Cable and power
Audio Connector Types Chart
Quick answer
A church sound system uses six connector families: XLR for microphone level, TRS and TS quarter inch for line and instrument, Speakon for loudspeaker level, RCA for consumer playback, and RJ45 for digital snakes carrying Dante, AES50 or ULTRANET. Speaker level must never share a microphone cable.
Most church audio problems that present as a mystery are a connector problem. A quarter inch plug in a jack that expected a balanced one halves the level and invites hum. A speaker fed down a microphone cable sounds thin and eventually melts something. A consumer laptop output into a professional input reads 12 dB low and gets fixed with gain that also amplifies the hiss.
This chart puts every connector a church touches in one place, with the signal level it belongs to and the specific failure each one causes. Level is the organising idea: connectors exist to keep incompatible levels apart, and almost every fault below is a level crossing a boundary it should not have crossed. Pinouts for the balanced ones are in the XLR and TRS wiring chart.
On this page
What connector carries what in a church sound system?
Read the level column first. Connectors are grouped by the signal they were designed for, and mixing levels is what causes damage rather than merely disappointment.
XLR carries balanced microphone level at roughly 1 to 100 millivolts, quarter inch TS carries unbalanced instrument level, and Speakon carries loudspeaker level at 10 to 100 volts, which is why the three are never interchangeable.
| Connector | Signal level | Balanced | Where it appears | What goes wrong |
|---|---|---|---|---|
| XLR 3 pin | Microphone and line | Yes | Every microphone, every stage box send, powered speaker inputs | Pin 1 lifted at one end causes hum. Bent pin 2 causes intermittent dropout. |
| Quarter inch TRS | Line, balanced | Yes | Console inserts, aux sends, headphone outputs, some DI outputs | The same plug is used for three different jobs. Label everything. |
| Quarter inch TS | Instrument, unbalanced | No | Guitar and bass to a direct box, keyboard outputs | Runs over about 20 feet pick up hum. Use a DI at the instrument. |
| Quarter inch TRS, insert | Line, send and return | No | Analogue console insert points only | Plugged in halfway it breaks the channel. A classic dead channel cause. |
| 3.5 mm TRS | Consumer line, stereo | No | Phone and laptop playback into the console | Consumer level sits 12 dB below professional. Use a DI, not an adapter. |
| 3.5 mm TRRS | Consumer line plus mic | No | Phone headsets, some camera inputs | Four conductors in a three conductor jack loses a channel and shorts the mic. |
| RCA phono | Consumer line | No | Playback devices, older CD players, hearing loop drivers | Unbalanced and long. The commonest source of buzz in a booth. |
| Speakon NL2 | Loudspeaker | n/a | Amplifier to a single passive loudspeaker | Not lockable in some clones. Always twist until it clicks. |
| Speakon NL4 | Loudspeaker, two circuits | n/a | Bi-amped cabinets, or two boxes down one cable | Pins 2+ and 2- are silent on a single amplifier channel. Check which pair. |
| Banana plug | Loudspeaker | n/a | Amplifier binding posts on older installs | Exposed metal at loudspeaker voltage. Superseded by Speakon for a reason. |
| Binding post | Loudspeaker | n/a | Amplifier rear panels, passive crossovers | Bare wire strands bridging the terminals shorts the amplifier. |
| Euroblock or Phoenix | Line and loudspeaker | Either | Installed processors, 70 volt amplifiers, ceiling speaker runs | A loose screw terminal is the hardest intermittent fault to find. |
| RJ45 | Digital audio network | n/a | Dante, AES50, ULTRANET and digital snakes | A cheap patch lead in a snake run. Use shielded Cat5e or better. |
| etherCON | Digital audio network | n/a | Stage boxes and digital snake panels | The locking shell is the point. An unlocked RJ45 on a stage is a failure waiting. |
| XLR 5 pin | DMX lighting control | n/a | Lighting consoles and fixtures | Physically fits nothing in audio, which is the intent. Never use mic cable for DMX. |
| TA4F or TQG mini XLR | Microphone, bodypack | n/a | Headset and lavalier microphones into a wireless bodypack | Manufacturer specific wiring. A Shure capsule will not simply work on another brand. |
| BNC | Word clock, SDI video, antenna | n/a | Wireless antenna distribution, SDI cameras, clock between digital devices | Video coax and antenna coax have different impedances. Do not mix them. |
| HDMI | Digital video and audio | n/a | Projectors, switchers, capture cards, confidence monitors | Fails completely rather than degrading. Length past 25 feet needs an extender. |
| USB-B and USB-C | Digital audio to a computer | n/a | Audio interfaces, console multitrack recording, capture cards | Bus length limits. Beyond about 15 feet needs an active cable. |
| D-sub 25 pin | Eight channels of analogue line | Yes | Multitrack interfaces and older install processors | Two incompatible pinout standards exist. Check before ordering a loom. |
| TOSLINK optical | Digital audio, consumer | n/a | Some playback devices and televisions | Rare in church audio. Easily broken by a tight bend radius. |
| Quarter inch TRS, headphone | Headphone | No | Console headphone out, headphone amplifiers, personal mixers | Driving long runs to a booth position loses level and bass. |
Balanced means the signal travels on two conductors in opposite polarity so that interference picked up equally on both is cancelled at the input. That is why a balanced XLR run of 200 feet is quiet and an unbalanced quarter inch run of 30 feet is not. Level definitions are in the table below.
What are the signal levels, and why do they matter?
Four levels exist, separated by huge margins. Sending one into an input expecting another is the single most common cause of a channel that sounds wrong rather than broken.
Microphone level is around 1 to 100 millivolts and professional line level is 1.23 volts, a difference of roughly 1,000 times, which is why a line source into a microphone input distorts immediately.
| Level | Nominal voltage | Reference | Usual connector | Source |
|---|---|---|---|---|
| Microphone level | 1 to 100 mV | -60 to -20 dBu | XLR, balanced | Any microphone, wired or wireless receiver set to mic out. |
| Instrument level | 100 mV to 1 V | -20 to 0 dBu | Quarter inch TS | Electric guitar, bass, keyboard with a passive output. |
| Consumer line level | 316 mV | -10 dBV | RCA, 3.5 mm | Phone, laptop, tablet, domestic playback equipment. |
| Professional line level | 1.23 V | +4 dBu | XLR or TRS, balanced | Console outputs, processor outputs, wireless receiver set to line. |
| Loudspeaker level | 10 to 100 V | n/a | Speakon, binding post | Power amplifier output only. |
| 70 volt distributed | 70 V | n/a | Euroblock, screw terminal | Constant voltage amplifier feeding ceiling speakers. |
The 12 dB gap between consumer and professional line level is why a laptop plugged straight into a console reads quiet and gets compensated with gain that also lifts the noise floor. The correct fix is a direct box, which converts level and unbalanced to balanced in one step.
Which cable do I use for which job?
The practical version. Two of these rules prevent damage rather than inconvenience, and they are the two churches break most often.
A loudspeaker fed down a microphone cable is the one connection that destroys equipment, because a conductor sized for milliamps is being asked to carry several amps.
| Connection | Correct cable | Common wrong choice | What happens |
|---|---|---|---|
| Microphone to stage box | Balanced XLR mic cable | None. This one is hard to get wrong. | n/a |
| Amplifier to passive loudspeaker | Speakon cable, 12 AWG | XLR microphone cable | Thin conductors overheat, insulation melts, amplifier sees a fault. |
| Guitar to direct box | Quarter inch TS instrument cable | Speaker cable with TS plugs | Unshielded. Picks up hum and buzz from every dimmer in the room. |
| Direct box to stage box | Balanced XLR | Quarter inch TS over a long run | Hum, and level loss over distance. |
| Laptop to console | Active direct box then XLR | 3.5 mm to dual quarter inch adapter | Unbalanced, 12 dB low, and a ground path straight into the console. |
| Console to powered loudspeaker | Balanced XLR | Unbalanced quarter inch | Hum over any distance, and no common mode rejection. |
| Console to amplifier in the same rack | Short balanced XLR or TRS | A 25 foot cable coiled behind the rack | The coil is an antenna. Buy the length you need. |
| Stage box to console, digital | Shielded Cat6A or etherCON | Office grade unshielded patch lead | Dropouts under lighting load. Digital audio fails completely, not gracefully. |
| Multiple microphones to the booth | A multicore snake | Sixteen separate cables taped together | Works, but the tape is the failure point and nothing is labelled. |
| Ceiling speakers on a 70 volt line | Two conductor, correct plenum rating | Ordinary speaker cable in a return-air ceiling | A fire code violation, and the item an inspector finds first. |
| Wireless receiver antenna | 50 ohm coax, BNC | 75 ohm video coax | Reflections and reduced range. It looks identical and is not. |
| Lighting control | 120 ohm DMX cable, XLR 5 pin | Microphone cable with an adapter | Works until it does not. Flicker and dropouts under load. |
The two rules worth memorising: never send loudspeaker level down a microphone cable, and never send an unbalanced signal more than about 20 feet. Everything else on this list degrades quality, but those two destroy equipment and create faults that are genuinely hard to trace.
Why balanced cable is quiet and unbalanced cable is not
A balanced connection sends the same signal down two conductors in opposite polarity, inside a shield. Interference from a dimmer pack, a fluorescent ballast or a mains cable crossing the run is induced roughly equally onto both conductors. At the far end the input subtracts one from the other, the wanted signal doubles because it was in opposite polarity, and the interference cancels because it was identical on both. That cancellation is called common mode rejection and it is the entire reason a 200 foot microphone run is silent.
An unbalanced connection has one signal conductor and a shield doing double duty as the return path. There is nothing to subtract, so whatever the cable picks up arrives at the input as signal. This is why a guitar lead is fine at 15 feet and unusable at 60, and why the correct place for a direct box is at the instrument rather than at the console. Putting the DI at the far end leaves the whole unbalanced run in place and solves nothing.
Two practical consequences follow. First, any run longer than about 20 feet should be balanced, which usually means a direct box or an active output. Second, a quarter inch TRS jack on a piece of equipment is not automatically balanced: the same three conductor plug is used for balanced line, for stereo headphones and for unbalanced console inserts, and the only way to know which is to read the panel. That ambiguity is the reason the wiring chart exists.
Where this chart does not apply
It does not cover proprietary connectors. Wireless bodypack inputs, in particular, look like a standard TA4F but are wired differently by each manufacturer, and a headset microphone terminated for one brand will not simply work on another. Buy the capsule terminated for the transmitter you own, or buy the correct adapter from the microphone manufacturer.
Digital audio over RJ45 is not interchangeable either. Dante, AES50 and ULTRANET all use the same physical connector and cable and none of them will talk to another. A Behringer stage box does not connect to a Dante network because the plug fits, and plugging an AES50 port into the church office network switch is a reliable way to take the network down.
Adapters are not a design. A single adapter in a signal path is a convenience and a chain of three is a fault waiting for a Sunday morning. Each adds two contact points, and contact points are where intermittent faults live. If a connection needs an adapter every week, buy the cable that has the right ends.
It says nothing about cable quality within a type. Conductor gauge matters for loudspeaker runs, covered in the speaker cable gauge chart, and shielding coverage matters for microphone runs. Beyond those two measurable properties, the marketing claims on premium audio cable do not survive contact with the physics.
Video is treated here only where it meets audio. HDMI, SDI and network video have their own distance limits, extender requirements and failure modes that belong with the livestream guides rather than here.
Sources
- AES14 and IEC 60268-12 for XLR polarity convention in professional audio
- Nominal signal level references, -10 dBV consumer and +4 dBu professional line level, from audio interfacing practice
- Connector application and current rating figures from manufacturer specification sheets for the connector families listed
Frequently asked questions
Can I use a microphone cable for a speaker?
No, and this is the one mistake on the page that destroys equipment. A microphone cable has thin conductors sized for milliamps and is shielded for a signal measured in millivolts. A loudspeaker connection carries tens of volts and several amps. The conductors overheat, the insulation can melt, and the amplifier sees a fault. Use Speakon cable of the correct gauge for the run length.
What is the difference between TRS and TS?
TS has two conductors, tip and sleeve, and carries an unbalanced signal such as a guitar. TRS has three, tip, ring and sleeve, and carries either a balanced signal, a stereo headphone feed, or a console insert send and return. The plug looks nearly identical, so read the equipment panel rather than assuming, because the three uses are not interchangeable.
Why does my laptop sound quiet through the sound system?
Consumer line level sits about 12 dB below professional line level, so a laptop headphone output into a console input reads low. Adding gain compensates but also lifts the hiss and any ground noise the unbalanced connection picked up. The correct fix is an active direct box, which converts the level and turns an unbalanced stereo output into two balanced feeds in one step.
How long can an unbalanced cable be?
About 20 feet before hum becomes a real risk, and less in a room with lighting dimmers. Unbalanced cable has no common mode rejection, so whatever it picks up arrives as signal. Anything longer should be balanced, which usually means putting a direct box at the instrument rather than at the console. A DI at the far end leaves the problem run in place.
Is a quarter inch jack always balanced if it has three sections?
No. A three section TRS plug is used for balanced line, for stereo headphones and for unbalanced console inserts, and the connector itself tells you nothing. The equipment panel is the only reliable guide. Plugging a balanced source into an insert point, or a mono TS plug halfway into an insert jack, are two of the commonest causes of a channel that has gone silent.
Can I use any Cat cable for a digital snake?
Use shielded Cat5e or better, and use a locking etherCON connector for anything crossing a stage. Office grade unshielded patch leads drop out under lighting load, and digital audio fails completely rather than degrading gracefully, so a marginal cable produces silence rather than a warning. Also note that Dante, AES50 and ULTRANET share the connector and will not talk to each other.
Researched, not professional advice. This page is compiled from published manufacturer specifications, operator manuals, FCC rules, published standards and owner-review consensus, not hands-on testing. Sound system design, rigging loudspeakers overhead, and any electrical work are jobs for a qualified professional: have flown loudspeakers and their attachment points signed off by a structural engineer or a certified rigger, and have all wiring done by a licensed electrician to your local code. Wireless microphone rules change, so confirm the current FCC position before buying. As an Amazon Associate we earn from qualifying purchases.