Home -> Magazines -> Issues -> Articles in this issue -> View
Auratone T6 Monitors | |
Article from Home & Studio Recording, October 1984 |
Auratone describe these monitors as 'sub-compact', but placed in perspective beside the other speakers we've reviewed, they're of average size, a little larger than the Celestion SL6 and a little smaller than the EV Sentry 100A. But perhaps there's another side to this description?
The physical characteristics of the T6 are shared with other monitors we've looked at: there's nothing spectacular to delve into, so I'll take you on a crash revision course to remind you just what each star feature should mean in practice.
To begin, the 6½" bass/mid driver has a polypropylene cone, like the Roger's Studio 1, say. If you recall, this spells low weight coupled with stiffness, to counter break-up, colouration and distortion. This material was first suggested by Dudley Harwood at the BBC, incidentally. Unlike paper (pulp) cones, polypropylene ones aren't affected by humid environments, which is handy to any of our readers sweating away in tropical climes.
The tweeter's a dome type (the shape of the diaphragm's inverted from a cone to a dome, to prevent diffraction and aid dispersion), with ferrofluid around the voice coil. This juice is highly conductive, both magnetically and thermally, and it's main advantages are (i) to put more magnetic power in the gap, and (ii), to conduct away heat energy better than air alone would. Overall, this spells high efficiency on account of the excellent magnetic coupling, and high PHC, owing to the improved cooling. Thus the unpleasant effects of thermal compression can be warded off, and the tweeter is less likely to come to grief if it's thrashed too hard.
The T6s have a programme power rating of 80 watts (ie. for music), but as we've come to expect, amplifiers of 150 watts or more are quite legit provided they're not overdriven or the cone doesn't bang against the magnet on low bass notes.
But what of the anechoic frequency response, quoted at 60 to 20kHz, +/-3dB? To get a common reference for all speaker measurements, we use a completely dead (non-reverberant) room, namely an anechoic chamber.
Now although anechoic rooms are totally out of order for listening to music in, the chamber is used because the frequency response performance we measure in there correlates quite well with what our ears perceive, even though we always listen in a reverberant space. This is because when we listen in the nearfield (close to the speakers), the sound waves which don't reverberate are inevitably the ones coming to our ears by the most direct path, therefore we hear them first. And this direct sound is perceived as dominant, even when it's closely followed by delayed reflections, thanks to the mind's holistic computing ability. But a frequency response measuring set-up can't usually distinguish between the direct wavefront and an equally large echo arriving 3 milliseconds later.
To use jargon, we could say that all frequency response curves are static, and belie events in the time domain. Hence the need for a non-reverberant space for meaningful frequency response measurements: in effect, we take our measurements in a room where the lack of time dimension doesn't obscure the salient data.
Back to the drive units: the mid/bass unit is Thiele-loaded and has a long throw cone. Suspended on a compliant rubber surround, it can move the considerable distances necessary to generate audible SPLs below 100Hz with a 6½" cone. As a broad comparison, it offers the same sort of bass response as a typical 12" driver with one third of the cone excursion capability.
For the tweeter, Auratone emphasise "Massive magnet structure", but excessive magnet size trades off bandwidth for efficiency and damping, so there's an optimum size, as is usual, and no sense in going to extremes. What Auratone probably intended to say was, "Most tweeter magnets are smaller than they need be, to save on costs, but ours isn't compromised in that fashion". It's also fair to point out that with ferrofluid helping to channel BH product (Magnetic lines) into the gap, a powerful magnet won't be wasted. Wide dispersion is also claimed, but for any direct-radiating driver, dispersion is primarily down to the cone's area and geometry. The T6 tweeter is a 1"/25mm dome like most others, and it's dispersion pattern isn't much at variance with its competitors. The packaging is similarly unexceptional: the enclosure on the sample model was high-density chipboard veneered in walnut, but a black finish is also available. Auratone's only innovative contribution on the constructional score is to incline the binding posts on the rear panel at 45°. This makes wiring up much easier when you come to thread bare wires into the terminals.
The crossover is PCB-mounted and comes up to the high standards enjoyed by many of the other enclosures we've looked at. All the inductors are air-cored, so there's no worry about saturating magnetic materials at high levels, and there's one special feature: electrolytic capacitors are eschewed for the sake of plastic film types - polyester in this instance. These types come with tighter tolerances, which helps the manufacturer produce accurately matched stereo pairs.
Although it's nice to see signs of innovative design in a new speaker, the absence of any new or special features needn't be taken as being negative in any sense. Why? Well, because speaker performance in real life only correlates approximately with abstracted physical facets. In other words, we can't predict at all accurately how good a speaker will sound on the basis of its individual physical and mechanical features alone.
And there's another angle to this: the T6 is unexceptional to our eyes, because it's a leaf straight from the book of UK Hi-Fi speaker philosophy. Meanwhile, in the States, many of the Auratone's features are 'new' in that they're at variance to US pro-audio practice, where, for example, pulp cones are still favoured, and plastics like polypropylene have yet to catch on in a big way.
In a nutshell, the point about the T6s is that their sound performance exceeds one's expectations. The sound is definitely on the bright side, but not unduly so, in a sense that overemphasises any particular aspect of the top end. Thus the snare and cymbal harmonics are sharp and very 'crisp' without being tizzy or overly 'bitey', and the effect overall is one of clarity and intimacy with the instruments. This is all kudos for sussing out fine details above 3kHz, but can lead to dull mixes, so some form of shelving EQ might be well advised to take down the top end as a whole, when assessing mixdown balance.
In the midrange, the mid/bass driver is capable of the sharp and incisive sound of a top class horn-loaded unit, eg. Turbosound, but there's inevitably more distortion and the high mid is definitely a shade 'forward'.
In essence, we have a largish magnet and well designed Thiele ducting contributing excellent damping. At the same time, the driver also has to handle low bass with correspondingly massive cone displacements, which leads to intermodulation effects. Here, high amplitude LF (bass) movements corrupt the much smaller midrange vibrations, giving rise to the spurious overtones we call intermodulation distortion.
The bass end comes across as one of the most successful I've heard in a small and relatively untreated room from an enclosure of this size, and is on a par with the EV Sentry 100A in some respects - for its funkiness, say. The T6 trades off a little of the detail you'd get from this model, or a Celestion SL6 say, offering a lower roll-off and more bottom-end PHC in exchange, almost to the extent that you'd swear there was a subwoofer hidden away somewhere!
Often, a healthy LF response will serve only to aggravate standing wave patterns in small rooms, leading to bass that's deep, yet muddy or boomy. This is certainly a possibility if the T6s are placed too close to the walls but failing this, is less of a problem than usual, because the Thiele response has evidently been tuned for optimum listening in the nearfield and in small spaces, up to 6 or 8 feet distant, say.
The T6's sensitivity is average, at 88dB SPL, but as you'd expect, the brightness of the top end, and the forward high mid coupled with the depth of the low bass lends an impression of considerably higher sensitivity and real 'Barlocks' (to be said in a cool Californian drawl, of course!). The T6s are loud in other words, yet they manage to achieve this without upsetting sensitive ears, unlike certain US speakers.
At high levels, it's not at all easy to bottom the cones on low notes (cf. many of the more delicate Hi-Fi models), and while the mid becomes distorted (on account of inevitable intermodulation effects), the top response remains unfettered well past the point where many tweeters begin to compress thermally.
Finally, we come to the coup de theatre: the stereo imaging is very much in the SL6 league. The sound stage is very powerful, so we can place the T6s near to our listening positon while keeping them spaced mutually well apart, broadening the stage without breaking it up. The result is an unusually spacious image which bears little relation to the room dimensions, with well defined and tightly focused height, depth and breadth. The Auratones don't place the image upfront or behind you like the Celestion SL6 or more exotic speakers: it's more passive and distant, but nonetheless it's equally vital, and perhaps ultimately more detailed.
To make up your own mind as to which qualities are ultimately the most valuable, the Auratone T6s should be auditioned beside their nearest rivals, like the SL6 and Sentry 100A.
Retail price/pair (inc. VAT) £263.35
Further details from UK importers: Turnkey, (Contact Details).
Review by Ben Duncan
Previous article in this issue:
Next article in this issue:
mu:zines is the result of thousands of hours of effort, and will require many thousands more going forward to reach our goals of getting all this content online.
If you value this resource, you can support this project - it really helps!
New issues that have been donated or scanned for us this month.
All donations and support are gratefully appreciated - thank you.
Do you have any of these magazine issues?
If so, and you can donate, lend or scan them to help complete our archive, please get in touch via the Contribute page - thanks!