Analog Audio Interconnect Workflow
Use one copy for each source-to-receiver interface and operating preset.
1. Interface Identity
Project / releaseDate / operatorVehicle / bench state
Source device / outputReceiver device / inputCable / adapter revision
2. Source Contract
- [ ] connector and verified pinout
- [ ] single-ended
- [ ] active-balanced
- [ ] impedance-balanced
- [ ] transformer / isolated
- [ ] differential / floating / BTL
- [ ] maximum clean differential level
- [ ] each leg to source reference
- [ ] source impedance each leg
- [ ] DC offset and common mode
- [ ] allowed open or grounded-leg state
- [ ] startup / shutdown / mute behavior
Unloaded level
Loaded level
Clipping criterion
3. Receiver Contract
- [ ] single-ended or differential sensing
- [ ] differential input impedance
- [ ] impedance each leg to reference
- [ ] common-mode input range
- [ ] maximum differential input
- [ ] input coupling and bias
- [ ] gain and headroom
- [ ] RF filtering and protection
- [ ] clipping and recovery
- [ ] powered-off input behavior
4. Reference And Shield Map
| Path | Connection / bond | Measured voltage or current |
|---|---|---|
| signal return | ||
| cable shield at source | ||
| cable shield at receiver | ||
| source chassis | ||
| receiver chassis | ||
| circuit common | ||
| vehicle power return | ||
| protective earth |
Safety bonds preserved: [ ] yes Unapproved lift present: [ ] no
5. Cable, Connector, And Route
ConstructionLengthCapacitanceResistance
Connector / adapterShield terminationVehicle routeCrossings / parallel runs
- [ ] strain relief
- [ ] connector retention
- [ ] service loop
- [ ] grommets
- [ ] heat protected
- [ ] moisture / drain protected
- [ ] moving parts clear
- [ ] restraints / airbags clear
6. Differential And Common-Mode Measurements
| State / frequency / content | V+ | V− | Vdiff | Vcommon | Receiver output |
|---|---|---|---|---|---|
Vdiff = V+ - V− Vcommon = (V+ + V−) / 2
7. CMRR / Isolation / Quality
CMRR frequency and levelSource imbalanceMeasured rejection
Bandwidth / responseNoise / bandwidthTHD+N / level
Isolation deviceInsertion lossHidden conductive paths checked
8. Noise-State Matrix
| State | Pass / fail | Noise / symptom | Evidence file |
|---|---|---|---|
| engine off / battery | |||
| crank / start-stop | |||
| idle / charging | |||
| lights / blower / motors | |||
| USB / phone charging | |||
| Bluetooth / Wi-Fi / displays | |||
| source / call / prompt / alert | |||
| DSP / amplifier mute | |||
| sleep / wake |
9. Transients And Final Acceptance
- [ ] power-up
- [ ] power-down
- [ ] source change
- [ ] cable connect
- [ ] cable disconnect
- [ ] crank / brownout
- [ ] sleep
- [ ] wake
- [ ] fault / recovery
- [ ] final trim
First limiting mechanism
Known limitations
Regression triggers
Technical approvalDate
Companion lesson: Analog Audio Interconnects, Grounding, And Noise Control.