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This review first appeared in the March 2012 issue of hi-end hifi magazine fairaudio.de of Germany. You can also read this review of the Heolo Gamma in its original German version. We publish its English translation in a mutual syndication arrangement with the publishers. As is customary for our own reviews, the writer's signature at review's end shows an e-mail address should you have questions or wish to send feedback. All images contained in this review are the property of fairaudio or Heolo - Ed.
Reviewer: Jörg Dames
Sources: Fonel Simplicité, Laptop with foobar2000 and JRiver, Northstar USB dac32
Amplification: Integrated - Fonel Emotion, Abacus Ampino; pre/power - Funk MTX Monitor V3b, Audionet AMP monos
Loudspeakers: Thiel CS 3.7, Sehring S 703SE, Quadral Aurum Megan
Cables: Low-level - Straight Wire Virtuoso, Vovox; high-level - HMS Fortissimo, Reson LSC 350; USB - Kimber Ag
Power: Quantum-Powerchords, Hifi-Tuning Powercord Gold with IeGo termination, MF-Electronic power strip
Rack: Lovan Classic II
Review component retail: €3.700/pr


Say hello to team Heolo of Italy - Heolo = High-End Omnidirectional LOudspeakers
Mad hatter? Whether a hat is fashionable or not is arguably a matter of taste. And even though today’s Heolo Gamma does stem from fashionably hip Italy, the head covering of our two Romans at least to me looked less inspired by a hot fashion designer and more by a fervent Starship Enterprise fan. But perhaps I’ve watched too much Kirk, Spock & Co. during my formative years. The immaculately finished Gamma which reaches to a bare 80cm tall without hat or space ship basically netted only positive feedback from the various visitors to my pad during its stay – and did so particularly from the female contingent. Not that Heolo’s treble solution was ever meant to be any fashionista statement. It has sound sonic reasons. About which…

Bent or beamed? Heolo’s developers are fans of omnidirectional dispersion, i.e. what ideally is a homogenous spherical radiation [on their website and excerpted below they reference a few white papers by SausalitoAudio who were involved in B&O’s Beolab flagship speaker – Ed]. Conventional sound radiators beam with rising frequencies. This has the sound act more like a spot light whilst the lower bands simultaneously act spherical, i.e. propagate in all directions including backwards. Beaming is a function of the reproduced wavelength being smaller than the diameter of its transducer. This is particularly typical for tweeters.

As a direct consequence of beaming, a linear frequency response remains associated with just a few listening positions—the so-called sweet spot—beyond which the higher frequencies become progressively under-represented and soundstaging suffers. But focused directivity has its own advantages too. It does minimize reflections and thus interacts less with a given playback acoustic. Hence certain designers pursue limited dispersion very deliberately. Particularly with larger listening distances this can be sensible.

Whatever the chosen design decision, the core of today's two-way speaker is a 16cm Seas paper midwoofer and Heolo’s "legally protected" treble solution. The tweeter itself is a classic 1-inch Seas soft dome which fires up rather than forward. Mounted recessed inside the enclosure, its connection to the outside world—and this Heolo says is their special trick—occurs through a perforated tube. It stick out of the cabinet top by a few centimetres where at least visually it finds itself "protected" by a thin cloth tent. Relative to the involved frequencies the perf holes are dimensioned small enough to perform a constant wave bend in all directions up to about 15kHz. Above that things get directional again but here the desired effect is assisted by a not visible dispersion lens that mounts directly in front of the tweeter to bend the sound horizontally before it ever enters the tube.