JBL 310S MKIII

The low end of Series 3 enters the MKIII generation

The JBL 310S MKIII continues the legacy of the Series 3 monitoring systems, designed to deliver a consistent, accessible studio listening experience with sufficient accuracy for music production. It occupies an essential position in the range: that of an active subwoofer designed to extend the low-end response when compact monitors cannot, by their very nature, reproduce the deepest frequencies.

This MKIII version complements monitors from the same generation and retains the principle behind the series' success: straightforward installation, easy-to-read controls and low-end reproduction that can be put to practical use every day. The 310S MKIII does not aim to artificially boost the low end ; its primary purpose is to help you hear what is actually happening below the range normally covered by 5-, 6- or 8-inch loudspeakers.

A studio subwoofer for producing, mixing and checking your mixes

The 310S MKIII is aimed at producers, beatmakers, sound engineers, content creators and musicians working in styles where low-end energy determines the final balance: electronic music, hip-hop, trap, contemporary pop, rock, film music and post-production. In particular, it makes it easier to assess the impact of a kick drum, the length of a synth bass or the presence of sub-bass.

In a home studio as well as in an editing suite, the benefit of a subwoofer is not limited to listening at higher volume. When properly calibrated, it reveals excessive frequencies, unwanted resonances and conflicts between kick and bass. This allows you to make more reliable mixing decisions, while reducing the risk of discovering too late that the low end is unclear on a more extended monitoring system.

The subwoofer is particularly well suited to complementing a pair of nearfield monitors. The main speakers remain responsible for the mids and highs, while the 310S MKIII handles the lowest part of the signal according to the selected crossover setting. This division improves overall clarity and can relieve smaller loudspeakers during demanding sessions.

Adjustable low end for more consistent monitoring

10-inch loudspeaker and built-in amplification

The JBL 310S MKIII features a 10-inch bass loudspeaker combined with active amplification. This configuration is designed to provide an energetic yet controlled low-end response without adding multiple devices to the studio. Its format remains suitable for nearfield installation while adding extra depth to monitoring systems that lack low-frequency extension.

A studio subwoofer must remain precise: a level that is too high can mask the midrange, distort the perception of balances and cause listening fatigue. The volume control therefore allows you to adjust the contribution of the 310S MKIII so that it blends naturally with the monitors. The goal is to achieve a homogeneous system, not to turn the control room into a sound reinforcement setup.

Active crossover, polarity and extended listening mode

The integrated crossover allows you to adapt the crossover frequency between the subwoofer and the monitoring speakers. With a coherent setting, the monitors are not unnecessarily driven in the extreme low end, while the subwoofer takes over more effortlessly. The polarity selection helps acoustically align the subwoofer with the speakers in order to prevent energy loss or an audible dip around the crossover frequency.

The 310S MKIII also features an XLF function, designed to check the behavior of very extended low frequencies. It is a useful tool for club productions, electronic bass, immersive soundtracks and any program whose sub-bass impact needs to be monitored carefully. This additional listening mode helps control excess low-end energy in the mix before export.

Connectivity suited to a professional environment

With its balanced XLR connectors, the JBL 310S MKIII can be easily integrated between an audio interface and a pair of monitors. This architecture is suitable for modern studio wiring and promotes clean signal transmission over balanced connections. The dedicated outputs then allow the signal to be routed to the main speakers in a clear and logical configuration.

To get the most from the subwoofer, it is recommended to position it carefully, start with a moderate level and check the result at several listening volumes. In a small untreated room, precise placement and patient calibration will often do more for low-end quality than simply increasing the volume.

Technical specifications

Bluetooth	No	EQ	No
Connection	XLR, Jack	Color	Black
Speaker diameter	10"	Quantity	1
Number of speakers	1

Bass loudspeaker	10 inches	Filter modes	80 Hz, XLF or external
Advertised maximum power	500 W	Power supply	110 to 240 V
Input sensitivity selection	-10 dBV or +4 dBu	Mains frequency	50 to 60 Hz