[This review originally appeared in issue 65 of Hi-Fi Plus magazine, which is published in the U.K.]
The 600 Series has been a constant stream of musical pleasure for entry-level and cash-strapped audio enthusiasts for the longest time. The latest iteration builds on this, but with a twist to two. Like the Krell S300i on pages 48-50 in this issue, the new 600 range – two standmounts, two floorstanders and a subwoofer – features local design and global production. The 684 floorstander tested here is typical; it is designed in the Steyning plant in West Sussex and built in China.
Curiously, the nomenclature is back to front. Normally, the higher the number, the better the speaker, but the top model in the 600 range is the 685, and below this model are the 685 standmount and the entry-level 686. It’s nothing to get concerned about of course, but might cause confusion when trawling through the price comparison sites.
The 684 is a ported, two-and-a-half-way design. It’s sporting the now standard B&W issue Flowport golfball-pitted port both fore and aft, a 25mm aluminium dome tweeter and a pair of 165mm Kevlar mid-bass units with hard ‘bullet’ phase plugs in the acoustic centre of each driver.
Each speaker comes supplied with a pair of ‘flexibungs’ (I’ve got all her movies); these allow the speaker to be extremely fine tuned to its environment, as you can have the front bung in, the rear bung out, in, out, in/out and the middle of the bung out. In total, this gives you nine different acoustic modifications to the same loudspeaker and that gives you a lot of freedom in positioning and room size. That being said, the best placement is in a medium sized room (5x4m or larger), firing down the longest axis and approximately half a metre from the rear and side walls. I found that after a lot of experimentation, the best sound came from using the outer portion of the bungs in both speakers, but the dynamics of my room meant it worked well (arguably better) with left bung being complete and the right being just the doughnut, not the whole bung, with a mild toe-in.
My only gripe here concerns the manual, which makes little useful mention of how to use the flexibungs and many will just give up because of this. It’s worth the effort and experimentation, because the loudspeaker benefits greatly from trying out all the different options. So, here’s what the manual should say on this – The two ports are tuned to slightly different frequencies with and without ports; the rear port can be used to subtly tailor the way the loudspeaker interacts with the room. If you have to place the speakers closer to the rear wall than the recommended half metre, try inserting the bungs into the rear ports (first the round outer section of the bung, then the bung entirely). Don’t make snap decisions. The front port tailors the bass output for the room; once you have positioned the speaker properly, experiment with the front bungs in order to accurately match the bass to the rest of the performance. Once again, don’t jump to any snap decisions.
Initially, Bowers and Wilkins supplied the 684 with just the spikes, and initial findings surrounding the speaker (‘best played loud’) reflected possible issues with centre of gravity. Pretty soon after, the 684 shipped with a black plinth with a set of spacers to raise the speaker a centimetre or so off the baseplate, house spikes and widen the footprint. That, plus the slight increase in mass at the base of the speaker, does help give the 684 a sturdy footing. The company includes both spikes and little white rubber feat for those mounting on bare floors. Purists might think anything other than spikes is an abomination, but this is a practical solution that – in practice – works better on a hard wood floor than spikes in this context.
The finish is very slick, although irrespective of whether you use the grilles or not, you are faced with a big slab of flat black to the front and the plinth. The rear and sides are finished in several vinyl woodprint wraps, including light oak, cherry, wengé and black ash. Personally, I think the speakers look better with grilles off, highlighting that distinctive off-centre Bowers & Wilkins tweeter surround logo. I also think the speakers benefit from grille removal where possible; although supposedly acoustically transparent, I’m not entirely convinced and felt the speaker lost a bit of mid and top clarity with the grilles in place. The bi-wire rear panel is usefully set low, so speaker cables rise only a few inches up the back of the speaker itself.