4 - The PatchMix DSP Mixer

Mixer Strip Creation

Meter Inserts

Keeping track of signal levels is important in any audio system, be it analog or digital. You want to keep the signal levels running as close to maximum in order to achieve high resolution and low noise. On the other hand, you don’t want the signal level so high as to cause clipping. To help you maintain optimum signal levels, we have included Peak Level Meters, which can be dropped into any insert location.

The insert meters are of the “peak hold” type. The topmost bar in the meter holds its highest level for a second to let you see transients that would otherwise be too quick for the eye. A numeric readout above the meter shows the peak-hold level in dB.

The peak meters are also color-coded to indicate the signal strength. The chart below outlines the meanings of the colors. Avoid lighting the topmost red bar, as this indicates distortion of the signal. Click on the clip indicator to turn it off.

Meter Color

Indicates

E Red

Indicates signal clipping.

E Yellow

Good strong signal level.

E Green

Signal is present.

One of the most obvious uses of the insert meters is to set input levels. On the analog inputs, the analog-to-digital converter (ADC) is one of the most critical points in the signal path. You want the input signal level to drive the 24-bit ADCs into their optimum range without clipping. A reading of 0dB on an input meter indicates signal clipping.

Level

70 60 50 40 30 2010

--12dB

Each bar of the meter equals 1dB. The yellow bars begin at -12dB below full scale.

The insert meters are also useful to monitor incoming digital signals such as ADAT, ASIO or S/PDIF to make sure the mixer is receiving a proper signal level. They’re also great for troubleshooting, since you can place them virtually anywhere in the mixer.

To Insert a Meter

1.Right-Click on an Insert location of the mixer strip. A pop-up dialog box appears.

2.Select Insert Peak Meter. A stereo peak meter appears in the insert location.

3.Select Effect in the Main Section. The meters are now shown in high resolution in the TV screen.

To Set the Input Levels of a Strip

1.Select the topmost Insert location on a mixer strip and insert a meter (see above).

2.Left-click on the meter insert to see the meter in the TV screen.

3.Feed your audio signal to the input of the mixer strip. The meter should now show the signal level.

4.Adjust the output level of the external device (synthesizer, instrument, preamp, etc.) feeding the AudioDock or 0202 Daughter Card. The meter should be in the yellow region most of the time with occasional forays into the red. If the clip indicator ever comes on, reduce the signal level.

fInput too weak? Use -10 Input setting.

Output too weak?

Use +4 Output setting

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Creative Professional

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Creative 1820M To Set the Input Levels of a Strip, Meter Inserts, 60 50 40 30 20, To Insert a Meter, Meter Color Indicates