Dune Duo 4KLast November we took a look at Dune HD’s first foray into 4K playback with their small form factor Solo 4K. The new Duo 4K not only promises 4K playback but with its high fidelity audio DAC, aims to take the line in a new and bold direction.

Read on for our full review.




The Duo 4K is the latest in a long line of Dune HD media players. Other than the Solo 4K, we have also taken a look at the previous generation Base 3D and TV303D media players in recent years.


Dune HD Duo 4KAt 43 x 30.5 x 7cm (including feet but without its wifi antennas connected), the Duo 4K returns the Dune HD media player line to the full hi-fi component sized form factor. In a throwback to the elegant Smart Series, the front top edge of the unit features an impressive logo roll, detailing the Duo 4K’s pedigree.

Beneath these neatly arranged logos, the front face features a relatively symmetrical design with a central LCD display sitting atop five buttons. The buttons are binded to the home, play, stop, previous and next commands. While some may find them useful, these “legacy” buttons feel a little superfluous in 2017 on an otherwise very clean layout.

To the left and right of the LCD screen are the two 3.5” hard disk drive bays which are neatly hidden by a fold down plate. These drive bays can hold up to 10TB each! The power button is joined by the Dune HD/Duo 4K logo on the left while an SD card slot and a USB 2.0 port (with dust cover) round out the right hand side. Visually, the Duo 4K still isn’t quite as pretty as the now 7+ year old Smart series but on the whole the front face plays the part of a high end hi-fi component well.

Dune HD Duo 4KBar the aforementioned logos, the top of the Duo 4K is unremarkable and other than some venting, so are the sides. Worth noting is that on the underside of the unit is a 16cm Noctua fan along with four proper hi-fi component legs.

As expected, the rear of the Duo 4K is loaded with ports. From left to right: antenna in/out; stereo audio output (RCA and XLR balanced); S/PDIF; a USB-B port marked “reserved;” HDMI; S/PDIF/TOSLINK optical out; CVBS out; Gigabit LAN; 2 USB A ports and a port for connecting the Infra-red extender. And above these ports are two screw in wifi antenna jacks.

Dune HD Duo 4KPower-wise, there is also a territory agnostic two prong power receptacle on the far right along with a physical on/off switch.

While the Duo 4K looks huge compared to the previously released Solo 4K, the size is perfect for high end component setups and its relatively high quality build and finish complement this.

Along with the unit itself, the Duo 4K comes with an all new remote control, two wifi aerials, an infra-red extender and foreign power cord. As always, Dune also includes a HDMI cable and a 1.5m CAT5E ethernet cable. The ubiquitous quick start guide and GNU licensing document is accompanied by a glossy multilingual user manual.

Dune HD Duo 4KDune HD no longer includes any analogue A/V cabling which some may consider an unexpected omission considering the Duo 4K’s ESS Sabre32 DAC and XLR balanced outputs. Of course, those who care about analogue output are likely going to ignore whatever cabling Dune included. And those that don’t care are just going to use the included HDMI cable anyway so we think this omission is a reasonable one.

Setup and Usage

Upon turning the Duo 4K on, we were greeted with “dialog” appearing on the front LCD and on our TV a wizard style setup dialogue asking for video settings, etc. After entering our details the Duo 4K’s crisp main screen greeted us.

Worth noting is that our initial testing was done with an outdated firmware which had some odd bugs: to achieve analog playback (and utilisation of the Sabre32 DAC) HD Audio needed to be turned off, for example. After updating to a pre-release firmware Dune HD supplied us with, we managed to resolve these issues and as of publishing, the updated firmware used for testing has become the latest publicly available firmware for the Duo 4K.

Dune HD Duo 4KOur usual test regimen for media players is to throw numerous high definition files at them and see how well it can manage. As expected, the Duo 4K had little trouble with whatever we attempted to play back. All the expected video formats played back flawlessly with Dolby Digital and DTS audio all working as expected. DTS-HD Master Audio and Dolby TrueHD streams also played perfectly through our Pioneer receiver. Unfortunately, we had no Dolby Atmos capable receiver on hand to test Dolby’s 3D audio encoding but Dune HD does list the Duo 4K as compatible.

Over the course of the review we tried a variety of SD, HD and 4K files from SD Card, USB and from the unit’s internal 3.5” HDD bays. We found that nearly all home rips and widely available “scene” videos all played back as expected. As with the Solo 4K, x265 files played back perfectly where the previous generation Dune HD Base 3D and TV303D media players could not. Other than the rare AVI or malformed WMV files, the breadth of playback was excellent.

Dune HD Duo 4KWe were especially impressed with both DVD and Bluray ISO playback, which incorporated full menu support. We tested a number of Bluray ISO files which not only looked and sounded superb but also displayed their unique Bluray menus. Bluray menus have been a touchy subject in recent years as the majority of “play all” media players dropping support for them. With last year’s Solo 4K and the new Duo 4K, Dune HD has reintroduced this much sought after feature.

During playback, the LCD screen on the Duo 4K displays the running time after initially displaying the title for a few seconds. While pretty much everything we threw at the Duo 4K worked well, despite looking superb, 4K content still has a maximum frame rate of 30fps. Our understanding is that as with the Solo 4K, this is a limitation of current hardware.

Dune HD Duo 4KWhile we did not have a great deal of 4K test material on hand, the files we played did work smoothly up to the 30 frames per second limitation. Downsampling of 4K content was excellent and looked relatively smooth on our old faithful Kuro TV.

When connected to our Sony 3D capable TV, Over/Under and Side by Side 3D content played without issue. Network playback was seamless over our CAT6 Gigabit network (utilising both SMB and NFS shares) with even Bluray ISOs playing back flawlessly.

While brute force playback has always been the forte of Dune HD’s media players, some users have lamented the omission for a movie poster inspired GUI. To combat this, Dune has opted to include a new “Collections” feature.

Dune HD Duo 4KThe Collections feature adds a built in visual jukebox, allowing the Dune to scrape for movie details based on file name (and if required), additional user input. Third party solutions have been available for Dune HD media players in the past but they have always involved an external PC/Mac to do the heavy lifting. The Collections feature replaces them with all setup, processing and storage done on the media player itself.

To test the Collections feature we setup up a test folder consisting of 256 movies in various formats ranging from Bluray ISOs to MKVs and even some old AVI files. With our setup, the strafing (or collection of information) phase took the Duo 4K 133 minutes and five seconds to complete.

Once complete, we painstakingly went through all 256 movies to check the details the Duo 4K had located and the success rate was pretty good. For example, the Duo 4K cleverly realised that “Untitled – The Bootleg Cut (2000)” was an extended cut of Almost Famous, although perplexingly “1945 – Extended (1979).mkv” and “Beverly Hills Cop (1984).mkv” bamboozled it. Luckily, when manually editing details, the Collections feature allowed for searching by IMDB number, which allowed us to easily fix false positives. The overall success rate of this automated system was around 80% by our reckoning.

Dune HD Duo 4K and Solo 4KThe only real negative of this process was that confirming details took a significant amount of time as there was a 30-40 second load time in between confirming a movie and the next one appearing (ready for confirmation) on screen. Of course, once confirmed, movies stayed confirmed so many may find the time spent worth it.

While time consuming to setup, the Collections feature was easy to use and the resulting collection made navigating files a very visual experience: Seeing movie details quickly was good as was the ability to find movies by genre and also via search.

The collections feature will likely appeal to those with a large static collection and certainly adds some flair to the standard interface. Having said this, the standard file browser isn’t particularly bad – it is logical and neat and matches the polished and neat GUI throughout.

Like it’s smaller brother, the Duo 4K features a built in TV tuner which allows for both watching and recording live TV. Setting up TV channels took less than five minutes with all local (Melbourne, Australia) channels appearing as expected. No channel logos were present however but the user editable text labels were accurate.

Dune HD Duo 4K Remote ControlUsing the Duo 4K to watch television was good other than two minor quirks. The first was that the front LCD displayed the time with seconds ticking over and the other was that each time we started the TV feature, the Duo 4K would display a dialogue to say it was adjusting the picture settings resulting in our TV blanking out for a few seconds before returning to regular programming. We’re sure both of these bugs will be ironed out in future firmware releases.

The included remote control is new to the Dune HD line and looks great. It measures 23cm long and feels well balanced, if light in the hand. The buttons are well spaced out and quite large compared to the Solo 4K remote. Along with some new buttons like TV Power and TV Info the remote has a built in orange LED backlight which can be turned on and off via a dedicated button (the illumination automatically turns off after ten seconds of inactivity).

The Duo 4K remote control also has a learning function with five buttons at the top of the remote able to learn commands. These buttons are labelled with an up/down arrow AV IN, TV Info and TV Power respectively.

In usage, the buttons on this new remote control give a satisfying click when depressed and after using the new remote routinely, we found it to be better than average and probably the best remote control shipped on a Dune HD media player to date.

The new recents mode (which gets its own dedicated button on the remote) is an excellent addition which unsurprisingly brought up a list of recently played files (along with a handy percentage of how much of the file had been played). While this percentage was not listed for Bluray or DVD ISO files, it did work across network shares so “recents” stored on remote network locations listed and played back without issue. This feature is great for series bingers as it helps you keep track of exactly which episode you might be up and even how far in in any particular episode!

The latest firmware also adds support for Apple Airplay (audio only) which we used to take advantage of the ESS Sabre32 DAC. The inclusion of the ESS Sabre32 DAC extends the Duo 4K to output audiophile quality analogue out via its RCA and balanced XLR connectors.

According to the manufacturers (Apogee), the Sabre32 DAC is an interface designed for audio and video professionals. The benefits of the ESS DAC are a low THD+N specification and large dynamic range. This translates to ultra low distortion, audio which is free from input jitter.

Dune HD Duo 4KPlaying back Apple lossless files via airplay (and also high resolution FLAC files locally) we found the analogue output to be excellent. A nice touch was that like the video, audio titles appeared on the LCD and if included in the music file, an album image displayed on the TV.

While our ears aren’t audiophile grade, we were very happy with how everything sounded through our Pioneer receiver and B&W CM series speakers.

Selected Specifications

Media processor: Sigma Designs SMP8758
Flash memory: 8GB
Connectors: 3xUSB host, SD card slot, HDMI output, optical S/PDIF audio output, coaxial S/PDIF audio output, composite video output, RCA stereo audio output, XLR balanced stereo audio output, coaxial S/PDIF audio input, external IR port, Ethernet (10/100/1000Mbit), two external Wi-Fi antennas, DVB-T/T2/C RF input/output, 100V-240V AC input
Internal storage: Two internal HDD racks for SATA HDD 3.5″, SD card slot
Ethernet: 10/100/1000 Mbit/s
Wi-Fi: internal Wi-Fi module with 802.11b/g/n/ac support, Dual Band 2.4/5GHz, 2T2R, two antennas; Wi-Fi client, Wi-Fi access point/router
Audiophile-grade audio DAC: Enjoy audio quality of the famous ESS SABRE32 Reference DAC (ES9018K2M)

Filesystems: FAT16/FAT32 (read-write), EXT2/EXT3/EXT4 (read-write), NTFS (read-write), exFAT (read-write), HFS/HFS+ (Mac OS Standard/Extended) (read-only)

Video codecs: MPEG2, MPEG4, XVID, WMV9, VC1, H.264, H.265, H.265 10-bit; support for very high bitrate video (up to 100 Mbit/s and higher)
3D video formats: MVC, Side-by-side, Top/Bottom
4K video formats: H.265 up to 4Kp30, H.265 10-bit up to 4Kp30
Video output modes: wide range of supported output resolutions (up to 1080p60 and 4Kp30) and framerates (including 23.976, 25, 29.97, 50, 59.94)
Video processor: VXP professional-grade video processing engine

Audio codecs: MPEG-1/2 layer I/II/III, AAC, LPCM, WMA, WMAPro, FLAC, multichannel FLAC, Vorbis, WavPack, APE (Monkey’s Audio), ALAC (Apple lossless), SACD (Super Audio CD) (stereo DSD, multichannel DSD, stereo DST), AC3 (Dolby Digital), DTS; support for very high quality audio (up to 192 KHz / 24-bit and DSD512 24.576 MHz); HD audio bitstream passthrough (including DTS HD MA, Dolby True HD, Dolby Atmos, DTS:X)
Audio file formats: MP3, MPA, M4A, AAC, WAV, WMA, FLAC, Ogg/Vorbis, WavPack, APE (Monkey’s Audio), ALAC (Apple lossless), SACD (Super Audio CD) (DSF, DFF, ISO), AC3, DTS, DTS-WAV
Subtitle formats: SRT (external), SUB (MicroDVD) (external), text (MKV), SSA/ASS (MKV, external), VobSub (MP4, MKV, external SUB/IDX), PGS (Blu-ray, TS, MKV)


Not only is the 4K duo more than double the size of its smaller 4K Solo sibling but in terms of generation differences, the new Duo 4K is more than double the previous generation Base 3D media player was.

While all the additional features are great to see, like the Collections, TV and recents feature – it is the inclusion of the Sabre32 DAC and XLR ports that really propel the Dune HD line into new territory. And these advances come at a cost which is the only real negative we can take away from our time with the Duo 4K.

At a suggested retail cost of $799USD the Duo 4K isn’t cheap but considering we think it’s currently the best all encompassing standalone media player money can buy, it’s lonely at the top.

And because we considered the Dune HD Duo 4k best in its class we’ve given this model our Editor’s Choice Award!

DR editorschoice

For more details about the Duo 4K and Dune HD’s other media players, please visit Dune HD’s Duo 4K product page.