JBL Pro 7 Series Master Reference Monitors Preview

JBL is no stranger to the professional market, where performance is critical and factors like aesthetics are afterthoughts at best. As such, when JBL Pro launched their new M2 Master Reference Monitor priced at ~$20,000/pair, people took notice. Of course, $20,000/pair for speakers isn’t chump change, even in the professional world. Enter JBL’s new 7 Series Master Reference Monitors. Consisting of two models, the LSR708i and the LSR705i, the 7 Series features trickle down technology from the M2 including the Image Control Waveguide. Individual pricing isn’t available as these speakers will be sold as part of complete systems; however, we expect those systems will be substantially less expensive than M2 based setups. Want to know more? Let’s dig in.

Design Overview

Starting at the top, both 7 Series monitors boast JBL’s new 2409H high frequency transducer, which features a lightweight annular diaphragm. The tweeters are loaded by the Image Control Waveguide, which allows for directivity matching of the high and low frequency drivers at the crossover point, and affords the 7 Series monitors neutral off-axis response. Covering the low end, JBL has two new custom long-throw woofers, the 5” 725G which is crossed in at 1.9kHz on the LSR705i, and the 8” 728G, which crosses in at 1.7kHz on the LSR708i. Both 7 Series models utilize vented enclosures made of birch plywood.

JBL Pro's new high frequency transducer (left) and 728G long-throw woofer (right).

Now one thing you might notice about the new lineup is that unlike many professional monitors, the LSR705i and LSR708i are passive loudspeakers. Both feature Phoenix terminals that can accept up to 12 gauge speaker wire, and the speakers can be driven by a single amplifier channel or bi-amped. JBL states that this simplifies installation by centralizing power versus needing an outlet at each speaker location, and also reduces the size and weight of the monitors. Unlike active monitors, the 7 Series fits into JBL’s strategy for a modular and scalable system built around Harman’s BSS networking controllers/processors and Crown multi-channel amplifiers.

Specified Performance

Obviously the big question is: what can these puppies do? Starting with frequency response, JBL rates the LSR708i at 45Hz-23kHz, and the LSR-705i at 48Hz-23kHz, both with a tolerance of only +0dB/-1.5dB which is exceptionally good. Given the comparable low end extension, you might expect a big difference in maximum output between the models, and you’d be right. The larger LSR708i can deliver up to 108dB at 1 meter (114dB peak), while the pint sized LSR705i can “only” muster up 101dB (107dB peak) at 1 meter. Unfortunately, nominal impedance and sensitivity are not rated at this time. However, one indicator of the power these models can absorb would be in the marketing material, which shows these speakers being used with a Crown DCI 8|300, which can deliver 300W per channel into 8 and 4 ohms.

Conclusion

With the new 7 Series Master Reference Monitors, JBL Pro is continuing to ape the naming scheme used by BMW, as seen in their 3 Series monitors and the M2. More importantly, JBL is bringing the technology seen in the costly M2 down to more affordable price levels. The rated frequency response is nothing short of superb, and both the LSR708i and the LSR705i can deliver ample output. While these might not be the most attractive speakers on the planet, we’re sure they’ll find their way into recording and broadcast studios around the world.

Unless otherwise indicated, this is a preview article for the featured product. A formal review may or may not follow in the future.