Mixer Strips
Each track and bus is represented in the mixer window by a mixer
strip that contains various controls related to signal flow.
There are two places in Ardour in which you can see mixer strips. The mixer
window is the obvious one (and the one we deal with here), but you can also
view a single mixer strip in the editor window by clicking the
editor mixer button.
this image needs replacing with labels and better resolution The mixer strip
for a bus is essentially identical to the one for an audio track, but it is
missing certain controls that make no sense - you cannot record into a bus,
so there is no record enable button, for example.
The mixer strips are designed to visually model signal flow. The input
button selects the input of the track that this mixer strip monitors. The
outputs of the track (the 'tape recorder') are 'hard-wired' to the inputs of
the mixer strip. Think of the input to the strip starting at the polarity
switch, flowing down through the prefader inserts/plugins/sends section,
through the gain fader, past the postfader inserts/plugins/sends section,
the panner, and out through the output selector. In the case of a bus, there
is no 'tape machine' inserted between the input selector and the actual
input of the strip, but the signal flow is identical otherwise.
Track Name
The track name displays the current name of the track as displayed in the
editor window. right-clicking on the name brings up a drop-down menu that
allows you to rename, activate, deactivate and remove the track. Selecting
Rename opens a new window displaying the name of
the track. to change it, type your change and press ok. to leave it
unaltered, press cancel. Selecting remove opens
a new window asking for confirmation of your track removal request.
removing a track removes that track from the project. If the playlist used
by the removed track is not used by any other track, it will also be
removed.
Track Speed Control
The track speed allows a varispeed setting to be applied to the track. a
setting of 1.0 corresponds to the normal playback speed
of the session. a setting of 0.5 will play at half
normal playback speed. when altered, the track will be redrawn to reflect
the new position of the audio resulting from the speed change. The Track
Speed Control has three decimal places of precision. A left or right click
on the displayed number will raise or lower the track speed by 0.1%. when
the speed is not exactly 1, the display will be coloured red. Hovering over
the displayed number will allow you to use the mouse wheel to set the
desired speed. A middle click on the displayed number will return the speed
to exactly 1.
Redirect Boxes
These dark areas above and below the fader allow you to place inserts,
sends and plugins into the signal path before and after the fader
respectively. you may also easily reorder them whilst playing.
collectively, the objects that belong in these boxes are called redirects.
If there are redirects present in the channel, they can be reordered by
dragging them vertically. because plugins and inserts can have different
numbers of inputs to outputs, sometimes you may reach a situation where the
inputs and outputs cannot be all connected sensibly. in this case, your
reordering change will be disallowed by the program.
Right clicking within the dark area will bring up a drop-down menu which
allows you to manipulate the redirects in various ways.
Redirect Boxes
new plugin
selecting new plugin will open a dialog which lists the plugins
available on your system. selecting a plugin which is compatible with
the number of streams in the channel at that point will result in the
plugin being placed in the redirect box in an inactive state. this is
indicated by the brackets around the plugin name. double-clicking the
plugin name will bring up a window that allows you to control the
parameters of the plugin statically (including bypass) or using
automation. all plugins that report their latency are time-compensated
automatically in ardour.
new insert
places at least two new jack ports at that point in the mixer strip (one
input, one output). these ports will then be available to any jack
client (including Ardour itself), allowing another program (or channels
within another program) to be inserted across the channel. hardware
ports may also, of course, be used, allowing the insertion of outboard
equipment. the insert will then appear in the redirect box in brackets
indicating that it is inactive. to activate or deactivate an insert,
right-click on it and select activate. double-clicking on the insert
will bring up a dialog which allows to to assign its inputs and outputs
to other jack ports.
new send
selecting new send will first bring up a dialog box that enables you to
select the number of outputs the send has, along with the destination of
each output. closing this dialog will reveal the name of the send in
brackets, indicating that it is inactive. to activate the send, right
click on it and select Activate. double-clicking on the send brings up
the previous dialog, which will now include a fader which is provided
for level control.
clear
selecting clear in the menu removes all redirects from the mixer strip
(pre and post fader). you can remove an individual redirect by holding
the shift key and right clicking it.
cut, copy, paste
these items allow you to cut, copy and paste plugins, including their
current settings, between Redirect Boxes.
rename
selecting rename will bring up a dialog displaying the name of the
selected redirect. change the name by typing into the text area and
pressing ok.
select all/deselect all
these two options select or deselect all plugins in the channel. this
could be used, for instance, in preparation to copy all plugins from a
channel to another one, along with the current settings.
activate/deactivate
selecting either of these will activate or deactivate the currently
selected redirect(s) respectively. deactivate is the equivalent of
bypass.
note that you can bypass a plugin from it's parameter window as well as
from here.
activate all/deactivate all
selecting either of these will activate or deactivate all redirect(s) in
the mixer strip respectively. deactivate is the equivalent of
bypass if you're a plugin.
edit
selecting edit brings up the controls relevent to the selected redirect.
this is the equivalent to holding control and right-clicking on a
redirect. note that the right click method will not bring up the
controls of the selected redirect, only the one beneath the mouse
pointer.
Pre/Post/Input Button
This button cycles between three metering modes, which determine which
signal is fed to the meters. the modes are pre-fader (the signal at the
input to the fader), post-fader and input (the level at the track input).
left clicking cycles through the three modes one step at a time, while
middle-clicking alternates between the current setting and the setting two
steps ahead. this allows one-click direct a/b comparison between all
available monitoring points.
Gain Display
this control displays the current gain of the fader to the nearest 0.1dB.
left clicking on the value will lower the gain by an amount dependent upon
the fader position the graduations become smaller as the fader nears 0dB
gain. right clicking increases the gain by the same amount. middle clicking
resets the gain to 0dB.
Unit Selector
Right clicking on the meter bars allows you to select the range of signal
levels displayed by the meters. the selected range will be displayed as a
column of numbers next to the meter. /*XXX this feature is currently not
working*/ Gain Level Display
Peak Meter
This control displays the highest peak since the last peak meter reset.
Resetting the peak meter is achieved by left-clicking the displayed number.
The peak meter monitors the signal selected by the Pre/Post/Input
Button .. the same signal as the meters. It should be noted here
that 0dBfs corresponds a value equal to the maximum input or output level
of your audio hardware, independent of it's bit depth.
Gain Fader
The fader changes the signal level within the mixer strip before the
post-fader plugins, which are before the output ports. 6dB of gain is
allowed. there are several shortcuts available for the fader. Using the
scroll wheel of your mouse while hovering above the fader will coarsely
change its position. Holding the control key whilst mouse wheeling will
give you finer control. Holding the shift key and clicking the fader will
reset it to unity gain. Holding control and pressing the middle mouse
button whilst over the fader will allow you to bind a midi control to it,
provided you have an available midi device set in the options menu.
Meters
The number of meters displayed next to the fader is dependent on the number
of inputs or outputs the channel has, whichever is greater. The meters
provide a colour-graduated scale from -50 dBfs to +6dBfs. They display the
instantaneous value of the signal at the monitoring point selected by the
Pre/Post/Input button. 0dBfs corresponds a value equal to the maximum input
or output level of your audio hardware, independent of it's bit depth.
Exceeding 0dBfs does not correspond to running out of headroom within the
mixer, or in any signal path subsequent to that point within the Jack
server. It merely means that if that signal is connected directly to a
hardware port whose resolution is less than the 32-bit floating point
resolution that Ardour uses (i.e. a soundcard), then that port will exceed
it's maximum output level, resulting in distortion. hitting 0dB within the
mixer (or any point in the Jack server) means that you have approximately
100dB of headroom remaining. as it is unlikely that you will reach this
point, it is not represented in any special way by the meter. Naturally, if
the input is selected as the monitoring point for the meter, exceeding
0dBfs means that the input of your a/d converter has clipped.
Panner
The panner in Ardour is actually two panners. Because any mixer strip in
Ardour can route any number of streams of audio anywhere, the idea of
panning can be a complex one. To allow for the current stereo-centric
mainstream world as well as the multi-speaker experimental one, one of two
styles of panner will appear here depending on the number of outputs the
channel strip has. In the simple case of mono channel input / stereo
output, a single panner will be present. The current pan position is
represented by a dot (the dot is the audio stream) which lies between the
letters 'L' and 'R', which represent the left and right outputs
respectively. To change the panning position of the stream, move the mouse
while holding down the left mouse button. the dot will follow your mouse
pointer. To introduce sudden changes to the pan setting, place the mouse
pointer over the desired position and click the middle mouse button. The
pan control will immediately snap to the mouse pointer position. The panner
may be bypassed by right-clicking the control and selecting
bypass from the drop-down menu. The panner will
immediately be bypassed. The increased level you notice when the panner is
bypassed is due to the way panning works. It is not a bug. XXX
what gain law is used in the panner?
In the case of a stereo input / stereo output combination, two panning
controls will appear, one corresponding to each audio stream. You can
link the controls together in two different ways in
this situation, using the direction arrows next to the
link button. Panners can be linked to travel either
in opposite directions or to maintain a consistent stereo width across the
travel of the control. These two modes are represented by the orientation
of the two arrows next to the link button, which
point in either the same or opposite directions. The
link button must be engaged before you can change
the link mode. To link all the panners in a mixer
strip, left-click the link button, then select the
desired link mode by pressing the button marked with arrows.
Let's get a little more complicated by adding another output to the mixer
strip. From this point onwards, the panning positions are represented with
numbered dots on a square field. Orange dots represent the outputs, and the
numbered dots represent the streams. the position of the outputs change
according to the number of outputs in the strip. This happens in order to
allow the most useful arrangement of the available space. At some point,
adding an output will cause the outputs to line up from the top left of the
panning square towards the centre. this is to allow for the 'multi-speaker
big sweep' to occur - where the sound is panned from speaker to speaker
around the room in sequence.
Don't forget that you can bypass the panner by right clicking and selecting
bypass from the drop-down menu. this may
simplify your multi-speaker setup, as often in this type of project panning
between all speakers or outputs is not required on all tracks.
Output Selector
The output selector allows you to assign the outputs of each mixer strip.
left-clicking the output selector causes a ready-made list of output ports
to appear in a drop-down menu, along with edit and disconnect options.
Selecting Edit will allow you to change the
number of outputs the channel has, as well as select software and hardware
ports to route signals to. For more information on the window that appears
when you select this option, see the .
Disconnect will leave the number of output ports
unchanged, but remove all assignments to output ports.
Scratch Pad
This is the text area below the output button. it
allows you to enter any notes that you feel may be relevant to that track.
The notes are stored when you save the session.