The idea that a wood plinth of some sort should be placed under a loudspeaker is not surprising or novel. Many speaker companies integrate plinths into their designs. Indeed, the Audiopax Ref100 in for review does precisely that. The Japanese prefer to place all their components on wood floors to then tune them accordingly, finding the sound of wood significantly preferable to the materials that most high end racks are made of. When it comes to speakers, the Japanese have long favored placing them on reasonably large wooden boards in order to produce sympathetic resonances. This is true whether the speakers are then placed on carpet, concrete or preferably wood. The worst surface for a speaker may well be artificial fiber carpets that just soak up sound.

(As an aside, the ideal listening surface is said to have your speakers on an elevated wood platform before you follow up with a rug or carpet of any sort, then for that rug or carpet to be made entirely of natural fabric. Big rooms should have a mid-sized area rug of natural fibers at most while smaller rooms should be adjusted accordingly). Many speaker designers and room tuners agree that some sort of wood underneath a speaker makes sense so I was not surprised by ERaudio's recommendation.

The questions that remained was what changes in sound and musical presentation I was supposed to expect from the Space Harmonizers in place, and whether in fact I was going to experience them at all. Answering these questions proved a bit more difficult than I had expected and for a pretty simple set of reasons. Siberian cedar turns out to be a relatively soft wood. It scratches very easily. In addition, the company recommends removing the feet or spikes supplied with your speakers from the speakers and then placing the speaker directly on the Harmonizer. The idea is that the Harmonizer/steel cone combination will substitute for the speaker designer's coupling/decoupling approach.

I don't like that since in the very best designs, the speaker designer has already voiced the speaker in a way that includes his approach to coupling/decoupling. This isn't always the case but now, more often than ever. For example, I know for a fact that John DeVore has spent considerable time listening to various cones and cone materials before settling on the ones that come with his Silverback Reference speaker. The rake of the speaker is extremely important to its ultimate presentation and that is accomplished through adjustments of the cones he provides. All this gets thrown out the window once you remove the feet or cones supplied with a speaker. I just wouldn't do it. There is no doubt doing so will change the sound of the speaker but I prefer to begin with the formula the designer had in mind and then make adjustments from there.

Next, this approach simply will not work for some horn-loaded speakers like the Hørning Hybrids whose horn vents at the bottom of the speaker. Such speakers require the clearance their feet provide to enjoy the required slot-loading with the floor that's intrinsic to their design. Interestingly, the sound of these speakers is affected tremendously by the choice of feet/cones and other coupling devices but you simply cannot eliminate the clearance required for the horn to work properly.

And again, many modern loudspeakers are just too heavy for the Space Harmonizer. Even if the wood could support them without cracking or breaking, the effect on tuning for any piece of wood will always be a function of optimal weight applied. This is true for all resonance control or tuning devices. So the number of speakers with which you could sensibly follow the ERaudio approach to the letter is limited. With what I had on hand, I could use the platforms only under the DeVore Gibbon 8 towers and the Combak Bravo stand-mount loudspeakers. In the case of both the Bravos and the Gibbon 8, I tried the Space Harmonizer as ERaudio recommends and with the use of supplied spikes (Gibbon 8) or other tuning feet (Bravo).

The good folks at ERaudio supplied me with four Space Harmonizers, two of the larger-sized platforms and two of the smaller ones. With the Devores, I could only use the larger ones. I tried both kinds on the Bravo. In addition, I tried both on a variety of very high end electronics from Combak/Reimyo and Shindo and CD players from Combak/Reimyo, Accustic Arts and Exemplar Audio. I did not have an opportunity to employ the platforms on a range of mid-priced or lower cost electronics.

Sonically, I can report the following. With the equipment I had on hand, the effect on sound was always subtle, marginal but basically positive. The changes invariably went in the same direction. The largest effect was on tonality. The sound warmed up a bit. The greatest impact was in the midbass. The second greatest impact was on image size, which expanded; and height, which increased especially with speakers. The platforms did not work favorably under either the Bravo speaker or the DeVore without other forms of tuning. The DeVore required its spikes to produce optimal rake. Once set up that way, the DeVore could be placed on the Harmonizer, then rake adjusted a second time. I did this with John DeVore present. Soundstage height increased and midbass warmth was enhanced. We moved the speaker around the room to compensate for room effects looking for an optimal location. The sound was very seductive and easy on the ears but the increased midbass warmth in this context gave an impression of shelving down and darkening the top end just a bit. Both of us preferred the sound without the Harmonizer.

The Bravo already is a tuned loudspeaker being the brainchild of Kiuchi-san, master of sound shaping and tuning. Placing either platform under the Bravos without other tuning feet had the effect of making the speaker too warm and its soundstage somewhat unfocused. The sound improved dramatically when I placed some of Kiuchi's tuning feet between the speaker and the Harmonizer, and I preferred this combination to the speaker without additional tuning. When it came to the electronics, my results were much the same. When placed under the Reimyo products, the Harmonizers required additional decoupling via Harmonix tuning feet to sound their best. Otherwise, the sound was larger than life and a bit unfocused and too warm for my taste. With the combination of tuning feet and Harmonizer, the sound was especially seductive and large, the soundstage deepened and the music had a denser bearing. I quite liked it.

I brought the Harmonizers to Connecticut and placed them under my reference Shindo electronics which were already in the Harmonic Resolutions Systems rack. That rack brings unwanted vibrations pretty much back to ground zero and is a perfect foundation from which experiment with additional tuning or sound shaping devices. In this environment, I found the platforms to work as advertised. They increased space and air, deepened the soundstage and warmed up the sound. This was impressive in its impact but a blunter, more indiscriminate instrument for sound shaping than a bag full of feet, cones and pucks.

I replaced my HRS M-3 bases under my amps on the floor with Space Harmonizers. My suspended floor is like a Tympani drum which I am hoping to control sufficiently so that it reacts more like a Bongo drum. (I am grateful to fellow moonie Jim Bosha for this analogy.) Relative to the HRS, the Space Harmonizer produced a livelier but significantly less controlled sound. No number of cones worked adequately to keep the vibrations from returning to the amplifier and thus to the musical chain where they did absolutely no good.

The Harmonizer had its advertised effect on two of the three CD players I used it with. It had no noticeable impact on the Reimyo. It was a wonderful addition to CD playback with the Accustic Arts. With a basic power cord, the Accustic Arts player is nicely detailed and easy to listen to. On the other hand, it sounds like CD playback. In other words, you cannot help but sense that it is somewhat processed. Placing the Accustic Arts on a smaller Space Harmonizer led to a more natural and life-like presentation. This was a wonderful match and led me to think that like most sound shaping tools, the Space Harmonizer could do wonders for some components.

To sum up:
The Space Harmonizer is no simple block of wood. It is a lateral butcher block sandwich of aged Siberian Cedar and has a distinct sound of its own. It is therefore an additive device for shaping sound. It can now be included alongside maple, birch plywood, cherry and other wood types as having its place in system design. It is a product that should be taken seriously and not dismissed because of its name. In every context in which I tried it, the Space Harmonizer had a similar effect though the magnitude of this effect differed. It increased soundstage height, warmed up the midbass presentation and deepened the overall soundstage presentation. It sweetened string tones especially with massed strings.

The Space Harmonizer is a sound-shaping or tuning device and this is how it shapes the sound. It is no small accomplishment that it succeeds at doing what it purports to do. It is a different question of course whether the sonic changes it produces take the music in a desirable direction. That is surely going to be system dependent. The Space Harmonizer also showed that it could be a good platform from which other additional tuning might be performed. This was the case with the Reimyo electronics and the Bravo speakers. These are all highly positive attributes. The platforms are not especially expensive either. The most expensive Harmonizer costs $375 whereas a set of four of my preferred Harmonix tuning feet cost considerably more than that.

But there are some limitations. The wood is very soft and thus scratches and dents very easily. I try to be very careful with review equipment but couldn't help but scratch and dent the Harmonizers. Eventually, I decided that if I was to listen to them as a reviewer, I would just have to also place them underneath speakers with their spikes connected. They worked well with the Gibbon 8 in this context but it led to holes in the wood - no way around that.

The company suggests that the biggest impact comes from using them under speakers but you have to be careful in choosing speakers. Many modern ones are just too heavy; others come with their own plinths; and others still require clearance for horn or transmission-line vents or floor-facing ports. The rubber feet are not secure either. Finally, a Space Harmonizer is a blunter form of sound shaping or tuning than are the usual array of feet, cones and pucks.

Still, they clearly work as advertised. They may just be the ticket for many systems and for those who want to increase the love and emotional impact in their system without devoting large sums of money and time to tweaking. The Space Harmonizer is a pretty effective and efficient way to get into sound tuning or shaping while bringing you closer to the music you love. I wouldn't mind having one or two in my bag of sound tuning devices.

Manufacturer's website
US distributor's website