User Operation Guide And Approved Limits

The user guide protects the approved system after it leaves the bench.

It explains which source and preset states are intended, how far controls may be moved, what warnings and protection events mean, which vehicle functions must remain available, and when the system should return for inspection.

What The User Must Know

Area	Delivered information
Sources	supported source paths, source-specific clean settings, normalization or EQ requirements, reconnect and fallback behavior
Presets	name, purpose, intended seats, source compatibility, output level, approved use, and restricted modes
User controls	master volume, phone volume, bass, sub, fader, balance, loudness, source trims, and permitted adjustment range
Warnings and protection	limiter, thermal, low-voltage, amplifier protection, BMS or charging alerts, mute, shutdown, and required response
Vehicle functions	calls, navigation, assistants, warning chimes, parking alerts, cameras, steering controls, factory menus, sleep, and wake
Service	release identifier, service contact, fuse and isolation locations, access notes, inspection triggers, known limitations, and prohibited changes

Source-Specific Limits

Do not hand over one universal “80 percent volume” rule. Record the clean and approved user state for every important source because phone volume, app normalization, projection, Bluetooth calls, USB, head-unit sources, factory prompts, and analog inputs may use different gain paths.

source
→ app and normalization
→ phone or host volume
→ head-unit or factory volume group
→ DSP input and preset
→ user control
→ amplifier and driver limit

Protection Is Not A Target

A limiter, amplifier-protection event, thermal warning, or low-voltage shutdown shows that a boundary was reached. It does not mean the system should be operated continuously until that event occurs.

reduce level and stop repeated fault cycling
record the source, preset, control state, duration, temperature, and vehicle state
inspect the system when the event is unexpected or recurring
do not replace protection devices or raise limits without a controlled redesign and regression test

Required Demonstration

The delivered workflow must demonstrate—not merely list:

every normal music source and its approved level state
every user preset and the seats or purpose it serves
calls, navigation, assistants, alerts, cameras, steering controls, and retained menus
source switching, disconnect, reconnect, key cycle, sleep, and wake
mute, startup, shutdown, and normal warning behavior
the service contact, release identifier, and where the operating card is stored

Restricted Modes

Competition, demonstration, service, endurance, high-output, or experimental presets require explicit access control and instructions. Their source, signal, duty cycle, seats, hearing-safety plan, monitoring, abort method, and recovery criteria must not be inferred from a preset name.

Known Limitations And Tradeoffs

Record compromises openly: driver-priority versus all-seat behavior, native versus derived center, rear-fill limits, unsupported source formats, reduced output in a service mode, phone-specific behavior, retained-function exceptions, or conditions that require a different preset.

One-Page Operating Card

The short card should identify:

approved sources and maximum user states
preset purpose and seat coverage
controls the user may adjust
controls that remain installer-only
warning and stop actions
release identifier and service contact

The complete technical evidence remains in the System Documentation Package.