Fohhn Xperience XT-4 & XS-4

Fohhn offer a slightly unusual approach to PA components, as they tend to provide all the amplifiers necessary to feed a sub and top in either the sub or the top box, rather than each speaker housing its own amplifiers. What's more, they offer a choice of configurations, so you can have active subs with passive tops or vice versa. Alternatively, the active tops can be used to feed a second passive top for stereo use, and active subs can feed a second passive sub, so you really can build up the most flexible system to meet your own requirements.

Perhaps the biggest difference in the new generation of Xperience boxes, though, is the inclusion of DSP speaker management, which can be remotely controlled from a PC using the included Fusion software to adjust the system EQ (10-band parametric), dynamic processing (compressor/limiter and noise gate), crossover characteristics and delay. These adjustments are made via an Ethernet connection, which can be run down a regular stage multicore by means of an adaptor box, and any adjustments are saved in the DSP's memory, so you don't need to run the system with a computer connected. The computer screens for these adjustments are very clearly set out and look very much like the hardware they depict, so anybody familiar with the processes involved will have no trouble operating them. The Fusion software also provides presets for all the top boxes in the Xperience range, so the user can create a bespoke system from any sensible combination of tops and subs knowing that it will function correctly.

A typical stereo system comprises two passive mid-high loudspeakers plus a powered subwoofer unit, or two powered tops and passive subs. Whichever box is the active one houses the necessary Class-D amplifiers and the DSP signal processing. Class-D amplifiers are extremely light, and because they are much more efficient than conventional Class-A/B designs, they dissipate far less heat.

The ported birch ply cabinets, which narrow towards the rear, use CNC machined joints for durability. Both the tops and subs have a dual-layer speaker protection comprising a powder-coated, perforated metal grille and a thin layer of acoustic foam. The XT-4As are constructed so that they can also double as an angled floor wedge (55 degrees) if required, and there are two built-in M8 thread mounting points for the optional VXT-3 U-bracket, as well as two built-in carry handles and a conventional pole-mount socket.

Digital sound processors running on DSP chips are built into all the current Fohhn amplifiers and active speakers, as well as their stand-alone FC-8 digital controller, and the five types of processing already mentioned may be used simultaneously. An operating status display comprising a four-line LCD read-out on the rear of the cabinet monitors the temperature of the system and also logs the total operating time by means of a tamper-proof system, so that if you buy a used Fohhn active device, you can easily check on how much work it has already done. All of Fohhn's current active tops, subs and rack amps have this screen where the user can access and edit everything that the remote laptop can, though the laptop is clearly an easier way of working. A practical option is to save a setup for a regular venue using the laptop, then recall it from the rear panel next time you play there.

The rear of the amplifier pack is presented as two channels, so if you're using a sub you only need one of them, but for stereo use when driving a passive top from an active top you'd need to use both. User adjustments may be entered directly using the LCD screen if required. Speakon connectors are used to feed out to the connected passive cabinets, and mains power comes in via a Powercon connector. These can be hard to find in an emergency, so keeping a few spares to hand is advised.

At the low end, we used the XS-4 passive sub, again using a neodymium-powered, long-throw driver — an 18-inch, 8Ω brute rated at 800W (1200W peak for 20ms). This has a frequency range of 35Hz to 135Hz, with four NL4 Speakon connectors to facilitate linking and a threaded pole socket in the top. A detachable wheel board is provided for transport. The audio connection is via Speakon. This boasts a maximum SPL of 132dB and measures 590 x 680 x 600mm, which is fairly compact for a sub of this power. Astonishingly, the weight is only 38kg, so one person can carry one easily if correct lifting procedures are used. Both top and bottom cabinets are finished in a textured, black plastic, scuff-resistant paint, though alternative colours are available.

Though we set up a laptop to check out the internal processing options, which were an absolute doddle to use, there was no need to add any system EQ, because an outdoor event like West Fest doesn't influence the sound of the system in the same way that a room does, as there are few significant reflections. Playing a couple of Steely Dan tracks from an iPod revealed virtually hi-fi quality: an impressive amount of tight, supremely well-controlled low end and pristine mid/high clarity without harshness. Overall, the impression was more like listening to a big pair of studio monitors than a PA system, and I can really understand why some people actually buy the smaller Fohhn systems for home theatre and music reproduction.

The coverage was subjectively very even up to around 45 degrees from the sides of the stage, after which the high end started to drop away a little. And as we had the stage facing across the width of a very long sports field, we decided to link up my Mackie 450s with their 70Hz low-cut filters switched in and set them up facing out sideways, just to fill in the high-end coverage in those directions. The 450s were pretty much inaudible from the front, but just added that missing top end quite effectively at the sides. We originally tried hooking in some additional subs and tops of a more budget provenance to give us more power, but they sounded so muddy and flabby by comparison that we removed them and let the Fohhn work alone. A good decision! For a system rated at a little under 4kW, the results were extraordinarily good, with plenty of projection across the width of the field and also down much of the half mile of approach road. According to some reports, you could hear the vocals well enough in Malvern Link to sing along to them, which is two miles away on the other side of the Malvern Hills!

The 'in-your-chest' punch from the low end sounded as though it belonged to a far bigger system, and nobody could really believe that we were getting such a high level of great-quality sound from just two 12-inch tops and a couple of subs. During the day, the system handled rock bands, jazz bands and fiddler Rik Sanders from Fairport Convention, with great results every time. What's more, the coverage right in front of the stage was pretty even too, whereas on previous years we've had comments that people right up against the middle of the stage at the front couldn't hear the vocals very well. Without doubt, this was the best sound we've had at West Fest, and it all seemed so effortless.