You are here

Barefoot Footprint 01

Active Monitors
Published August 2017
By Phil Ward

The Footprint 01 is Barefoot’s most affordable monitor yet. Does it give away much in terms of performance?

We’ve reviewed a couple of Barefoot active monitors over the past few years, and on both occasions found them to offer seriously high-quality monitoring — at a cost. I think it’s fair to say that Barefoot don’t find design or engineering compromise particularly easy, and it reflects in the price of their monitors. However, that looks like it may have changed a little, with the launch of the new Footprint 01, the company’s least expensive monitor to date.

Barefoot Footprint 01 monitor.At first glance, the Footprint 01 doesn’t look a million miles away from other Barefoot monitors. The opposing side-mounted bass drivers and the aluminium sub-baffle are both present, as is the ring-radiator tweeter and compact metal-diaphragm mid-range driver. But the price, while still not really at the lower rungs of the monitoring ladder, isn’t quite up at the height where you’re best advised not to look down.

Along with being the least expensive of the Barefoot monitors, the Footprint 01 is also one of the smallest. It’s a good size for a nearfield monitor though — compact enough that it can be installed in relatively bijou studio and workstation environments, but large enough that it can aspire to the kind of extended low-frequency bandwidth that makes you begin to wonder why midfield monitors are really needed.

In aesthetic terms, the Footprint 01 is unlikely to be mistaken for a monitor from any other manufacturer. Like its siblings further up the product range, its soft-edge wooden cabinet is finished in a dark textured paint with just the anodised aluminium sub-baffle to relieve the blackness. Around the back is an aluminium plate that carries mains and analogue XLR signal inputs, a detented gain control, connections sockets for the Multi-Emphasis Monitor Emulation system (more on MEME later) and a USB socket that’s present only for in-house setup and diagnostics. There are no switched EQ options provided.

The Barefoot aesthetic is not, if I’m honest, a look that’s ever really won me over. While I appreciate that it’s the performance and sound that’s important, nearfield monitors, by definition, spend their lives in line of sight so I do appreciate ones that are a bit more rewarding to look at. However, the other side of this aesthetic story is of course that if less of the manufacturing budget has been spent on, say, the cabinet finish (and the black textured paint of the Footprint 01 is a relatively inexpensive way of finishing a wooden box), there’s more to spend on the electro-acoustic components. Which brings me conveniently to describe the electro-acoustics of the Footprint 01.

Can I Kick It?

A feature of all the previous Barefoot monitors we’ve looked at has been their evidently high-quality and high-performance drivers, and the Footprint 01 continues that trend. Starting at the low end of the audio bandwidth, the monitor is fitted with twin, horizontally opposed 200mm paper-diaphragm bass drivers, each said to be capable of ±9.5mm linear cone displacement. An outward sign of the bass drivers being capable of such extended displacement is their oversized rubber roll-surround, and to put ±9.5mm into perspective, a more normal figure for a 200mm driver would be between, say, 4 and 6 mm. There are actually few more expensive technical targets to aim for in a bass driver than extended cone displacement, as it has unavoidable implications for the most expensive components — the magnet and associated metalwork. But it has some knock-on benefits too; distortion performance, thermal power handling and compression are all likely to be improved.

Along with the Footprint 01, a couple of other Barefoot monitors employ a similar configuration of side-mounted, opposing bass drivers, so perhaps a short discourse on the subject is worthwhile. The logic behind the idea has two main strands. Firstly, multiple smaller bass drivers (rather than one big one) can offer higher thermal power handling for a given diaphragm area, and secondly, mounting the two drivers on opposite sides of a cabinet, taking advantage of the omnidirectional nature of low frequencies, delivers the great benefit that mechanical vibrational energy that might otherwise excite cabinet resonances is cancelled out.

In common with many other Barefoot designs, the Footprint 01 employs two identical woofers mounted on opposing sides of the cabinet.In common with many other Barefoot designs, the Footprint 01 employs two identical woofers mounted on opposing sides of the cabinet.The one potential downside of side-mounted bass drivers is that an extra factor is thrown into the mix of those that define the low/mid crossover frequency. Place the crossover frequency too low and some of the cabinet resonance advantages are lost, but place it too high and the bass drivers will start to radiate significant mid-range energy sideways into the room. Interestingly, the low/mid crossover on the last Barefoot monitor we reviewed, the MM35, is 100Hz. On the Footprint 01 the crossover frequency is 250Hz and that, to my mind, marks a noteworthy change of design philosophy.

The Footprint 01 requires such extended cone displacement because its low-frequency bandwidth is not so much defined by the inherent response of its drivers and 18-litre closed box, but by its electronic low-frequency equalisation. The equalisation bolsters a low-frequency system that, left to its own devices, I’d estimate would be -3dB at around 70Hz, to a -3dB point at 36Hz. In other words, the EQ makes the bass drivers work extremely hard. But it’s not only the bass drivers that need to work hard to achieve -3dB at 36Hz from an 18L closed box. The Footprint 01 LF amplifier section necessarily needs the spare headroom to accommodate probably something like 10dB of extra gain at low frequencies, and this is betrayed by the Footprint 01’s amplifier specification. Where its mid/high-frequency amplifier gets by on 150 Watts, its low-frequency amplifier is rated at 500 Watts. It’s Class-D amp technology that makes this possible. Traditional amp technology would demand a huge power supply and vast heatsink.

In The Mids

Moving on up from the low-frequency end of the Footprint 01, the mid-range driver takes over at 250Hz via a DSP-implemented filter network (the Footprint 01 incorporates internal DSP, but has only an analogue input). Said driver is a relatively small device with a diaphragm diameter of 100mm but, like the bass drivers, it is endowed with a pretty healthy ±3.5mm maximum linear displacement, which will compensate for its slightly limited cone area. The smaller-diameter diaphragm will bring benefits, however, in that it will reach a higher frequency before becoming significantly directional or suffering too seriously from cone break-up effects.

The mid-range diaphragm is manufactured from aluminium, and rather than a traditional dust cap it features an aluminium bullet-style ‘phase plug’. The phase plug, much more commonly seen these days than it was back in the early years of speaker and monitor design, perhaps warrants another minor discourse. See the ‘Phase Plugs’ box.

Tweetest Thing

The last Barefoot 01 driver I need to describe is of course the tweeter. Now, normally I’d write something about the tweeter being located above the mid-range driver, but with the Footprint 01 I can’t, because it’s not. It’s located beneath the mid-range driver.

This inversion of the usual arrangement can make reasonable sense and has been tried by various manufacturers, particularly in the hi-fi sector, over the years. That sensible justification is that, ideally, the acoustic path length from each driver to the listener ought to be the same. However, simply due to the geometry of mid-range drivers and tweeters, the path lengths, at least perpendicularly forward, are rarely equal: the depth of a mid-range cone diaphragm means the driver’s effective acoustic source position is located a few centimetres behind that of the tweeter. Having said that, there will always be a line of positions forward of the monitor where the driver path lengths equalise, but it will be at an angle rather than perpendicular to the monitor’s front panel. With the typical arrangement of tweeter above mid driver, the angle of the line of equal path lengths will be downwards, usually around 10 or 20 degrees from the perpendicular. So, flipping the layout of the two drivers, so that the mid-range driver is on top, also flips the direction of the angle of equal path length. It will now point upwards.

Although it only has an analogue input, the Footprint 01 performs all its crossover duties in the digital domain.Although it only has an analogue input, the Footprint 01 performs all its crossover duties in the digital domain.Now, having the equal path length line angled slightly upwards is useful on monitors where the listening position is typically slightly above the monitor, but of course that isn’t always the case with nearfield monitors — in fact, listening slightly below or perpendicular to the monitors is perhaps just as likely. Having said all that, the slightly upward angle of the line of equal path lengths is probably not hugely significant on the Footprint 01.

It won’t have escaped your notice that mention of the Footprint 01 tweeter resulted in me digressing about driver layout somewhat, so in the interests of dragging the review kicking and screaming back on track, I should say that the tweeter itself is a 25mm ring-radiator device of a type originally conceived by the Vifa/Scanspeak company in Denmark. I have direct experience of similar ring-radiator tweeters and can confirm that they are high-performance drivers that offer some particularly useful characteristics. One of these is that the fundamental resonance (that of the mass of the diaphragm against the compliance of its surround and suspension) is located at an unusually low frequency: around 500Hz, rather than a more typical 1kHz plus. The tweeter resonance is important because, especially in speakers with passive filters, it ideally needs to be as far away from the mid/tweeter crossover point as possible so as not to mangle the high-pass slope characteristics. But, I hear you say, the Footprint 01 is an active speaker, so its filters wouldn’t be compromised by the tweeter resonance anyway. And that’s where you’d be wrong, because the Footprint 01 is not fully active: it’s a three-way system (bass, mid and tweeter), but only has two ‘channels’ of power amplification — one driving the bass section and one driving the mid-range and tweeter via a passive crossover at 3.6kHz.

The use of only two power-amplifier channels along with a passive crossover clearly constitutes a compromise in terms of other Barefoot monitors, and presumably is where a significant cost saving lies for the Footprint 01, but from my perspective, I reckon passive crossover networks are sometimes unfairly dissed. Designed thoughtfully and built with high-quality components, passive crossovers can work well and are not always as evil as they are painted. After all, some of the best speakers I’ve ever heard are passive, and it’s not as if recording engineers only started turning out decent-sounding records when monitors went active. So, assuming Barefoot have done a good job on the design and engineering of the crossover, it’s not actually as big a deal for me as it may be for many.

What Does It All MEME?

There’s one more element of the Footprint 01 to cover before I cut to the chase: the MEME monitor emulation system. MEME comprises a small metal box incorporating a four-position rotary switch marked Hi-fi, Flat, Old School and Cube. The box connects to each monitor of the pair (daisy-chained or individually) by supplied 3.5mm jack cables. The MEME concept is that, at the turn of the switch, the Footprint 01 takes on the character of one of three alternative types of monitor. The Hi-fi switch position emulates a supposed hi-fi speaker with a slightly sucked-out mid-range; the Old School position takes on the character of, well, you know, the one with the white cone; and the Cube setting emulates a full-range driver in small box. The ‘flat’ MEME position selects the default character of the Footprint 01 (MEME is also optional, you don’t have to use it).

Diagram 1: The frequency responses of the various MEME modes, above 200Hz.Diagram 1: The frequency responses of the various MEME modes, above 200Hz.

In the marketing material that accompanies the Footprint 01, the MEME system is said to emulate the distortions, time-domain performance, and dynamic characters of the alternative monitors, along with aping their frequency responses. The FuzzMeasure data I took, with the four alternative frequency response curves shown in Diagrams 1 and 2, didn’t reveal too much evidence of anything beyond frequency response changes, so I suspect deeper investigation would be required to reveal the detail of the emulations. The FuzzMeasure data also reveals that the Cube setting actually mutes the Footprint 01 bass drivers, so the Cube is not included in the LF data of Diagram 2.

Diagram 2: As above, but in the frequency range of 10Hz to 200Hz.Diagram 2: As above, but in the frequency range of 10Hz to 200Hz.

The Barefoot MM35 I reviewed a couple of years ago also included the MEME system, and I wasn’t entirely convinced by it back then. I’m still not. I have a couple of issues with MEME. Firstly, while it’s possible to emulate some characteristics of a speaker (or, more accurately, imprint them on the monitor’s existing character), some things can’t be done. In particular, it’s not really possible to emulate one fundamental aspect of another speaker’s character; its dispersion. Dispersion is essentially a function of driver size, driver layout and cabinet dimensions, and in the absence of the MEME system being able to trigger some serious Footprint 01 shape-shifting, its dispersion fundamentally remains fixed.

Secondly, I’m not convinced of the need for MEME. Without wishing to get too deeply into the philosophy of monitoring, it seems to me that the role of a monitor is to be the fixed reference on which the sound of the material on other potential downstream playback devices is founded. So if a monitor is doing its job properly by enabling a good mix to be created (ie. one that translates well), it really shouldn’t be required to sound approximately like something else. And speaking of making the Footprint 01 sound like something else, flicking the MEME switch does indeed impart the approximate appropriate range of characteristics. I suspect though that if I used a pair of Footprint 01s regularly, the MEME box would pretty soon be consigned to that drawer full of rarely used studio bits and pieces.

Listening In

With the Footprint 01 set to its default response, I began listening. It only took a moment to establish that the Footprint 01 is fundamentally a very good monitor. The quality of its component parts and engineering shines throughout, especially in its mid-range imaging, clarity, top-end detail and low-frequency power. Another positive sign is its consistency with level. Its character and quality doesn’t vary, loud or quiet. And speaking of loud, the Footprint 01 can play at seriously high levels with ease. The bass end offers as much bandwidth extension as I think anybody could realistically need for nearfield monitoring, and the Footprint 01’s closed-box design contributes to an assuredness and assertiveness on low-frequency transients that helps greatly in establishing the mix foundations of kick drum and bass guitar. Five hundred Watts of amplifier power no doubt helps on that front too.

So all is good with the Footprint 01? Well yes, except for one frustration: its overall tonal balance is, I feel, slightly over-cooked in the low mid-range for nearfield listening — and there’s no onboard EQ to help fix it. In my room, one that’s usefully neutral, there was an excess of warmth on voices and acoustic guitars, a little like a microphone proximity effect. It’s the kind of characteristic that will be room and position dependent, but my suspicion is that the 250Hz low/mid crossover combined with side-firing drivers perhaps results in excess low/mid energy in the room. This was reinforced by some re-voicing with an EQ plug-in. Cutting 2dB below 250Hz substantially sorted the balance. I used the term ‘frustration’ earlier because it seems to me, in the absence of any rear-panel EQ settings, that the MEME device might have been better deployed offering a few of those instead.

Despite my misgivings about the MEME device and the low/mid balance, the Footprint 01 is still a fine monitor that I’d be very happy to use as a primary mix tool. It may also of course be the case that in another room the low/mid balance will be spot on. Fundamentally, the quality of the drivers, the ample power of the amplification and the engineering integrity with which everything is bolted together triumphs in the end.

Phase Plugs

The concept of the phase plug is actually borrowed from horn-loaded drivers, where phase-plugs serve to modify the way in which the diaphragm couples to the air and help equalise the effective radiation path length from different parts of the horn to the listener — hence the reference to phase. In their application in direct-radiating drivers, despite the ‘phase’ function being far less significant, the phase element of the name has survived. I guess ‘plug’ on its own just didn’t sound technical enough.

Typically, a phase plug in a direct-radiating driver comprises nothing more than a ‘streamlined’ (usually) extension to the pole piece. It protrudes forward of the apex of the diaphragm through the region where the dust cap traditionally would sit. The dust cap took its name entirely from its original function, in that it protects the fine-tolerance moving parts of a driver from the ingress of foreign bodies. However, once modern laser-based and finite-element diaphragm analysis techniques arrived, it didn’t take long for speaker engineers to realise that the action of sticking a dust-cap on a diaphragm quite often didn’t do the driver many favours in terms of acoustic performance. So phase plugs began to appear and drivers began to live more dangerously as their internals became open to dust. Even so, I don’t think I’ve ever come across a driver that definitely failed thanks to having no dust cap (foreign bodies that cause a problem are usually there from the start), so that potential disadvantage of the phase plug is probably a red herring. The phase plug can have some genuine advantages though: it can help linearise a driver’s dispersion and response towards the top end of its frequency range (assuming the loss of damping/rigidity potentially provided by a dust-cap is acceptable), and, if metallic, it will improve heat dissipation from the voice coil. Employing a phase plug will also remove the potentially resonant cavity between the underside of the dust cap and the top of the pole piece.

DSP Latency

A benefit of characterising a speaker with FuzzMeasure is that any in/out latency is revealed. The Footprint 01 incorporates internal A-to-D and D-to-A conversion, with some DSP between, so it can’t avoid delaying the signal between input and output. I measured the delay at round 6ms, which would perhaps be on the cusp of noticeable if I was using the monitors for overdub tracking.

About The Author: Phil Ward’s loudspeaker career began in 1982 when he joined UK hi-fi company Mordaunt-Short in a junior design role. After leaving Mordaunt-Short in 1987 for a spell in audio PR, Phil joined Canon as Design Manager for the Japanese multinational’s range of consumer and custom install speakers, and then Naim Audio as speaker design and project manager. Since 2001 Phil has worked as a freelance consultant and writer across both the pro and consumer audio sectors. Phil plays electric and double bass and has recorded, produced and mixed numerous bands and artists. Phil's blog can be found at http://musicandmiscellany.com   

Published August 2017