KRK S10.4 subwoofer review

Looking for some extra bass in your monitoring system? We fire up this latest yellow-coned beast

  • £350
KRK S10.4 subwoofer
(Image: © Future)

MusicRadar Verdict

A bulky subwoofer that you’ll need plenty of space for… but we can’t really fault its features or delivery which are both excellent.


  • +

    Balanced and unbalanced inputs.

  • +

    Good bass extension.

  • +

    Foot switch bypass option.

  • +

    Flexible crossover settings.


  • -

    Reasonably large enclosure.

  • -

    No dedicated LFE input.

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KRK S10.4 subwoofer: What is it?

Monitoring the lowest frequencies in your productions can be tricky and is influenced by factors including your workspace and your studio monitors. Most of us don’t have the space to accommodate large monitors with an extended frequency range and often use workarounds such as frequency analysers or headphones to get a better feel for the low end. However, one option is to add a sub bass unit to your monitors.

Choosing a sub that fits the bill often boils down to the features on offer, size and of course price. As you may have deduced, the S10.4 is built around a 10” driver, and this makes it their mid-size design, between the S8.4 (8”) and S12.4 (12”). It’s worth saying that KRK also produces another more high-end and considerably more expensive 12” sub, the 12sHO.

Choosing a sub often boils down to features on offer

The S10.4 uses a front fitted 10” glass aramid composite driver with KRK’s distinctive yellow colour scheme. Low frequency delivery is further enhanced by a front-facing slotted port and if you position the sub on its longer side, as intended, the port is vertical and up the right-hand side. Either way, at almost 48cm wide the S10.4 is still a reasonable size to accommodate. 

KRK S10.4 subwoofer

(Image credit: Future)

KRK S10.4 subwoofer: Performance and verdict

The S10.4 is designed to be used in line with monitors and, to that end, on the back you’ll find stereo inputs and outputs on both unbalanced (RCA) and balanced (XLR and TRS) connectors. There’s no separate LFE input, which you would use with an external monitor controller system. 

Rear mounted controls are Volume, Input Sensitivity (Normal/High), Polarity (0 or 180 degrees), Ground lift (on/off), auto Standby (on/off) and the all important Crossover. This has four notched settings (60, 70, 80 and 90Hz) allowing you to tailor the sub to your monitor frequency response. 

There’s also a footswitch input and when engaged this bypasses the sub and the filter so your monitors receive the full frequency signal. You can use any generic latching footswitch, and though this is an additional expense, it’s a vital addition so that you can easily switch between monitoring with or without the sub engaged.

KRK S10.4 subwoofer

(Image credit: Future)

KRK’s manual includes helpful setup and placement info and the advice is to keep the sub close to your monitors and away from room corners. Further, more detailed, advice includes using pink noise and a decibel meter to set levels and polarity. Nevertheless, positioning a sub does often require trial and error and when we positioned the S10.4 where our existing sub is, we found the polarity-inverted setting delivered the best results. 

The S10.4’s Class D amplifier delivers plenty of punch. With 160 Watts to play with and a maximum peak SPL of around 117dB you can generate shuddering frequencies, and in testing it handled 30Hz very well.

A well engineered sub, with a quality finish and setup. Follow KRK’s advice and you’ll achieve a reliable low frequency extension of your monitoring system.

MusicRadar verdict: A bulky subwoofer that you’ll need plenty of space for… but we can’t really fault its features or delivery which are both excellent.

KRK S10.4 subwoofer: Hands-on demos


Jacob Dark

Produce Like A Pro

KRK S10.4 subwoofer: Specifications

  • KEY FEATURES Front loaded front ported subwoofer with reinforced MDF enclosure
  • DRIVER: 10” glass aramid composite
  • FREQUENCY RESPONSE: 30Hz to 110Hz 
  • AMPLIFIER: 160 Watts Class D 
  • DIMENSIONS: 479x 310 x 341mm 
  • WEIGHT: 15.88kg
  • CONTACT: KRK Systems