You need a bare wire to RCA adapter or a powered speaker with bare wire terminals

Old speakers with bare wire terminals cannot plug directly into an aux jack. An aux input expects a 3.5mm stereo plug or RCA connectors, not exposed copper wire. You have two working paths: buy a bare wire to RCA adapter (around $10 to $20) and run RCA cables to your device's aux output, or replace the speakers with powered speakers that have bare wire input terminals built in.

The adapter route works if your speakers are passive (no power source of their own). The powered speaker route works if you want a simpler setup and don't mind replacing the speakers. Both let you hear audio from phones, computers, or tablets through old speaker hardware.

Key Takeaways

  • Bare wire to RCA adapters are the cheapest way to connect old passive speakers to an aux output, costing $10 to $20 and requiring no soldering.
  • The adapter has two RCA plugs that connect to your device's aux output, and two bare wire terminals where you strip and insert the speaker wires.
  • You must match the positive and negative wires correctly — red to positive, black to negative — or the speakers will sound wrong or not work.
  • If your device has no RCA output, you need a 3.5mm aux to RCA cable in addition to the adapter.
  • Powered speakers with bare wire inputs skip the adapter step entirely and connect directly to your device's aux output via a single cable.

How to wire a bare wire to RCA adapter

Start by identifying the positive and negative wires on your speaker cable. The positive wire is usually marked with a stripe, ridge, or color (often red or white). The negative wire is plain or black. If both wires look identical, check the speaker itself — the positive terminal is usually marked with a plus sign or a red dot.

Strip about one-quarter inch of insulation from each wire end using wire strippers or a utility knife. Twist the exposed copper strands together so they form a tight bundle and don't fray. Loosen the terminal screws on the adapter (they turn counterclockwise). Insert the positive wire into the red terminal and the negative wire into the black terminal, then tighten the screws firmly. Repeat for the second speaker if you have a stereo pair.

Plug the RCA connectors into your device's aux output. If your device has a 3.5mm aux jack instead of RCA inputs, use a 3.5mm to RCA cable between the device and the adapter. Power on the speakers (if they have a power switch) and test the connection at low volume.

What to do if your device only has a 3.5mm aux jack

Most phones, tablets, and laptops have a 3.5mm headphone jack or aux output, not RCA inputs. In this case, buy a 3.5mm to RCA cable in addition to the bare wire adapter. This cable has a 3.5mm stereo plug on one end and two RCA plugs (red and white) on the other.

Plug the 3.5mm end into your device's headphone or aux jack. Plug the RCA ends into the adapter's RCA inputs. Then connect the bare wires to the adapter's terminals as described above. This adds one extra cable to your setup but lets you use any device with a standard audio output.

Powered speakers with bare wire inputs as an alternative

If you want to avoid adapters and extra cables, powered speakers with bare wire terminals offer a simpler path. These speakers have a built-in amplifier and power cord, so they don't need an external amp. Models from brands like Edifier, Klipsch, and Audioengine include bare wire inputs on the back panel.

To set up a powered speaker, strip and insert the bare wires into the speaker's terminals the same way you would with an adapter. Then run a single 3.5mm aux cable from your device to the speaker's aux input. You get stereo sound from two speakers, or mono from one, depending on the model. The trade-off is that powered speakers cost more upfront ($50 to $200+) but eliminate the adapter step and usually sound better than passive speakers with a cheap amp.

Common wiring mistakes and how to avoid them

The most common error is reversing the positive and negative wires. If you wire them backwards, the speakers will still make sound, but the bass will sound thin and the stereo image will collapse. If you have two speakers and reverse only one, the sound will come from the wrong direction. Always double-check that red goes to positive and black goes to negative before tightening the terminal screws.

Another mistake is stripping too much insulation. If you strip more than half an inch, the bare wire can touch the opposite terminal and short the circuit, which may damage the adapter or your device. Strip just enough to get a solid connection — about one-quarter inch is right.

A third error is not twisting the wire strands together. If you insert frayed wire into the terminal, some strands may not make contact, and you'll get crackling or no sound. Twist the strands tight before inserting them.

Checking your work and testing the connection

Before you power anything on, visually inspect the adapter. Make sure the positive wire is in the red terminal and the negative wire is in the black terminal on both channels (left and right). Make sure the terminal screws are tight and the wires don't move when you tug gently on them.

Plug the RCA connectors into your device's aux output (or into the 3.5mm to RCA cable if you're using one). Set the volume to the lowest setting on both your device and the speakers. Power on the speakers and play a familiar song or voice recording. You should hear sound from both speakers at roughly equal volume. If you hear sound from only one speaker, check that both wires are inserted and the screws are tight. If the sound is distorted or crackling, the wires may not be making good contact — remove them, twist the strands tighter, and reinsert them.

Frequently Asked Questions

Can I solder the wires instead of using an adapter?

Yes, if you have soldering skills and a soldering iron. You can solder the bare wires directly to RCA plugs, then plug those into your device or amp. This creates a permanent connection and eliminates the adapter. However, soldering takes practice and the wrong technique can damage the wires or plugs. For most people, a screw-terminal adapter is safer and faster.

What if my speaker wires are different colors, like red and white?

Red is positive and white is negative. Insert red into the red terminal and white into the black terminal on the adapter. The color names don't always match — what matters is that red always means positive and the other color always means negative.

Do I need a separate adapter for each speaker?

No. A single stereo adapter has two pairs of terminals — one pair for the left speaker and one pair for the right. If you have two speakers, both connect to the same adapter. The adapter's single pair of RCA plugs then connect to your device's aux output.

Will this work with wireless speakers or Bluetooth speakers?

No. Wireless and Bluetooth speakers don't have bare wire inputs — they receive audio over radio signals instead. Bare wire adapters only work with passive speakers or powered speakers that have a wired aux input.

What if the speaker wires are too thick to fit in the adapter terminals?

Most speaker wire is thin enough to fit standard adapter terminals. If your wire is unusually thick, you can strip a longer section and fold the wire back on itself to make it thinner, or buy a bare wire adapter with larger terminals. Some adapters are designed for thicker gauge wire and have bigger screw terminals.