Maximum SPL / Headroom (Panel)#

The Maximum SPL / Headroom panel presents users with a detailed analysis of both peak and RMS headroom and allows to get the most out of the system.

Stimulus and Input Level

Stimulus, level and Set Max in the 3D View header.

The stimulus and its input level are set in the 3D View’s header, beside the SPL switch (switch SPL mapping on to show them). The headroom analysis always follows the stimulus selected there. The input level affects the mapped pressure in the 3D View and any panel with SPA mode (like the Microphones Panel).

The level is the RMS signal level, in dBu, with which the stimulus is fed into the system. By default, System Optimiser uses the Pink Noise stimulus with an input level of -8 dBu. A fixed level reflects feeding the system with a defined signal. When you switch to another stimulus, the current level is kept.

Click Set Max to set the level to the maximum the system can take: the loudspeaker with the least headroom will just hit a limit and has exactly 0 dB headroom. All other loudspeakers will have 0 dB or more headroom. Use it to analyse the system at its maximum.

The selected stimulus and its level are saved with the project and stay in sync across every tab and window.

Attention

If the level field is outlined in red (OVR), you have entered an input level that is too high: you’re compressing the system’s dynamics / headroom, and relative gain levels won’t match anymore because at least one loudspeaker is hitting the limiter. Lower the level, or click Set Max.

Note

Earlier versions of System Optimiser had an Auto mode, which followed the maximum level automatically. Projects saved in Auto mode open at their maximum level, as a fixed level. Click Set Max again after changing the system to return to the maximum.

Headroom Analysis / Breakdown

The panel shows a detailed headroom analysis of the entire system for the selected stimulus. Headrooms are split up into ‘RMS’ and ‘Peak’ and facilitate optimal system design for any kind of music or signal. The headrooms are calculated by CODA’s innovative and no-compromise realSPL technology. No approximations, e.g. based on signal crest factor, are made. Instead a highly precise time-domain model of the entire signal chain is used.

Each headroom is shown as a number and a bar. The bar is longer the more headroom is left (a full bar is 12 dB or more), and is coloured:

green - more than 8 dB headroom
amber - between 1 and 8 dB headroom
red - less than 1 dB headroom

Rows with negative headroom are highlighted in red. Muted sources are dimmed and show ‘-‘.

Important

The headroom of an arbitrary level is the minimum of the headrooms of all its children for ‘Peak’ and ‘RMS’ separately. For example, the headroom of an array controller is the minimum of the headrooms of all its assigned instances. The headroom of an instance is the minimum of the headrooms of all the Link Groups in it.

The headroom analysis has a hierarchy of multiple levels that reflect the user’s group assignment as well as the system as it is:

Groups
Array Controllers (Vertical Array, Horizontal Array, Subwoofer Array)
Instances (Stacks / Hangs)
Link Groups
Channels

Please note that for Subwoofer Arrays and Horizontal Arrays, the link groups are automatically created without any possibility for manual adjustment and also do not take the maximum current capability of amplifiers or recommended number of speakers per amplifier into account. This will be addressed in a future update, when a deeper integration of CODA’s amplifier platform is implemented.

Items can be expanded or collapsed by clicking them. The toolbar at the top of the panel has two dropdowns:

Sort - Source order (the default) follows the order of the Source Manager. Lowest headroom lists the items with the least headroom first, so problems are always at the top.
Top level - chooses the level of the hierarchy shown at the top of the list (Array Controllers by default). Pick a lower level for a flatter list:

If levels are collapsed, their names are appended to each other to still allow clear identification.

As with all Panels, the Maximum SPL / Headroom Panel can be resized and moved using Panel Drag & Drop, and ‘popped out’ into an additional System Optimiser window. The location of this Panel will be saved as part of the current tab.