Coming in at $299, the Dekoni Audio Blue headphones are the least expensive of the group we put together in Sound+Image this issue (click right for the full group as a PDF >>). Indeed, they’re less than a quarter of the cost of the most expensive.

They do seem to be a little more expensive, however, than the Fostex T50RP Mk III headphones (our review at avhub.com.au/fostex). These I mention because it seems that the Dekoni Audio Blue headphones are a ‘custom variant’ of that model. Indeed, these headphones are labelled ‘Fostex’ on the headband.

Dekoni says that it has made a number of “proprietary changes” to the headphones, including tuning the sound and changing the ear pads. They come fitted with one set of ‘Dekoni Hybrid Ear Pads’ and a second set of “Dekoni Audio Elite Velour Earpads that utilise the Premium Slow rebound, high-density memory foam Dekoni is known for”.

They use planar magnetic drivers. That’s something rarely seen at this price point. The design is neither open nor entirely closed-back. Instead there seems to be substantial venting on the outside of the earcups, but not quite the full flow of air implied by open-backed. Dekoni doesn’t say either way.

They are over-ear headphones, but the inset in the cups for one’s ears are fairly small. Still, mine fitted in, even if a little folded in the process.

The two-metre cable is fairly thick, and detachable. At the headphone end the cable uses a 90-degree 3.5mm plug. This is inset a little and uses a locking collar for security. If the cable fails you should purchase an official one, of course, but at a pinch you should be able to use any 3.5mm cable with a body less than 8mm in diameter, although of course it won’t lock.

All but one of the headphones included here come with connections for both 6.35mm and 3.5mm sockets. This is the only one that does it the right way around, I’d argue. The amplifier end of the cable is terminated with a gold-plated 6.35mm plug. A gold-plated 6.35mm-to-3.5mm adaptor is provided. If you do it the other way around (as do most of the others) you do gain the advantage of compactness when using portable gear, whereas the Dekoni arrangement results in a 3.5mm plug some 105mm in length! But if you’re a high-fidelity person concerned with purity first, as are so many of our Sound+Image readers, then you’ll want to reduce the contacts in the signal path. Your high-end gear is most likely to have a 6.35mm socket, so a direct connection to that is preferable.

Listening
I started with the Melanie track (the music list for this group test is on the opening page) and three things became immediately apparent. First, these are true high-fidelity headphones, not some kind of cheap implementation of planar magnetic technology. They do deliver that open, expansive feel of true quality headphones. They are revealing and deliver pretty much everything in the recording.

Secondly, the Dekoni Audio Blue headphones will be extremely pleasing to those who love their bass. The bass line in this track was delivered at a significantly higher level than with any of the other headphones in this collection. It wasn’t florid or booming. The control was excellent. It was just louder. That might make it too loud with some music, but most of the test tracks I used were subjectively improved, or at least not damaged.

The one exception, arguably, was the Liszt piano work. Some sections of the music are heavy on the left hand, and these tended to overpower the rest of the keyboard in their louder parts. By contrast, the Eminem track was even better for the bass strength. I guess with hip-hop there’s not really such a thing as too much bass!

It seems that it isn’t just the mid or upper bass, either. Dekoni talks about how its tuning was aimed amongst other things at ‘an extended bass response’. This was borne out by the 1812 performance. With both the bass drums and the cannon, the hard, hard slam was accompanied and followed by plenty of ultra-deep, near-infrasonic tones. Those are the kinds of things you tend not to notice the absence of, but when they do appear you can’t help but marvel in the greater authority they grant the music, and the sense of the performance space that they provide.

The other stated tuning aim of Dekoni in producing these headphones was to make them ‘less fatiguing and smoother all around’. The third thing I immediately noticed on the Melanie was a certain upper midrange/ lower treble zing. I wouldn’t call it fatiguing, but neither would I call it ‘smooth’. Her voice even had a touch of sibilance injected into it. This carried through to the Eminem track. Mr Mathers’ voice had an edge that zinged, not altogether realistically. The percussion also had a harsh edge that did make this track a little fatiguing.

That was not apparent with the Schubert. Here there was a fine sweetness in the violins, while the cellos benefited from the greater weight leant by the bass forwardness. Likewise for the orchestral work in the 1812. It was clean and clear and entirely pleasing.

Well, almost entirely pleasing. These headphones are not very sensitive. Using a headphone amplifier/DAC, they went plenty loud enough with the Eminem and the Liszt and the Primus and the Laura Marling. But I could not get the first three quarters of the 1812 quite up to a fully pleasing level. I’d say another three decibels would have done the trick. That’s a pity, because when the cannon-laden climax is reached, it was handled with comfort by these headphones, including, as mentioned, a good dose of infrasonic bass.

When used with a Pioneer portable player with EU-hobbled output level, even inherently loud material such as the Eminem and Primus were short of satisfying.

That said, one thing you don’t have to worry about is the line impedance of the source device. These headphones share the planar magnetic characteristic of a flat impedance curve across the audio spectrum. Even with a ridiculously high 466 ohms in line, the signal delivered varied by only 0.5dB across the audible frequency range.

Or just make sure you use a headphone amplifier with plenty of oomph. These headphones are rated to cope with up to 3000mW of power. I’m not sure I’d want to be wearing them when they were doing that...

Dekoni Audio Blue 
Price: $299

+ Good, open high fidelity sound
+ A bass-lover’s delight
+ Very affordable

– Quite insensitive, so need a high input voltage
– A touch bright on some recordings

Drivers: Planar magnetic
Quoted frequency response: 15Hz-35kHz
Nominal impedance: 50 ohms
Sensitivity: 92dB (1mW)
Weight: 320g