Each of the three outputs has its own gain, mute, polarity, delay, crossover, EQ and phase settings. This chapter covers what each one does on NEXUS, how to link Output 1 and Output 2, and how to add a subwoofer.
The Mixer
The Mixer tab on the device page has one strip per output and a Master strip. Volume on the Master strip sets the level of all three outputs at once.
The Output page
Click an output under NEXUS in the sidebar to open its page. The tabs are Controls, EQ, Phase, Crossover and Settings. To rename an output, click its name at the top of the page.
| Setting | Range | Factory setting |
|---|---|---|
| Gain | -90 to +24 dB (the fader shows -60 to +12 dB; type a value for the full range) | 0 dB |
| Mute | On or off | Off |
| Polarity | Normal or inverted | Normal |
| Delay | 0 to 8.5 ms | 0 ms |
| Crossover | 20 to 200 Hz, high pass or low pass, 24 dB/octave | Bypassed |
| EQ | 15 parametric bands: ±24 dB, Q 0.1 to 10, 20 Hz to 20 kHz | Flat |
| Phase | 6 all-pass stages | Bypassed |
The delay value can be shown in ms, metres, samples, centimetres, inches or feet. Click the unit to cycle through them. For gain, delay, polarity and EQ in depth, see the Shaping sound chapter of the Omnissiah manual.
Measuring resets gain, delay, polarity and EQ on every output being measured, and applying a correction writes new values. Make hand adjustments after applying a correction, not before measuring. Measuring and applying never change the crossover.
Crossovers
A crossover splits the frequency range between speakers: a high pass on the main speakers removes the deep bass, and a low pass on the subwoofer removes everything above it. NEXUS ships with every crossover bypassed, so all three outputs play the full range until you set one.
On an output's Crossover tab:
- The type list offers BW HP, LR HP, BW LP and LR LP: Butterworth or Linkwitz-Riley, high pass or low pass. The slope is fixed at 24 dB/octave.
- The frequency runs from 20 Hz to 200 Hz. Reset crossover returns the crossover to 90 Hz.
- Bypass switches the crossover off; the button reads Bypassed while it is off.
Use Linkwitz-Riley (LR) for a sub and main speakers. A Linkwitz-Riley high pass and low pass at the same frequency add back to a flat response through the crossover region.
Adding a subwoofer
Finish Chapter 3 — Quick start with your main pair first. Then:
- 1Turn the subwoofer down. Connect NEXUS Output 3 to the subwoofer's input.
- 2On the subwoofer itself, turn its own low-pass filter to its highest setting, or switch it off (often labelled LFE or bypass). NEXUS does the crossover, and two low-pass filters in a row would cut too much.
- 3Open Output 1, then the Crossover tab. Choose LR HP, set the frequency and click Bypassed so the crossover is active. Do the same on Output 2.
- 4Open Output 3, then Crossover. Choose LR LP at the same frequency and make it active.
- 5Bring the subwoofer volume up to roughly match the main speakers by ear.
- 6Measure again: Calibrate → Start from: Left + Right + Subwoofer. Check that Left Speaker uses Output 1, Right Speaker uses Output 2 and Subwoofer uses Output 3, then follow steps 6 to 9 of the quick start.
Which frequency. Start at 80 Hz. If your main speakers roll off above 80 Hz, set the crossover close to the frequency where their low end starts to fall, which their specification lists. The measurement sets the sub's level, delay and polarity so the sub and the main speakers add up at the listening position.
Output 3 receives a mono sum of every input in the factory routing, which is the right feed for a subwoofer (Chapter 7 — Routing & sources).
Linking Output 1 and Output 2
Linked outputs mirror each other's settings, so one change sets both speakers of a pair. Outputs ship unlinked.
- 1On the Output page Settings tab, click Link… next to "Not linked". The Link card on Controls and the Link section on the Mixer strip open the same dialog.
- 2In Channel Linking, pick Output 1 and Output 2 and click Link 2 channels.
- 3Under Shares, choose which settings the group shares: Mute, Gain, Delay, Polarity, EQ and Crossover.
To undo, open the dialog again with Manage… and click Unlink all.
Room correction measures and corrects each output on its own, linked or not, because each speaker sits in a different part of the room.
