Review: L-Acoustics X Series

Andy Coules travels to SSE Audio Group’s newly refurbed Park Royal facility in London, where the French manufacturer’s new coaxial collection has been kindly set up for his perusal…

L-Acoustics is well known as a pioneer of the modern line array, thanks to the development of its seminal V-DOSC system in 1994. Since then, led by Christian Heil, the manufacturer has continued to develop and innovate line source solutions such as ARCS, dV-DOSC, Kudo, Kiva, K1, Kara, ARCS II and K2 – all of which are common sights at concerts and festivals around the world. But L-Acoustics has also been involved in the development of point source solutions; as a matter of fact the very first product it launched, back in 1989, was a coaxial point source speaker system called the MTD115/LLC and it’s this tradition that it has carried forward with the new X Series.

The X Series comprises four models, the 5XT, X8, X12 and X15 HiQ (pictured from left to right) and offers a variety of different sized speaker enclosures with differing characteristics. They’ve been designed to satisfy a wide variety of roles in both the install and rental markets and are equally at home being deployed as fills to complement a main PA system in large venues, as the main PA system in smaller venues, or as monitors. The smallest model, the 5XT, was launched back in 2013 so for the sake of this review I’m going to focus on the three newer models.

The X Series benefits directly from the experience gained in designing the flagship K2 variable curvature line source speaker system, which in itself is a rescaling of the K1 into a more compact format – the result being an optimised design, improved ergonomics and better acoustical performance while still being relatively light. Just to illustrate the attention to detail applied to the design they actually modelled the interior of the cabinets and were able to identify where the wood was needed and where it had no effect on the performance of the speaker and thus were able to sculpt out any excess.

All of the speakers in the range are two-way coaxial and the only active model is the X15 HiQ; the numbers in the name of each model denote the size (in inches) of the low-frequency transducer. The compression driver is mounted directly onto the low-frequency transducer in a bass-reflex tuned enclosure – the compression driver in the X8 is 1.5in in diameter while the X12 and X15 HiQ both have 3in drivers. The obvious advantage of a coaxial design is much better off-axis response consistency in both the vertical and lateral planes resulting in a more even sound field and the elimination of the minimum listening distance inherent in vertically- or horizontally-stacked driver designs, the trade-off typically being the possibility of greater intermodulation distortion as a result of the two drivers interacting.

The dispersion patterns differ for each model, getting tighter as you go up the range; the X8 is 100º (conical), the X12 is 60º x 90º and the X15 HiQ is 40º x 60º – the latter two achieving their tighter patterns as a result of a brand new ellipsoid waveguide. All three models also feature laminar vented ports, which reduce the turbulence and port noise at high levels thus increasing low frequency efficiency.

All of them are lighter than previous models and there are a number of neat features that are worthy of note. They’re all designed to be used either horizontally or vertically; the larger two models also have a wedge-like shape, which enables easy floor deployment. The logos even rotate 90º so that they can be the right way round regardless of orientation, something which will make obsessive-compulsive installers very happy. The pole mounts on the X12 and X15 HiQ are designed in such a way as to guide the pole into the hole as you lower the speaker onto the pole, which should avoid those awkward moments of holding the speakers aloft with tired arms trying to slot them in.

The handles are also now much more ergonomic with a pleasing curve to the inside of the grip which makes them much easier to lift and move about without cutting off the blood supply to your fingers.

There are a bewilderingly wide range of mounting options, which should accommodate just about any positioning imaginable. These include pole mounts, clamps, wall brackets and U brackets, all of which enable precise and rigid mounting to ensure they stay where you put them and continue to address the precise region you decide. The X12 and X15 HiQ also include integral risers, which hinge out such that when they’re deployed on the floor their angle, with respect to the vertical, can be changed from 35º to 55º. All models are designed to be run via the LA4X or LA8 amplified controllers, both of which contain presets for each model, including three low-latency presets for monitoring.

In Use

In listening tests all models displayed a clear and concise sound with a tight bottom-end. The difference in sound between them is reasonably subtle but quite discernable; the top-end and mid-range was pretty consistent through the three models I tested – the main difference was in the lower mids and the bottom-end. According to the specifications the difference between the lowest frequency the X8 and X15 HiQ can handle is just 5Hz (the X8 being 55Hz and the X15 HiQ 60Hz) but there is a noticeable difference in the clarity and roundness of the bottom-end. The X8 is lighter with a less well-defined lower mid range and bottom-end but this is perfectly understandable for a speaker of this size. The X12, as its name suggests, sits in between the two with slightly more clarity in the top-end, which makes it sound more like the X15 HiQ than the X8, and a firmer bottom-end although not quite as fully rounded as the X15 HiQ. You can, of course, extend the bottom-end of any of the models with the addition of an SB15m or SB18 subwoofer.

All models generate impressive SPLs for their size, thanks to neodymium magnets, ranging from 127dB in the X8 to 134dB in the X12 and 136dB in the X15 HiQ (when using the appropriate presets in the amplified controllers). As the level increases they maintain an impressively consistent sound well into almost uncomfortably loud levels and I felt no need to try to push them to their limit. It’s good to know you can get the levels you require without having to run them flat out; in my experience it’s always better to run any speaker system at about 80% of it’s capacity to ensure a consistent, distortion-free sound while also ensuring longevity of use.

Typically, when dual-purpose (i.e. floor- and stand-mounted) speakers are used as floor wedges the proximity of the floor boundary causes reflections, which can enhance the bottom-end in an uneven and unpredictable way. Thankfully, in this instance, the monitor-specific presets in the LA4X and LA8 amplified controllers take care of this by applying an EQ curve, which subtly deals with this potential problem. The coaxial design also means that if you plan to pair them up you don’t have to worry about creating matched pairs with complementary tweeter orientations and the improvement in the off-axis frequency response should help reduce the risk of unpredictable bursts of feedback.

As a front-of-house engineer who occasionally dabbles in monitors I’m clearly more drawn to the larger X12 and X15 HiQ models as they are immediately more relevant to my daily life. However, the X8 is a really handy size for lip fills on wide stages or as subtle delays in odd-shaped or balconied venues and I can see them providing an above-average listening experience in bars and restaurants or any venue that requires good quality background music.

Anyone who has used any of the previous point source coaxial speakers from L-Acoustics will be familiar with the sound of these; they’re not groundbreakingly different – they don’t really need to be – but they do provide an evolutionary refinement based on newer technology and techniques.

The attention to detail in design and usage is impressively high – you can clearly tell that they’ve talked a lot to end users and worked really hard to include the range of features that people want but aren’t always given.

As such they proudly uphold the tradition established back in 1989 and prove to be fitting successors to an impressive lineage.

Key Features:

  • High-excursion neodymium drivers
  • Ellipsoid directivity
  • Laminar vented port
  • Low-latency monitor presets
  • Range of flexible rigging accessories

£1,265 (X8) – £2,615 (X15 HiQ)

Andy Coules is a sound engineer and audio educator who has toured the world with a diverse array of acts in a wide range of genres.