Specifications

Operating Manual - 24.24M Matrix Processor

Using the location of the driver diaphragm farthest back as a reference point, measure the distance to other drivers

in the cluster, and set the output delay for each accordingly, with the driver diaphragm closest to the front getting the

longest delay and the driver at the very back getting no delay at all. The minimum adjustment is 0.02 milliseconds, or

about 1/4 inch. When appropriate, always time align the loudspeakers before applying EQ to the outputs of the 24.24M.

9.2d Output EQ

The Protea 24.24M Output EQ section is the same as the input EQ (see section 9.1f), with the exception of the

ability to view the combined effect of input EQ for each installed and linked input channel to a given output channel.

Within the output EQ frame, each installed and linked input channel has its own <Overlay Input EQ> check box, through

which the interaction between input and output EQ is displayed.

9.2e Output Gain

Output Gain operates in the same manner as Input Gain (section 9.1d), ranging from +12dB to Off, with an option

to reverse polarity.

9.2f Output Limiter

A full function compressor/limiter is included on each output channel. A limiter is

commonly used to prevent transient audio signal spikes from damaging loudspeakers, man-

age analog and digital recording levels, optimize broadcast levels, or "thicken" the sound of

an audio source (compression). The adjustable parameters include Limiter In/Out, Thresh-

old, Ratio, Attack Time, Release Time, and Link Bus.

The 24.24M limiter threshold range is -20dBu to +20dBu, or -24VU to +16VU if the

metering option is selected to VU. The Threshold control determines the signal level above

which gain reduction begins, and is indicated by an amber LED (S/L) on the 24.24M face

panel, as well as indicated in the Matrix Meters in software. Increases in audio level above

the threshold will be reduced according to the ratio settings.

The Ratio control determines the amount of gain reduction above limiter threshold. Ratio ranges from a gentle

1.2:1 to a very abrupt INF:1. To illustrate how the ratio control works, imagine a commonly used loudspeaker protection

ratio of 10:1, which means that for every input signal increase of 10 dB above threshold, the output level will only

increase by 1dB. The higher the ratio, the more pronounced the audio effect, so use the lowest ratio possible to suffi-

ciently address the problem.

Attack and Release settings adjust the time it takes the limiter to engage and then disengage when the signal

increases above threshold and then subsequently falls back below threshold. Attack time is adjustable from 0.2ms/dB

through 50ms/dB, while release time ranges from 5ms/dB through 1s/dB. A very fast attack time can sound unnatural,

while a very long attack time can miss some of the initial transient. Similarly, a very short release time can make the

audio sound uneven, while a very long release time can create "pumping", or "breathing" characteristics depending on

the kind of signal. Experiment to find the best solution for a given application.

The Link Bus allows up to four output channels within a group to share a threshold detector, so that any channel

with a transient signal above threshold will apply equal gain reduction to all other channels within that group which is

assigned to the link bus. The channel which furthest exceeds threshold will determine the resulting reduction on all

linked channels. Channel limiter linking is particularly useful when processing stereo signals.

9.2g Output Mute

Output Mute turns off an output channel. When an output channel is muted, that channel’s red mute LED on the

face panel is lit. To mute or unmute all outputs at once, go to the <Mute> menu heading.