Sound

Sound

Audio for the two main spaces. The auditorium is mixed on an Allen & Heath dLive and processed by a NION DSP; the Atrium and Legato share a Harman BSS BLU-100. Files are in Sound/ (Auditorium/ NION project, Atrium/ Audio Architect, dLive safes/firmware, REW captures).

Auditorium signal path

Mics → wireless receivers (AV room right) → Dante → dLive rack processor (Under-Stage Right) → NION DSP (M21-left) → amplifiers (M21-left).

  • The dLive surface is at the FOH position; its rack processor (MixRack) is Under-Stage Right.
  • The NION is the loudspeaker/drive processor: it takes the dLive mix and distributes it to the amplifiers with per-zone delay, EQ and limiting, drives the balcony zones, and produces the stream/broadcast and assistive-listening feeds. It can also take a direct Dante feed from the Projection Mac into the main mix, so playback reaches the speakers even with the dLive off. See NION loudspeaker processor below.

Dante — small and auditorium-only

Dante is not the audio backbone. It carries just two things, and its traffic never leaves the auditorium: PCs → the network (e.g. the FOH audio PC via Dante Virtual Soundcard), and wireless mic receivers → the dLive rack. It runs on a physically separate pair of Cisco SG-300 switches (Dante A/B, AV room right); VLAN 26 is being introduced to start bridging Dante A into the M4250s, with an eventual plan to replace the SG-300s with M4250s. The full Dante device/address list (two planes, 192.168.10/11.x) is on the network map; the wireless mic receivers are Beyerdynamic units, and AMX N4321 transceivers bridge SVSI/Dante audio.

NION loudspeaker processor

The NION (control 192.168.30.100, Dante 192.168.10.100) is the auditorium’s loudspeaker-management processor. The running project is authored on SOUND-PC (Documents/DSP/) and committed under Sound/Auditorium/ (currently SPAC NION 2025 Rev 4 June 16 - 2026 JB.npa).

Two consoles, one MixRack

A single dLive MixRack (control 192.168.30.101, Dante card 192.168.10.103) is shared by two surfaces — a room/FOH console and an online/broadcast console. Both mix the same inputs; the room surface drives the mains and monitors, the online surface builds the stream mix.

Dante clocking

The dLive MixRack is the Dante PTP clock leader — it is configured as Preferred Master (it advertises the preferred flag and a better clock tier), so it takes grandmaster whenever it is powered. The NION is the fallback, holding the clock while the dLive is off or still booting. On a cold start the clock therefore hands from the NION back to the dLive once the console finishes booting — this is by design.

Inputs and outputs

The NION receives over Dante: the dLive’s aux/main sends (its main programme, RX 1–13), plus the balcony wireless mics and SVSI decoder audio (via CAB4N-M21). Audio leaves the NION as analog through the two CAB 4n boxes — the amplifiers are analog, not Dante:

  • CAB-FOH (0001): 8 analog outs — Mains 1–5 and Subs 1–3.
  • CAB-M21 (0002): 4 analog outs — stage-side zones.

The NION’s Dante transmit carries only the broadcast feeds (web encoder L/R, stream recorder, signage DA, and the ALD/assistive-listening transmitter).

Processing and operator modes

Each speaker zone has its own drive chain (Delay → Gain → PEQ → HF shelf → limiter + brickwall), fed from MAINS/FILLS SYSTEM PEQ and a subs crossover; the balcony zones are delay-aligned. Operator scenes select an SPL cap (No Limiters / 106 / 100 / 94 dB A-weighted), a MAIN FOH TECH tuning scene, and Front Fill From Mains on/off.

dLive-independent playback

The mains are fed through a summing mixer with no dLive-gated selector, so a direct Dante source reaches the speakers whenever the NION and amps are on. The intended source is the Projection Mac (192.168.10.155, powered from RackLink .22 outlets “Mac Studio” / “Mac IO”). It is normally powered off and not subscribed.

Where the names live

The NION project’s DSP blocks are generically named (Gain, PEQ, Hard Limiter). The meaningful labels live in two other layers: the Dante channel names (inputs/outputs) and the control layer inside the project (data.pdn — the amp/zone/preset names).

Streaming / broadcast feed

The online console builds the stream mix in a dedicated stereo matrix (“STREAM”). The MixRack transmits it on Dante as MIX 12/13 STREAM L/R, and an Audinate AVIO-AES3 adapter (VIDEO, 192.168.10.14) subscribes to it and outputs AES3 to the stream/video encoder. The NION also receives this mix and has outputs intended for the broadcast feeds (TO WEB ENCODER, STREAM REC, ALD), but nothing currently subscribes to them — the live stream runs straight from the MixRack to the AVIO, so it does not pass through the NION’s broadcast limiters.

Atrium & Legato

Both share a single BSS BLU-100 (Soundweb London, configured in Audio Architect) in the atrium rack, feeding the atrium amplifier and the legato amplifier (both in that rack).

FOH & other

  • FOH audio PC (SOUND-PC) + FREQOUT feedback-suppression hardware live in the FOH Audio rack. It has its own page: SOUND-PC (FOH Audio).
  • An Allen & Heath ME personal-monitoring system (ME-1 mixers) runs off a dedicated unmanaged switch Under-Stage Right.
  • A Sound Recording PC sits in the video control room rack.

Where the config lives

The NION project (.npa), dLive safes and the Atrium Audio Architect files are under Sound/. Changes are logged in the Sound changelog.