JBL Pro, part of the mammoth Harman group, which also includes companies such as AKG, BSS, DBX, Lexicon and Soundcraft, to name just a few, has been designing and manufacturing loudspeakers and enclosures for more than 70 years, although it wasn't until 1955 that it did so under the JBL brand (for those who like trivia, I recommend reading the company's history, which can be found on its website). Such longevity in its industrial activity, together with the fact that almost 70% of professional venues are equipped with its products (according to the company's own figures), gives us an idea of the enormous reputation it enjoys. This time, the one charged with defending the brand's honor through its qualities is the big brother of the new series of bi-amplified digital nearfield studio monitors: the LSR4300.
LSR + RMC = Total Control
LSR stands for Linear Spatial Reference and is the name of a JBL technology that achieves flat response at the mix position within a range of off-axis movement of +/- 30º horizontally and +/- 15º vertically. This results in neutral reproduction of mid and high frequencies, which are more position-dependent than low frequencies.
The 4300 Series is the third generation of studio monitors to incorporate this technology. It is not, however, the only one JBL has added to these speakers with the aim of minimizing the impact of an "imperfect" listening room. These monitors have an internal processor running the second generation of RMC, or Room Mode Control, technology which, together with the analyzer microphone included in the monitor pair package, makes it possible to analyze the room's response at low frequencies (up to 150 Hz), detecting any primary modes that may exist in order to compensate for them by applying EQ correction. It also controls the level of each monitor to adjust for the differences perceived at the listening position, thus balancing the mix.
Unlike the first generation of RMC, this entire process is carried out automatically and elegantly thanks to another major contribution from the manufacturer to these monitors: Harman's HiQnet protocol. This is an intercommunication protocol that allows all the monitors in an installation (stereo or multichannel) to be managed in a coordinated way by connecting them to each other with standard CAT5 network cables with RJ45 connectors.
Each monitor has two HiQnet ports, which must be occupied either by the cable connecting to another speaker or by an RJ45 terminator, supplied with the monitors. On the rear panel of the speakers there is a set of DIP switches with which we must indicate each monitor's position within the listening room (front-left, center, etc.).
With all the speakers in our setup interconnected via the network cables (and switched on), and the microphone placed vertically at the listening position and connected to the speaker identified as "front-left," we can start the analysis simply by holding down the RMC button on the front panel of any monitor for about 5 seconds.
In a few moments (a truly surprising amount of time for an analysis of this kind), the system calibrates all the speakers in a coordinated way, compensating for any acoustic deficiencies in the room and ensuring monitoring that does justice to the material we are mixing. Pressing the RMC button again lets us bypass the correction and return to the initial state, and pressing it once more returns us to RMC mode.
It's advisable to stay away from the speakers during calibration, both to avoid possible interference and to avoid the acoustic harm that the sine-wave sweep emitted by the monitors during the process could cause. The system gives us about 5 seconds from when we press the button until the sequence begins, enough time to move a few meters away.
Remote control
One of the selling points JBL emphasizes most when talking about the LSR4300 Series is that these are digital studio monitors aimed at computer-based studios (and therefore at digital audio). Apart from the technologies mentioned above, which help users achieve reliable monitoring in their work environment, the LSR4300 come with a remote control that handles all their management: the overall volume of the monitor system, switching RMC on and off, +/- 2 dB high- and low-frequency corrections, custom EQ curves, the solo function for each individual monitor, DIM, which lowers the volume by 12 dB (if the overall system volume is set to maximum), and selection of the input source to be amplified.
Many of the functions simply replicate what can be done from the buttons on each monitor's front panel, but conveniently from the listening position. The front of the speakers also has LED bars that indicate signal level while serving as a guide for some of the EQ adjustments. From this point of view, this system eliminates the need for a monitor control unit in rooms where everything is done inside a computer.
In addition to all of the above, the speakers have a USB port for connecting them to a computer (PC or Mac) and controlling everything from it via the Control Center Software application (the USB cable must be connected to the monitor acting as the left monitor, like the analyzer microphone). This program makes managing the system even easier, as well as storing user settings, in case we work with these speakers in more than one environment. Allow me to stress that all this is possible thanks to the intercommunication enabled by the HiQnet protocol.
When it comes to audio connections, the LSR4300 also shine. They have analog inputs on XLR and ¼" TRS jack with an input level selector (+4 dBu / -10 dBV). The incoming signal is routed internally to 96 kHz, 24-bit A/D converters. They also have high-quality digital inputs in S/PDIF phono and AES/EBU formats that can be monitored independently, handling sample rates of 96, 88.2, 48, 44.1 and 32 kHz and resolutions of up to 24 bits. There are also digital outputs for connecting to the corresponding stereo partner (the cable coming from the sound source must be connected to the left monitor… sound familiar?). Finally, on the rear panel there are LEDs indicating which input is active at any given moment.
Put to the test
The monitors I received from EARPRO for the test were the LSR4328P, the largest in the series. They have an 8" woofer and a 1" tweeter, both shielded, each with its own amplifier of 120 and 70 W respectively, plus a rear reflex port.
Both transducers have neodymium magnets, and in the tweeter's case the heat sink is integrated. The woofer cone is made of polymer coated with paper fiber, and the tweeter has a silk dome. Frequency response extends from 50 Hz to 20 kHz (+/- 1.5 dB), although it goes down to 43 Hz at -3 dB. The crossover is at 2.6 kHz and is 4th order in both directions. They deliver a sustained SPL of 106 dB and 112 dB peak at 1 m, which is frankly a very acceptable figure, but not a record for monitors of this size.
As is usual in the LSR series, the speakers have handles built into the sides, which makes them very easy to handle. For information, the series is completed by the LSR4326P monitor, with similar features but a 6.25" woofer, and the LSR4312SP subwoofer, with a 12" cone and ferrite magnet.
The monitors come in a box that includes a pair of LSR4328s, two power cables, a pair of CAT5 Ethernet cables, documentation (excellent, although only in English) and a box containing the analyzer microphone with its clip (which, curiously, did not have the usual small-thread adapter), the remote control with batteries, two RJ45 terminators, the type 1 USB cable and a CD with the Control Center Software application for PC only; although a quick visit to the JBL Pro website let me download the Mac OS X version in no time.
I connected the speakers (analog connection) to the system on the alternate monitor outputs, so that I could do an A/B comparison at all times. The first thing I did was test the RMC system: I placed the microphone on a stand at the height of the listening position, connected it to the corresponding speaker (which was already connected to its partner via HiQnet), switched them on and pressed the calibration button.
First surprise: calibration took no more than 20 seconds. Second, more important surprise: the effectiveness of the system. The calibration really "fit" the room, making material rich in lows and low-mids sound more defined and detailed with RMC on than in bypass. In any case, the speakers seemed a bit sluggish, an unmistakable sign that they needed some break-in time to reach the elasticity needed to reproduce transients with the speed one expects.
While listening to very sonically complex material (traditional acoustic instruments competing with electric instruments, in a rock-style lineup), I installed the control software, which turned out to be child's play. It installed, launched and worked the first time. It should always be that way, and I shouldn't have to point it out, but we all know that it usually isn't the norm. From the program you can control the entire speaker system, change parameters and EQs, and store configurations. It's much more than a remote control, especially because of its graphics and storage capabilities.
After about 40 minutes of operation, the initial clumsiness they seemed to have disappeared, bringing out the characteristic sound of JBL speakers. I had the opportunity to attend the test this publication carried out some time ago on the LSR6328. And everything that was written then, which I endorsed, holds true again for the series we are looking at now. They have a direct, clear, detailed sound. The highs are present without ever being shrill, perhaps even a bit shy, but tremendously pleasant, and the lows are powerful, round and especially well defined.
The always problematic midrange, where a nasal sound can so easily appear, clearly presented all the nuances of the instruments fighting to emerge from the mix. And, above all, the worst area for any room that hasn't spent a fortune on studio design and acoustic treatment, namely 100-250 Hz, was full of nuance and free of those strange bumps that result from interference between the sound material and the room's response to it. The range of movement you have without losing the stereo image was also remarkable.
Conclusions
The LSR4328P sound very good. I would get used to them in no time; perhaps I'd only correct the highs, but bear in mind that I usually work with monitors that "come from the north" and I have their brightness ingrained. However, the LSR6328 already sounded very good; I'd even venture to say I liked them even more than these. So what value do they offer over the previous series? The fact that they have tools better suited to the world we're heading toward, if we're not already fully in it… A world in which many people will have their entire studio inside a computer and in which the money spent on treating a room won't exceed the cost of a good coat of paint.
