I'm fairly sure the type of audio file, whether it be FLAC, WAV, whatever the bitrate is, etc. has nothing to do with Bluetooth transmission and signal reliability. Any audio from your Bluetooth audio device (phone) is going to be transcoded with whatever codec (and bitrate) the two devices can mutually agree upon, whether it is aptX or SBC or whatever. Headphones are not being sent native audio data; if so they would need to be able to decode FLAC, MP3, or whatever dozens of audio codec standards. High resolution audio, low resolution audio, none of it matters.
Headphones that support aptX do so as a bonus; the aptX (per advertising) is supposed to offer a higher bitrate among other benefits. However, the headphones most certainly fall back to the (sufficiently competent, IMO) SBC codec when aptX support isn't mutually supported.
I don't have the Sennheiser Momentums, though I own several Bluetooth headphones, and it seems to me that connectivity problems tend to come from bad antenna implementations (on either device), bad Bluetooth software stacks, and also -- general RF interference. The 2.4 Ghz spectrum that Bluetooth occupies has a ton of other traffic, from Wifi, wireless telephones, microwave, and other things.
As a newbie on this site, I've been following this thread with great interest.
Thanks to all your feedback so far, I made my purchase for the wireless momentums in the UK from John Lewis @ £379.
My initial observations after my first commute (using iPhone 6 in my left jacket pocket) into Central London using the bus and underground tube are:
- ANC worked really well on the bus, but no more so than my Sony in ear H1's. But then again there's more isolation using in-ears, right.
On the underground tube, noise was successfully drowned out but I'll see how I get on going home.
- Bluetooth
Right this is where it gets interesting. I had no cut-outs or interference at street level using 4G.
However I started experiencing interruptions in Mile End station when changing trains, more specifically when station announcements were being made. I initially thought the iPhone was blocked in my pocket and when I altered the position the interference stopped. But then when the next announcement was made, I heard another crackle.
Back on the next train, passing through Liverpool St station, again same problem. Interference. Once I was in the tunnel again, no issues with interference.
- Sound quality.. You are all correct it is really good. I mean really good. However using an iPhone 6, sound could be brighter / louder because I had to raise the volume 1 bar above the usual mid-scale threshold to feel fully immersed in the music.
- Design.
Right I had some issues here. Quite annoying but might be down to my head size / position of headphones.
It's cold at this time of year which means I have to wear a jacket. The volume rocker on the headphones seems to get caught with my collar which means that the volume increases or decreases by itself. This happened around 5 times. But my collar isn't bigger than a normal collar should be.
I've not decided whether I can deal with this for £379. But I hate wires, so I expected a better Bluetooth implementation and positioning of the volume rocker.