How to Choose an Earphone Cable: A Buying Checklist

To choose an earphone cable, check six things in order: the connector on your IEMs, the plug your player needs, the conductor material, the length, whether you need a microphone, and your budget. The first two decide whether the cable fits at all. The rest decide how it feels, how it lasts and what it costs.

This guide is a buying checklist for anyone replacing or upgrading an earphone cable for in-ear monitors (IEMs). It explains each choice in plain terms and shows which Null Audio cable lines use which conductor, so you can narrow the field quickly.

What does an earphone cable actually do?

An earphone cable is the detachable lead that carries the audio signal from your player to your IEMs. It has three parts: the connector at the earpiece, the conductors in between, and the plug at the player end. The Y-split is where the cable divides into left and right leads.

A cable can change real, measurable things: whether it fits your IEMs and source, its resistance, how it handles and how long it lasts. How much it changes the sound is a separate question. We cover what can be measured in Do IEM upgrade cables make a difference?

Which connector do your IEMs use?

This is the first check, because the wrong connector simply won't fit. The connector is the plug that goes into the earpiece.

• 0.78 mm 2-pin is used by most custom IEMs and most current Chi-Fi IEMs. Sockets are flat (flush) or recessed, and our standard 2PIN (0.78) plug fits both.
• qdc or "extended" 2-pin has its pins inside a raised shroud. A qdc plug won't seat on a standard recessed 2-pin socket (Headphonesty).
• MMCX is a snap-on coaxial connector that rotates in its socket. Shure SE, Campfire Audio and older Westone models use it.
• IPX is used on current Ultimate Ears customs; our IPX plug also fits T2 sockets.
• Brand-specific connectors include A2DC, Pentaconn Ear, Sennheiser IE 300/600/900 and Sony IER-Z1R.

Our configurator lists 29 earphone-side options, including headphone connectors. If you own IEMs with different connectors, FlexiPlug gives one cable interchangeable tips: 0.78 mm 2-pin, IE 300/600/900 MMCX, IPX, A2DC, qdc 2-pin and Pentaconn Ear.

Which player plug do you need?

The player plug must match the socket on your phone, dongle, DAP or amp. Single-ended means the left and right channels share one ground. Balanced means each channel has its own return wire.

• 3.5 mm single-ended has 3 contacts: left, right and a shared ground.
• 2.5 mm balanced has 4 contacts. Astell&Kern's AK240 used it in 2014 (Stereophile).
• 4.4 mm balanced has 5 contacts. JEITA added it to standard RC-8141C in 2016 (Phile-web).
• 4-pin XLR or a pair of 3-pin XLRs suit desktop amps.
• Lightning and USB-C DAC plugs connect straight to a phone.

Balanced output can deliver more power. FiiO rates its KA13 dongle at 170 mW or more from 3.5 mm and 550 mW or more from 4.4 mm at 32 Ω (FiiO). If you are unsure, buy the plug your source has now. 3.5 mm, 2.5 mm or 4.4 mm balanced? and our player plug guide go further.

Copper, silver or hybrid: which earphone cable conductor?

The conductor is the metal that carries the signal. Silver's resistivity at 20 °C is 1.59×10⁻⁸ Ω·m against copper's 1.68×10⁻⁸ Ω·m, about 5% lower (HyperPhysics). In practice, thickness matters as much as the metal. A typical IEM cable measures under about an ohm.

Resistance matters most with multi-driver IEMs, whose impedance varies with frequency. A common rule of thumb is that source output impedance should be no more than 1/8 of the earphone's impedance (Headphones.com). Silver-plated copper (SPC) is a copper conductor with a silver layer; at audio frequencies the copper carries almost all the current.

Sound descriptions are our own: we describe Arete as dynamic with deep bass, and Thera as accurate, with vocal definition. Materials also age differently. Silver tarnishes to silver sulfide, and copper forms a green patina. Copper vs silver vs silver-plated copper explains OCC, 7N, cryo and Litz.

Length, weight and fit

Most of our cables are 1.2 m (48 inches) as standard. That suits a phone in a pocket or a player on a desk. For a different length, check the product page or contact us.

Weight and flexibility matter for comfort. Lune MKVIII, for example, weighs about 24 g at 24 AWG. A thicker cable can feel heavier on the ear. Ear guides of about 10 cm come fitted by default on common connectors such as 2-pin, MMCX and IPX.

Handling also affects noise. Microphonics is the noise a cable makes when it rubs or moves (Sennheiser). A soft, flexible jacket with little memory effect is easier to coil and carry. How to make your IEM cable last covers care.

Do you need a microphone or a DAC in the cable?

If you game or take calls on your IEMs, you need a microphone. A microphone option is available on selected cables. Ethos MKIII Pro-Gaming has a recording-grade microphone. Capri USB-C adds a DAC and microphone in one plug. Our guide to the IEM cable with mic compares them.

If you listen mainly on a phone, a DAC in the cable saves carrying a dongle. iPhone 15 and later use USB-C; iPhone 5 to iPhone 14 used Lightning (Apple). Ethos Ultra has a detachable player end, with 3.5 mm, 4.4 mm and USB-C DAC plugs in the box. See IEMs with your phone for the trade-offs.

How much should you spend?

Spend enough to get the right connector, plug and build quality first. After that, price mostly follows the conductor and construction.

Under USD 100

Capri USB-C starts at USD 39 and Brevity Pro at USD 49. Ethos Ultra, from USD 89, includes three player plugs. For pairings with Moondrop, Truthear and 7Hz, read upgrade cables for budget IEMs.

USD 100 to 400

Arete MKV, Epsilon MKIII, Lune MKVIII, Tiburon MKIII, Hakone MKIII and Thera MKIII sit here. This is where you choose between copper, silver and hybrid conductors.

Above USD 400

Aoraki MKIII, Istana and Moebius use gold-silver, graphene-coated copper and gold/silver fusion conductors.

Every Null Audio cable carries a 1-year transferable warranty, and most lines can be repaired at a flat rate of USD 30 or USD 50 within 3 years of purchase; Capri and Brevity are not covered by flat-rate repair. Details are on our warranty page.

Your earphone cable checklist

1. Find your IEM's connector in Find My Cable.
2. Match the player plug to your source.
3. Choose a conductor: copper, silver, hybrid or SPC.
4. Check the length; 1.2 m is standard.
5. Decide whether you need a microphone or a built-in DAC.
6. Set your budget.

Then browse all IEM and headphone cables. If you are stuck on any step, contact us and we'll help you choose.

Frequently asked questions