Review: JBL 3 SERIES Monitors & Sub

JBL’s development of its M2 Master Reference Monitor became like an in-house space program. Mimicking the trickledown effect of a concept car, the rest of JBL’s monitor range is slowly benefiting from the tech breakthroughs first built for its flagship; most noticeably, the waveguide.

The reverse pillow appearance of the M2’s Image Control waveguide is designed to give a sweet spot like no other. The sort of sweet spot you could park a car in, or more practically, move from rack to rack without losing the detail from either side. It’s odd to have that much freedom of movement. It feels intrinsically like you’d have to make a sacrifice somewhere else — say, precision panning — for it to work. But in practise, the imaging is precise, with the added benefit of not having to hold your head still like it’s clamped in a vice. 

The 3 Series is the first range to get the M2 touch up. They’re at the lower end of JBL’s monitor range, but you wouldn’t know by looking at them. The waveguide technology is on full display, with slight differences as the same equations are solved for different dimensions and hardware specs.

There are two monitor sizes in the range, a five-inch and an eight-inch — both two-way designs. The waveguides on the 3 Series have a rectangular form — as opposed to the square shape of the M2 — presumably to make the dispersion wider in the horizontal plane and render them more suitable to desk/console-top use. Also, the four uninterrupted surfaces of the M2’s waveguide have been broken up by central ridges on the 3 Series variation, which apparently helps the high frequencies stay on track. Undoubtedly, these monitors have the widest sweet spot of any I’ve heard, and the phantom centre, while wide, is always in the middle. Even the detented level knobs on the rear manage to give a very accurate balance between the two sides. Sometimes these are imbalanced depending on the quality of the rear volume pots, but the 3 Series had no such issues.

THE BIG GUNS

I had the LSR308 eight-inch, two-way monitors on review, as well as the companion LSR310S 10-inch powered sub. The 308s themselves are what you’d expect in size, but not weight. For an eight-inch monitor, they’re quite easy to handle — probably aided by the lighter-weight moulded plastic fascia. Both drivers are physically aligned, so you don’t get any odd phase discrepancies that have to be compensated for out of the box.

The 308 is biamped, with two 56W Class D amps giving plenty of oomph (112dB SPL, C-Weighted) and eliminating the need for a heat sink — which helps keep the cost down and the weight too. The 305 has a little less power, but still biamped with two 41W Class D amps.

Even without the sub, the 308s had a satisfying amount of low end. My first impressions of the speakers were that they tended to bring out the ambience in recordings more than my other monitors. I was listening back to some room Royer drum room mic recordings, and they sounded much more ambient than my Dynaudios, which seemed like a combination of good high-end detail with a wider sweet spot.

On kick drums, they had a much more instantly satisfying scooped sound, but compared to all my other speakers and headphones, they seemed to miss a bit of the low end shell resonance — it was mostly thump and click.