Commissioning and System Testing

Commissioning is the structured process of verifying that an installed AV system performs as designed, tuning all adjustable parameters to specification, documenting the final system state, and transferring operational knowledge to the owner. It is not a single event — it is a discipline that begins during system design and concludes with a signed owner acceptance. The CTS-I certification (Certified Technology Specialist — Installation) specifically tests commissioning knowledge, and AVIXA maintains a formal commissioning checklist standard. For AVC technicians, commissioning is what separates a professional delivery from a system that works on the day of installation and degrades within six months. This note covers the commissioning workflow for commercial AV systems including audio conferencing, video conferencing, distributed audio, and control systems.

Effective commissioning begins before the technician walks in the door.

Review design documents: Read the system drawings, equipment list, rack elevation, cable schedule, and IP address list. Understand the signal flow from every source to every destination. Identify any deviations from design discovered during installation and note them for as-built documentation.

Verify installation completeness: Commissioning cannot begin on an incomplete installation. Confirm:

All equipment is installed and powered
All cables are run, terminated, and labeled
All conduit, boxes, and wall plates are complete
Network is active and IP addresses assigned
Room construction is complete (ceiling tile in, doors hung) — acoustic measurements taken in an open-ceiling room are invalid

Pre-load configurations: Where possible, load DSP, control system, and network configurations in advance and transport them to site on a laptop. Pre-loading dramatically reduces on-site configuration time.

Prepare test equipment: Standard AV commissioning toolkit:

Laptop with measurement software (Rational Acoustics Smaart, Room EQ Wizard, or QSC Q-SYS Reflect)
Calibrated measurement microphone (miniDSP UMIK-1, Earthworks M30, or similar)
Reference audio source (pink noise generator, test tone files)
VOM/DMM (Fluke 117 or similar) for continuity and voltage checks
Cable tester (Fluke CableIQ or Psiber CT30 for Cat6; XLR cable tester for audio)
Signal level meter (SPL meter for acoustic measurements)
Video test signal generator or laptop-based test patterns
RTA / SPL meter app as backup (NIOSH SLM, Decibel X)

Signal verification is systematic confirmation that every cable carries the correct signal from source to destination at the correct level and polarity.

Work through the signal chain from input to output:

Physical continuity: Use a cable tester on all audio runs before powering up. Short circuits on balanced lines can damage output stages.
Input gain check: Feed a known reference signal (−20 dBFS or 1 kHz tone at defined level) at each source. Verify the signal appears at the DSP input at the expected level. Typical mic preamp gain: 40–60 dB above mic capsule output to reach line level.
Routing matrix verification: Confirm every DSP routing matrix connection — every input that should reach every output does, and no unintended connections exist. On Q-SYS: use the Reflect monitoring view. On Biamp Tesira: use the routing matrix verification checklist.
Polarity check: Verify balanced connections are wired pin-2-hot throughout (XLR standard). A polarity inversion causes comb filtering when combined with its complement signal. Use a polarity tester (Gold Line PP1 or similar) at each speaker output.
Output level check: With the system at operating levels, measure SPL at the primary listening position with pink noise. Reference level for speech systems: 70–75 dB SPL (C-weighted) at primary seating.

Cable test: Use a dedicated test signal generator (Kramer, Atlona, or Murideo) to send HDMI test patterns through every routing path.
Resolution and refresh rate: Verify the display and switcher negotiate the intended resolution and refresh rate. Check EDID management — the switcher should present a consistent EDID to sources regardless of which display is active.
HDCP compliance: For content requiring copy protection, verify HDCP handshake completes successfully. HDCP failures produce a black screen.
Color accuracy: Use SMPTE or EBU color bar test patterns to verify the display is not color-shifted. Set display color mode to "custom" or "professional."
Latency check: For rooms with separate camera and display positions, verify lip sync within 80 ms.

Proper gain structure ensures every component operates in its optimal dynamic range — above the noise floor, below clipping. See fundamentals/gain-structure for the complete treatment. During commissioning, verify:

System reference level: Define the operating reference level (typically 0 dBu at the DSP output for a line-level system, or 0 dBFS at −20 dBu for digital).
Microphone gain: Adjust mic preamp gain so a standard talker at normal conversational level produces −20 to −18 dBFS at the DSP analog input stage.
Amplifier input sensitivity: Match amplifier input sensitivity to DSP output level. Set so DSP at 0 dBu delivers amplifier at full rated output without engaging the clip limiter.
Speaker level calibration: With DSP at reference level and amplifier at calibrated sensitivity, measure SPL at primary seating. Document this measurement as the baseline for future troubleshooting.

Acoustic Echo Cancellation eliminates the room echo that occurs when far-end audio from speakers is picked up by microphones and retransmitted. Poor AEC tuning is the most common cause of conferencing audio complaints. See audio/echo-cancellation for complete treatment; commissioning steps:

Physical setup first: AEC cannot compensate for a microphone placed on top of a speaker or in a severe reverberation field. Verify microphone and speaker placement before AEC tuning begins.
Reference signal connection: The AEC reference input must receive the exact signal going to the speakers — post-volume-control, at the actual loudspeaker signal level. Verify this connection in the DSP routing.
Set delay: Acoustic delay = room distance (m) ÷ 343 m/s + processing delay. Enter the total delay in the AEC configuration.
Adaptation test: With AEC engaged, have a local person speak while far-end audio plays. Use Q-SYS or Biamp AEC monitoring meters to verify echo suppression is engaging.
Non-linear processing (NLP): Enable NLP for residual echo cleanup. Set to minimum effective level — excessive NLP produces "underwater" speech artifacts.

Test every button, every trigger, every scheduled event:

Every source selection routes the correct signal to the correct destination
Every display powers on/off on command
Every volume control adjusts the correct zone
Every preset recalls correctly
Scheduled events (auto-shutoff) trigger on schedule
Occupancy sensor triggers activate and deactivate correctly

Test boundary conditions: what happens when a source is not connected? What happens at system power-on with simultaneous equipment start (inrush sequencing)? Document the control system software version, processor IP, and program checksum at commissioning.

The punch list is the formal record of deficiencies discovered during commissioning requiring remediation before acceptance.

Document every issue with:

Specific description of the defect (reproducible steps)
Priority: P1 (system non-functional) / P2 (significant feature missing) / P3 (cosmetic/minor)
Responsible party (AVC, subcontractor, or client-supplied equipment)
Status: open / in progress / resolved / verified

Agree on acceptance criteria before commissioning begins. Common criteria: all P1 and P2 items resolved; P3 items documented and scheduled; owner training complete; as-built documents delivered.

Training content (minimum):

Powering the system on and off (if not automated)
Source selection and volume control
Video conferencing: joining a meeting, adjusting camera and audio
Basic troubleshooting: display is black, no audio
Who to call for support

Deliverables at handoff:

As-built drawings (rack elevation, cable schedule, floor plan with device locations)
IP address list for all networked devices
DSP and control system backup files
Equipment list with model numbers, serial numbers, and warranty expiration dates
User guide (1–2 pages, plain language)
AVC service contact information

Obtain written sign-off from the owner or representative confirming the system was demonstrated, training provided, and documents received.

Commissioning in an incomplete space. Acoustic measurements taken before ceiling tile, flooring, or furniture is installed are invalid — each material change alters room acoustics significantly. Schedule commissioning after construction is fully complete, and plan a follow-up tuning visit if the timeline forces a pre-completion commission.
Skipping polarity testing on speaker outputs. Inverted polarity on one speaker causes acoustic cancellation in the overlap zone — thin or hollow sound that is often mistaken for an EQ or acoustic problem. Test polarity at every speaker with a dedicated polarity tester before tuning EQ.
AEC reference signal connected to the wrong output. The AEC reference must see the signal after all volume adjustments. A pre-fader reference means AEC does not track volume changes — at high volume, echo breaks through. Verify the reference routing before AEC tuning begins.
Accepting subjective approval without objective measurement. "It sounds good" is not commissioning. Measure and document SPL, frequency response, and speech intelligibility (STI or STIPA). These measurements are the evidence of performance and the baseline for future service calls.
No version control on control system programs. A program modified after commissioning without version control loses the baseline. Require version-controlled program files delivered with the as-builts.
Owner training rushed at end of commissioning day. A tired client at 5 PM absorbs nothing. Schedule owner training as a separate session. Record a short video walkthrough of the UI — it will be watched more than any printed guide.

Commissioning and System Testing

Pre-Commissioning: Before You Arrive

Signal Verification

Audio Signal Path Verification

Video Signal Path Verification

Gain Structure

AEC Tuning

Control System Testing

Punch List Management

Owner Training and Handoff

Common Pitfalls