PH61

Reviewer: Srajan Ebaen
Financial interests: click here
Main system: Sources: Retina 5K 27" iMac (i5, 256GB SSD, 40GB RAM, Sonoma 14), 4TB external SSD with Thunderbolt 3, Audirvana Studio, Qobuz Sublime, Singxer SU-6 USB bridge, LHY Audio SW-8 & SW-6 switch, Laiv Audio Harmony; Active filter: Lifesaver Audio Gradient Box 2; Power amplifiers: Kinki Studio EX-B7 monos & Gold Note monos on subwoofer; Headamp: Enleum AMP-23R; Phones: Raal 1995 Immanis, HifiMan Susvara; Loudspeakers: Qualio IQ [on loan] Cables: Kinki Studio Earth, Furutech; Power delivery: Vibex Granada/Alhambra on all source components, Vibex One 11R on amps, Furutech DPS-4.1 between wall and conditioners; Equipment rack: Artesanía Audio Exoteryc double-wide 3-tier with optional glass shelves, Exoteryc amp stands; Sundry accessories: Acoustic System resonators, LessLoss Firewall for loudspeakers, Furutech NCF Signal Boosters; Room: 6 x 8m with open door behind listening seat; Room treatment: 2 x PSI Audio AVAA C214 active bass traps
2nd system: Source: FiiO R7 into Soundaware D300Ref SD transport to Cen.Grand DSDAC 1.0 Deluxe; Preamp/filter: Lifesaver Audio Gradient Box 2; Amplifier: Kinki Studio EX-M7; Headamp: Cen.Grand Silver Fox; Loudspeakers: MonAcoustic SuperMon Mini + Dynaudio S18 sub; Power delivery: Furutech GTO 2D NCF, Akiko Audio Corelli; Equipment rack: Hifistay Mythology Transform X-Frame [on extended loan]; Sundry accessories: Audioquest Fog Lifters; Furutech NFC Clear Lines; Room: ~3.5 x 8m
Desktop system: Source: HP Z230 work station Win10/64; USB bridge: Singxer SU-2; DAC/Headamp: iFi Pro iDSD Signature; Speaker amps: Nord NC500 monos with v2 input buffers; Speakers: Acelec Model One; Headphones: Final D-8000, aune SR7000
Upstairs headfi system: FiiO R7, COS Engineering D1, Cen.Grand Silver Fox; Headphones: Raal 1995 Magna, Meze 109 Pro, Fiio FT3
2-channel video system: Source: Oppo BDP-105; All-in-One: Gold Note IS-1000 Deluxe; Loudspeakers: Zu Soul VI; Subwoofer: Zu Submission; Power delivery: Furutech eTP-8, Room: ~6x4m
Review component retail: €1'990/pr basic, €2'590/pr advanced [incl. VAT]

"Hi Srajan, I haven't written for a long time. Hope the Cubes haven't disappointed during this time and are still working. Back when you reviewed them, I was very surprised that you advised using them for home-based playback. For me they have a very monitor-like 'tasteless' sound but the idea of making a superb 'genius' computer speaker stuck in my head. And I've made them now especially for you. This PH61 is a 2-way with 6½" aluminium Purifi mid/woofer. It uses the same DSP approach to amplitude + phase correction so has the sonic precision of the Super Cube. It has wide dispersion at all frequencies but more bass and far less nonlinear distortion at LF. Most importantly, the sound is very 'tasty'. What do you think?" Signed Andrew Starstev, I took a quick look at his Russian DMAX pages. Those added to his quick specs a build of Oak-veneered 18mm MDF, a xover point of 3.6kHz, -3dB bandwidth of 45Hz-20kHz and weight of 5.8kg. The built-in amps pack 25wpc for the tweeters, 80wpc for the mid/woofers. 1.8m network cables include.

To rewind, the 5" single-driver Super Cube at right gained our Blue Moon award in March 2022. Tuned for nearfield mastering and brought to my attention by reader Russell who runs a home-based studio, it had set my desktop on a path of outa-the-HeadFi just as the original Raal SR1a ribbon headphones had steered my subsequent speaker adventures. Outa-the-HeadFi is self-explanatory. Take the time-domain excellence of filterless headphones from their virtually hardwired on-ear proximity to speaker imaging nearly 2-metres across in the office nearfield in front of us. Just as we don't need 'phones to pulverize our bone marrow with LF pressure waves, so does the intimacy of the desktop not warrant it either. There we need sufficient not ludicrous bandwidth at ideally the highest resolution so that lower SPL conducive to 0.7-1.5m closeness still hear everything. Andrew's approach uses affordable OEM class D plus his own FIR-based corrective DSP for active drive.

Whilst he always viewed his SC5 as a dedicated pro-audio appliance—'tasteless' is his word for neutral aka zero voicing—my review suggested that some home-based pleasure listeners could just get on like lox does with cream cheese and bagels; or fox with chickens. In fact, my SC5 exposure had led me to speaker dates like Voxativ's Hagen2 and Lindemann's Move Mini, two passive widebanders of similar ambitions. Now the PH61 promised a step-up of the SC5 concept and Andrew asked what did I think? My inner hifi floozie was aghast that he even had to ask. Kidding aside, I had occasionally wondered how DMAX fared since my review but aimed mostly at recording studios, I'd not heard anything when that's not an area I canvas. Needless to say, now I wanted to hear more than just about this grown-up Super Cube. Surely he could make that happen and let me test its intrinsic PH value?

By concept alone, that's acidic to purists. The 61 only works with Andrew's compensation code embedded in his class D platform. Whatever analog you feed it gets converted to digital. Inputting 1s+0s requires digital volume control in software. Andrew's code optimizes the time domain across the bandwidth to enforce a clean impulse response. Where classic widebanders opt out of all compensation, DMAX leverage the real-time computational horse power of modern DSP. If one can measure the nonlinearities of quality drivers across their amplitude/phase plots, why not null them in the digital domain by way of error-forward correction? The original Super Cube answered the how and why. With the PH61 and now two drivers, that story evolves. Will traditional audiophiles give it the time of day? I doubt it. Today is for those other guys and gals, whatever listening title they might claim on their business cards. Pragmatic connoisseurs? No-nonsense surfers? Amongst them, some will opt for the speaker package with basic plate amplifier at €1'950 all in. Some will splurge on the €600 surcharge Hypex FA122 Fusion amp with 5th-gen nCore tech. The same DSP labours aboard regardless though Hypex add EQ features potentially useful for room tuning.

Super Cube 2022. Simple does it.

Then there's Andrew's dry promise of "very tasty" vis-à-vis the Cube's "tastelessness". This suggests tailored voicing. And isn't that what many of our kind profess to want rather than studio-monitor neutrality? In which case, what is a recording engineer's idea of a very tasty flavour profile? I was curious to find out since with such a nearfield system, the room can be quite removed from the equation whilst the rest is locked in by the designer to guarantee an unusually high degree of us hearing what he heard. Also, the PH61 would be my first op to hear one of Purifi's ultra-low distortion drivers with that trademark ropey surround. From Germany's speaker pope Joachim Gerhardt to Kroma Atelier's Javier Milán, those drivers populate some very ambitious speakers. With DMAX, I'd make that acquaintance on a rather tidier factory-direct budget. To return back to the beginning, the arguably core distinction of this speaker is the promise of digitally optimized broadband time fidelity for a two-way with technically superior direct drive which connects amplifier outputs to voice coils without interceding passive filter parts. That part is a classic active sealed speaker. The difference is the proprietary digital filter code which corrects not only the frequency but also phase response.