JBL Rebuilds the 3 Series Studio Monitors as MkIII From $199 — but North America Waits Until 7 January 2027

HARMAN announced the JBL Professional 3 Series MkIII on 3 November 2026, from a release datelined Northridge, California and reported by Mix the same day. The range runs to three powered two-way studio monitors — the 305P, 306P and 308P MkIII — plus the 310S MkIII powered subwoofer. JBL describes it, as quoted by StereoNET, as the most extensive redesign the 3 Series has had.

There is a catch for readers on this side of the Atlantic. Sales began on announcement day across Asia-Pacific, Europe, the Middle East and Africa. North America waits until 7 January 2027 — a gap of roughly nine weeks. That date is stated both in Mix's report and on JBL Professional's own 3 Series MkIII family page, where the monitors currently show as "Coming Soon" with the line that they will be available in the US and Canada on 7 January 2027. No US retailer should be holding stock before then.

What they're listed at

JBL's product pages carry no pricing. StereoNET is the only source quoting figures, and it gives official US prices alongside local ones, so no conversion is needed for the American numbers:

• 305P MkIII — $199 (£165 / €195 / A$329)
• 306P MkIII — $249 (£208 / €245 / A$429)
• 308P MkIII — $299 (£245 / €289 / A$529)
• 310S MkIII subwoofer — $499 (£429 / €489 / A$829)

The sources do not say whether the monitor figures are per unit or per pair, so read them simply as list prices. GearNews notes a slight price increase over the MkII generation but gives no figures for it, and UK street pricing already varies: GearNews cites £415 (about $560) for the subwoofer at one retailer against StereoNET's £429 list.

Inside the redesign

JBL's own description of the changes, carried by Mix and StereoNET, covers both ends of the driver complement. The high- and low-frequency drivers are new, the Image Control Waveguide has been updated, cones are stiffer, and the magnet assemblies have been upgraded with aluminium shorting rings — the usual engineering route to lower distortion in the midband.

The most visible change is structural. JBL's patented Slipstream port, which on previous 3 Series cabinets fired from the rear, now exits the front baffle. For anyone working in a small room where the monitors sit close to a wall — which describes a great many home studios — that moves the port's output away from the nearest boundary.

Amplification is Class D throughout. The 305P MkIII runs 43W to each driver for 86W total; the 306P and 308P both step up to 110W; the 310S subwoofer carries 300W. GearNews's Stefan Wyeth writes that the previous generation had an audible hissing noise floor and that the new Class D amplifiers improve on it considerably. That is his description rather than a published measurement, and no source presents a figure for it.

Room controls without software

Four controls on the rear panel combine to give 81 EQ settings. JBL's approach here is deliberately analogue in spirit: there is no calibration software to install and no measurement microphone in the box. You set the switches by ear and by room, and the 81 figure is simply the number of combinations those four controls can produce.

Connectivity is balanced Neutrik combo inputs with a switchable +4dBu / -10dBV sensitivity setting, so the monitors sit equally happily behind a professional interface or a consumer-level output. The 310S adds selectable crossover points and an external bass-management bypass, for rigs where crossover duties are handled elsewhere.

The numbers

Taking the 305P MkIII as the reference point, JBL's specification page lists a 5-inch woofer and 1-inch soft dome tweeter crossing at 2160Hz, 109dB maximum peak SPL, and a cabinet measuring 320 x 175 x 250mm at 5.3kg. Mounting is catered for with eight M4 points on a 75mm VESA pattern.

Two different low-frequency figures circulate for this model and they are not in conflict once labelled. The 45Hz quoted by StereoNET is the -10dB extension point; the 55Hz quoted by GearNews is the lower limit of the ±3dB response window, which JBL gives as 55Hz to 27kHz.

Moving up the range, the 306P MkIII uses a 6.5-inch woofer with 110W of amplification, reaching 43Hz and 112dB max peak SPL. The 308P MkIII takes an 8-inch woofer, also with 110W, for 41Hz and 113dB. The 310S MkIII subwoofer carries a 10-inch driver on 300W, with a quoted 26Hz low end and 116dB max peak SPL.

One naming note: GearNews refers to the subwoofer as the LSR310S MkIII, carrying over the older prefix. JBL's own designation is 310S MkIII.

Context

The 3 Series has been one of the most widely sold entry points into powered studio monitoring for a decade, and the MkII sat at a price where it was often a first serious monitor rather than a considered upgrade. The MkIII keeps that position — the 305P's $199 listing is squarely in the same territory — while reworking the drivers, the port geometry and the amplifier stage underneath it. These are professional studio monitors, and none of the sources positions them for domestic hi-fi listening.

Owner's manuals for the range were updated on JBL's site in October 2026, which is consistent with a product that was ready to ship outside the Americas on announcement day. For US and Canadian buyers, the relevant date remains 7 January 2027.

Dollar figures for non-US prices are converted at the ECB reference rate for 3 November 2026.