What is the StormAudio ISR Fusion 20 AVR?
StormAudio traces its origins back to the early 1980s and Belgium-based Galaxy Studios. Founder Wilfried Van Baelen was importantly responsible for developing the Auro-3D concept and ensuing formats over the coming years. Not only did he and his Galaxy Studios operation carry out the first 11.1 Auro-3D installations, but the soon-to-be-formed StormAudio in 2014 produced the first 3D audio receiver, the 16-channel Auriga.
The company’s arsenal of components shares that rarified air inhabited by such esteemed brands as Acurus, Lyngdorf and Trinnov
Following an ownership change in 2017, StormAudio released the ISP Elite MK1 processor. The MK2 followed in 2019 sporting the full gamut of immersive audio codecs, including Dolby Atmos and DTS:X. The processor is now in its third iteration and consequently named the ISP Elite MK3 with its 32 channels of available processing. The latter product hailed a stylish new 2022 face lift with a larger integrated display screen and beefed up front display graphics, an aesthetic which is echoed in the 2023 20-channel ISR Fusion 20 receiver we review here. This product is the only receiver in the line and now sits alongside three AVPs (including the flagship ISP Elite MK3) and both 8- and 16-channel power amplifiers, the latter two of which employ the MK3 revamped housings to visually match the processors.
Key to the ISR Fusion 20 is that, although it has a fixed architecture, the HDMI board can be upgraded when updates become available. It is also officially the first product to use Dirac Live’s ART (Active Room Treatment) enhancement to the Dirac Live room correction system. StormAudio is at pains to stress that the ISR Fusion 20 is ‘separates in one box’ and it uses the same DSP chips and HDMI boards as the Elite products.
StormAudio now resides in France with full product assembly taking place there. The company’s arsenal of components shares that rarified air inhabited by such esteemed brands as Acurus, Lyngdorf and Trinnov. We might class all these as ‘premium’ home cinema integration products. Not surprisingly, all these brands require car purchase type outlays of cash and represent a big jump up from the likes of, say, Denon, Marantz or Yamaha for the average user. Among the premium players, Lyngdorf setup and operation is broadly more consumer friendly, while StormAudio and Trinnov components allow no end of options to dig in and customise to personal preferences and environments.
Design
The ISR Fusion 20’s housing is pretty substantial with its 19.3-cm 4-rack-unit height and 46.6-cm depth. You will know about it when you lift its 17 kg from the box. The unit comes with a pair of rack ears, so the 17-inch width allows the bulky frame to slide into the standard steel IT assembly. Just make a note to review these dimensions if you plan to place the ISR on a shelf.
The ISR is a fine-looking and sophisticated device. A large acrylic plate dominates the receiver’s black fascia. It is flanked by two black steel plates with diagonal line borders which mark the novel design convention of the MK3 generation products. Behind the plastic centre-piece is the graphic LED home display screen which includes a large volume indicator and details of the detected audio format and selected room layout profile. Just to the right and embedded into the acrylic is a rotary volume dial with a push for select and mute functions. To the left of the home display are rather flimsy plastic buttons for up/down and home screen access. To the far right of the front panel is another plastic standby button, IR remote receiver and ‘on’ indicator LED.
Running down the right side of the receiver are three fans which audibly trigger for a timed period both during startup and after shutdown. Along the top panel of the rear plate are seven HDMI inputs and two outputs, all 2.1a/HDCP 2.3 compliant. These complement four RCA stereo, XLR stereo, three Coax S/PDIF and three optical inputs. It’s worth mentioning that the pairs of RCA line-level inputs can also configure for a 7.1-channel analogue input. To the right side of the rear are four XLR outputs, numbered 17 to 20, and the corresponding speaker outputs 1 to 16 run along the base of the enclosure. There is also one optical output for a zone 2 downmix.
Features
The ISR Fusion 20 is, as mentioned, a 20-channel receiver with 16 Edge power amplifiers, courtesy of Denmark-based ICE Power. Amp power per channel measures 150 watts into 8 ohms and 300 watts into 4 ohms. You can also bridge three channels, which will deliver 500 watts into both 8 and 4 ohms. This would still facilitate a thirteen-channel satellite layout if, as most likely, the user chooses to give the extra heft to the front LCR loudspeakers. There are still the remaining four XLR outputs, which also will most likely be applied to up to four powered subwoofers. None of the channels is preassigned, so the user has complete flexibility in configuration. StormAudio rates the continuous power at 2,000 watts and peak output of 2,500 watts.
... the user has complete flexibility in configuration
The processing section includes decoding and DSP functionality to decipher Dolby Atmos, DTS:X Pro, IMAX Enhanced and, of course, Auro-3D immersive audio formats. Although we touched on the HDMI spec in the previous section, the 2.1a protocol supports 8K video and 4K/120, as well as dynamic HDR systems, including HDR10+, HLG and Dolby Vision. Smart home control systems are supported with Control4, Crestron, RTI, Savant and ELAN drivers. For streamers, the Roon Ready platform is available onboard or you can connect a streaming device, while Wi-Fi is conspicuous in its absence.
Of course, Dirac Live is the room correction system of choice here. The ISR includes the basic room alignment algorithms, along with the proprietary Bass Control and ART functions. The second of those adds filter adjustments to optimise the response of multiple subwoofers while minimising room deficiencies for tighter, more controlled bass. ART analyses all speakers and subs and eliminates bass resonances and decays. Getting rid of bass hotspots and lingering resonances promises to mitigate the effects of low frequencies muddying up the performance of the satellite speakers so the soundstage should, as a result, sound cleaner and clearer.
... Wi-Fi is conspicuous in its absence
You can download the free Dirac Live app to a PC or tablet and run the full operation from there. Once the ISR Fusion 20 is established on your network, the Dirac Live app identifies the device upon which you wish to apply the process.
Find out more
Control
The ISR Fusion 20 employs fully-featured set-up and control options. The first of these is the Web UI which can be accessed by entering the unit’s IP address into an internet browser. Within this ecosystem, you can manipulate system parameters, input assignments, speaker sizes, presets and more. It’s a dizzying interface with many options, but the workflow is laid out in such a way as to make sure you enter the most pertinent information to get you up and running. Storm Audio also provides excellent walk-through video tutorials and documentation to support an integrator or customer with the setup and operation routines. (The Web UI acts not only as a system configurator, but also allows full playback control of the unit remotely.)
It’s a dizzying interface with many options, but the workflow is laid out in such a way as to make sure you enter the most pertinent information to get you up and running
Although a default 2.1 ‘Theater’ configuration is preloaded into the software, you can immediately trash it and set up your own profile in the Theater Configurator. Here, the prime goals are to define the speaker characteristics (full-range, bridged load, Dolby Atmos Enabled etc.), and then the layers within your loudspeaker layout (base, height and top channels). At this point, there is an option to dig in with Dirac Live or use StormAudio’s own simple bass management and level finding set-up procedure.
Control of the unit is also possible from the excellent StormRemote app available from either the Apple or Google Play stores. Meanwhile, the least appealing of the direct control options, but also least likely to be used day-to-day, is the included plastic-framed IR remote control which feels a little unrefined for a top-end home cinema component. It supports most used function selections, such as volume, listening presets and navigation buttons. It also handily includes the key upmix modes for the selected ‘Theater’ profile(s). We found we deferred to the mobile phone app for volume and input selections but be aware that there is something of a lag when changing the latter.
Set Up and Operation
The setup we chose to use for the ISR Fusion 20 was a 5.2.4 layout. There are seven ear-level M&K 150 Series loudspeakers in my cinema room, but there were wiring practicalities that prohibited using the full 7.3.6 array in this instance. (The challenges of juggling receivers and AVPs in a reviewer’s home will be familiar to all those involved in the AV press!) The two M&K X10 subwoofers used in this test sit in the front two corners of the room, and there are four M&K MP-150 truss-mounted top channels toed in towards the listening area.
... even from running the basic Dirac Live calibration, the results were superb
There are several steps to running even the basic Dirac Live 3 (latest version) room alignment procedure. It involves placing a UMIK-1 microphone on a tripod and taking measurements in the main listening position or sweet spot first, and then at varied height positions around the seating area. There are options for 9, 13 or 17 microphone positions. Given that my seating area is quite narrow, I opted for the ‘tightly focused’ imaging with 9 measurement positions. The Dirac software generates a graphic display for each channel and subwoofer’s frequency response individually. After selecting and calculating results by clicking on Full Bass Optimisation, the resulting profile can be named and saved with all polarity, level and delay data viewable. This is a broad overview but there are several steps involved in the full procedure which will become clear when you read through the documentation. In future, we hope to explore generating ART measurements and profiles in a future article here at AVF. But even from running the basic Dirac Live calibration, the results were superb.
Performance
Bass response in my room after running Dirac Live and emanating from two subwoofers was tight, beautifully controlled and seamlessly integrated. I initially experimented with listening to content by repeatedly disengaging my named ‘Theater 1’ Dirac profile to compare soundfields. At once, the soundstage would lose its grip, the bass response would regress, and the dialogue focused position and crispness would dissolve.
... precisely the kind of performance attributes you expect from a truly high-end cinema processor
With my profile once again in play and in the opening sequence of Tron: Legacy (2010, Blu-ray, 7.1), Jeff Bridges’ narrating voice is rich and full and isolated. It needs to be because the pounding deep bass notes underpinning the scene immerse the room. This is a truly cinematic experience. Even when Bridges leaves his son’s bedroom shortly after, there is a marked and real-sounding door creak from the right-side surround which appears to come from directly behind (where there is no loudspeaker). During the light cycle race in the same movie, the sonic weight of the front soundstage is brutal as the players speed past the viewer and whizz into the surrounds. As Quorra (Olivia Wilde) drives Flynn (Garrett Hedlund) away from the stadium, the music score’s trombones are deep-seated and widely dispersed. The ISR’s confidence and gravity are precisely the kind of performance attributes you expect from a truly high-end cinema processor.
Not only are directional cues in immersive soundfields precise, but the delicacy of discreet sound effects is exquisitely handled, too. In the quieter moments of the launch preparation sequence in Apollo 13 (1995, 4K UHD, DTS:X), the metal contacts of the tightening buckles in the command module are perfectly placed in the left and right speakers, after which the hatch clanks closed clearly towards upstage right. Meanwhile, the intensifying music score of horns and sweet-sounding strings are finely distinguished. In the final sequence, the rescue helicopter performs a flyby which bounds through the left height channels. After splashdown, the orchestra and choir take command of the full array with luscious dynamics and scale.
Not only is ISR’s music interpretation supremely detailed, but it’s also refreshingly neutral and truthful
I spin up the CD of Kate Bush’s 'Aerial' (EMI) and the gentle rock track Joanni. During the song’s verse, Bush’s breathy voice is textured and centred, and the bass guitar, lightly prodding kick drum and airy string synth image precisely. Not only is ISR’s music interpretation supremely detailed, but it’s also refreshingly neutral and truthful. The sparing and undistorted guitar break in the middle section is powerful and layered. The interpretation is a little more mechanical and cooler than my Lyngdorf AVP (but the Danish manufacturer sets a very high musical bar).
... none of the edginess that can plague mid-price amplifiers
Even in the track I Believe in You from Talk Talk’s 'Spirit of Eden', the sampled choral refrain is clean and undistorted with none of the edginess that can plague mid-price amplifiers. The ISR excels in its handling of midrange detail and there’s a fine separation of the organ keys and guitars. Bach’s Easter Oratorio (CD, Harmonia Mundi) is a lively if rather bright recording, but the ISR ekes out and keenly resolves all the nuances of the woodwind, reverberating timpani and multi-faceted brass section.
Conclusion
Should I buy one?
The StormAudio ISR Fusion 20’s performance is obviously targeted at the top end of the market. If you like, that peak you attain when moving to the luxury category is simply the preserve of a select few manufacturers. It’s all in that perceived performance weight, or gravitas, of the finest home cinemas which separates the men from the boys.
After running the all-important Dirac Live room correction, the overall performance is so beefy yet accurate, that it inspires many hours of hugely satisfying listening. The M&K loudspeakers we use here already embody a calculated neutrality, but to share that with the Storm’s openness is a sheer delight. Furthermore, Dirac Live’s deft ability to achieve such a tight, non-invasive bass response in a small room is surely another defining moment in the ever-changing landscape of home cinema.
... an utterly addictive listening experience
Keep in mind that the ISR Fusion 20, like the ISP AVPs from the same stable, are primarily designed for custom installers. No leaf has been unturned in the pursuit of allowing the user to tweak to his or her heart’s content. But unlike some of StormAudio’s competitors, there is quite a big learning curve getting to grips with the many layers and features of the system through the proprietary GUI and Dirac Live. If you’re up for a challenge, though, go for it. The StormAudio ISR Fusion 20 is a receiver I would have preferred to spend many more days and weeks with, both optimising and ever improving upon an utterly addictive listening experience.
