For this comparison, I'll be using Flares Pro to all other amps since the Flares Wireless that included with the Pro only works with itself as it is using unconventional outputs (two mmcx connector for balanced out). The setup will be from the Onkyo Granbeat CMX1, connected using either aptX or aptX HD codec (whichever higher is available) to the amp, and from the amp straight to the Flares Pro using the single-ended 3.5mm headphone jack. Exception will be the Flares Wireless itself that connect directly with mmcx and even if the amp have 2.5mm balanced jack, it will be ignored as I don't have the cable (XB10 and BlueDAC).
Let's start from the Flares Pro and we'll be going on to the other amp as we go on. The advantage of supplying their own wireless module is that they can directly tune the DSP to compensate with Flares Pro frequency response and it certainly seems to be the case. Listening to Flares Pro with the wireless module is a pleasing experience, the sound signature is just spot on, maybe just slightly elevated on the lower end, which I enjoy.
The bass position is just right at where I wanted it to be, slightly more than neutral but never become bloated or bleed into the mid. However it wasn't very tight or fast, and the definition is just average. The mid however, is lovely. Warm, smooth and sweet are the words that I would like to use to describe it. It is just right, with enough body that doesn't make it sounds too thick nor thin. This transition into the high nicely too, which is also spot on. Never became sibilance and it has enough sparkle that it never sounded dull.
I have a lot of praise to their tuning, but then there is limitation to the technology. The Flares Wireless only support aptX codec, there is no higher resolution codec like aptX HD and LDAC on board. This certainly apparent, as while the resolution is pretty good, it's not great. A complex passage will sounds a bit compressed, making it hard to discern what's going on.
Next, let's compare it to AT-PHA50BT, this Bluetooth amp is only sold in Japanese market I think. This is the older model that was released back in 2014, while they have released a newer version called AT-PHA55BT last year (stay tuned for that, I guess
). Same as the Flares Wireless, this also only support aptX codec so I don't expect any improvement, and right I am.
What the PHA50BT output is actually not far off from Flares Wireless, they sounds very similar indeed. The differences is that the low is not as elevated anymore, instead the elevation shifted into the high region. This make the PHA50BT the brighter sounding of the two, but only slightly. I wouldn't consider the PHA50BT sibilant, actually far from it. Basically, less bass, less smooth and a bit more sparkle, that's it.
Other than that, the resolution is also similar, if not slightly behind. Whatever the Flares Wireless struggle to resolve, this is also happen to be the same case here. While PHA50BT came up slightly worse, this also cost the less of the bunch here, around $75 and it came with some features that none the other amps had, like the small display on front and 5 different sound profiles to choose from.
Next, let's try the aptX HD on AK XB10. This is possibly the more popular Bluetooth amp on the market and I think it just got a price drop recently. This is actually the first Bluetooth amp I bought, which sounds so good that it convinced me that Bluetooth audio can rival the wired solution.
The aptX HD codec advantage is clear from the get go, the resolution is so much better. It's like it opened the curtain and all the details just scream out layer by layer. It's very close to the wired sounds, which is a quite amazing feat. The bass is tight, punchy and well defined. However, gone were the warmth and sweetness from the Flares Wireless. The XB10 sounds a bit cold, the body is a bit thin but it is capable to render every details very well.
The high is also a bit elevated here, making it the brightest sounding of the bunch. That said, I found it to be just on the borderline before it got sibilant, it's in border and it is still acceptable to me. I might get fatigue on a long listening session, but it also have the shortest battery life here, clocking just at 3 hours, so I might never reach this fatigue (to be fair, I would pair XB10 with U12 than with Flares Pro). What XB10 really excel here is listening to orchestra, as it capables to clearly layer each instrument, never feel being compressed.
Next is the newest addition to my collection, the Bluewave GET. This retails at $129, but you can get it on Massdrop at just $99 whenever it drops from time to time. This has the most recent specification out of the bunch, namely Bluetooth 5.0 and also, of course, the aptX HD codec. Again, I expect a lot from the GET and boy, I wasn't disappointed.
The aptX HD codec, again, show it superiority here. The resolution is great, it is slightly behind XB10 but got very close and it's far better than both the Flares Wireless and PHA50BT. While the XB10 can sounds cold, the GET has a hint of warmth instead. It is still not as warm nor sweet as Flares Wireless, but with much better details, it came off very pleasing. However, something feels lacking and I'm not really sure what it is until I switch back and forth against XB10. It's the bass. The bass is tight and punchy, it's well defined... but it doesn't render the sub as good as XB10, it seems to drop off a bit sooner, losing some details I would hear on XB10.
But the high is pretty much spot on. It seems to be slightly brighter than Flares Wireless, but just slightly, it never came into XB10 territory. What I like about the GET is the analog volume control, allowing me to fine tune the volume with a greater amount of precision. Just be careful not to slip and blast high volume into the ear, it can get pretty loud. However, the GET also appear to have more hiss than all the others. Flares Pro is not that sensitive to hiss and I still can hear it slightly, which isn't the case with the other amps I'm comparing here.
Finally, let's go against the behemoth here, the CEntrace BlueDAC. As you can see, the size is much bigger and it is strictly for listening to music only, you can't retrieve call as it is the only one without microphone. It is also the most expensive, retailed at $399, there is a lot of expectation here. Disappointingly, it only support aptX, no higher resolution codec available. But can the better amp circuit compensate the lack of high resolution codec? Almost.
It is clearly able to resolve better than the other two aptX amp here, but still came off behind both XB10 and GET. The bass is tight, punchy with great extension. The mid is pretty smooth and warm, but here it can get somewhat uneven. The mid-low area seems to be a bit thin, causing the mid-high to be unnecessarily harsh sometime. This is quite weird, and not something apparent in all the music I tested. It doesn't bother me when I paired it with U12 and Aeon Flow Closed, but it does here with Flares Pro.
The high is also quite good, still more elevated than the Flares Wireless but not much. It doesn't come off as bright to me and it is very smooth. Again, it is capable to resolve and layer details better than the other aptX amp. Other than the weirdness in the mid, I found BlueDAC to sounds very good indeed, but still it can't outclass the superiority of higher resolution codec. However, while BlueDAC can be used in wireless, I think it is much better suited to be used wired. There's a couple reason for that, first being that the size is too clunky to take around as Bluetooth amp, and second, it is also prone to interference from mobile radio (forget about putting it into the same pocket as your smartphone).
In summary, I think the Bluewave GET ended to be the superior one out of this comparison. But the hiss might make it not suitable to use with sensitive IEM, especially those with BA driver. In that case, the XB10 is preferable, but you had to live with the 3 hours battery life (the other amps here have 6+ hours battery). For Flares Pro user, the GET is a good purchase to upgrade the Bluetooth experience, but other than that, you will be served better with the included Wireless module.
Here is how I'll score this based on sound quality:
Bluewave GET: 9/10
AK XB10: 8.5/10
CEntrace BlueDAC: 8/10
Flares Pro Wireless DAC: 7.5/10
AT-PHA50BT: 7/10
Thanks for reading. Hope it helps.