The chipset shortage led HiFiMan to re-design the Bluemini from scratch and adopt the classic R2R method. On the downside, I can definitely point out that it has a certain tendency to a very slight hiss at low volume levels or with high resistance headphones like the HE-R9. I think he's right about this, but up until now I haven't heard a headphone that sufficiently delivers the kind of audiophile sound I want in a wireless headphone. The BT module features the Hymalaya R2R DAC inside, which is supposed to offer high sampling rates with low energy consumption.

I’m not gonna lie – I really like the appearance and the color scheme of the original Deva, but I know many people that found it…controversial. Now we have them in both HiEnd Susvara, in basic HE-400SE, and everywhere in between, except the Ananda. It is not as holographic but still has some good depth layering and the soundscape is equally extended to the height as it is in the width while the listener is rewarded with some natural reverb and echo that gives a very open and spacious feeling. After some more detailed listening, the sound is not identical to the HE400se but it is very similar, at least in my opinion, with some slight changes that could actually be dependent on the pad difference between the two units. It's impressive how Fiio has considered the upgrade path for E7 DAC owners by integrating an iPod-style dock connector into the E9.Together with the cleaner presentation and better control the biggest change however is the placement of objects or instruments in the space. As for bass levels, slam and punch themselves, these are not designed to batter your head or hit you with a hammer while you get up and yell for more, the bass is tuned towards a more neutral or reference approach and it fits like glove given the newly added technicalities. It’s yet another Hifiman box, their packaging has been very consistent lately, and it’s no different here.

This is a system that allows the Deva Pro to be used with both the BT module and the normal cable that is included. fashion supporting all the widely used formats like SBC, AAC, AptX-HD and LDAC and becoming a USB DAC if you decided to sit down cabled to your notebook or PC. Now I’m led to believe that the ‘open’ character of open-back headphones is often related more to the fact that sound leaks in and you can hear the world around you, but I still think this imparts additional advantages for the way sound waves are handled in general. The packaging is the usual Hifiman packaging which they changed recently with an all cardboard look, bundled with an average dual 3.

For bass and mids, this difference in detail is maybe not as noticeable but I think that’s just because treble frequencies often have an easier time of indicating these issues.

Comfort wise I find it almost identical to the HE400se, which can still be improved with nuggets or the addition of a comfort strap, but is not a necessity. The treble does sound a bit bright but somehow it is subtle to the point where it does not sound harsh and is not fatiging. Having that in mind, I expected a lot by the midrange of the Deva Pro, and I wasn’t disappointed…quite the opposite actually. However, we must remember that these are planar headphones with an open design and while they sound phenomenal with the bluemini, they require a proper amplifier and a high-quality DAC. Yes, the new Bluetooth module for the Deva Pro uses an R2R architecture for improved sonic quality and very impressive, low energy consumption.

Now comes HiFiMAN's latest product, an entry-level (for their lineup) wireless open-back planar magnetic headphone. Compared to mainstream Bluetooth headphones, the Deva Pro are more resolving in the bass and treble and have better imaging. The other key difference between the Deva and the Sundara is that the Deva also rolls off a bit in the upper treble by comparison. Personally I much prefer this as I find the other material causes me to itch (and produces more heat).