South Gym Audio Plan

Goals

• Provide clear, even audio coverage for spoken word and music playback
• Operate as an independent, self-contained audio system

Current State

The existing DSP is a MediaMatrix Xframe88 (1U) with an MM8802 I/O panel (1U). This is being replaced by two BSS BLU-100 units because:

• End of life: The Xframe88 is a legacy platform (Motorola 56002 DSPs) that is no longer supported or serviceable. Replacement parts and expertise are increasingly unavailable. (See equipment reference for specs.)
• Better AMX integration: The BLU-100 supports direct control via IP or serial, allowing AMX to recall presets, adjust levels, and select inputs natively. The Xframe88’s control interface is more limited and harder to integrate with the current AMX system.
• More capable DSP: The BLU-100 offers modern DSP processing, flexible routing, and the ability to act as the system’s mux point – accepting M32R output as an input and switching between sources under AMX control. (See equipment reference for specs.)

Architecture

The South Gym audio system has two operating modes:

• Base mode (BLU-100): For everyday use – school gym, meetings, announcements, background music for dinner events. BSS BLU-100 processors handle all audio processing and routing, controlled entirely by AMX. No operator required.
• Complex event mode (Midas M32R): For live-mixed events – weddings, funerals, youth worship, concerts, banquets with live music. The existing Midas M32R mixer is the foundation, operated by a live sound volunteer.

The BLU-100s are the always-on backbone of the system. The M32R is patched in when an event calls for full live mixing capability.

Why two systems? The BLU-100s provide preset-driven, unattended operation for everyday use, but they can’t provide the real-time fader-per-channel mixing that a live operator needs for complex events. The M32R fills that role and is an existing investment that works well – there’s no reason to replace it. (See equipment reference for M32R specs.)

Signal Path

The rack-mounted DL16 is the central physical I/O point in the system. Wireless mic receivers connect to its inputs, and amplifier feeds come from its outputs. It connects to the M32R via AES50 when the M32R is in use.

Physical connectivity

                                          ┌───────────────────┐
 ┌───────────────┐                        │   Midas M32R       │
 │ Wireless Mics │──► split ──┬──────────►│   (cart)          │
 └───────────────┘            │           │                   │
                              │           │  AES50            │
                              ▼           └─────┬─────────────┘
                        ┌───────────┐           │        ┌──────────────────┐
 Arylic LP10 ──────────►│ BLU-100s  │           │        │ DL16 (portable)  │
 (network streamer)     │ (AMX ctrl)│         AES50      │ (stage)          │
                        └─────┬─────┘           │        │ keyboards,       │
                              │           ┌─────┴──────┐ │ guitars, etc.    │
                              │           │ DL16 (rack)│ └──────────────────┘
                              │           │            │        ▲
                              │           │ Wireless   │        │
                   ┌──────────┘    split──► mic inputs │      AES50 (via M32R
                   │                      │            │       umbilical)
                   │                      │ Amp outputs├──► Amps ──► Speakers
                   │                      └────────────┘
                   │                            ▲
                   │           MUX              │
                   └────────────────────────────┘

Base mode (BLU-100)

For everyday use – no operator, AMX-controlled:

1. Wireless mic receivers are split to the BLU-100 inputs
2. Arylic LP10 feeds the BLU-100 as a line-level input (background music via AirPlay 2, Spotify Connect, Bluetooth, etc. – see equipment reference)
3. BLU-100s process the audio (EQ, levels, routing) under AMX control
4. BLU-100 outputs feed the amplifiers (via MUX)
5. Amplifiers drive the speakers

The rack DL16 and M32R are not in the active signal path in this mode.

Complex event mode (M32R)

For live-mixed events – operator at the M32R:

1. Wireless mic receivers are split to the rack DL16 inputs
2. Rack DL16 sends mic audio to the M32R via AES50
3. Portable DL16 on stage sends instrument inputs to the M32R via AES50 (daisy-chained through M32R)
4. M32R operator mixes all inputs
5. M32R sends mix output back to the rack DL16 via AES50
6. Rack DL16 analog outputs feed the amplifiers (via MUX)
7. Amplifiers drive the speakers

Multiplexing (MUX)

The Peavey Pro-LITE 5.0 amps have a single combo XLR/1/4“ input per channel – they can’t accept two sources and switch between them. This means the mux must happen upstream of the amps.

Approach: BLU-100 internal routing. The M32R/DL16 output feeds into the BLU-100s as an input. The BLU-100 DSP selects between its own processing and the M32R passthrough, controlled by AMX. The BLU-100s are the single point feeding the amps in both modes.

This approach was chosen for three reasons:

1. It’s the only viable option for switching – the Pro-LITE 5.0 has a single combo XLR/1/4“ input per channel (see equipment reference), ruling out amp-level input switching. An external AMX-controlled audio switcher was ruled out as unnecessary complexity given that the BLU-100’s internal routing can handle the switching natively.
2. Equipment protection – routing the M32R output through the BLU-100s allows limiters to be applied to the M32R feed before it reaches the amplifiers. This protects the speakers and amps from damage due to operator error at the M32R (e.g., feedback, accidental hot levels).
3. Consistent output processing – regardless of which source is active, the BLU-100s can apply system EQ, delay, and zone routing to everything going to the amps.

BLU-100 to amp cabling

Balanced connections are required between the BLU-100 outputs and amp inputs. The BLU-100s are on UPS-isolated ground (via the RLNK) while the amps are on building ground (dedicated panel circuits). An unbalanced connection would allow the ground potential difference to appear as audible hum. Both devices support balanced I/O (BLU-100 balanced outputs, Pro-LITE 5.0 balanced combo XLR inputs at 20kΩ), so this is straightforward – use XLR cables, not 1/4“ TS. See Electrical Plan – Grounding for the full ground boundary analysis.

With three amps serving different roles — ceiling speakers (amp #1), subwoofers (amp #2), and floor monitors (amp #3) — each amp likely needs its own output pair from the BLU-100s. The BLU-100 DSP handles crossover, zone routing, and monitor mix processing, so the signal sent to each amp is different. This means 6 BLU-100 output channels are needed (one stereo pair per amp).

The Pro-LITE 5.0 has line-level through outputs (1/4“ jacks) that can pass signal to another amp (see equipment reference). These are useful if any two amps share the same signal, but with three distinct roles, daisy-chaining is unlikely to apply.

The amps also support parallel input mode (one input drives both channels) and selectable input function (full-range, sub, through). Parallel input mode is useful here — each amp drives two identical outputs (2 ceiling speakers, 2 subwoofers, or 2 floor monitors) from a single BLU-100 output channel, reducing the BLU-100 output count from 6 to 3.

Requirements

• Full-room coverage for spoken word (meetings, announcements, ceremonies)
• Music playback capability (background music for events, youth nights, wedding receptions)
• Wireless microphone support (handheld and lapel)
• AMX-controlled presets on the BLU-100s for unattended operation
• Ability to switch between BLU-100 base mode and M32R live mixing mode

Considerations

• Room acoustics: Gymnasiums are notoriously reverberant. Acoustic treatment or speaker selection should account for this. The room has concrete/brick walls to 10’, wood paneling above, dark green rubber gym floor, no windows, and no acoustic treatments — all hard, reflective surfaces.
• Room partitions: No operable walls, partitions, or windows. All walls are fixed.
• HVAC and reflections: No bleachers or in-room HVAC units. The air handler is external with supply/return vents into the room. Ceiling-mounted circulation fans are present. Flutter echo assessment is pending on-site measurement.
• Stage position: Fixed at the front of the room, under the projection screen / future LED display(s). Monitor/fill speaker requirements are TBD.
• Speaker coverage modeling: EASE Focus 3 (free) will be used for speaker coverage prediction — SPL distribution, frequency response, and coverage uniformity. DXF floor plans can be imported as a background reference for tracing room geometry. Speaker manufacturer GLL files provide the directivity data. This should be done once the room dimensions (from DWG files) and speaker model are known.
• Speaker placement: Ceiling-mounted or wall-mounted speakers to keep the floor clear for sports and events
• Durability: Equipment must withstand a gym environment (temperature swings, ball impacts on grilles, etc.)
• Input splitting: Microphone and input splits need to be clean and reliable. Passive mic splitters or an analog split patch may be simplest. Digital splitting (e.g., a shared stage box with dual outputs) is another option if the M32R’s stage box supports it.
• Balanced connections by default: All analog audio connections will use balanced wiring unless there is a compelling reason not to. This applies regardless of cable length – even short in-rack runs. Balanced connections reject common-mode noise and eliminate ground loop hum at ground boundary crossings (see Electrical Plan – Grounding).
• AMX control of BLU-100: AMX communicates with the BLU-100 via serial or IP to recall presets, adjust levels, and select inputs.

Equipment

Wireless Frequency Coordination

The MIPRO ACT-727a receivers cover 482-698 MHz across three switchable bands, each 72 MHz wide:

ISED Regulatory Restrictions

ISED’s Decision on the Technical, Policy and Licensing Framework for Wireless Microphones and SAB-003-17 define the following rules for the 470-698 MHz range:

Impact on the ACT-727a:

• Band 5UA (482-554 MHz): Safe. Entirely within the legal 470-608 MHz range. This is the primary operating band.
• Band 5US (554-626 MHz): Mostly safe. 554-608 MHz is legal (54 MHz). The top 18 MHz of the band crosses into restricted/prohibited territory (channel 37 at 608-614, guard band at 614-617, and prohibited auction spectrum at 617-626).
• Band 6UA (626-698 MHz): Mostly prohibited. Only 11 MHz (652-663 MHz duplex gap) is legal. The remaining 61 MHz is auctioned mobile broadband spectrum. Operating in this band risks regulatory violation and interference from/to LTE/5G base stations.

Compliance concern: The ACT-727a’s ACT auto-scan selects clear RF channels based on signal presence, not regulatory compliance. It does not know which frequencies are legally prohibited in Canada. If set to band 6UA, the auto-scan could select a frequency in the 617-652 or 663-698 MHz prohibited ranges simply because no strong signal is detected there yet. Restrict both receivers to band 5UA or 5US only. Band 6UA should not be used unless frequencies are manually set within the 652-663 MHz duplex gap and verified against ISED rules.

Edmonton Market UHF TV Stations

The following UHF broadcast stations in the Edmonton market (which includes Sherwood Park) must be avoided. Source: RabbitEars Edmonton market.

Each TV channel occupies 6 MHz. The ACT auto-scan should detect and avoid these as occupied channels. With 4 stations in band 5UA, the usable spectrum in that band is reduced from 72 MHz to ~48 MHz — still ample for 4 wireless mic channels (each needs ~200 kHz).

Multi-Receiver Coordination

The ACT-727a has 7 preset frequency groups with pre-calculated intermod-free channel sets:

For a fixed installation with 2 receivers (4 channels), preset groups are the right approach — not auto-scan. Set both receivers to the same group (e.g., Group 1) and assign different channel numbers: channels 1-2 on receiver #1, channels 3-4 on receiver #2. Since the channels within a group are pre-calculated by MIPRO to be intermod-free, they coexist cleanly. Set once during commissioning and leave it.

The auto-scan is designed for portable use in unknown RF environments. For a fixed install where all wireless is controlled, the preset groups give deterministic, repeatable results.

MIPRO also offers RCS27 software (connects via the rear RJ-11 port) for PC-based monitoring and control, and the newer RCS2.Net for network-based coordination of up to 64 channels — but both are overkill for 4 channels in a fixed install.

Cross-facility coordination with the auditorium’s wireless systems is not needed — the auditorium is a few hundred feet away through concrete/brick walls, putting any signal well below the receiver noise floor.

Recommended Operating Configuration

1. Set both receivers to band 5UA (482-554 MHz) and the same preset group. Band 5UA has the most usable legal spectrum and sits entirely within the ISED-approved 470-608 MHz range.
2. Assign channel numbers during commissioning: channels 1-2 on receiver #1, channels 3-4 on receiver #2 (within the same group). Verify selected frequencies do not land on the 4 local TV stations (RF 16, 17, 25, 27 — see table above). The preset groups should avoid these automatically, but confirm during setup.
3. Band 5US (554-626 MHz) is the secondary option if band 5UA proves unusable. Manually verify selected frequencies stay below 608 MHz.
4. Do not use band 6UA unless frequencies are manually locked to the 652-663 MHz duplex gap.

Open Questions

Room Acoustics & Speaker Design

• What are the room dimensions (length, width, ceiling height at speaker mounting points)?
• Has any acoustic measurement been done (RT60, STI), or is there a baseline reverberation estimate?
• Is there budget or structural willingness for acoustic treatment (hanging baffles, fabric panels, banners), or must the speaker design compensate for the room as-is?
• Can the ceiling structure support pendant-hung or flown speakers, or is wall mounting the only option?
• Are there existing speaker mounting points, conduit, or wire pulls reusable from the previous system?
• Room aspect ratio – does it favor a center cluster, a stereo pair, or a distributed grid?
• Is stereo imaging a priority for any use case, or is mono coverage uniformity more important?
• What is the maximum tolerable SPL variation across the listening area (+/-3 dB, +/-6 dB)?
• What is the target max SPL at the mix position or far seat for live music events?
• What is the ambient noise floor during a typical school day (HVAC, gym activity)?
• During live music with the M32R, does the PA carry the full mix, or does stage volume from backline/drums compete?
• If subwoofers are added, where can they be placed while keeping the floor clear for sports?
• Has cardioid subwoofer configuration been considered to reduce rear-wall reflections?
• What low-frequency extension is needed – 80 Hz (speech reinforcement) or 40-50 Hz (youth worship, music)?
• What clearance height from floor to lowest speaker point, and is it sufficient to prevent ball impacts without netting or guards?
• What grille material or protective cage is needed to withstand direct ball contact?
• Is the space climate-controlled during off-hours, or must speakers handle temperature extremes?

Signal Path & DSP

• How will the mic/input split be handled – active buffer, or direct patching to line-level inputs? Passive transformer splitters designed for mic-level signals are not suitable (the ACT-727a outputs line level). Options include: (a) a simple Y-split of the balanced line-level XLR, (b) an active buffer/distribution amp, or (c) routing one channel’s XLR to the BLU-100 and using the mixed output for the DL16 (or vice versa).
• How many analog inputs does each BLU-100 have? Is there enough I/O across both units for all mic splits AND the M32R return feed?
• How many BLU-100 analog outputs, and which map to which amp channels? Are any spare for monitor feeds, record outputs, or future zones?
• Which DL16 outputs carry the M32R mix return to the BLU-100 vs. the amplifier feeds? Are there enough outputs for both simultaneously?
• What is the BLU-100 DSP processing chain order (gain trim, EQ, compressor, limiter)?
• What target output level (dBu) should the BLU-100 deliver to the Pro-LITE 5.0 inputs at nominal program level? What is the amp’s rated input sensitivity?
• What speaker delay values are anticipated (per-speaker or per-zone)? Does the BLU-100 have enough independent delay blocks?
• What room EQ target is planned (flat response, speech intelligibility voicing, or a blend)? Has a measurement session been planned?
• BLU-100 limiter configuration: absolute clip limiter, program limiter with release time, or both in series? What threshold?
• In M32R passthrough mode, does the signal bypass all BLU-100 DSP, or still pass through the output limiter and delay?
• What is the expected nominal output level from the DL16 when the M32R is feeding it? Is that compatible with BLU-100 input headroom?
• When AMX switches from base mode to M32R passthrough, is there a crossfade or mute during transition, or a hard switch? A hard switch could produce an audible transient.
• Can the BLU-100 limiter threshold for M32R passthrough be set independently of the base mode limiter?
• AES50 port assignment: which M32R port connects to the rack DL16 (A or B), and which to the portable DL16?
• What AES50 cable type and max run length is specified for the umbilical? Has the planned distance been confirmed within spec?
• If the portable DL16’s AES50 passes through the M32R, does a rack DL16 fault also drop the portable DL16?
• Has the end-to-end gain structure been documented for both modes (mic capsule → receiver → split → BLU-100/DL16 → DSP → amp → speaker)?
• Pro-LITE 5.0 front panel attenuation controls: set-and-forget trim or operator-accessible? What happens to gain structure if an untrained person adjusts them?
• Is there a documented level agreement for M32R operators (e.g., M32R master at 0 dBVU = X dBu into BLU-100)?
• If one BLU-100 fails, does the system lose all zones or just those assigned to that unit? Has zone assignment been designed for partial-failure resilience?
• Is there a bypass path (DL16 direct to amps) if both BLU-100s fail during a live event?
• If AMX loses communication with a BLU-100, does it hold its last preset, fall back to a safe default, or go silent?
• With 3 amps x 2 channels = 6 amp channels (or 3 if using parallel input mode), do the BLU-100s have enough analog outputs? What is the output assignment plan?
• Has cable dressing been planned to separate audio signal cables from power cables in the rack?

Wireless Microphones & Inputs

• With 4 wireless channels available (2x ACT-727a), what is the typical channel assignment for weddings (e.g., officiant + reader + musician + spare)? Is 4 sufficient, or could larger events need more?
• For youth events, what is the maximum simultaneous wireless channel count needed, and is it expected to grow?
• Are wireless instrument transmitters (guitar, bass) or IEM packs sharing the frequency pool with vocal mics?
• What antenna type is appropriate for the gym environment (omni paddle vs. directional log-periodic) given the metal ceiling structure? The ACT-727a uses 50Ω TNC connectors with DC bias for MIPRO antenna boosters.
• What is the worst-case distance from the rack closet to the farthest transmitter location? Does this exceed reliable range without remote antennas?
• Is remote antenna mounting (outside the rack closet, on a wall or ceiling) needed? Where, and what cable type/length? Note: If remote antennas are used, they must be electrically isolated from building ground (e.g., non-conductive mount or isolating bracket). The receivers are on UPS ground via the RLNK – if the antenna mount is bonded to building steel, the coax shield bridges the two ground references and creates a ground loop. See Electrical Plan – Grounding.
• Will the mic split be a labeled patch panel point for troubleshooting, or hidden in the back of the rack?
• How many simultaneous wired inputs are expected on stage at the largest event? Does the DL16’s 16-input count accommodate that?
• Are there instruments or sources requiring phantom power on the portable DL16?
• Is there a floor pocket or wall box for wired XLR drops (backup mics, DI boxes, podium mic), or do all wired sources go through the portable DL16?
• What does the M32R umbilical need to carry (network, AES50 for portable DL16, IEM returns, power)?
• How many stereo IEM mixes are expected, and do IEM transmitters need power and frequency coordination alongside vocal mics?
• What is the planned maximum umbilical length? Has it been verified against AES50 spec (100m for Cat 5e) including the daisy-chain to the portable DL16?
• Does the umbilical floor drop need to accommodate the M32R cart on either side of the room, or is a single fixed drop sufficient?
• What is the battery management plan for wireless mics (rechargeable vs. disposable, charger location)?
• For multi-hour events, who monitors receiver battery status and initiates swaps?
• If rechargeable, does the charge cycle fit back-to-back event scheduling (afternoon rehearsal → evening ceremony)?

Amplifiers & Speaker Wiring

• How many discrete speaker zones with independent level control are needed?
• Will all three amps be used simultaneously in all presets, or are the sub and monitor amps only active for certain event types?
• If the subwoofer and/or floor monitor outputs are removed (both TBD), what happens to the freed amp(s) — repurposed for additional speaker zones, kept as spares, or removed?
• Will the crossover for subwoofers be in the BLU-100 DSP or the amp’s “sub” input function? What crossover frequency and slope?
• What is the minimum speaker impedance the system will present? Confirm amps won’t go below 2Ω under any wiring configuration.
• At what impedance will the system most likely operate? This determines actual per-channel power and heat output.
• Has a room SPL calculation confirmed whether 15,000W of amplification (3x Pro-LITE 5.0) is appropriately sized, or significantly oversized?
• What is the expected speaker sensitivity (dB SPL/1W/1m)?
• If amps are oversized, is there a risk of front panel attenuation at very low levels reducing control resolution?
• What is the distance from the rack closet to the farthest speaker? Has wire gauge been calculated for run length and load impedance to maintain damping factor?
• Speaker wire type: in conduit, plenum-rated, or CL2/CL3? What does local code require for in-ceiling runs?
• Are speaker wires home-run (one per speaker back to rack) or daisy-chained within zones? Daisy-chaining changes the impedance the amp sees.
• Speakon pin assignments: consistent between amp output and speaker ends (NL4 1+/1- vs. 2+/2-)?
• Field-installed Speakon connectors at junction boxes near speakers – who terminates, what is the testing process?
• What is the BLU-100’s maximum analog output level (dBu) vs. the Pro-LITE 5.0’s input sensitivity for full power?
• Critical: do the Pro-LITE 5.0 through outputs carry pre-attenuation or post-attenuation signal? This determines whether amp #2’s input level is independent of amp #1’s attenuation setting.
• Is the BLU-100 limiter threshold set relative to the amp’s clip point or the speaker’s power handling?
• What is the power-on sequencing plan for amps vs. BLU-100s? Can RLNK enforce sequence for RLNK devices, and what about the amps on dedicated circuits?
• Is there AMX monitoring of amp fault conditions (DC fault, thermal protection), or will faults only be discovered when audio stops?