VAF Research doesn't tend to change its models very often. The company takes the view that it spends so much time and money getting its designs right in the first place that unless there's specific reason to create a new design or update an existing one, it would prefer not to. So it was rather surprising to see a recent flurry of activity that's resulted in the company releasing several newly upgraded models, including those that make up the system reviewed here: the DC-X Gen IVs, DC-6 centre and DC-7s.
The impetus for these new designs stems from switching from fibreglass-coned bass/midrange drivers to newer drivers with cones made from Kevlar. These new models also have new, neodymium-powered tweeters.
Equipment
All the speakers in this system have bass/midrange cones made from a new Kevlar 'composite' material, but perhaps more importantly, they all have a new motor system that involves T-shaped pole-pieces, high-temperature voice-coils, and 'former venting'.
Venting the voice-coil through its former is a well-known technique, but instead of putting the vents above the spider, VAF puts them underneath, which is a clever twist. This enables the spider to pump hot air away from the coil, enabling higher power-handling, great efficiency and increased dynamics.
The bass drivers in the DC-X are a little larger than those in the DC-7 and DC-6. The DC-X drivers are 210mm in diameter whereas those in the DC-7 and DC-6 are 170mm in diameter. Remember, however, that in all three speakers, because VAF is using two drivers to cover the same frequency range, the available cone area is doubled. However, good bass isn't only dependent on cone area. Cone travel must also be considered, and it's here that VAF's new Kevlar cones excel. The DC-X drivers travel 22mm from peak to peak, and the smaller diameter drivers in the DC-7 and DC-6 aren't far behind. All drivers are fully magnetically shielded.
All cabinets in this system are bass reflex types in order to make best use of the energy from the rear of the cones. This not only extends bass response but also increases efficiency, so the system makes the most of low-powered AV receivers and enables even greater dynamics from higher-powered models. VAF has also worked on ensuring minimal acoustic propagation through the speaker diaphragms, using a combination of sloping internal baffles and its super-absorbent 'Hypersoft III' foam, so sound quality is very 'clean'.
The tweeters in all these speakers are all identical 25mm diameter soft-dome designs driven by neodymium magnets. All have large heat sinks attached to their magnets to ensure adequate cooling - an extra but necessary expense that many manufacturers avoid. Keeping the magnets cool in this way means significantly less dynamic compression.
You may have heard that VAF is a 'kit' manufacturer. It's true: you can buy these speakers as DIY kits, for which VAF supplies a full set of parts, including pre-assembled crossovers. However, they're also available fully-built and tested, complete with individual test reports showing measured frequency response. VAF's three-year warranty applies in all cases - even if you build them yourself. This system would cost you $5097 fully built and assembled; $4299 as a kit of parts including the cabinets; or $2447 for everything except the cabinets. The only rider is that VAF sells 'factory-direct', so unless you live in Adelaide, freight is extra. All speakers are available in VAF's standard finishes (American Oak, Black Oak and Australian Jarrah) but you can have just about any finish you want to special order.
