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This model from Krix will most likely im­prove the sound of your home the­atre speaker sys­tem, no mat­ter what brand it is…

Want to know a dirty se­cret about multi-chan­nel home the­atre speaker sys­tems? It’s that most of them are us­ing the wrong cen­tre-chan­nel speaker: one that’s not a tonal match with the front-left and front-right loud­speak­ers.

Let’s look at what’s re­quired in a cen­tre-chan­nel speaker. In an ideal world, that speaker would be a per­fect acous­tic match for your main front left and right speakers. That is, it must be not only be made by the same man­u­fac­turer, but should also use ex­actly the same driv­ers as your main front speakers. And for best ef­fect, it should ac­tu­ally have at least one ad­di­tional driver, mean­ing that if your main speakers each have a bass/midrange driver and a tweeter, your cen­tre-chan­nel should have two bass/midrange driv­ers and a tweeter. If each of your main front-chan­nel speakers has two bass/midrange driv­ers and a tweeter, your cen­tre chan­nel should have four bass/midrange driv­ers and a tweeter.

Why are so many driv­ers re­quired in a cen­tre-chan­nel speaker? It’s all about tonal quality, fre­quency re­sponse and sound-stag­ing.

Think about an or­di­nary stereo sys­tem. You wouldn’t dream of us­ing a three-way floor­stander as your left-chan­nel speaker and a small two-way bookshelf as your right speaker, would you? You wouldn’t do it even if they were made by the same man­u­fac­turer.

Yet if you look at the cen­tre-chan­nel speaker that’s of­fered with most home the­atre sys­tems, ei­ther in­cluded in a pack­age, or avail­able as an op­tion, you’ll most of­ten see that the front-left and front-right chan­nel speakers are completely dif­fer­ent from the cen­tre-chan­nel. The left and right-chan­nel speakers will usu­ally have more driv­ers, and of­ten larger ones than the cen­tre-chan­nel.

Does this mat­ter? You bet it does!

In a stereo sys­tem, sounds that ‘ap­pear’ to come from ex­actly mid­way be­tween the left and right speakers are cre­ated by those speakers… ex­actly what the stereo il­lu­sion is all about. The bet­ter the left and right speakers are matched, the bet­ter the il­lu­sion that the sound is com­ing from an imag­i­nary point mid­way be­tween them. And be­cause both speakers are matched, the tonal char­ac­ter of the sound com­ing from mid­way be­tween the speakers will be the same as that com­ing from ei­ther the left or the right speaker alone.

How­ever, in a home the­atre speaker sys­tem, sounds that come from mid­way be­tween the left and chan­nel speakers come not from the front left and right speakers, but from the cen­tre-chan­nel speaker. So if the cen­tre-chan­nel speaker is not iden­ti­cal to the left- and right-chan­nel speakers, the tonal char­ac­ter of the cen­tre-chan­nel’s sound will be dif­fer­ent.

Let’s look at an ex­treme ex­am­ple. Imag­ine a sys­tem where the front-left and fron­tright chan­nel speakers are large, three-way

floor-standing mod­els with ex­cel­lent bass re­sponse and the cen­tre-chan­nel speaker is the size of a match­box, with no bass re­sponse at all. You’re watch­ing a movie in which the lead ac­tor is a male, and he’s standing at the left of the screen. As he speaks his lines, his deep, bari­tone voice will be re­pro­duced by the left speaker. If his image moves across the screen un­til he’s po­si­tioned at the far right, his deep bari­tone voice will now be re­pro­duced by the right speaker with ex­actly the same depth and clar­ity as it was by the left speaker. But now our hero walks to cen­tre stage and, as he speaks, we hear not a deep bari­tone voice but a pip-squeaky sound be­cause the match­box-sized cen­tre-chan­nel speaker just can’t han­dle the ac­tor’s voice.

So you can see why the cen­tre-chan­nel speaker should be iden­ti­cal to your left and right speakers. How­ever, it’s ac­tu­ally prefer­able if the cen­tre chan­nel speaker has more bass/midrange driv­ers be­cause in a home the­atre sys­tem the cen­tre-chan­nel is do­ing al­most all the work when im­ages are cen­tred… which they are most of the time. So whereas in a nor­mal two-chan­nel sys­tem you have two loud­speak­ers com­bin­ing to pro­duce a cen­tral image, in a home the­atre sys­tem, the cen­tre-chan­nel has to do it all on its own. In fact, in most home the­atre sys­tems the cen­tre-chan­nel speaker de­liv­ers more than 50 per cent of the movie sound track and the ma­jor­ity of the movie’s di­a­logue.

So why don’t man­u­fac­tur­ers of­fer cor­rectly-matched cen­tre-chan­nel speakers?

In smaller home the­atre sys­tems from rep­utable man­u­fac­tur­ers you’ll find they of­ten do. The front-left and front-right speakers will have sin­gle bass/midrange driver and a tweeter, and the cen­tre will have two iden­ti­cally-sized bass/midrange driv­ers and a tweeter. You do have to look care­fully at driver size, be­cause some man­u­fac­tur­ers still use slightly smaller bass/midrange driv­ers in their so-called ‘match­ing’ cen­tre-chan­nel speakers.

How­ever once the left and right chan­nel speakers be­come larger, al­most all man­u­fac­tur­ers cut back on the size of the cen­tre-chan­nel cab­i­net, the num­ber of driv­ers in it, and the size of those driv­ers. Why? Be­cause they know that con­sumers who are given the choice be­tween a sys­tem with a small cen­tre-chan­nel speaker and one with a proper-sized cen­tre-chan­nel speaker will mostly opt for the one with the smaller speaker cab­i­net… and most es­pe­cially if they’re buy­ing with their eyes in­stead of their ears.

All of which is a re­ally, re­ally long ex­pla­na­tion as to why Krix’s Epi­cen­trix Mk2 cen­tre-chan­nel speaker is so large, as well as why it costs $2,495. It’s de­signed to be a per­fect sonic match with Krix’s Ne­u­phonix Mk2 stereo loud­speak­ers.


As you can see, the front panel of the Epi­cen­trix Mk2 has lots of driv­ers—six to be pre­cise. Four of them are ded­i­cated solely to bass re­pro­duc­tion, each one of these be­ing 130mm in di­am­e­ter, with a 26mm voice-coil wound on an alu­minium for­mer. Four driv­ers means in­creased ca­pac­ity to de­liver bass, thanks to a greater cone sur­face area, but it also means four voice-coils to dis­si­pate heat and thus an in­creased power-han­dling ca­pa­bil­ity. Also, be­cause us­ing four driv­ers means each one has lower cone ex­cur­sion, they can move in the most lin­ear part of their oper­at­ing range, where dis­tor­tion is least.

The four bass driv­ers cross to a sin­gle midrange driver, which is phys­i­cally and elec­tri­cally ex­actly the same de­sign as the bass driv­ers, so tonal co­he­sion across the cross­over point is per­fect, as is the sonic tran­si­tion from the bass to the midrange.

The tweeter is a 25mm dual-con­cen­tric di­aphragm model with a neodymium mo­tor sys­tem, a non-res­o­nant alu­minium rear cham­ber and a patented phase-plug.

So far as the cross­over net­work is con­cerned, the Epi­cen­trix Mk2 is a true three­way de­sign, us­ing a hard-wired and hand-sol­dered cross­over net­work with com­po­nents that in­clude air-cored cross-mounted in­duc­tors, Krix-branded MKP ca­pac­i­tors and high-power cer­met re­sis­tors that de­liver nom­i­nal cross­over points at 300Hz and 2.5kHz. The midrange driver op­er­ates from its own sealed en­clo­sure while the bass driv­ers op­er­ate in a bass re­flex en­vi­ron­ment, with dual sym­met­ri­cally-po­si­tioned re­flex ports.

The cab­i­net of the Epi­cen­trix Mk2 is 233mm high, 910mm wide and 370mm deep and is avail­able in Black Ash, At­lantic Jar­rah, Wal­nut, Black­wood and Cola ve­neer fin­ishes.


In­stalled in a 5.1-chan­nel home the­atre sys­tem com­prised ex­clu­sively of Krix loud­speak­ers, in­clud­ing the Ne­u­phonix Mk2s as frontleft and front-right speakers, I was completely floored by the front-chan­nel sound: and not just by its out-and-out quality, but also by the seam­less way sounds shifted across the front sound-stage. So seam­less that I never had a sense of there be­ing a tran­si­tion at all: im­ages were just pre­cisely placed, and that was that.

The fact that the sound also moved so seam­lessly right across the width of the room from ex­treme left to ex­treme right, with­out chang­ing tonal quality as it shifted was re­mark­able enough, but what was even more re­mark­able was the performance of the Epi­cen­trix Mk2 when it was de­liv­er­ing its sound al­most so­lus, par­tic­u­larly the silkys­mooth highs which have the kind of ‘air’ around the high-fre­quen­cies that you usu­ally hear only from high-end stereo hi-fi speakers. But good though the tre­ble sound was, the midrange was at the same high performance level, a level that’s es­sen­tial for the cor­rect re­pro­duc­tion not only of singing, but also of the spo­ken voice… not least be­cause when watch­ing movies, af­ter the im­ages them­selves, the di­a­logue is the most im­por­tant part of the movie, and it’s es­sen­tial that you hear ev­ery word clearly.

With ev­ery movie I watched, whether it was an old black-and-white movie, rich with di­a­logue ( Rais­ing Baby) or a more mod­ern fare, where back­ground sounds and ef­fects are con­stantly threat­en­ing to ob­scure the di­a­logue ( The Fifth El­e­ment), the di­a­logue was beau­ti­fully ar­tic­u­late and crys­tal-clear. Our fam­ily movie nights, which are no­to­ri­ous for my mother-in-law, who’s hard of hear­ing, con­stantly ask­ing ‘ what did he say?’ dur­ing our movies sud­denly be­came much qui­eter af­fairs… though we still did get the oc­ca­sional query from her.

So why don’t man­u­fac­tur­ers of­fer cor­rectly-matched cen­tre-chan­nel speakers?

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