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HK Audio Elements

Modular PA System
Published August 2011
By Paul White

If you're looking for a lightweight PA setup that can be scaled to suit your needs, HK's Elements system warrants closer inspection...

HK Audio Elements

For those of us who are used to working in the studio, getting out and engineering a live performance can be a bit of a culture shock. We're used to accurate studio monitors in an acoustically treated space, and there's very little carrying involved. By contrast, live sound often means dealing with heavy chipboard monoliths that sound nothing like studio monitors and often sound even worse when set up in a venue designed primarily for efficient beer delivery, with scant thought applied to acoustics. On top of this, PAs usually need a van and a fair bit of muscle power to cart them around To compound the problem, many pub‑gig organisers expect you to set up your show in a space the size of a telephone booth.

These issues presented the design team at German company HK with a challenge: to develop a compact, musical‑sounding system that would be both portable and scalable. To achieve this goal, the system is modular, making it suitable for anything from solo performances and conference work to amplifying a full band in a large venue.

Modular Might

An Elements system may comprise up to six different components (or Elements), though you don't need that many to create a basic system. Our review system, in fact, uses only three elements. In common with many compact systems, Elements takes a 'subs plus satellites' approach, with both active and passive subs in the range. It's there that the similarity with the majority ends, however, as the Element E435 satellites are tiny line‑arrays that can be used singly or in stacked multiples, depending on the application.

The line-array format has a big acoustic advantage. Unlike a conventional 'horn and cone' box, a line array has a much wider dispersion in the horizontal plane than in the vertical. This gives better coverage for audience members (including those close to the front and standing in the centre), while minimising the energy wasted on the floor and ceiling. Not only is it a more effective way to direct sound energy, it reduces the effect of room reflections on the sound reaching the audience, particularly ceiling reflections.

There are 44 combinations of modules on offer with HK Elements, using different configurations of active E110 Sub A, passive E110 Sub, E435 mid and high satellites and EA600 power amps. The passive subs can be driven using an active sub or from a separate amplifier module, which is capable of driving both satellites and passive subs in various combinations.

Raw Power

Unusually, the separate EA600 power‑amp modules are the same shape and size as the satellite speakers, and include the same E‑connect system, allowing them to be placed between a passive sub and satellite in a stack. A single EA600 amp can drive one or two passive E110 Sub subwoofers, or one passive subwoofer plus either one or two E435 satellites. Alternatively, the EA600 amp can drive a column of four E435s, if you use active subs to fill in the low end.

Due to acoustic coupling effects, the frequency response of a line‑array changes depending on how many speakers are stacked together, so the EA600 amps include four switchable EQ settings, corresponding to the number of satellite speakers used. A button steps through the EQ options sequentially, with one illuminated LED denoting a single satellite, two LEDs denoting two satellites, and so on. There's also built‑in safety limiting, a subsonic filter and a temperature‑controlled fan.

The E100 Sub A active subs have a similar amplification capability to the EA600 amp modules, enabling them to drive two E435 units or another passive subwoofer. There are only two EQ filter settings on the E110 Sub A, as one sub can only power a maximum of two tops. The crossover frequency between the subs and tops is quite high, at 140Hz with a 12dB per octave roll-off, but this allows the satellites to be made very small.

A small HK Elements setup could consist of just one active sub and two tops in mono, while the maximum practical stereo system features eight subs and two stacks of four E435 mid and high units. In such a configuration, the E435s would need to be powered by EA600 amp modules and the subs would normally be a mix of four active and four passive, with Speakon cables linking the active and passive sub pairs. For small venues where an average stereo system is required, the 1200W review setup of one active sub and two tops on each side is both practical and very portable.Here you can see how an E435 takes power from an E110 active sub, using the integrated 'E‑Connect' system.Here you can see how an E435 takes power from an E110 active sub, using the integrated 'E‑Connect' system.


HK have also devised a connection system that eliminates pretty much all the usual wiring, other than signal and mains feeds to each side of the stage. Connection to the satellites uses a system that HK call 'E‑Connect', a rugged version of the common quarter-inch jack, which is built into the connector points of the speakers and mounting poles.

Using the review system as an example: if you're using both powered sub and two passive satellites per side, a short section of pole with an integral E‑Connector protrudes from the bottom of each E435 speaker and latches into the mating part of the speaker pole. A matching recess at the top of the E435 permits stacking of another on top, again with an E‑Connector carrying the signal. The mounting pole clicks into the sub and the stack is assembled. The mid‑range and high output resides in the sub, and the pole feeds it to the lower of the satellites. Each satellite then passes the signal onto the satellite mounted above it.

In all cases, the latching system uses a spring-loaded peg that protrudes through a hole in the mating part — simple, but effective. Hook up a mixer to feed each sub, plug in the locking IEC mains cables that come in the package, and you're good to go. One benefit of this physical arrangement, especially in smaller venues, is that the small satellites don't block the audience's view of the performers.


Each E435 mid and high unit is fitted with four 3.5-inch speakers, developed specifically for HK by Celestion. When stacked up, E435 units are wired in parallel, and most of the benefits of line‑array directional coverage are achieved with two or more of them stacked. The nominal power handling of each E435 is 150W RMS, with a quoted frequency response (‑10dB) of 140Hz to 20kHz and a sensitivity of 97dB for an input power of one Watt at one metre. The horizontal dispersion is 70 degrees, while the vertical dispersion tightens up according to how many speakers are stacked.This diagram shows some of the possible configurations for a single side when using various HK Elements models. Since HK Audio hail from Germany, active units in this image are marked with 'Aktiv'.This diagram shows some of the possible configurations for a single side when using various HK Elements models. Since HK Audio hail from Germany, active units in this image are marked with 'Aktiv'.

A frequency response of 45Hz to 150Hz (‑10dB) is quoted for the active sub, determined by the integral active system crossover and subsonic filter. The amp power is divided into 250 Watts for the sub and 300 Watts to power the tops. A 'combi' XLR accepts balanced XLR or jack inputs, and there's a Speakon parallel output for feeding a second passive sub, while the aforementioned E‑Connect output is built into the pole mount. There's no control to adjust the sub balance: it's preset to work harmoniously with the satellites. Similarly, there's no input gain control, though there is an input sensitivity switch offering +4dBu or ‑10dBV options. The EA600 amp modules are much like the active subs, in that they use lightweight, class‑D circuitry to deliver 600W into a 4Ω load.

Fit & Finish

At the sides of the ply cases are two 'runner style' feet with a non‑slip bases that are used when stacking multiple subs horizontally. Matching grooves in the other side of the case accommodate the feet of the cabinet above, adding to the stability of the system. Both models of sub are equipped with 10‑inch drivers, making them impressively compact (30 x 48 x 46cm) and quite portable, at just 19kg per sub for the active version, while the passive model is a little lighter. A recessed carry handle is built into the top of each sub to help with transportation.

Where a larger system is put together using multiple subs, an EF45 base is available to support satellites and power amps, with an E‑Connect bus built in. Jack connections accept the input signal and route it through to further speakers.

Weighing just 2.35kg each, the speaker enclosures and perforated grilles are made of aluminium, and there are no tweeters, as the small-cone drivers cover everything from the crossover point upwards. Despite their high power rating, the EA600 amp modules weigh in at just 2.75kg each, making them just as portable as the rest of the system.

Elemental, My Dear Watson

Setting up the review system was straightforward. In fact, getting the system out of its cardboard boxes was the most time‑consuming part of the operation! For protection during transport, you can also buy optional covers for the subs, and a semi‑rigid bag that holds up to four tops and one pole, though it would probably hold four tops plus both poles at a push. The mounting poles themselves are telescopic, and the minimum height puts the satellite line-array at about head height for a standing person, though for applications where the listeners are seated, there's an EP2 short-pole option.

Sonically, the use of small-cone drivers gives the system rather better mid‑range clarity than you'd expect from, for example, a 12-inch cone driver plus horn. The highs aren't quite so extended nor the lows quite so tightly controlled when auditioned alongside a good studio monitor, but playback of commercial recordings confirmed that the sound was generally well‑balanced and detailed, with the subs providing the necessary depth but not over‑hyping the bass end. Most PA systems sound dreadful next to studio monitors, but the Elements system compared pretty well, with great stereo imaging to top it off.

Level‑wise, there's enough power to carry the vocals plus the odd instrumental solo from a typical pub band, and you can even get away with adding in some kick drum and bass guitar, as long as you don't expect too much from it. If you feel you need more power, doubling up on the number of subs might be the first step. I've already mentioned that the wide horizontal dispersion, coupled with the narrower vertical dispersion of a line array, helps to put the sound where you want it, and helps minimise the negative effects of less than optimal room acoustics. This was certainly evident with the Elements system. Having a wide, even dispersion also helps to avoid feedback problems: always a bonus when setting up a live show!


HK Elements is a professional system and is priced accordingly, but it's designed to offer many years of service. The modular nature of the system should appeal both to acts playing venues of different sizes and to hire companies servicing the live and conference markets. Depending on which modules you take along with you, Elements can provide anything from a 600W mono system in the corner of a bar to a powerful stereo system in excess of 3kW. In such a situation, stacking multiple subs adds additional efficiency and bass extension, both through extra drivers and the acoustic coupling between cabinets.

Working in the studio certainly raises your expectations as to what good sound quality really is, and I'm pleased to report that Elements really delivers in this area. My impressions are very favourable, both in terms of ease of use and of sound quality. After using the PA system for a number of gigs, I think it's an impressive system.

For me, the most important aspect of any PA system is a clear mid-range that can project vocals and a clean and accurate way, and the HK Elements system does exactly that. Everything is very nicely engineered, setup is easy and the E‑Connect system cuts down on the cabling and makes for a tidy appearance. If you're in the market for a high-quality modular PA system, Elements comes recommended.


The smaller Linea Live line arrays from Fohhn offer exceptional sound quality but don't have a modular approach, other than the ability to vary the number of subs used with the tops. Similarly, Bose produce the L1 compact line array (from £899$899), providing high-quality sound but lacking the Elements system's modular capability.

Published August 2011

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