I made a cable for AKG K702 using Bispa's wire (BSP-NXOFC-104QCL). I'll write about the method and changes in sound.

Overview

I purchased AKG K702 at the end of August. It's an open-back headphone that supports recabling, and I got it for 15,000 yen. It shines with its good frequency balance and high resolution relative to its price. However, it's tough in environments with insufficient power, like direct smartphone connection, but if you have an amplifier that can drive it, it's a high-cost-performance headphone.

Since I got it cheaply, I wanted to try upgrading it further with an inexpensive cable, so I decided to make one.

Materials

You can get all the wires and connectors from Bispa.

• BSP-NXOFC-104QCL 3m
• TNXLR-3FGN5 1 piece
• BSP-STMP-S207AU5+adapter 1 piece

Total: 5,480 yen

The wire is unplated OFC. It's a simple wire, but with annealing treatment and the use of low dielectric constant XLPE, it's quite luxurious compared to the stock cable. The MINI XLR uses beryllium copper, and the stereo plug supports both 3.5mm and standard sizes.

I'm using solder like Wako Technical's SR-4NCu. I wanted to enhance the bass of K702 a bit and make the sound warmer. If I use only SR-4NCu, male vocals might feel a bit lacking, so I'm using other solders as well, assigning one type each to the MINI XLR and stereo plug.

When using solder sold by Bispa with the above materials, avoid Kester, DUTCH BOY, Kirkson, and Cardas. Depending on your preference for high frequencies, as long as you avoid silver (Ag)-containing solder, anything should be fine. Since this wire provides solid high frequencies, silver-containing solder might have hit-or-miss results.

DIY Process

The wire comes pre-twisted when purchased. As long as you're not increasing the number of cores, you can just strip the insulation and proceed with soldering the plugs.

The Mini XLR has the following configuration.

The connectors are properly numbered, so please check the actual item. The pin assignment is: Pin 1 for GND, Pin 2 for Right, Pin 3 for Left. Since the cable has 4 cores, assign 2 cores to Pin 1, and 1 core each to the rest, then solder them.

For the stereo mini plug, it's assigned as Left, Right, and GND from the tip. Use a tester or similar to check the pin configuration of your stereo mini plug, and solder each channel and GND to correspond with the Mini XLR pin assignment.

Completion

Finished product pic.twitter.com/5GtYlvk7b7

— K (@rmc_km) September 4, 2021

Review

Compared to the stock cable, the sound becomes denser while remaining light and with fine grain. This is especially noticeable in the mid to high frequencies, enhancing the extension of high frequencies and the delicate sound that K702 possesses. The bass doesn't go as deep as K702's capability, but it gains more weight and presence, resulting in a somewhat harder sound.

The stock cable feels more balanced and lighter in tone. On the other hand, it seems to lack in resolution, localization, and range.

Additional Notes

Each has its pros and cons, but since you can try stock cables or DIY cables for around 5,000 yen, it's good to experiment. Note that it's a 3-pin Mini XLR, so if you want to go balanced, you'll need to modify the headphones themselves, which means it's not as straightforward for recabling.

Summary

Compared to other headphones, K702 has more potential for improvement through recabling, and it's attractive because you can try it cheaply and easily. I hope this serves as a starting point for you to enjoy various recabling configurations.