Chapter 9 - Mixer

 

Overview

The mixer lets you control the pan/volume of the instruments ; as well as chose effects plug-ins and edit their parameters.

 

User interface

Standard view

Since Bhajis Loops can load up to 64 instruments ; and since the screen of your handheld is... small, you can view only 4 instruments simultaneously.

To select the set of instruments you want to work on, use the Parts popup lists on the right. They let you select which instrument is affected to the first, second, third and forth columns of controls. An option is available in the preferences to change all the parts 4 by 4. For example, if you select the instrument 5 for track 1, instruments 6, 7 and 8 will be automatically assigned to tracks 2, 3 and 4.

For each one of the four instrument displayed, the following controls are available:

These are the famous mute (M) and solo (S) buttons.

This control modify the amount of signal to send to the current effect unit. Note that if the effect is an insert effect (for example, a distorsion or EQ), you can't modify continuously this amount (0: no effect ; another value: effect).

This control modifies the position of the instrument in the stereo field.

The fader modifies the volume of the selected instrument.

The effects are modified by the controls at the right of the screen:

The pushbuttons allow you to select the current effect bus among 4 buses. Please note that the send knob of each "slice" of the mixer apply to the current effect.

The popup-list allows you to choose an effect plug-in for the current bus ; and a knob can be used to adjust the return level.

The Settings icon allows you to display and modify the details and parameters of the plug-in.

Note that the contents of this dialog box may depend on the plug-in you use. Some plug-ins (such as a simple distorsion) don't have any parameter, so this dialog box will be empty. On the other hand, some plug-ins might have a lot of parameters. In case the plug-in has more than six parameters, a popup box is displayed in the bottom right of the dialog, allowing the selection of the parameter modified by the sixth knob. Finally, in case the plug-in has a time-related parameter (for example, a delay interval), an extra set of buttons appears to set this parameter to a given number of steps:

A tap on the icon will display the plug-in help or, if it is not available, the plug-in copyright and version information. The help and copyright information are both accessible using the menus.

It is very important to understand a difference in the behaviour of send and insert effects. Send effects are for example reverbs or delays - effects adding something to the original signal and requiring to be mixed with it. In this case, the send level for each instrument is taken into account, and the result is mixed with the source signal. Insert effects are for example a distorsion or an equalizer ; they equally affect each instrument ; and the result replace the source signal.

Plug-ins settings are saved with the module, but not the plug-ins themselves. Thus, if a song uses a plug-in which is not available ; it will be replaced by (none).

Finally, please note that in case you want to launch Bhajis Loops from a memory card, the plug-ins must be installed in the /PALM/programs/AudX/ directory.

 

Master faders

You can alternatively display on the right of the mixer a global fader controlling the volume of the left and right channels. To do so, use the Toggle Master section command in the View menu.

The blue fader controls the global volume of the left channel ; the right fader controls the global volume of the right channel. You can enable the link feature to modify these two volumes simultaneously.

If you experience distorsion (or clipping), try to reduce the volume of each individual channel, and then beef up the mix using the Master section. The later you apply the gain in the signal chain, the better.

 

Good news for the owners of devices supporting the 480x320 landscape mode: both the plug-ins / part selection controls and master faders can be displayed in landscape mode!

 

Master plug-in

Bhajis Loops allows you to apply a final plugin effect to the global mix. To select a final plug-in, enable the Master section view and tap on the Master label on top of the global faders. It will display all the plug-ins in a popup list:

To change the master plug-in, select a new plug-in in the list. To display the parameters of the master plug-in, tap on the already selected plug-in.

In case you use a plug-in in which the "wet" signal has to be mixed with the "dry" signal, an extra potentiometer is added to let you control the amount of "wet" signal to add to the mix. For example, if you select the Reverb plug-in:

 

Menus

Toggle master section enables or disables the display of the master faders.

Automation switches to the automation view.

XY pad displays the XY Pad.

What's in this bus? displays a list of all the instruments sent/mixed in the current effect bus.

(Song) Open / Save / Save are similar to the functions available in the arrange window.

Settings, Preferences, and About are detailed later.

Where are the VU-meters? Since they are using a bit of CPUs, they are not enabled by default. Go to the Preferences dialog in the Options menu, and enable them!

 

Automation

This feature allows you to draw curves to control automatically the evolution of instruments settings, plug-ins parameters, pan or volume. To switch to the automation view, use the Automation command of the mixer.

You can create as much automation tracks as you want. An automation track is made of:

Please note that:

 

Creating and setting automation tracks

The Track popup-list lists the available automation tracks. It also contains an Add... entry that creates a new automation track. By default, this track controls the volume of the first available instrument.

You can modify the target and the parameter of the selected automation track using the Target and Param popup-lists. The available targets (with their parameters) are:

The checkbox in front of the Track popup list disables or enables the selected automation track.

The up and down keys of the 5-way navigator can be used to move from the selected track to the next/previous one.

 

Drawing a parameter curve

The main control of the page is where you draw the curve describing the variation of the selected parameter. The x axis represents the time (the numbers on the top are the bar numbers). The y axis represents the value of the parameter. In the background you can see a simplified view of the song structure:

The curve is made of linear segments interpolated between control points. This way, you can describe complex variations without entering too many control points.

The selection tool allows you to modify the position of one of the control points. The first control point (at bar 1) cannot be moved horizontally. This tools also allows you to select a segment of the curve (by tapping and dragging the stylus), or to drop a marker (by tapping). The segments and markers are used for the editing commands (cut, copy, paste...) and are displayed in pink :

The draw tool lets you add control points by tapping on the screen or moving the stylus continuously. You cannot add two control points at the same x position. In case you attempt to do so, the control point already present will be moved at the location of the stylus.

The eraser tool removes control points. Note that while you are removing control points, the automation track is temporarily disabled.

The kick tool moves the part of the curve at the right of the stylus 1 bar on the right.

The last tool enables or disables the "Follow" mode. When this mode is enabled, the view scrolls automatically to follow the playing of the song.

The left and right keys of the 5-way navigator can be used to scroll the song, as well as the scroll bar on the bottom of the screen.

 

Menus

(Song) Open / Save / Save as are similar to the functions available in the arrange window.

Undo undoes the last editing operation.

Cut removes the selection, and stores it in the clipboard:

Cut and leave space copies the selection in the clipboard, and removes all the control points in the selection:

Copy copies the selection to the clipboard.

Paste inserts the contents of the clipboard at the location of the marker:

Replace replaces the control points at the right of the marker by those from the clipboard:

Select all select the entire automation curve.

Simplify removes useless control points from the selection. It results in a simpler control curve, and can help reducing the CPU usage. You can apply this function several times.

Smooth smoothes the selection:

Transform displays a dialog box in which you can draw a transformation curve with the stylus. The x axis is the input, original value, and the y axis is the transformed, output value. The following table lists examples of curves and the corresponding transformations:

Identity. Does nothing.

Inverse. Inverts the values. For example, a fade-in is transformed into a fade-out.

Exponential. The smallest values are attenuated, while the highest values are kept.

Expand. Increases the contrast between the average values.

Half. Divides all values by two.

Port'Nawak. Don't try this at home.

The maps menu of this dialog generates default curves, while the transform menu performs elementary modifications of the transformation curve.

Delete track removes the selected automation track. You are prompted to confirm the suppression, since there is no possibility of undo.

The different options of the View menu modify the number of bars displayed in the curve editor. With a 1 bar view, you can do precise editing at the sequencer step level. With a 16 bars view, you can do global, long, editing for fades. You can as well increase or decrease the spacing of the grid on which breakpoints are aligned.

The Mixer command switches back to the mixer mode.

The XY Pad command displays the XY Pad.

Settings, Preferences, and About are detailed later.

 

XY Pad

The XY Pad provides an intuitive way of controlling synthesis parameters with the stylus, and recording automation tracks.

Select a target and a parameter for the X and the Y axis, and control these parameters by moving the stylus in the upper part of the screen.

The checkbox in front of X and Y allows you to record the stylus moves in automation tracks. For example, you can loop a section of the song, and record filter cutoff changes by drawing in the XY Pad as the song plays.

The parameters of the XY pad can be saved in scenes. 5 scenes are available. The entries in the Save menu copy the current settings of the XY pad into the selected scene. The entries in the Load menu retrieve the settings of the selected scene. You can also use the Tréo keypad (keys 1 to 5) or the Up/Down keys to navigate from one scene to another.

The Smoothing command in the Options menu allows you to create smooth parameter changes in the XY pad.

The popup list lets you select one of the 3 possible smoothing modes:

The Speed slider sets the duration of the transition. The Glide slider can be used to create interesting "skidding" effects. The curve displayed on the bottom of the screen shows how the parameter will react to sudden changes (transitions) and dragging (smoothing).

 

All contents and code © Olivier Gillet 2003-2006 - ol dot gillet at gmail dot com

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