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Before I segue into my listening impressions, we need to get one item squared off. Due to the far from gimmicky adjustments, this speaker is not possessed of a fixed sonic character. The 4dB window between 400 and 1.200Hz and the 6dB leeway between 1.200 and 20.000Hz, in conjunction with the optional 2dB shelving at 10K, afford profound fine-tuning of the sort usually achievable only via component or cable swaps. The PHIO speaker can be made to sound midrangey, bassy, brighter or darker, less airy or less nervous with certain recordings. After some back 'n' forth, I ended up with the 'neutral' 88dB settings for both modules. (Occasionally, I'd tone down the horn to the 86dB setting but I never did touch the 10kHz cut.)

According to Herr Wendt, increased bass heft may be approached not only via reduced midrange output but closer wall proximity - true for most other boxes too. Alas, the usual boom side effect supposedly won't make a visitation since that's often due to chassis resonances which are excited by room resonances - and Wendt's enclosures are simply deader than his competitors' by a fair margin he says. Cough. At least in my room, I could cash in on this promise only partly. Close to the front wall, I indeed didn't suffer the dreaded boom but... instead of the expected low bass boost, I strangely obtained a noticeably more confused and ill-defined upper bass. Because in that position, the music seemed too distanced and stage depth too shallow, I simply repositioned the PHIO where most all other floorstanding speakers end up: ca. 80cm from the wall.

The treble too is even more variable since its base isn't solidly fixed to the bass box. You can move it fore and aft, create toe-in, float your boat whichever way. Unfortunately, I have no secret tips about that. I got best results flush with the bass module and aimed directly at the ear in standard posture. (Devotees of time alignment should know that according to PHIO, this will require a 5.5cm forward position of the horn and inverted cable polarity. A/ this looks funky and B/, you really have to believe very hard in hearing any difference if you ask me.)

PHIO's speaker is far from flashy. It convinces more deeply after longer exposure. Quickly running through three tracks to form an opinion won't work. Hunters of superlatives in specific disciplines won't hit gold though tremendous transparency is rather obvious right off the bat - about which more anon. The Signature is dynamic but not "typical for horns". Nor does one detect a solid tonal fingerprint. Even soundstaging is more realistic than particularly holographic or stunningly cavernous. The fundamental understatement-as-strength approach had me flash on the Ascendo C8 and Sehring 700 reviews. Despite being different, those speakers too impressed me with their overall balance. Short and sweet then, for a new player in the market like PHIO Audio, things sounded very mature indeed.

With both modules set to the same voltage sensitivity and driven to room volume, the PHIO Signature is a poster child for tonal balance. At higher levels, there's a tendency toward brightening (which can of course be countered with the rear-mounted pots if desired). Upper mids at goodly volumes become forward but the PHIO never turns lean due to its solid grip on the lower octaves. Those offer substance, speed and structure, play with agility and zero boom nor restraint, i.e. offer complete pleasure bass. Where the upper bass is already informative, this tendency seems to increase as you climb up the frequency ladder. I'd not call it 'analytical' to avoid that term's negative implication because this is true resolution, not simulation via treble trickery. Even in pursuit of upper mid/treble trace elements as it were, there's always a gain in enjoyment, no exhausting pursuit of a compulsion. The musical presentation gets denser, more complex and hence, more involving. It's not denser for being more colorful than the real thing but by offering more detail than is common. Plus, this resolving power doesn't hit sleep mode at low levels. I don't think I'm overstating when I call the PHIO Signature the most discerning speakers at low levels I've yet encountered. That's with the necessary conditions that regardless of whisper levels, the tonal balance doesn't tilt (it does not) and 2/, that the smaller horn be employed.

While delivering his goods, Herr Wendt had in tow both of his horns. The bigger one runs a larger enclosure but also a ceramic membrane with twice the mass - a 'hefty' 0.2 grams instead of 0.1. We kicked off our listening session with the bigger horn and though I had no cause for complaints, the switch to the smaller one offered higher transparency at more subdued levels. Quite a plus, that, particularly with the parallel savings of 800 euros. Unfortunately, nothing in life is free and this advantage failed at levels above room volume, first slowly (at higher levels, the resolution of both PHIO horns leveled out) and then, instantaneously. At party levels, the smaller model simply craps out and starts to distort audibly. The only solution then is a manly left-hand turn on the master gain. One thus has to be clear going in how large of a room one intends to energize, what type of music one will listen to mostly and at what SPLs. Heavy metal at concert levels in he-man caves? Big horn; if one would even consider a PHIO speaker for those circumstances.

In a moderately sized space meanwhile -- say ca. 20m² and not necessarily my own high-ceiling'd brownstone either -- I envision only small limitations relative to sound pressures since lower signal and reduced driver excursion will produce the same subjective results. Otherwise, there's a superior alternative. To revisit the resolution angle, even the highest octaves give best-case results, with the vaguest decay trails of softly struck brass tracked to their very ends quite as endlessly as good ribbons. Unlike is often the case with ribbon-tweeter speakers, there's coherence from top to bottom as long as one doesn't listen too loud. Transparency in the bass and treble don't suddenly pursue separate paths. Perhaps this is partly due to the horn kicking in at 1,200Hz to cover four rather than the usual three octaves. Regardless, there's no sudden detail boost while crossing the mid-to-treble line. Everything is of one piece.

Hence, if you will, everything also sounds coherently clean. The material worship of the bass enclosure goes after a reduction of distortion. The composition, geometry and decoupling from the bass box of the PHIO horn do the same. The absence of mud spots anywhere then contributes to the seamless impression of this speaker. It is a bona fide clean transmitter of the signal. Macrodynamically, the PHIO can dish it without delaying transients. There's clear pep but not in a mouth-agape fashion. Others are better, many worse. This speaker plays in the upper half but not at the very top. It counters with microdynamics charms and rather successfully. Well recorded, finely nuanced violin is precisely rendered and alive. Ditto for song, acoustic guitar, double bass et al. Everything is bare out in the open. Nothing covers up even the tiniest output fluctuations or tonal shadings yet the presentation never defaults into the cheaply exhibitionist. "Spot light on and step three feet forward!" is not on the menu for solo vocals. All that occurs rather more finessed on the line between the speakers or farther back in the stage which, thanks to great spatial transparency, allows insight to the very back.

So nothing is forward. That's true also for the soundstage perspective which is realistic rather than spectacular - realistically broad, realistically deep, realistically focused, quite a dream for Jazz and piano lovers. Those who'd trade such high accuracy for scale, pressure and kick have other alternatives like the just-reviewed Zu Audio Presence. As I said in the opening paragraph, reviewing can be quite the kick. While still in the thrall of the Red Hot Chili Peppers, one realizes that the next candidate doesn't quite get it up but offers considerably more detail. Okay, perhaps not with the Peppers but on other material...

With its Signature, the PHIO Audio company offers a modular speaker system which adapts to living and listening habits. But even past the main decision between two horns and three bass systems, there's wiggle room because both drivers offer individual adjustments. "Success shouldn't depend on the room" seems to be PHIO's commendable motto. The review loaner of middle bass and small horn modules showed the following sonic tendencies with the pots in the central detent position:
  • The core trait is one of understatement, not showiness. This speaker wants to be discovered.
  • The PHIO is tonally neutral, with a lively, well articulated and powerful bass. The midrange is flawless and exceptionally detailed. The treble connects seamlessly and is equally resolved and free of artifacts.
  • Higher levels incur a shift into more lit-up terrain.
  • Very high levels can induce tweeter breakup. SPL fiends need the bigger horns.
  • Magnifying power particularly in the midband is truly unusual particularly since it doesn't diminish at subdued levels. This trait is free of artifice and doesn't cause long-term fatigue. Au contraire, one rather wakes up since the music is more informative than usual.
  • The soundstage is realistically broad and deep, with good focus and body.
  • Microdynamics are impressive and even large-scale attacks cause no troubles. Don't expect a hyper-dynamic horn sound however.


  • Model PHIO Audio Signature
  • Concept: 2-way bass reflex floorstander with separate tweeter module
  • Trim: All common veneers and available automotive lacquers for no surcharge
  • Sensitivity: Bass ca. 91dB (adjustable from 86 – 90dB from 400 – 1.200Hz, from 84 – 90dB between 1.200 and 20.000Hz)
  • Nominal impedance: 8 ohms
  • Weight and dimensions: Bass bin 79 x 28,5 x 43cm (HxWxD), 30 kg / tweeter horn 18,2 x 18,2 x 34cm (HxWxD), 10 kg
  • Other: Volume pots for both drivers, ultra HF cut, pure silver wiring available for surcharge and retro fittable
  • Website
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