcuts
The plug-in interface is designed for mouse operation. 
There are two commands with these keyboard shortcuts: 
 Store Parameter Memory: [M] (for “memory”)
 Toggle Parameters: [S] (for “swap”)
Solo mode
Since there is no dedicated solo bus, all solos are inplace, 
i.e. all other (non-solo) channels are muted.
Functionality and available conversions
The speaker configuration of the input mix (Input Configu-
ration) is defined by the width of the channel it is inserted 
in. It is displayed automatically. The speaker configuration 
of the output mix (Output Configuration) is automatically 
selected when Mixconvert is inserted in the panner posi-
tion of a channel or aux send. If it is used as an insert ef-
fect, the output configuration can be selected either from 
the corresponding menu or by loading a preset. 
Note, however, that not all theoretically possible combina-
tions are actually available. Mixconvert is limited to channels 
with 8 audio paths (this means that 10.2 or 8.1 are not sup-
ported). In the tables presented (see “Mixconvert Appendix” 
on page 72) you can find all available combinations.
Brief description of Mixconvert parameters
Available conversions
For a list of the available conversions, see “Mixconvert Ap-
pendix” on page 72.
Mixconvert-ControlRoom
The Mixconvert-ControlRoom plug-in is identical to the Mix-
convert plug-in. It can convert surround mixes into other 
surround formats such as mixing a 7.1 Cinema surround 
format down to a 5.1 home theater format. The decisive dif-
ference to the Mixconvert plug-in is, that this plug-in has no 
latency.
Parameter Description
Width Modifies the panorama
– 0 % (minimum width)
– 50 % (normal width, unaltered)
– 100 % (maximum width)
Global Gain Attenuates or increases all channels to compensate for 
clipping or low levels in the converted signal.
Surround level Level of the surround channel.
LFE level Level of the LFE channel.
Center level Level of the front center channel.
Phase shift Phase shift of a channel (settings: 0°, 90°, 180°, 270°), 
available for front and surround left/right. Click once for 
shifting a further 90°. Right-click/[Ctrl]-click to reset to 0°.
Speaker Click a speaker symbol to set the speaker to mute or solo 
mode. [Alt]/[Option]-click for activating the Mute mode. 
[Ctrl]/[Command]-click for activating the exclusive solo 
(mute all other channels even if they are also solo). Click 
again on a speaker to reset the channel.
Solo button Soloes all front and surround channels.
Mute button Mutes all front and surround channels.
Output Config Only available when used as insert. Sets the output 
speaker configuration.
Store Memory Temporarily saves the current parameter set.
Toggle Memory Toggles between the current and the temporary parame-
ter set.
Clear Memory Clears the temporary parameter buffer.
Save Preset Saves or deletes the preset specified in the preset text 
field.
Preset pop-up 
menuLoads a preset.