Review

Symphonix Complete Review - Australian Hi-Fi - Australia

01 Dec 2002

When you buy a four-wheel drive vehicle, you expect that at some stage in its development, the manufacturer will have actually taken the vehicle off-road to see how it performs. So you might be surprised to learn that some speaker designs have never been tried out in a lounge room at all!

Instead, the designers have relied on data from anechoic chambers and specially constructed sound rooms. Valid stuff, but not terribly realistic. So you’ll be pleased to hear that the Symphonix were developed in a ‘real’ lounge-room complete with sofas, coffee table and curtains, purpose-built along-side Krix’s very well equipped research and development laboratory in its factory in Hackham, South Australia. Not that’s what you call ‘real-world’ design.

The Equipment

The first requirement for a real-world loudspeaker design is that it should be very room-friendly and the Symphonix cabinet is certainly that, standing just over a metre high (1045mm) with a very narrow (240mm) front profile. What it lacks in height and width however, it more than makes up in depth, because the cabinet is 305mm deep.

As you can probably tell from the product shot accompanying this review, the Symphonix are very easy on the eyes. Krix’s new top and bottom plinths, with their curved front edges, make the otherwise mostly rectangular cabinets look remarkably ‘unboxy’. Like almost all Krix speakers, the cabinets are finished in real timber, with a choice of veneers. It’s interesting how many speakers these days – even very high-priced ones – do not have real wood veneers, but instead are covered with vinyl wrap.

However, if you plan on owning your speakers for a long time, what the cabinets are finished with is not just ‘interesting’ it’s of crucial importance, because whereas a good timber will tend to improve with age – particularly if you take care of it – a vinyl wrap will only deteriorate as it gets older, first beginning to fade and finally to peel (especially if its bumped or nicked). Although I can appreciate that the world’s wood resources are dwindling, I think loudspeakers have a sufficiently long life (upwards of 20-30 years or more) that choosing a real wood veneer over vinyl wrap makes good sense (aesthetically and economically), even if it means paying a premium. In the event you decide to change speakers, a pair of speakers with a real wood veneer will always fetch a higher price than a pair wrapped in vinyl.

The other requirement for a real-world design is that it should be easy to drive, and with a nominal four-ohm impedance and a sensitivity of 92dBSPL at one metre (for 2.83V), the Symphonix are certainly that.

The driver layout is a classic D’Appolito (after famous US speaker designer Joseph D’Appolito) with a single tweeter positioned exactly midway between a pair of bass / midrange drivers to give perfect ‘point source’ (because the path lengths from the drivers are equal) imaging. Krix is using a 26mm fabric dome tweeter that’s quite seriously horn-loaded by its front plate. This helps efficiency (as does the ferrofluid cooling in the magnetic gap) but it also affords mechanical protection, because the fragile dome is tucked quite a distance down the horn throat. The horn does, however, limit extreme off-axis listening positions a little (not that you’d want to sit that far off-axis anyway!).

Krix is obviously aware of the problem of the ‘foam rot’ that eats away roll surrounds made from foam, because the two bass / midrange drivers in the Symphonix have rubber roll surrounds. The cones are made from coated paper. Coated paper is an excellent choice for a cone material, because paper has the lowest mass of any material used for cones, yet is also very strong. Its only real failing is that it’s hygroscopic (tends to absorb water), a failing Krix addresses by coating the cone with an impervious material. The 134mm diameter cone (the Thiele / Small measurement) is driven by a coil wound on an aluminium former, powered by a substantial magnet assembly that’s supported by a fibre-reinforced polymer basket.

The cabinet is constructed entirely from 19mm MDF except for the top and base (25mm) and is a bass reflex design, ported to the rear of the enclosure. The port comes with a foam insert that’s supposed to ‘fine-tune’ the bass response below 50Hz. In fact, inserting the foam plug effectively converts the enclosure from a bass-reflex type to an infinite baffle. The bottom of the enclosure can be filled with kiln-dried sand or lead shot to improve the stability of the cabinet (by lowering the centre of gravity). It’s worth doing this not just for the increase in stability but also because you’ll find the bass response improves slightly as a result.

Listening Sessions

It didn’t take me more than a few moments to discover I far preferred the sound of the Symphonix in their bass reflex incarnation, though I can see how some listeners might prefer the taut ‘drier’ sound the bass takes on when the vent is stopped. It’s certainly worth taking the time to experiment with the plug even while you’re in the showroom. If you can find some mono material, or use an amplifier that can be switched to mono, a very efficient method of comparison is to play music in mono, put the speakers side by side directly in front of you, one with the plug in and the other with it out, then use the balance control to listen first to one speaker, then to the other.

As I said, I preferred the bass reflex sound, which seemed to go deeper, with a bit more authority, but I’ll admit at the cost of some accuracy – the sound seemed to be a bit ‘looser’ and the tonal quality not so evenly balanced over the bottom octaves – though truth be told, I could discern this only when listening to single notes played on a piano keyboard. Once a whole band fired up, or an orchestra, the subtle tonal differences all but vanished. But this is not to discount the sound with the port closed off. That ‘looseness’ disappeared, and sound tightened appreciably, such that electric bass, for example, took on a much more strained sound. The tone was restored to perfect consistency over the bottom octaves, with beautiful reproduction of a recording of single notes played on a Yamaha C3 grand. The only other down-side of the sealed box was the volume of the very low bass, which was quieter than with the vent open. However, whichever way you like your bass, the Krix provides it in just the right proportion – not too much, not too little, no matter whether the port is plugged or not.

The bass / midrange drivers transfer seamlessly across to the tweeter, so you’ll be unaware of any change in tonal quality, which is excellent design. And, since I am speaking of the midrange, I can report it was very clear-sounding, reproducing vocals very accurately. Female vocalists were very sympathetically treated, particularly in the upper regions of their range. Janis Joplin would be well-pleased with the way the Symphonix handled her voice, delivering that rough, raspy quality beautifully, but just dulling the edge from her tendency to screechiness. Cleo Laine, whose voice is like honey, didn’t need the Symphonix to do her any favours at all, would nonetheless love the slight bloom that enhances her lowest register.

When replaying instruments the midrange sound assumed a slight ‘fullness’ that was highly pleasing to the ear, if not perhaps entirely accurate. This quality of fullness also gave a very realistic ambience to the sound that was particularly useful in terms of enhancing the art of solo instrumentalists in small ensembles. The extreme treble was beautifully fluid, smooth and soft. If you’re one of the many who complain modern tweeters have become too brittle and scratchy, you’re going to love the Symphonix’s treble.

Stereo imaging was another stand-out area of performance, with these Krix speakers giving a very real impression not only left / right across the stage, but also of stage depth and image height.

Conclusion

Although I’m not a betting man, I am prepared to bet serious money that Krix’s new Symphonix will become the best-selling speakers in the company’s range – and if they don’t they certainly deserve to. They’ve got the looks, the sound quality and the performance…and most importantly, the price is right!

- Australian HiFi - Australia , Chris Croft

Back to previous page