Three Legs Good?

The hidden price you pay for ‘stability’…

By Roy Gregory

The tripod might seem like God’s geometrical gift to the audio fraternity. It’s inherently stable and perfectly embodies that catch all mantra, “less is more.” But dig a little deeper into the actual application of three point support and you soon come to realise that it’s a mixed blessing at best, an impediment to optimum performance at worst.

Perhaps the most obvious example of this is the three-legged rack. Again, at first glance it seems like an obvious solution. Guaranteed stability and, as long as you approach the problem correctly (that is, using the ‘base’ of the isosceles triangle as your starting point for horizontal reference) easy to level. If the feet don’t have a symmetrical layout? No problem – as anybody familiar with Linn turntables will tell you, just pick two as your reference plane and work from there.

The problem with three-legged racks isn’t one of installation, it relates to practicality. Placing a leg in the middle of the back of a rack places it in the middle of the back of the equipment – and that ain’t good, from the point of view of cable access and dressing. Too many power amps have centrally located AC sockets and too many audiophile power cords have massive connectors and inflexible cable to ever make this an acceptable arrangement. And that’s before you start worrying about multiple interconnects and other connections…

The solution is, of course, simple: just put two legs on one side of the rack and one on the other – but when was the last time you saw an audio rack built like that?

But what is an inconvenience with a rack becomes a significant issue with loudspeakers – an issue that was underlined by recent experience with the exceptionally interesting and remarkably capable new AvantGarde Trio G3. Almost every part of the loudspeaker has been reconsidered and redesigned, with only the actual bass and midrange trumpets remaining from the previous design. That’s partly because the Trio G3 is now an active speaker (there is also a passive version that is upgradable to active operation without cost penalty). The electronics (active or passive) are housed in a tall, rectangular section cabinet to one side of the speaker, a structural element that also serves to support the mid and bass horns. With the all-new tweeter ‘flown’ from a narrow, vertical panel on the opposite side of the speaker, the structure forms a natural triangle and that leads in turn to a three-point footing, based on a trio of adjustable spikes, two arranged fore and after under the outer edge and the third placed centrally on the inner side.

So far so good: the spikes offer plenty of adjustment, which is just as it should be, given the spherical horns’ sensitivity to listening axis. The tweeter housing is now also adjustable, for the first time making this a tuneable, time-aligned speaker. Getting the Trio G3 perfectly level is a piece of cake. The challenge starts when it comes time to make those critical adjustments to toe-in and rake angle. With the speaker level, toe-in is easy enough, even with an all-up weight of 135kg. It’s when you try to adjust rake angle that suddenly things flip out of control. Drop the front of the speaker to tilt it forward slightly and it also tilts outwards, altering both azimuth and toe-in – and to a surprising degree.