One type of speaker needs an amplifier and a speaker cable. The other has its amplifier built in and needs a line-level connection instead. Telling them apart takes a few seconds, and getting it wrong is the most common reason a new pair of speakers appears not to work.
Quick answer
| Passive speaker | Active or powered speaker | |
|---|---|---|
| Amplifier | External, you supply it | Built in |
| Input | Speaker terminals | Line level — RCA, XLR, TRS, or 3.5 mm |
| Cable | Speaker cable | Screened line-level cable |
| Mains power needed at the speaker | No | Yes |
| Typical examples | Home theater satellites, bookshelf speakers, guitar cabinets | Studio monitors, PA tops, computer speakers, subwoofers |
What separates them
A passive speaker is a driver, a crossover and a pair of terminals. It needs an amplified signal at speaker level, which means tens of volts and real current. That is what speaker cable carries, and it is the only thing that should be connected to those terminals.
An active or powered speaker contains its own amplifier, usually one per driver, and sometimes its own crossover and DSP. It needs a small signal and mains power. Its inputs are line level — RCA, XLR, 6.35 mm TRS, 3.5 mm, or increasingly a digital connection — and none of them will survive an amplifier’s output.
How to tell them apart before you connect anything
Four checks, in order.
Look for a mains inlet. A powered speaker has an IEC socket, a figure-eight inlet, or a captive mains lead. That alone settles it. A passive speaker has no power connection at all.
Look at the input. Push terminals or binding posts mean speaker level. RCA sockets, XLR sockets or a 3.5 mm jack mean line level.
Weigh it. A powered speaker carries a transformer or a switch-mode supply and heat sinking, so it is heavier than its size suggests.
Read the name. "Active", "powered" and "monitor" almost always mean built-in amplification. "Bookshelf", "satellite" and "cabinet" usually mean passive.
The phrase "speaker power cable" is a trap
People search for a speaker power cable meaning one of two entirely different things, and the wording makes them sound interchangeable when they are not.
If you mean the mains lead to a powered speaker, that is a mains cable — IEC or figure-eight — and it has nothing to do with audio signal.
If you mean the cable from an amplifier to a passive speaker, that is a speaker cable, and it carries the amplified audio signal, not mains power.
Buying the wrong one of those is a common mistake, and the consequence of plugging mains into a speaker terminal is worth avoiding.
Connecting an active speaker
The connection is line level, and which cable depends on the sockets at each end. A mixing desk to a powered monitor is usually balanced XLR or TRS. A computer to a pair of powered desktop speakers is usually 3.5 mm to RCA or 3.5 mm to TRS. A television to a powered soundbar is usually optical or HDMI.
The one thing all of those have in common is that none of them is speaker cable. If you find yourself reaching for speaker cable to feed a powered speaker, the correct answer is a line-level cable — the 3.5 mm case is covered here and the balanced case here.
The exception: speakers that accept both
A few devices genuinely accept speaker level and line level, and a subwoofer is the usual example. Subwoofers commonly carry high-level speaker terminals alongside RCA inputs so they can be added to a system with no dedicated sub output. That is a documented feature, and it has its own article, because it is a real input rather than a workaround.
Rarely, an install speaker or a zone amplifier will accept speaker level on a screw terminal. The manual will say so.
Outside those cases, an input is one kind or the other.
What goes wrong when you mix them
Feeding a powered speaker from an amplifier’s speaker output puts a signal around 40 dB too hot into an input that expects a fraction of a volt. You will know immediately, because it will sound like a fault — harsh, clipped, or silent because a protection circuit has engaged.
Feeding a passive speaker from a line-level output produces almost nothing, because a line-level source cannot supply the current a loudspeaker needs.
Neither direction is fixed by changing the cable. The mismatch is in the signal, not the conductor.
Scenarios
A studio desk driving nearfield monitors. Balanced line level to active monitors. No speaker cable anywhere in the signal path.
An old stereo amplifier driving bookshelf speakers. Passive speakers, speaker cable, sized by gauge and run length using the selection guide.
A bar install with ceiling speakers. Usually passive ceiling speakers on a 100-volt distributed line, fed from one amplifier. Speaker cable, sized for the tap load rather than the speaker count.
A desktop setup where the speakers hum. If they are powered, the fix is usually the signal cable and the ground relationship, not the audio cable’s gauge.
FAQ
Can I connect a powered speaker with speaker cable? No. Its inputs are line level and the level from an amplifier output is far too high.
Can I connect a passive speaker directly to a computer’s output? No. A line or headphone output cannot drive a loudspeaker.
How can I tell whether my speakers are active? Look for a mains inlet. If there is one, they are active.
Do active speakers need speaker cable at all? No. They need a line-level signal cable and mains power.
What is a speaker power cable? Usually the mains lead for a powered speaker. If someone means the cable from amplifier to passive speaker, that is a speaker cable.
My subwoofer has both RCA and speaker terminals. Which do I use? One or the other, depending on whether your amplifier has a sub output. Using both at once is not correct.
Related reading on this site
- Speaker wire to RCA: why there is no plain adapter
- 3.5 mm to speaker wire: what actually works
- XLR and TRS to speaker wire: line level vs speaker level
- Speaker cable selection: gauge, in-wall ratings and the two code ladders
- Speaker cable termination