Borresen Z2

Hardware Review

Borresen Z2
Monday, June 21, 2021
floorstanding loudspeakers
Jason Kennedy

The Danes appear to have a knack for building hi-fi, maybe it’s because they have been doing it for a long time what with brands like Bang & Olufsen and Ortofon being in the business for so long. Michael Børresen was formerly with high end specialists Raidho but started to build loudspeakers under his own name alongside the electronics brands Aavic and Ansuz when he partnered with Lars Kristensen. Børresen launched with the flagship 0 range and followed that with the Z series of which the Z2 is the most affordable floorstander, a solid 2.5-way with a bass driver near the floor and twin reflex ports in the back, the whole thing supported by a metal outrigger base.

With its custom drive units and matte paint finish this is a particularly nicely executed metre and a bit high loudspeaker, the attention to detail is superb, but given that it costs as much as some rather larger and better known high end alternatives this is pretty much essential. When you start looking at the components it becomes clear why the price is what it is, little if anything in the Z2 is an off the shelf part, there are elements shared with other Børresen speakers of course but nothing you’ll find on a more affordable box. The cones in the mid and bass drivers don’t look conventional because they aren’t, these are a sandwich of lightweight carbon fibre skins either side of a 4mm honeycomb core built in-house. This composite arrangement provides an excellent stiffness to weight ratio, high stiffness combined with low mass means the driver will be less inclined to deform and can be more easily controlled.

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The motor system for these drivers is provided by neodymium magnets, a costly material rarely seen on anything bigger than a tweeter. Børresen uses them because they provide a highly linear magnetic field for not one but two voice coils. Using two halves inductance which is a high priority in this loudspeaker, the lower the inductance the easier it is for an amplifier to control the loudspeaker which means that you don’t need huge amounts of power nor is the amplifier having to work outside its comfort zone. Despite the 86dB/4 Ohm sensitivity of the Z2 Børresen claims that it can be driven by a 50 Watt amplifier and even tube amps. 

The tweeter is a ribbon type but one for which Børresen claim unusually high efficiency of 94dB, which is pretty good for a tweeter of any kind especially one that’s said to be good at handling power. You’ll note that all the drivers have shallow horns carved into the thick front baffle, this should increase sensitivity but Børresen has chosen to make the Z2 an easier load instead.

Most loudspeaker makers provide threaded inserts for spike feet on floorstanding models, but Børresen’s sister company Ansuz is all about resonance control so this speaker takes its own approach. Instead of threaded inserts the Z2 has machined aluminium feet that are round with a circular groove underneath. The idea is that you combine them with Ansuz Darkz feet which fit into each foot and have titanium balls trapped within them, these feet are said to “allow vibrations a path out of the component” and provide grounding. As it stands the Z2 can be used solely with its own feet which have the benefit of not being likely to mark hard floor surfaces. The feet can be adjusted for height as they are on a large M10 stud that’s covered by the caps you see, this speaker has more metalwork than most and that’s before you consider the reflex ports. These vent the mid and bass volumes of the cabinet separately and have metal inserts and are lined with precisely notched foam on either side, both elements are designed to reduce port noise. The metal inserts act like spoilers to break up the air flow and allow greater pressure while the foam kills standing wave resonances across the slot shaped port.

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One other unusual detail in this loudspeaker is that all the ‘metal components’ can be cryogenically treated, which presumably means the signal carrying components rather than any other metalwork. Cryogenic treatment of audio cables was pioneered by Townshend Audio and involves using very low temperatures to align the grain structure in metal, it’s use is not uncommon among cable makers while less so in loudspeakers but has considerable potential given the amount of copper in inductors. The Z2 has two on its crossover and one is pretty big. Cryogenic treatment is an optional extra that adds a not inconsiderable 25% to the price of this already quite spendy loudspeaker.

Sound quality
The vast majority of loudspeaker makers do not give hard and fast instructions about how to set up their products so it’s refreshing to find one that has a specific idea about this critical factor. Børresen recommends placing speakers three metres apart and angling each one so that a thin sliver of the inside face of each cabinet is visible from the listening seat, they also suggest that a space of at least 60cm be left between speaker and rear wall. Apparently it doesn’t matter if this puts them relatively close to the listener in the near field as became the case in my room where only the largest speakers need 30cm or more behind them. The Bowers & Wilkins 802s for instance work at 80cm to the tweeter which leaves 28cm behind them, so putting 60cm behind this rather smaller speaker seemed a bit odd but there was no shortage of bass so it clearly works. In fact the Z2s produce better controlled and more extended bass than would be expected for a speaker of this size.

I usually have around 2 metres between speakers so this extra width made a clear impact on the imaging which became truly cinematic in its scope, making space for every voice and instrument in a band to breathe. Occasionally you get a mix where the drums are spread across both channels which can seem a bit extreme but in most instances and particularly with live recordings this widescreen presentation worked a treat.

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I used a Moor Amps Angel 6 power amplifier to drive them for the majority of the review and the pairing of this powerful and agile amplifier with the Børresens worked really well, at least it did after a few days. Initial results seemed thick and dull and I tried pulling them further from the wall and putting them on Townshend Seismic Podiums to get some more life out of them but after a week realised that they had become more open and lively through run-in. Given that Børresen had run them in for 48 hours prior to shipping this was surprising but the end result was well worth the wait.

The Z2 is one of those speakers that does everything well, it is remarkably consistent in its ability to reflect the nature of the recording that’s being played, that and the character of the source, amplifier and cables of course. The ribbon tweeter is more dynamic and precise than many of its kind which tend to be soft and sweet, this isn’t a bad thing but the Børresen brings a bit more definition without any tendency to edginess that you can get with domes. It’s impossible to separate its contribution from that of the midrange really and I suspect that this is where most of the sense of revelation really comes from. Even by the standards of similarly priced speakers the detail level is unusually high, and equally important is that its presented in a fluent, musical fashion that removes any sense that you are listening to a mechanical device. 

Playing some vintage vinyl I was blown away by the differences in recording styles, Odetta’s version of 900 miles puts her strong voice front and centre but also reveals the character of the acoustic guitar accompaniment. Lou Reed’s Transformer has always been a great album but I’ve never heard so much dynamic range on Andy’s Chest before, and once again the voice was perfect. I also let JJ Cale’s Really play in the background but had to sit up and take notice after a few tracks, there was just so much country blues goodness coming out of the system it warranted maximum attention.

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The Børresens did the same thing with digital as well it’s just that the record player is better than the streaming system, but so long as comparisons between the two were avoided the digital sounded blindingly good as well. Joni Mitchell’s live version of Big Yellow Taxi often sounds quite thick through the mid and bass but these speakers managed to cut through the grunge and deliver her exceptional voice and the superb playing of the LA Express backing her, the nimble bass playing being particularly well rendered thanks to the wideband clarity of the Z2. Radiohead’s Desert Island Disk is a relaxed piece but can often seem rather homogenous and vague, here it was possible to hear right into layers in the production and appreciate how artfull a construct it is. Lou Reed’s Vanishing Act is a far simpler affair of voice and piano but what a voice, this system delivered all of its depth and timbre beside the beautiful restraint of the keyboard playing. In an attempt to plumb the depths of bass delivery I put on Lorde’s Royals for the first time in a few years. I don’t recall hearing so much in it before, there are so many small details and the bass is as clean and controlled as you like. Deep, powerful but not overblown. Another low end favourite is the Hadouk Trio’s live version of Vol de Nuit which has a deep bass drone that can overwhelm ported speakers, here it just energised the room in an even and surprisingly clean fashion.

Toward the end of the time spent with these remarkable speakers a Rogers E20a/ii integrated tube amplifier turned up, this push-pull unit is not particularly powerful with a 20W rating but was able to deliver decent levels through the Z2s. The bass in particular struck me as being particularly appealing, not as solid or extended as with the much more powerful transistor power amp used before but generous and substantial with tracks that didn’t require rapid transients, those with snappy bass lines were a little lazy however. Clearly 50W is a minimum requirement if you want control.

This Børresen is a highly capable and revealing loudspeaker in a compact and attractive cabinet, the deep sculpted baffle contrasting beautifully with the white and silver elements. It requires a bit of space to achieve the three metre spacing but that does allow the creation of a truly wide and deep soundstage. Børresen’s Z series is clearly a welcome addition to the world of high end loudspeakers, that this is the most affordable floorstander in what is the brand’s more affordable range bodes very well for its larger stablemates.

Specifications: 

Type: Reflex loaded 2.5-way floorstanding loudspeaker
Crossover frequency: not specified
Drive units:
Bass – 8 inch sandwich cone

Mid/bass – 4.5inch sandwich cone
Tweeter – closed ribbon tweeter
Nominal frequency response:  40 – 50,000 Hz
Nominal impedance: 4 Ohms
Connectors: single wire binding posts
Sensitivity: 86dB 1w/1m
Dimensions HxWxD: 1025 x 225 x 330mm
Weight: 34kg
Finishes: matte black, matte white
Warranty: 5 years

Price: 
£16,000
Manufacturer Details: 

Børresen Acoustics ApS
www.borresen-acoustics.com

Distributor Details: 

Auditorium HiFi 
T +44 (0) 7960 423194
www.auditoriumhifi.co.uk