DALI Rubicon 6 Floorstanding Loudspeakers Review
Rubicon 6 Floorstanding Loudspeakers
AUD $7,599 RRP
Described by DALI as “the beginning of the high end”, the company's Rubicon series is what many non-audiophiles would regard as seriously esoteric stuff. By contrast, those of us who've been bitten by the hi-fi bug – which is far less transmissible than certain other maladies, yet still pretty debilitating – would see it as bargain-basement gear. The Rubicon 6 you see here is most people's idea of what a real loudspeaker looks like, inasmuch as it's big, shiny and has lots of drive units, at least one of which looks very exotic. More on this later…
Its price point is where things start to get interesting, as far as the market for hi-fi loudspeakers goes. You can spend a third of its cost and end up with a decent budget floorstander, but one that's still pretty compromised in real terms. However, go up to the Rubicon 6's market position, and speaker designers can bake much more quality into the products. You begin to find high-quality cabinets that don't resonate away in time to the music, and drive units that are no longer the lowest common denominator. In effect, the cost of packing, shipping and distribution isn't as punishing relative to the end price, and the money starts getting spent on serious engineering solutions.
The result of all this is a welter of serious price rivals – from Monitor Audio's Gold 500 to B&W's 702 Signature and Spendor's D7.1. The means DALI's Rubicon 6 has a lot of work to do to set itself apart in this crowded arena. Take a closer look, and you'll see that this is very much the case; it's a big, solid and well-engineered design for the money and one that's packed with interesting design features.
Unusually at this price – or indeed at any price – is its tweeter array. It boasts a combination of a 29mm soft dome tweeter that runs from 2.6kHz to 14kHz, and a 45mm ribbon super tweeter that goes from 14kHz up to a claimed 34kHz (-3dB). This is impressive stuff and will give any bats you may have nearby a wake-up call. Beneath this, the speaker sports a pair of DALI's own custom designed and made SMC 165mm wood fibre coned drivers; the upper one is effectively a midrange unit, and the lower one kicks in at 800Hz and below. The manufacturer describes this, somewhat confusingly, as a 2.5 way plus a 0.5 way – which does make sense if you think about it hard enough!
The largish cabinet is made from MDF, measures 990x200x380mm and weighs 20.2kg. The drivers are screw-mounted directly into the 25mm thick front baffle. To ensure the best possible hold on the woofer and thereby integration with the cabinet, the five screw holes are placed along the arms of the woofer chassis, DALI says, and the tweeter module is held securely in place with four screws. Interestingly, the outer rims of the drivers also feature recesses for the speaker grille retaining pegs – meaning that magnetic grille mountings aren't needed, but there are no unsightly speaker grille mounting holes in the front baffle. That's likely a cost-saving measure, but a novel and neat one all the same!
Inside the cabinet, the midrange and bass drivers are divided up into their own chambers, which helps to prevent cross contamination between the drive units and aids overall cabinet rigidity. The twin woofers each have an associated rear-firing bass reflex port located directly behind the woofer to minimise turbulence and optimise timing. They're also a handy aid to picking up the speaker, should you wish to move it. Additional internal bracing is used to further damp down the cabinet. The result is one that's pretty inert when you hit it with your knuckles; certainly, it's far better in this respect than your average budget box, but it doesn't approach the solidity of pricier high-end designs.
The crossover is directly affixed to the bi-amped terminal board on the lower rear of the speaker to keep signal paths to a minimum. DALI says its design has been kept as simple as possible, and high-quality components are used. This, along with the modern drive units and their light diaphragms, plus a large internal cabinet volume, makes for a quoted sensitivity of 88.5dB/w/m. This isn't stellar, but decent enough, and you should be able to drive the speaker with relatively low powered valve amplifiers should you so wish. Nominal impedance is put at a lower than average 4 ohms, so do check your amplifier matches. Power handling is specified at 180W RMS, so this speaker will soak up pretty much any amount of power in real-world conditions.
Thanks to its sizeable cabinet volume and twin bass reflex ports, the Rubicon 6 delves down to an impressive (quoted) 38Hz. That's a good result for a speaker of this price, considering that DALI is using standard and sensible -3dB roll-off points, rather than the -6dB or even -9dB points that some manufacturers are now quoting. The downside is that these reflex ports fire a lot of energy to the rear wall, so you'll need to give the speaker room to breathe. I reckon most folk will need at least 30cm of clean air to the back wall, and likely more. I also found that a slight toe-in helped the stereo imaging snap into focus, too, although less so than some rivals I've auditioned of late.
My reference system sources were a Technics SP-15/SME Series V/Lyra Dorian turntable, and a Cyrus CD Xt Signature CD transport feeding a Chord Electronics Hugo TT2 DAC. Amplification came courtesy of Copland's CSA-150 integrated and Sony's TA-E86B/TA-N86B pre-power combination. Loudspeakers used included Yamaha NS-1000Ms, B&W 702 Signatures and Spendor D7.2s.
This loudspeaker delivers a large, powerful, wideband sound that doesn't disappoint, regardless of the type of music you play. It has a rich tonality which makes everything come across as fulsome and engaging. Its bass response is particularly impressive, going down very low and having plenty of punch in reserve. Even though it is strong down below, it doesn't overpower the rest of the music, providing you've positioned it correctly. The Rubicon's midband is satisfyingly smooth and decently detailed, with an expensive feeling. This joins up seamlessly with a super-civilised treble, which never spits or hisses at you, even when playing poor recordings. The result is a speaker that sounds far more refined than you might expect.
Indeed, one could almost say that the Rubicon 6 is unusual for its price. So many modern speakers are forward and apparently incisive, firing detail out at you thanks to a slightly lively tonal balance. Yet, the DALI is different. Queue up a forward sounding slice of new wave music, such as Echo and the Bunnymen's The Killing Moon, for example, and this can sound quite searing through many modern speakers, but not so here. Singer Ian McCulloch has quite an acerbic voice that is edgy and almost grating through the wrong system. This speaker seemed to take some of the sting out of it whilst preserving its distinctive grain, and faithfully conveying his fragile vocal style.
At the same time, the light and chewy bass guitar work assumed a little extra body compared with some other speakers at this price. It wasn't as if this floorstander was adding excessive overhang, but still, there was a subtle tonal warmth helping the proceedings along. This was in no way an unpleasant sensation, but still, some listeners might dismiss it as low-end colouration. Of course, it all comes down to personal taste, as others would see it as the charming side to this big floorstander's personality. Indeed its coated wood bass driver cones have a rather nice timbre to them, one that's the diametric opposite to the thin, nasal sound of some modern plastic or glass fibre coned woofers.
The midband is similar in its fundamental character to the bass. There's nothing shouty or harsh here; instead, it merges seamlessly with that ever so slightly warm upper bass to take you into a clean and open presence region where you'll not get assaulted by forward sounding recordings. Norman Connors' Romantic Journey was a sensation for sore ears. This is a lovely slice of mid-seventies jazz-funk, with shades of easy listening thrown in; the track has beautiful, soaring strings which would grace any five-star hotel elevator during the decade that fashion forgot. It's a nice enough recording as it is, but the DALI decided to flatter it a wee bit more. This loudspeaker pulled me into a large, immersive recorded acoustic, where I seemed to be able to wander around at will and take in all the individual strands of the mix.
The Rubicon 6 is good at conjuring up a wide stereo soundstage, within which all the instruments were accurately located. In absolute terms, compared to speakers substantially more expensive than this, you could say it's a little limited in terms of stage depth. Yet I'd wager that it does as well as any price rival I can think of, and it did make a lovely job of Slave to the Rhythm by Grace Jones. The sumptuous Trevor Horn production on this late eighties pop classic was quite something to behold. Combine the DALI's ability to stretch out to far stage left and stage right, with its large and physical sound, and the result was a suitably dramatic rendition of this electropop masterpiece.
This speaker's fine high-frequency performance is another one of its impressive facets. It's rare to hear a dome tweeter/ribbon super-tweeter combination, and DALI has certainly got this one to work. I loved the sound given to the drum machine hi-hats on the Grace Jones track, allied to a general sense of air and space that made things sound almost larger than life. This and the fact that there was absolutely no grain to this track, when sometimes it can be a little bit spitty, made for a wonderful listening experience. That unusual hybrid tweeter module is even more impressive when asked to play high-quality acoustic jazz recordings, for example. Dave Brubeck's classic Take Five was a joy, with a really natural sound to the ride cymbals, plus excellent resolution of the piano's bristling harmonics.
However, if you are coming from a substantially more expensive speaker, you might find the Rubicon 6 ever so slightly lacking in dynamics. In normal use, it sounds powerful and articulate, but in absolute terms, it doesn't quite deliver the last one-tenth of thump when listening to, say, the hard-hit snare drum in Simple Minds' Someone, Somewhere in Summertime. That doesn't mean to say that it didn't make a fine fist of this classic early eighties indie rock track, however. Indeed it displayed very decent rhythmic prowess, being well able to get into the groove. The track's propulsive bassline was great fun and showed how this floorstander could really drive a decent-sized listening room when called upon so to do.
When put against more expensive rivals such as the Spendor D7.1, you can hear a wee bit of cabinet colouration. This manifests itself as a slight softening of the midband and the loss of some low-level detail. At this price, it's more of an observation than a criticism, but it shows you that DALI is correct when it speaks of this being the entry to the high end, rather than the high end itself. What I find so pleasing about this floorstander however, is that it offers a valid alternative to the usual thin sounding, forensic modern loudspeaker that so many manufacturers now sell.
DALI's Rubicon 6 is an excellent package at the price. It has been extremely well voiced considering the audience it is aimed at yet doesn't follow the crowd to end up sounding like a clone of its rivals. For example, it's not a B&W soundalike that sprays detail at you and has a clinical tonal balance. The company has chosen to do something different, and the result is a speaker that's never not nice to listen to and one that doesn't tear apart every recording, trying to deconstruct it.
Instead, this big floorstander is more music-focused, preferring to just get on and enjoy what it's being asked to play rather than analysing it. For this reason, the Rubicon 6 is just a little out of the ordinary, a bit special in its way. That's why, if you're in the market for an entry-level high-end design, then it's well worth hearing.
David started his career in 1993 writing for Hi-Fi World and went on to edit the magazine for nearly a decade. He was then made Editor of Hi-Fi Choice and continued to freelance for it and Hi-Fi News until becoming StereoNET’s Editor-in-Chief.