South Australian loudspeaker maker Krix seems to believe that if you go for its Epix in-wall models, ‘epic’ would be the right word. And, indeed, they are right. Stephen Dawson explains.

In-wall loudspeakers inevitably suffer limitations compared with their free-standing counterparts. That many work so well despite their constrained sizes and lack of enclosures is a testament to the skill of modern engineers.

Still, how big a sound can you expect from something that fits into a wall?

Hiding
You won’t have seen many in-wall loudspeakers like the Epix. They’re modelled on the company’s top of the line Neuphonix floorstanding loudspeakers, carrying the same extensive driver complement, organised into a three-way configuration.

That said, there are of course massive differences as well, although fewer than you may think.

So how can an in-wall loudspeaker possibly carry six high fidelity drivers? Krix has been clever. The Epix comes with its own enclosure (or ‘back box’ in the installation lingo), specifically designed to fit in a wall cavity. The enclosure is only 80mm thick, so it ought to fit comfortably in all standard wall cavities (these are usually 90mm thick deep), with a little room left over for any wiring already in there. The box is solidly made: 12mm MDF heavily braced internally, while the front baffle which carries the drivers is 18mm thick. There isn’t much space for significant internal volume, so Krix has blown out the dimensions in width to 390mm and even more so in height to 1,700mm. Again, these should be compatible with most standard constructions.

The result is an internal volume of 34L. That’s only half that provided by the Neuphonix loudspeakers, but must surely be more than provided in just about any installation loudspeaker anywhere.

The bulk of this enclosure will be sitting behind the sheet panelling, so installation involves a bit of room deconstruction and repanelling. That’s the price you pay for high performance loudspeakers that don’t use any floor space.

The front baffle should align reasonably closely with the re-installed Gyprock. A standard cloth grille clips over the front of the baffle, so all that will be left with the finished installation is a 265 by 995mm black cloth rectangle sitting on wall about 400mm above the floor.

You will need to run the speaker cables through your walls of course. The Epix support bi-wiring. They have substantial screwdriver tightened binding posts under a panel in the front baffle, accessible behind the grille. A channel is provided for running the cable up from within the wall cavity.

Treble above 2,500Hz is provided by a 26mm tweeter. Rather than the usual dome, this uses Krix’s preferred dual concentric design, in which there are two toroidally shaped rings in the surface on the tweeter. A phase plug sits at the centre.

This tweeter would typically be at a height of 960 or so millimetres from the floor, depending, of course, entirely on your installation. It can’t be below about 930mm.

Immediately under it is a 130mm midrange driver, covering the frequencies between 340Hz and 2,500Hz. Krix says that this has a 26mm voice coil on an aluminium former for good head conduction, oversized magnet and a copper shorting ring. This last is usually a fail-safe to limit cone excursion in the case of it being over-driven.

Both above and below this midrange/tweeter set is a pair of woofers, totalling four for each Epix. These also are 130mm units, again with 26mm voice coils and aluminium formers. No mention of oversized magnets or shorting rings with these ones.

There are three internal enclosures: the central one sealing off the midrange and tweeter from the larger drivers and upper and lower ones for each pair of woofers. There is a fairly shallow front-facing bass reflex port for each of these two. Insofar as I could see and feel through the two ports, there did not appear to be internal padding, which was a bit surprising. Padding is often used to mimic the effects of a larger enclosure.

You should choose your electronics with reasonable care. The impedance of these loudspeakers is rated at 4Ω, which a lot of modern home theatre receivers are not comfortable with. Krix rates their sensitivity at 90dB and says they are suitable for use with amplifiers offering up to 200W of power into 4Ω.

You can purchase smaller installation loudspeakers from Krix to fill out the other positions in the surround system. Krix prices all these on a per unit rather than per pair, presumably because some high-end installations may involve the use of five or even seven of these speakers.
Sound
I must confess at the outset that my commitment to my reviewing task was insufficient for me to cut large holes in my walls. Instead I merely strapped a pair of them vertically against the wall, so the acoustic results are going to be a little different to having the faces of the drivers immediately in line with a large flat surface. Also, my wall is faced with acoustically absorbent material – again a likely difference from many installations.

But that’s the thing with installed rather than freestanding loudspeakers: your options will be relatively limited. Their positions will be determined in part at least by the locations of your wall studs, and where other furniture may be placed. So you can’t wiggle them around to optimise bass performance, or to increase a sense of air that they might deliver. You can’t toe them in or out to adjust stereo imaging or brightness. If you want to change the sound, you will have to do so electronically.

So, once semi-installed, I listened extensively in two modes. First, with my receiver (a high end one from Pioneer that is perfectly happy with 4Ω loads) set to ‘Pure Direct’, and then with the EQ calculated by the receiver.

In both modes these loudspeakers proved to be exceptionally clear and clean performers. Their distortion levels were so low I initially thought that Krix may have been a little optimistic in specifying their higher-than-average sensitivity figure. But my sense that the volume wasn’t as high as expected was because undistorted sound doesn’t sound as loud. It is smoother and easier on the ear and thus subjectively less loud. I ran a lot of music through these at extremely high levels.

The sound was unusual, entirely due to the against-the-wall location. It simply isn’t what I am used to, with my loudspeakers normally sitting just about a metre forward of the wall.

This changed the sense of stereo imaging, diffusing it somewhat, making the music instruments seem less clearly focussed. Again, though, that is an artefact of in-wall/against-wall placement. Another price you pay for eliminating loudspeaker footprints.

That’s not to say it was unpleasant, just unconventional, with the diffuse effect even improving certain elements of the sound. The animal noises, for example, in Pink Floyds’ Animals were at times startlingly realistic in both tone and presence.

Also on the positive side, the imaging and sound balance stayed remarkably even throughout the room, rather than being maximised in a tightly constrained area as tends to be demanded by conventional loudspeakers, conventionally placed.

The sound was bright and detailed and revealing in Pure Direct mode, but a touch light on the bass. Again, your room will have a lot to say about how that works for you. With the EQ operating, that slight thinness was eliminated and the excellent power handling capacity of the speakers, combined with their high output, meant that the boosted bass levels didn’t challenge them in the slightest.

Because you don’t have the option to tweak the sound by moving the speakers, purchasers would be wise to couple them with home theatre receivers fitted with high quality EQ capabilities. Since you will want one supporting four ohm loudspeakers anyway, that’s almost a given.

With the bass levels set properly, there was still a slight absence in the deeper content. They did a reasonable job on kick drums (around 41Hz), but that was pretty much the limit. I’d suggest the use of a high quality subwoofer, and have it carry the load below 40 or 50Hz.

Conclusion
If you want in-wall loudspeakers, you’re going to have a very hard time indeed finding something capable of doing a better job than the Krix Epix. Just be prepared to do some wall re-finishing after installation.