Status, October 2026: current. JBL Professional still lists the 306P MkII.
What it is
The 306P MkII is a powered two-way studio monitor with a 6.5-inch woofer from JBL Professional, part of Harman (JBL Professional product page). JBL announced the 3 Series MkII in January 2018 for that year's NAMM Show as an update to the original 3 Series, in three sizes: the 305P MkII with a 5-inch woofer, the 306P MkII and the 308P MkII with an 8-inch woofer.
It pairs a 165 mm (6.5") woofer with a 25 mm (1") soft-dome tweeter in JBL's Image Control Waveguide, which comes from the M2 Master Reference Monitor. The crossover sits at 1425 Hz. Two Class D amplifiers give 56 W each, 112 W in total, and a Slip Stream port extends the bass. JBL quotes 47 Hz to 20 kHz at ±3 dB and a peak output of 110 dB.
The inputs are one balanced XLR and one balanced 1/4" TRS, with a +4 dBu / -10 dBV sensitivity switch and a volume control. There is no RCA or 3.5 mm input. Boundary EQ cuts the bass shelf at 50 Hz by 1.5 or 3 dB for a desk or wall position, and HF Trim sets the treble to -2, 0 or +2 dB. JBL's LSR310S 10-inch subwoofer pairs with the series.
Each monitor measures 224 x 361 x 282 mm, weighs 6.1 kg and runs on 100 to 240 V. It is sold singly. The carton holds one monitor, a power cord, a quick setup guide and four rubber pads; signal cables are not included.