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PreSonus StudioLive AI PA

Active PA Speakers With Remote DSP Control
By Mike Crofts

PreSonus StudioLive AI

PreSonus’ new StudioLive PA range brings serious onboard processing and remote DSP control to the masses.

PreSonus have created quite a buzz with the development of their expanding range of ‘Active Integration’ products, and after the success of the StudioLive digital mixing consoles comes the StudioLive AI series of portable self-powered speakers. The ‘AI’ tag is the clue to what’s under the hood, and when I got to play with a couple of sets of these units I was glad to realise that we’re not in ‘just another powered speaker’ territory here, not by any means...

StudioLive AI speakers are intended to deliver the audio quality and precision of ‘studio monitors’ but at the very high output levels demanded by live-sound situations. This requires a combination of accurate and capable hardware, working together with specific DSP design, and to achieve this the PreSonus designers worked closely with Dave Gunness at Fulcrum Acoustic to produce speaker and enclosure designs that were based on the use of coaxial drivers and licensed Fulcrum TQTM (Temporal Equalisation) technology. The other main standout feature of this StudioLive series is that every speaker has a multicore processor inside, which includes a complete operating system, Ethernet and wireless comms, USB access and onboard RAM — so yes, it’s got an actual computer in it!

Line Up

The StudioLive AI range consists of four models: three full-range versions and a subwoofer. One of the first things you notice from the outside is the use of coaxial drivers for the MF and HF sections, which is an interesting feature in itself, but that’s literally only on the surface.

The three full-range models are all active tri-amplified designs, offering a choice of driver format. The physically smallest of the family is the SLS328AI, which uses three eight-inch drivers; two for the low frequencies and a further ‘CoActual’ driver for the mid-range, which incorporates a coaxially mounted one-inch tweeter to handle the higher content above the crossover frequency of 1.7kHz. The other two full-range models are also three-way designs — the SLS312AI and SLS315AI are equipped with 12-inch and 15-inch woofers respectively, but the mid-range and high frequencies are output via the same eight-inch/one-inch coaxial combination as used in the SLS328AI. It’s somewhat unusual for relatively compact live-sound speakers to use coaxial speaker arrangements (although they are becoming more widely used in high-quality stage monitors), and it’s good to see this technology applied to a portable product line. Amplifier-wise, each full-range speaker features the same overall 2000W power capability provided by four 500W power stages, delivering 500W to the HF and MF sections and using two modules to power the LF drivers — one for each of the SLS328AI’s eight-inch woofers and a bridged pair powering the single 12-inch and 15-inch woofers in the other variants. However it’s laid out, that’s a lot of power on tap and, especially with the relatively compact enclosures involved, the onboard DSP plays a crucial role in achieving the levels of performance these boxes are capable of. It’s worth mentioning that, in the case of the StudioLive AI series, the term ‘DSP’ doesn’t just mean an active crossover, EQ and protection circuitry — as mentioned earlier there’s an awful lot of processing power in these speakers, and when you get deeper into seeing what they can do and the levels of control available to the user it’s not difficult to understand why.

Let’s not forget the SLS18SAI subwoofer, which again uses a pair of bridged 500W amplifiers to drive a single 18-inch speaker in a ported wooden cabinet. The speakers are designed to run as a complete scalable system, and the capabilities of the full-range boxes are complimented by the subwoofer’s feature set.

I collected a pair of each model (except the SLS312AI) to have a play with in the workshop, and to get them out ‘for real’ to see what they were like to work with. First off, these are not ultra-lightweight boxes, although they are manageable — the full-range models weigh between 51 and 71 pounds (just over 23kg to just over 32kg), although I wouldn’t fancy carrying them too far on my own, and the SLS18SAI is definitely a two-person job, at 94lb or around 42kg. All the speakers are furnished with good, strong carrying handles which do give good protection to ungloved hands and are well-positioned for balance, which is a nice touch and not something to be taken for granted!

Out Of The Box

The first unwrapping of any new and previously unseen product (especially speakers) is an interesting and important stage in the product-owner relationship, and I liked the look and feel of the StudioLive speakers from the start. The wooden enclosures are very well finished in a textured black coating, and build quality is very good. There were no creaks or rattles from any of the six units, and although removing the subwoofers from their boxes necessitated the old upside-down-and-roll-over method (I was on my own that day) they were all stacked in place within a few minutes.

All of the mid/top speakers feature a basic two–channel mic/line mixer and XLR link output, plus DSP preset switching and an Ethernet network port.All of the mid/top speakers feature a basic two–channel mic/line mixer and XLR link output, plus DSP preset switching and an Ethernet network port.I rigged up the speakers in every combination (ie. with and without subwoofers), and I set up single 328/sub and single 315/sub stacks side by side for direct A/B comparison with a mono source. I was using our studio live room, which is a bit over 200 square feet and, of course, a much smaller space than where I’d normally be using such a rig, but it’s a fairly neutral place which finds much favour with rehearsing bands, and it’s where I do all my first listening tests.

I played my usual selection of CD tracks and was immediately aware of the latent power of the StudioLive AI speakers. These boxes play loud, no mistake! One thing that struck me was that the upper mids and HF sounded exactly the same when comparing the 328 and 315 units, although the 315 exhibited a more rounded bottom end and I slightly preferred its all-round performance when used without a subwoofer. The 328, on the other hand, maintained an exceptional clarity and focus on vocal material, and I would definitely choose it for floor-monitor duties. When operated without subs, both the 328 and 315 boxes sounded clean and tight in the lower regions, with no suggestion of flabbiness or over-hyped bass performance — clean, clear and powerful was the overall impression. At lower volumes I think the 315 sounded the slightly smoother of the two, although when I dragged in two people from the business next door for a quick ‘man in the street’ test, one agreed with me and one went the other way, so as always these things are a matter of personal choice and, all other things being equal, a proper listening test is the only way to go. When coupled with the StudioLive AI subs, the system sounded rock solid from top to bottom, and delivered an exciting yet always controllable output. Even when I ran the rig at a stupidly loud volume (for far too long, really, but it was great fun), there was an impressive dynamic to the music, which still managed to sound lively and exciting even when I was hitting the limiters. I think the way the limiting has been implemented is one of the best features about the StudioLive AI speakers, although it’s perhaps not something you’d be able to try out for very long in a retail store!

The Great Outdoors

I took advantage of a weather window to take the rig outdoors into the Buckinghamshire countryside, and I was impressed with the evenness of coverage. The quoted 90-degree horizontal coverage angle seemed about right, but there’s another few degrees of usable coverage available, and the HF/MF seemed to fall off quite smoothly. Using live-sound gear outdoors, all the power can get quickly sucked up, but provided you can maintain even coverage and balance, reduction of SPL further from the speakers isn’t so much of an issue. The polarity and delay settings on the subs can also be used to optimise performance for any given venue.

I was only able to run the system into limiting for a very short time, as I didn’t particularly want to attract too much attention from the local population, but I really liked the tightness and clarity throughout the whole coverage area. I’d happily use this system (with either the 328s or 315s as top boxes) in any appropriate outdoor situation. Back in the studio again, I happened to be working on some operatic material with a soprano soloist, so I got her to sing in the booth and fed her voice and live piano into the StudioLive rig. This kind of music isn’t always something that PA speakers handle too well, but the AI speakers were beautifully clean and smooth, right up to the point where the volume was starting to fight with the room — I can think of at least two live gigs with very discerning and particular clients coming up where these speakers would be my obvious choice if I still had them to hand!

Controlling Interest

Before moving on to the remote control features, let’s take a quick look at what’s provided on the back panel. In true portable PA style, the full-range models have both line and microphone inputs, which can be mixed and fed through to another speaker or system. The mic input has permanent phantom power applied, so you need to be careful what you plug in, and it’s only around 12 volts (I say ‘around’ because the manual says 12V in the description and 15V in the spec table), but of course I wouldn’t envisage using my large-diaphragm studio condensers with it. The mic preamp is a PreSonus XMAX Class-A stage with up to 48dB of level adjustment provided by the local rotary input control.

The control software provides access to the many DSP functions, including delay, EQ and limiting.The control software provides access to the many DSP functions, including delay, EQ and limiting.The line input is accessed via one of those XLR/TRS combination jacks, which are, in my opinion, essential for avoiding cable stress when using portable PA gear at different venues and with different performers. The line and mic controls set appropriate input levels to the mixer stage, and there’s a third knob called ‘Speaker’, which controls the overall level, post-DSP and just before the limiter stage at the power-amp front end. Interestingly, the line and speaker controls operate as attenuators only — unity is achieved when they are fully clockwise. I like this arrangement as it serves to properly illustrate their function within the system structure. On the SLS18SAI subwoofer the expected left and right inputs and direct pass-through connections are provided, and the two inputs will be summed into the amp section in situations where only one subwoofer is to be used with two full-range speakers. There are also delay options, which can be accessed directly from the subwoofer’s control panel, to provide placement compensation for 1m and 2m offsets.

Preset DSP contours are programmed in and accessed by a single button push. These are more than simple EQ curves, as they also apply appropriate adjustments to the FIR filtering, crossover and alignment settings. Dynamic presets are becoming more common these days, but the inclusion of a preset called LBR (for ‘low bit rate’) isn’t something I’ve seen before. It is designed to compensate for lower-quality audio produced by MP3 players, by addressing the audible compression artifacts to output a ‘nicer’ smoothed-out sound . The other two settings are for using the speaker in normal (main speaker) mode or as a floor monitor. On all models there is a custom user contour setting, which is programmed using the remote control feature but can be recalled and applied locally. A full suite of internal protection keeps everything running safely, and feeds important monitoring data to the SLAI’s telemetry system.

So, let’s take a look at the StudioLive Room Control system....

Room With A View

StudioLive Room Control is a remote control and monitoring application for the StudioLive AI speaker family, and versions are available for Mac, PC and iPad, freely downloadable from the PreSonus web site (you have to go to the Apple App Store for the iPad version).

Now, I’ll admit that wireless networking is something I try to enjoy in the privacy of my own home, where it causes no offence or distress to other humans or animals, but when it comes to speaker management systems I prefer to let someone else do all the setting up part so that I can just rock up and use it. On this occasion I had no option but to work it all out for myself, so I did what I always advise everyone else to do, and followed the instructions. The user guide is very clear and helpful and sets out everything you need to know in a logical way. Things did get a little difficult at the point where I was instructed to rename the wireless router and change the password (both must be set to ‘StudioLive’ in order for the speakers to find them and log on to the network), but I got everything working properly without any other issues. I have to thank Chris Korff at Sound On Sound for talking me through this part of the process — he made it sound easy, and it all made perfect sense, although I can’t for the life of me remember what he said...

Anyway, once all the router excitement had passed I was able to follow the setting-up instructions as provided in the SL Room Control user guide without needing to call for more help. Once the router itself (and its password) has been renamed as ‘StudioLive’ then each speaker must be formally introduced to the router by connecting it via an Ethernet cable — this only has to be done once, and thereafter any recognised StudioLive AI speaker within range will automatically join the network when both are live and the speaker’s wireless function is on. From here on in, the user can enter a world of setup and control functions, by creating and saving ‘venues’ (you simply drag available speaker units onto your on-screen stage and set their positions, and leave the crew to do the actual moving — a wonderful idea). You can then use the various monitoring and control functions to tune the system and keep an eye on it during the performance. This application immediately brings to mind school, house of worship, club and theatre installations, which would benefit greatly from this kind of facility, although it’s not any real trouble to carry a pocket-sized wireless router around with the gear and use it wherever and whenever you like.

The on-screen controls work smoothly and precisely, and setting virtual faders back to zero is just a Ctrl-click away. The EQ section has a one-click reset button, which is useful, but if you want to do A/B comparisons then each control function can be switched on and off independently. Having set up a new (or recalled a saved) venue, speaker groups are then created by selecting from the available speakers (you can save names for them too, for example ‘main left top’ or ‘sax monitor’ or just ‘Eric’) and adding them to the Group Design area. A really neat feature is that, whenever any individual speaker is selected on screen, its illuminated front logo changes from blue to white, so you can identify which actual box you’re dealing with.

When you’re done with setting up the main speaker group, you can then set up the monitor system in exactly the same way with all speakers and placement saved for future use. Each speaker and/or speaker group can be monitored and controlled using the Room Control telemetry, and the Speaker Edit page gives access to a whole range of parameters including level, limiter settings, alignment delay, parametric/graphic EQ and more — it’s like the Formula One of live sound. The app can be freely downloaded and installed, but of course it won’t actually do anything unless a StudioLive AI speaker is connected. It would be really good if PreSonus could include a ‘play about’ mode where a pretend set of speakers made the controls come alive, which I think a lot of potential users might find very interesting indeed.

Summing Up

The StudioLive AI series of powered speakers represents something different from the norm for portable PA. The use of coaxial MF/HF drive units, abundant power output and serious helpings of onboard DSP make these interesting and appealing in their own right, but when teamed up with the Room Control application a whole new set of possibilities opens up, and brings ‘big rig’ functionality into the portable live-sound domain. I’ve been using them in isolation, but remember that they are part of an integrated product range, and the functionality can only increase in the future.

Alternatives

There are systems that offer a similar level of remote DSP control, but they almost all reside in the high-end touring sector, rather than the compact PA market.

Pros

  • Well thought-out design, bringing advanced technology to the portable live–sound world.
  • Integration capabilities with other equipment and provision for future technology developments.
  • Excellent audio quality, very consistent coverage and powerful performance from modest-sized boxes.
  • Scalable and great-looking rig.
  • Many setup, monitoring and control options with SL Room Control.

Cons

  • I’m struggling to think of any — they are not the lightest speakers on the market, but then you probably wouldn’t be using them at the village fête.

Summary

A very interesting range of speakers that not only include an advanced set of features, but that sound excellent too.

information

SLS312AI £789, SLS315AI £879, SLS328AI £879, SLS18SAI £789. Prices are per speaker, including VAT.

Source Distribution +44 (0)20 8962 5080

www.sourcedistribution.co.uk

www.presonus.com

SL312AI $1399, SL315AI $1599, SL328AI $1499, SL18SAI $1299. Prices are per speaker.

PreSonus +1 225 216 7887

www.presonus.com

Published June 2015