Review

Seismix 7 Complete Review - Audio & Video Lifestyle - Australia

01 Oct 1997

If you think a subwoofer that weighs in at over 50kg and takes up as much space as a large blanket box is a bit over the top for (mere) home theatre, then think again, because the Krix Seismix is designed to accurately reproduce the incredible bass energy of surround sound-tracks, not merely render a pale imitation of it.

To do that you need, among other things, a heavy duty speaker design with high power (absorbing and operating) capabilities. And Krix believes that its Seismix 7 embodies the companies philosophy for subwoofer design and application and speaker building in general. Sound is caused by differences in air pressure and included in the Krix design philosophy is: “To produce bass you need to move lots of air. To move lots of air you need a large radiating area.”

To do this, move a great deal of air, that is, Krix’s principle research and development designer, Mianne Bagger, opted for a 380mm diameter woofer (15 inches in old measurement parlance), powered by an equally impressive amplifier capable of putting out 400 watts or power. RMS power, what’s more.

It’s an understatement to say that low bass sounds are ‘important’ to effective home theatre. Rather, they are ‘vital’ if you want to take part in the scope and power available in modern soundtracks.

The action movie genre was effectively made for bass sounds and movies like, Eraser, Jurassic Park, Outbreak (even The Lion King which is adventure of a sort) fall very short of bass sounds don’t grumble, pump and explode and shake our internal organs just a little.

But it’s not sufficient to simply make bass sounds through a subwoofer, those bass sounds must be high quality as well as abundant, omni-present, and powerful. In other words good low bass for home cinema must have impact and refinement for long lasting enjoyment.

Enter the Seismix 7. A big product both physically and aurally? Yes. Capable of real impact in a home scenario? You bet. But also well mannered and refined? Absolutely.

Krix has managed to do all this by considering the subwoofer’s design right from the start. And right from the start a big bass driver with a big electromagnetic moving system and driven by a big amplifier were the obvious choices.

Multiple driver systems were tried, tested and failed to measure up to Krix’s performance expectations. Sealed enclosures were also eliminated early because distortion was unacceptably high. The result is a large driver in a large bass reflex enclosure with a large portal opening. A combination that provides sensational performance indeed. As Mianne Bagger says, “more of all this would have been better, but Krix had to operate on the field of responsibility and stop somewhere.”

The Seismix 7 is a true stand alone product, producing exceptional bass for hi-fi and home cinema systems without contribution from other speakers. It is self powered, which is a good thing, since it frees the power reserves of the audio-visual processor and amplifier to concentrate on other areas of sound reproduction. It produces high sound levels independently and yet manages to integrated beautifully with other speakers in a music or movie set-up.

Remove the front grille of the Seismix 7 and you’ll see a large diameter paper cone driver, similar to the type normally seen in high level sound reinforcement situations, but in this instance domestic sonic bliss is the aim. Behind this driver is a big magnet and voice coil system that moves the diaphragm with almost deadly linearity and accuracy; accuracy assisted by electronic filtering to make sure the diaphragm stays within safe operating limits.

Krix has established an almost foolproof method of protection for the subwoofer. It’s not what could be called whiz bang in terms of its sophistication, but has been engineered for minimum adverse affects on sound quality while still protecting the speaker beautifully from most forms of intentional and unintentional abuse.

Positioned near the low bass woofer are controls that adjust the various parameters of the Seismix 7, including level (or volume) control. It’s here that Krix has incorporated design elements that make this subwoofer so versatile.

Firstly, there is a control that varies the acoustic output of the Seismix 7 so that it matches the level emanating from other speakers in the system and maintains the right balance across the audio spectrum. Another control varies the point at which the Seismix 7 cuts into the performance of the other speakers in a system and where they crossover to it. This lets you pick the right match between the subwoofer’s acoustic abilities and those of the rest of the speakers. You can even adjust the filter rate where the subwoofer interfaces with the other speakers.

Both crossover and level controls also allow optimum adjustment to cater for the differences found in music and mobile soundtracks, so that the best balance and performance are possible with each performance.

On an equally practical note, these (and other) controls make it possible to match the Seismix 7 subwoofer with home cinema speakers and hi-fi speaker systems. It means that it these often divergent home entertainment situations that performance is always as good as it can get.

There are also some automatic features that are useful, most interesting of these is the Seismix 7’s ability to sense when there’s sound going through it and turn itself on. The Seismix 7 has a very crisp and neutral sound quality, courtesy of an amplifier with super fast circuitry, good quality electronics overall and a driver that’s naturally imbued with a pleasing performance quality.

There’s obviously a healthy dearth of distortion happening with this speaker, because all you hear is low bass, very low bass when it’s there, as the performers and engineer intended it.

This can be a tad distressing, though, because neutrality of this subwoofer exposes myriad wayward effects and sonics which really shouldn’t be there in the first place, but with equipment of this high calibre you must take the good with the bad.

Though the Seismix 7 goes very low indeed into the regions of bass reproduction, it is always delightfully tuneful and brilliantly detailed. And if you think these attributes don’t matter in the bottom, listen and be converted. In essence this speaker is a sensational piece of engineering. It breathes life into home cinema sound and makes real sense out of small satellite speaker systems.

Sure it’s big and it’s also beautiful. And if you have the resources and the room at your place, this could be the ideal subwoofer for you. So if you are in the market for a high performing subwoofer system, do yourself, and your movie and music endeavours a huge favour and check out the Seismix 7.

Rating:

Performance - * * * * ½
Build Quality - * * * * ½
Compatibility - * * * *
Value for Money - * * * * *

- Audio & Video Lifestyle - Australia , Richard Morgan

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