Heco Celan Revolution Sub 32A Sub Woofer

Finding a subwoofer that can be integrate into a true hi-fi system is always a challenge. Sadly the mass market demands something that is either too small to offer an expansive dynamic range or too uncouth to work musically, so we’re excited to report that this Heco model offers exactly what we have been looking for.

At the time of writing we have not done a deep dive into the innards and taken measurements, but the ingredients go a long way to explaining the results. A 12” front facing paper drive unit is a great start, allowing lower distortion than a smaller cone without being too large that it subjectively sounds slow. The hefty and heavily braced cabinet is another great sign, and it sounds reassuringly dead when rapped with the knuckles. The large cabinet litreage may not go down so well with those tight for space, but it’s a necessary evil for good results where sub woofers are concerned, and the stylish shape makes them a nice feature rather than an eyesore (and the shape even lends itself to stacking multiples on top, should the ‘need’ ever arise!).

Inside it appears that there’s a linear powers supply, a powerful 300 watt class D amplifier along with analogue adjustment of level and frequency (i.e. no DSP). The latter bodes well for sound quality, but does point to the one omission that some might have a problem with - no remote control, but after the initial run in and setup has been performed there really shouldn’t be any need to touch it.

On the rear are three large ports which will help to keep the sound of any turbulence to a minimum, the controls for frequency, phase and volume are on the rear panel along with the all important high level inputs (in my opinion the only way to correctly integrate a subwoofer into a hi-fi system).

Onto the sound, even when using only one sub woofer (a pair is always the ideal), the results are already very good. The bass is very well extended, it’s tuneful, fast and dynamic yet delicate when required. There is also no intrusion into the upper registers if you don’t want their to be, the crossover filter allowing sharp roll off along with the rigid cabinet means that there’s no obvious audible intrusion into the frequency range covered by your main speakers, whether they are wide or narrow bandwidth designs.

To mangle a saying into a metaphor, a sub woofer, unlike children, should be seen but not heard. When set appropriately, the old trick of really hearing what it’s doing by turning it off has never been truer, the addition can and should be subtle and seamless when set correctly, but certainly missed when not running.

The benefit of very well extended low frequencies are well documented, they can better portray the space of a massive recording venue, restore the fundamentals to notes that previously were only audible by their harmonics (and therefore ‘correct’ them tonally) and add an element of composure, scale and even menace when the recording requires it.

Product specifications:

Amplifier Class: D
Frequency Response: 18 - 150 Hz
Low-Range Driver: 15" Woofer
Enclosure Type: Bass Reflex
Speaker Inputs: Bi-Wirable Binding Posts
Subwoofer Inputs: Dual RCA, LFE Line In
Enclosure Material: MDF
Dimensions (W X H X D): 400 x 610 x 535 mm
Weight: 27.1 kg