To box, or not to box. That’s the question: whether’s it’s better to control and contain resonances and standing waves within a small enclosure via crafted crossovers and cabinets, or to free them into the larger enclosure of the listening room and thereat fettle them with DSP. Within the last decade, I think we arrived at a moment when active open-baffle speakers began to answer some of the most fundamental questions about what audio systems should and should not do.
Conventional, boxed, passive speakers project a preset signature that may or may not suit the listening space. Active open baffles interact with, and can be shaped to, a room acoustic. Box speakers have inherent resonances that are difficult to correct. Ported and sealed bass enclosures constantly operate in their own turbulence.
Many musical instruments use a sounding box to amplify tone and create distinctive timbre, but when a transducer is called on to reproduce that tone, it should ideally do so without such artificial – and homogenising – bolstering. It shouldn’t sound boxy, or have a sonic signature of its own. Furthermore, there are two, significant compromises involved in U-turning the backwave of a speaker within a cabinet: additive and subtractive. Boxes have to be tuned and damped to prevent reflected sound interfering with projected sound. This sound energy is absorbed and turned into heat (ie, wasted) – lowering efficiency. The ‘lost’ energy creates dead areas behind speakers, which radiate energy asymmetrically in a pattern quite unlike that of a live voice or instrument. The effect is analagous to collimated torch light versus diffuse sunlight.
Why are box speakers so ubiquitous then? Well, There’s something visually gratifying about a box. Putting a bass driver in a box artificially boosts its low frequency output – partly by cancelling nulls – which certainly improves the quantity, if not the quality, of lower register rendition – doubling down on the visual advantages of box speakers: they’re good value in the optics:performance metric. Such received wisdom has been the starting point for so many speaker designs, the question seems rarely to be asked: what if we don’t put the drivers in a box?
Against box-less speaker design a number of fair and unfair criticisms are levelled:
A. They have to be huge to work.
B: They don’t really do bass.
C: You need a huge room, with lots of space behind them
D: They’re expensive
E: They’re ugly
However, most agree that boxless speakers have undisputed benefits:
A: They don’t sound boxy.
B: Sound dispersion more like real instruments
C: Excellent dynamic range
D: High sensitivity, enabling a wider variety of amplification to achieve high-end results
E: Less cabinet resonance
So what if we started from a position where the sonic disadvantages of box speakers were unacceptable, and worked on that list of suddenly trivial-seeming disadvantages?
No Cheats, No Shortcuts
The physics of open-baffle speakers is inalienable. Large drivers are needed. If our driver choices consistently appear to err on the side of over-sizing, it’s in service of two design goals: live-sounding dynamics and low-overhead amplification. The sensitivity of our entry-level model is aimed at matching the plethora of inexpensive, competent chip amps now available to deliver the old-school OB sound in a wallet-friendly package for today.
In the case of bass, specialised drivers are needed. In fact, only one company in the world is really making drivers suitable for open- and infinite-baffles: they’re hand-made in small quantities, expensive and sound amazing. You can hear them in our 2988cc subwoofer and Series 4 speakers. The challenge was to bring as much of that goodness as possible down to the lowest viable price point.
All speakers to some extent – but open baffle speakers more than most – operate within the adamant confines of the ‘Dynamic / Cheap / Refined’ triangle. A buying choice sets priorities by drawing a line through it. You can buy a dynamic, cheap product (like a PA speaker) but it won’t be refined. You can choose a cheap, refined speaker (like a well-made stand-mount), but it won’t ‘feel loud’. Or – if you can afford it – you can have a speaker that’s both. ‘Loud’ here doesn’t refer to decibels but the physical effects of SPL: realistic instrumental dynamics: for instance, drums that sound – and feel – like drums.
A key design goal of our 2023 range was to shrink that triangle as far as physics and economics permits – to create dynamic, refined speakers that aren’t too expensive; and to allow customers better control of their speaker’s voicing. The search for components and assembly techniques that are both effective and cost-effective felt very ‘of the moment’ in 2021/22. Some of these designs hinge entirely on the availability of one driver or material. Needless to say, models may therefore evolve or become obsolete as supply permits.
Item’s 2023 open baffles were built from the bass up.
The first design challenge was to deliver real bass without wardrobe-sized boxes. Compared to the standard LS50-on-a-stand with a square footprint of 35x25cm, Series 1 speakers require 41x32cm of floorspace. Series 4 speakers have a square footprint of 41x41cm, but the cylindrical Slim Edition comes in at just 34x34cm – roughly the same size as a stand-mounted bookshelf speaker.
Will the Real Bass Please Get Down?
When audiophiles talk about ‘real bass’, they’re often referring to different things. Sealed and ported subwoofers pressurise a room differently to bare drivers – more impactfully, but less realistically. Open-baffle purists advocate the view that bass not emitted by a transducer (ie, ‘distorted’ by the trickery of cabinets, ports and room modes) isn’t ‘real’. Whatever the truth of that, Item’s CC Open Baffle subs are designed for music first and movies second. The higher end models are equally at home in both applications, but at no point have we sacrificed musical realism while chasing lower-frequency output.
Although we like to look at output charts showing ‘how much’ bass is delivered at a given SPL, one chart doesn’t tell the whole story. ‘Going low’ isn’t the same as ‘feeling low’, which – without major reinforcement from a cabinet, is largely a function of moving air. That’s why our subs are designated ‘CC’: a measure of the pistonic capacity (Vd = Sd x Xmax) of each unit. For instance, the entry-level (single-channel) 1008cc sub and mid-level 1884cc model are both dual-15-inch units capable of hitting 20Hz at 90dB, but the extra ‘horsepower’ of the larger capacity sub translates to better palpability, control and articulation. For comparison, the single six-inch driver of the Kef LS50 has an estimated Vd of 65cc per channel, which is efficiently amplified by its ported cabinet to deliver 47dB at 90dB.
“Too much sub” for the room? No more than that other old chestnut about an amplifier ‘too powerful’ for a speaker. While it’s possible to damage a speaker by overwhelming it with current, you’re more likely to destroy a driver with the instability of a low-power amp, especially when protected by a crossover. Similarly, too much voltage for a component is destructive, but ‘too much amperage’ is an oxymoron: amperage is capacity. The false analogy of the car with a hyper-powered engine and stock brakes and suspension is also misleading: when driving transducers, power is control; similarly, when generating low frequencies in-room, ‘too much bass’ is always a function of insufficient control: either uncontrolled triggering of room nodes, or uncontrolled movement of the cone. I have heard rooms with strong nodes at 40Hz that went unstimulated by a lightweight speaker that became problematic when a full-range speaker replaced it, but that’s not only a function of room size, and it wasn’t the speaker’s fault. Which brings us, shortly, to DSP, but first . . .
Much more important – and too-rarely discussed – problems with bass in room are:
A. Too few subwoofers
B. Not having EQ on each sub
C. Locking bass transducers to higher frequency drivers
These aren’t my laws, they are The Laws:
A. An audio system with one subwoofer is broken. It’s not possible to equalise in-room response with a single sub-80Hz emitter. Two is a minimum; four is the ideal. In terms of musical articulation, it’s better to have more small subs than fewer (or one) big one(s).
B. Unless a room is meticulously treated, EQ below 300Hz (particularly below 150Hz) is necessary to avoid major anomalies in phase and frequency response.
C. Putting woofers in the same box as tweeters (assuming an XO below 150Hz or so) is a recipe for trouble: correct placement of each has entirely different priorities. Placement of bass drivers is dictated by the enclosed space containing the listening triangle. Placement of the directional upper frequency drivers is dictated by the listening triangle – creating a suitable soundstage at the listening position(s). Very rarely is the best location for each coincident. With an open-baffle subwoofer, even the angle of orientation affects its behaviour. That’s why Series 4 speakers have separable bass units.
All Item open baffles DSP tuned, offering several game-changing benefits:
A. Relatively lossless per-speaker fine-tuning for flat in-room response
B. Switchable modes for high- and low-volume listening
C. DSP extracts refined performance from lower-cost drivers, leading to lower retail pricing
D. Bass correction to help deal with difficult rooms
E. Time alignment not possible with physical driver positioning alone
Passive v Active
It’s gratifying to see active speakers finally making inroads into a domestic audiophile market that has traditionally obsessed over interconnects and speaker cables and crossover components and which frequently failing to put things in the right location and order. In most cases, active crossovers are simply better. They should never have been downstream of the amplifier in the first place, being particularly detrimental to bass response.
Not to be underestimated – and not often enough discussed – is the lossy nature of interconnects, or, more specifically, junctions in the signal path. If we trace back a signal from the speaker, counting soldered junctions between the ‘modules’ of an ideally streamlined digital audio system consisting of a DAC/Preamp with volume control plus power amp we find:
Transducer > Crimp
Crimp > Hookup cable
Hookup cable > crossover
Crossover > Speaker terminal
Speaker terminal > spade/banana plug
Plug > cable
Cable > Plug
Plug > amplifier terminal
Amplifier terminal > amplification output module
Amplification output > Amplification input (usually socketed, not soldered)
Input terminal (RCA or XLR socket) > Amplification input
RCA/XLR plug > Amplification input
Interconnect cable > RCA/XLR plug
RCA/XLR plug > interconnect cable
RCA/XLR output socket > RCA/XLR plug
DAC output stage > RCA/XLR output
D/A module > DAC output
If we add an analog preamp and another set of interconnects into the picture, the number of unpredictably soldered junctions increases from 17 to 21 or more. By contrast, the active system of the Series 1 and Series 4 speakers consists of just four junctions:
Transducer > Crimp
Crimp > Hookup cable
Amplifier output module > Hookup cable (socketed)
DAC/DSP output > Amplification input (socketed)
The combination of this streamlined signal path, Hypex and Class D amplification, and digitally precise control over not only driver behaviour, but also in-room response, facilitates an unusual level of civility and clarity.
Flavour & Flexibility
Traditionally, audiophiles visited a Great House of HiFi and at first meekly – then loyally – acquiesced to its fixed view of how a component should be voiced. You probably auditioned it in a system and room misleadingly different from your own. If you guessed well, it might have sounded OK when you took it home. Often, gradually, you realised it wasn’t right – and when its flaws began to grate you picked up the magazines, or watched the channels of audio influencers, or scoured the bickering forums, or returned to a dealer for more of the same – in the increasingly vain hope that purchasing the same brand of amplifier, DAC, speaker cable, speaker, mains accessory, interconnect et al would restore missing synergy and balance. And when you moved house, or even rearranged the room, it all sounded wrong again.
Ironically, active speakers have struggled commercially because they were perceived as inflexible (though mainly because they are too unprofitable for dealers to get behind). It’s comforting to think you can tweak your way to audio satisfaction by adjusting in-room tonality with cables, amplifiers and upstream gadgets: ‘tame’ a bright sound with ‘mellow’ valves; ‘perk up’ treble with silver interconnects, etc. Such approaches fail because they’re either irrelevant, or not enough of the wrong thing. Digital DSP and EQ provide unmatched control over many aspects of system performance – not least because they allow correction of the room itself, which for the audio business remains the elephant in the room: the major unaddressed factor.
In our ‘Audio Principles’ book, we advise buyers to work back from the room: allow the room to dictate the speakers; allow the speakers to dictate the amplification; allow the amplification to dictate the preamp and analog stages and (in a digital system) allow the preferences of the DAC to dictate the nature of the source. We also recommend beginning a buying decision by being sure of the audio ‘flavour’ you prefer. All components have a tone of voice. An abidingly fine principle is to choose equipment that has minimal impact on the recording – ie, without an inherent tone – but this is an impossible goal to reach absolutely.
When choosing speakers – or, at least before committing cash to them – it’s important to be clear about your preferences: are you so sibilance-averse that metal dome tweeters are intolerable? Do you find polypropylene cones smooth or boring? When you hear planar drivers do you find them beguilingly airy or frustratingly insubstantial? At a gut level, do horns make you get down and dance, or get up and run off? While these audio clichés aren’t applicable to every case, the physics of sound generation gives rise to certain styles of presentation, and numerous sub-tongues.
Item’s range of open baffles tries to address both the needs of different rooms, and the preference for different flavours, but most importantly allows you to fine-tune them to whatever listening environment you currently have, or later move into.
One Series models are small speakers made for small rooms. Mainly, this derives from the limitations of a single 15-inch bass driver at this price point to generate high SPL (back to the cheap / refined / loud triangle). One Series speakers can therefore quite effectively be ‘let off the leash’ in a big room when accompanied by one or more subwoofers. The larger models naturally at home energising larger spaces, but your house rules apply: if you like the big drama of a bigger speaker in a little room, you’ll appreciate the even greater necessity of tailoring their response to obtain a properly integrated sound.
Having (hopefully) allowed your choice of room to dictate the size of speaker, your choices are now about budget, utility and ‘flavour’. Each model has the option of functional, inexpensive amplification or a lower-distortion, more expensive alternative. Each model also permits a choice of digital-only, digital and analog, or analog-only inputs. Some options include an integral headphone amplifier. Digital-only options that rely on computer-based DSP come with a ‘free audio recorder’, as they rely on the use of a USB studio interface. Some have out-of-the-box wifi, Bluetooth or Roon functionality depending on whether you intend to stream music or play a locally-stored digital library, or vinyl. Crucially, each model can also be upgraded or altered as your requirements change.
We spent twenty years listening to customers before making speakers, so we know that what happens between the ears is more important than what happens outside them. Despite the difficulties, and the excellent financial advice were given about providing ‘too much choice’, we wanted each basic model to be available with a pre-selectable tonality based on unavoidable audio fundamentals.
The entry level three-way dipole we consider ‘studio standard’ has a choice of competent or excellent linear Class D amplification. However, for customers that find it too bright, revealing or ‘digital-sounding’, we offer a ‘Smooth Edition’ at a premium of £250. This involves replacing the steel-basket paper-cone pro audio driver with a high quality polypropylene unit with a cast iron frame, swapping the ultra-flat compact one-inch tweeter for one with a slightly less revealing, but gentler and more airy character, and deploying six channels of valve amplification.
There’s also a ‘White Edition’, offered with the same linear amplification choices as the studio standard, but deploying higher-quality ceramic cone drivers. The ‘Black Edition’ switches to a carbon-fibre midrange and uses planar tweeters.
All versions can be tuned for an in-room response that is flat, rolled off, or mid-range dipped, as customers prefer. Each can be adjusted around room modes. But the fundamental physics of their construction endows each with a particular character: the Black Edition is tonally similar to the Studio Standard (ie, neutral), but offers less distortion, more detail, and a more palpable sense of ‘space’. If you like the base model, the Black Edition is a no-brainer upgrade at a £500 premium. Flanking them, the White Edition and Smooth Edition are polar opposites: one offers superb detail retrieval, super-fast transients and low harmonic distortion – while the other offers richly upholstered textures, creamy vocals and an effortless ease of presentation.
Between these small room speakers and the planar arrays lie two interesting larger speakers with distinct identities: one is a proof of concept that essentially upscales the One Series with dual 15-inch drivers and demonstrates that a full-range open baffle speaker can be very refined, not too big and not too expensive. The other is a cinema/rock monster: built for speed and power – a compression-driver speaker for the home – with the vices of PA speakers digitally dialled out. Both speakers have two amplification options, and both are offered with different bass modules: as standard the dual 15-inch polypropylene drivers typically reach 32Hz in-room. Their sonic imprint is clean and agile. If they were wine, they would be a good Marlborough Sauvignon Blanc. The upgraded version similarly hits 32Hz in-room, but with almost double the ‘horsepower’ (1884cc v 1008cc) delivers richer, dynamic and more palpable bass. If they were wine, they would be a good Chateauneuf du Pape.
The range-topping planar open baffles are clearly superior to the models below them. We’ve worked hard to get this configuration to market at the lowest possible price point. They only use the 1884cc bass units (or better), and deserve the best amplification possible. In term of character, they combine the effervescent weightlessness of true ribbons and the speed and power of big, unfettered cones. Despite the sub-£5K price tag, they suffer little from comparison with much more expensive designs, and will be considered by many an endgame purchase.
Models are priced per pair (below) as turnkey active speakers, complete with amps and crossovers. All models are available ‘bare’ (without amps and crossovers) for those wishing to got it alone with alternate digital or analog crossovers. See product pages for details. If you just wish to bring your own amplification, it is recommended that you opt for the ‘crossover only’ option which includes a multichannel DAC and a software crossover. All speakers are available as singles, too. Typically, we recommend the Hypex Version in that case.
540 and 730 Series speakers are designed for small rooms. 1000 and 1800 Series speakers better energise large spaces. All Editions and versions have fully customisable DSP and EQ.
|Price per pair||Size (cm)||Freq.Resp (±3dB)||Options|
|540.2||£899–1500||W:29 / D:43 / H:85||37Hz–18KHz|
|540.3||£999–1700||W:29 / D:43 / H:89||37Hz–19KHz|
|730 White||£1850–2400||W:35 / D:46 / H:89||28Hz–25KHz|
|730 Black||£2200–2600||W:35 / D:46 / H:95||28Hz–20KHz|
|Bighorn||£1850–2500||W:48 / D:48 / H:115||32Hz–19KHz|
|1000 White||£2700–3200||W:48 / D:48 / H:110||32Hz–35KHz|
|1800 Black||£3250–3750||W:48 / D:48 / H:110||26Hz–20KHz|
|1800 Planar||£3950–4500||W:48 / D:48 / H:125||26Hz–20KHz|