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Balancing Your Music

Where to find Balanced Audio Cables for In-Ear-Monitors

There is some debate in the audio world about the advantages of using balanced audio cables for in-ear monitor connections. The best place to start is to explain what a balanced cable is. The simple version is that a balanced cable is one where the left and right grounds have completely separate signal paths. Ok, so what? What difference does it make?

The theory is that be separating the grounds for each channel allows for longer runs of cabling with reduced vulnerability to noise and interference. This works great if you are wiring up a stage but how does it relate to short cable runs for in-ear monitors and headphones?


It turns out that there are a few companies out there like Astell & Kern that make high-end digital audio players with balanced outputs. To take advantage of the internal circuitry of the player and the balanced approach, you need a custom made balance compatible audio cable for you in-ear monitor or headphone.

The custom cable needs to have a four-pole audio connector to interface with the device.


Some devices such as media players or amps have unique balanced output connectors, but the scope of this article is a 2.5 mm four-pole and a 3.5 mm four-pole audio connector.

These types of connector are sometimes referred to as TRRS connectors or Tip-Ring-Ring-Sleeve. In the case of the current Astell & Kern media player model, a 2.5 mm four-pole TRRS audio connector is used.

Where do you find this type of connector? How do you properly interface it with a quality audio wire? There are four versions of a TRRS audio connector. These are available in 2.5 mm and 3.5 mm versions as well as straight and right angle versions. In addition to these options, all four connectors need to offer flangeless pins to prevent shorting the connector to the metal case of the audio device.

In a 2.5 mm audio connector, the 623 straight audio connector from PlasticsOne includes molded finger grips for easy gripping and disconnection from the audio device.


623 2.5 mm 4-pole

The right angle version of the 2.5 mm balanced audio connector is the 624, both of which are designed as flangeless connectors.

3.5mm right angle

624 2.5 mm 4-pole

If you need a 3.5 mm balanced audio connector, PlasticsOne has the 625 straight version that


625 3.5 mm 4-pole

also includes finger grips. Finally, a 3.5 mm right angle balanced audio connector is the 626. Here again, both 3.5 mm versions are designed to be flangeless audio connectors.

3.5mm right angle

626 3.5 mm 4-pole

These new balanced connectors from PlasticsOne are available on several types of high-end audio wire. The Silver Motion cable provides great sonic detail through the use of silver plated copper. The special jacketing eliminates the issue of cable discoloration. Another option is the highly flexible tinsel wire used in the Motion Series IEM Cables which provides excellent wearability as well as a warm, analog sound.

PlasticsOne can build custom balanced IEM cables with either the traditional 2 pin connector or the newer MMCX IEM connector. Contact an experienced Sales Engineer at PlasticsOne to start designing your own custom balanced in-ear monitor cable.

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Andy Bishop - Engineer - PlasticsOne, Inc.