REVIEWED: RCF SUB 702-AS MK3
In the last issue of Pro Mobile (issue 122), I wrote a review on RCF’s ART-910AX, the Italian speaker manufacturer’s 10” professional active Bluetooth speaker. If you read the review or indeed heard that particular speaker yourself, you’ll be aware of just how much deep bass is produced by a comparatively small speaker cab.
One of my conclusions was that for a large percentage of mobile DJ gigs, you don’t need anything larger, and certainly no additional subs. For me, this was a stark admission. In fact, I have never actually performed as a DJ using speakers without subs. My own music tastes are varied to say the least. From classical to heavy metal. Hip-hop to deep house, R’n’B, reggae – whatever the genre, if it has a deep bass sound, I’m in my element. I just absolutely love bass. (Am I the only DJ to turn up to kids’ parties in village halls with two 15” subs? With 20 kids as an audience?)
In the world of audio, a subwoofer is often the unsung hero, adding depth and richness to the overall sound experience. These speakers have become an integral component in professional audio environments, enhancing the overall audio quality and creating a more immersive listening experience. They play low-frequency sounds, often felt more than heard, and add a tactile dimension to audio, making music more dynamic and overall soundscapes more immersive.
I have no idea how many subs are in my local Showcase cinema, but it’s that kind of experience which makes me want to ensure my audiences are experiencing the feel and sound that subs produce. If my dance floor have experienced those deep notes watching the latest Marvel film, I feel they should hear a professional DJ produce the same rich depth of sound.
A few years ago, I was on a mission to simplify my life and work wedding ceremonies as well as wedding breakfasts without subs. I visited my usual retailer and tested a range of options, all of which did a decent job. Then I paired one of the better options with a sub and quickly realised that my mission was a failed one. I was never going to be satisfied with my sound without the extra work of carting subs in and out of venues! (I’m sure you’re getting the idea: I love subs.)
But all that changed with the RCF ART 910-A, the stripped-down predecessor to the 910-AX. Here was a 10” speaker that could genuinely be used for any wedding, either on its own or in pairs, and would sound like I had hidden subs. Given the right room, it could also be used for the party – a complete mobile DJ solution and at a great price. So, would additional subs improve the sound?
The RCF SUB 702-AS MK3 – successor to the 702-AS II – is an all-wood active subwoofer finished with a black scratch-resistant polyurea coating. The subs are stackable and lightweight (21kg), with a pair of rubberised ergonomic handles on either side. Due to the sub’s interior design, the cabs are thinner than they are tall, which makes lifting and carrying them much easier than any other subs I own (too many, since you asked!). The overall look is rugged – it looks and feels solidly built.
The powder-coated front grille integrates a special, acoustically sound, transparent foam backing to protect the transducers from dust. The speaker design is energy efficient, so there’s no need for a cooling fan. The amplifier is attached to a solid-aluminium heat exchanger in the rear of the cabinet, with no moving parts. Housing a 12” woofer and a 1400W class-D digital amplifier, the 702-AS MK3 is designed and marketed as the ideal complement to 8” or 10” speakers to create small but powerful satellite systems. Using the built-in digital stereo crossover (DSP) with adjustable crossover frequency makes connecting the satellite simple.
On the rear panel are XLR inputs and outputs. There are three lights: power, signal and limiter. The built-in limiter circuit prevents clipping or transducers overdriving, and will blink orange when at the sub’s limit. Much like the lights on your controller or mixer, it’s fine to hit the limit sometimes, but if it’s constantly on you need to fade that volume back down!
RCF also includes a volume dial and three switches. The Link/Xover (or crossover) switch will produce flat sound (output is same as input) when in the off position and high-passed when switched on. You can set the crossover via the Xover switch at either 80 or 120hz. The third switch is to reverse the phase to suit the setup of your speakers and/or room/speaker placement.
As covered in that last review, you can select your DSP setting in a 9-AX series speaker from the list of RCF subs. This means you reverse the norm of signal input into your sub and out to tops. Alternatively, you can use the sub as you normally would, but you’ll only have the two pre-sets of 80 and 120hz to choose from – using them in this way loses that exact matching of crossover. All of this ensures that the sub is doing the heavy lifting when it comes to low-end sound and working exactly as it should. Plus, by having that extra speaker you can comfortably go that bit louder when needed. The subs add a lot more sound and you aren’t pushing the tops any harder.
Distinct from its predecessor, the SUB AS MK3 comes with a new feature called Bass Motion Control (BMC). Apparently RCF’s engineers have found a way to remove the high-pass filter, replacing it with a newly advanced woofer excursion management feature. The BMC method works by creating a complete map of the dynamic behaviour of the woofer, to generate a custom algorithm that only limits over-excursions, giving total freedom of signal reproduction to the transducer.
When high-pass filters normally protect the woofer motion from becoming destructive but change the phase behaviour, the new BMC algorithm breaks conventional rules.
But what does all this mean in real-life use? The output is as you would expect from RCF speakers – clear, loud and very detailed. The ART series of speakers have been a game changer for RCF, and the pick of the bunch is the 910-AX. I’ve used the 910-A and the 910AX in many settings from small house parties to my favourite setting for them, corporate bookings, where I put microphones and video output through them.
If you’ve done corporate events like that, you’ll know that your client invariably asks for walk-up music (on one occasion, just seconds before the chairperson walked on, when it hadn’t been asked for in the briefing!).
This is when the 10” cabs need that additional support – you really want that music to be full of drama and feeling. Just the same as a party, when you need volume, you want lots of bass.
The first time I did an awards event, I realised that I would only need small speakers; I needed to play music quite loud for brief moments. The ART 910s gave me exactly that, but now I have even more power to suit larger events. I’m pretty sure I can easily handle 300 people at corporate award events, simply because whilst I need loud, I don’t need DJ levels. The audience is sat down, listening and paying attention, so my 910s are perfect and the subs give me that bit more.
I’m not entirely sure it isn’t my imagination, but at low levels, the 702-AS MK3s barely seem perceptible. But go louder and start to push them so that you go beyond the sound you’d have with the tops, they start to assert their authority. That feel you only get with good subs is there, and very lovely it is too.
Furthermore, this RCF series gets even better with the addition of Bluetooth and all the fine adjustments you can make. For example, it’s now possible to run a very powerful speaker with a sub in Bluetooth mode. This is a game changer for performers who want to be in and out quickly – you could easily do an entire gig without XLR leads, something that’s been around for a while but perhaps not with this amount of output.
The full review can be found in Pro Mobile Issue 123, Pages 74-76.