Dear all,
I still confuse about the music reproduction process among devices, in my case:
- I have high-quality music, for example, DTS, Flac 3261 kbps 96000 Hz, PCM 1411 kbps, and I open them using Foobar2000.
- I have a Bluetooth transmitter, Creative Bluetooth W2 with Aptx
- I have a Sennheiser headphone with Aptx also.
I still have a feeling the music, when I hear it via my headphone, is not very good when comparing them when I listen on my speaker system.
Regardless of your music encoding quality (resolution, sample rate, etc) BT Apt-X can
not transmit beyond 16/48kbps and around 500kbps. Your source computer is basically converting to slightly higher than 320kbps on the fly so it can go through BT.
Despite that though: what exactly are your speakers? Because you can test how much degradation really matters by converting some of your music to 320kbps VBR then play it through both. How bad is the degradation when the source files are not being downsampled? If the degradation is not too bad when you control file format as a variable vs when you're not using essentially the same source file anymore (due to down conversion for BT), then, yeah, you're getting degradation, and you need to switch out the hardware. If the difference is really bad, then it's not just BT downsampling but everything after it (ie the BT headphones). Either you really need to replace your headphone hardware because they're nowhere near as good as your speakers (even when accounting for inherent disadvantages of using headphones)
or just have a drastically different sound signature.
It's not all just about using a DAC and headphone amp to drive the same BT headphones though in case it can work with a headphone cable and bypass the internal amplifier. BT headphones are designed to be very efficient so a tiny headphone amp running off a tiny battery can last several hours driving them instead of using an enormous amp huge caps around the transformer. Getting high efficiency drivers is not hard; what is hard is making drivers with very high sensitivitywhile keeping the response flatter. More likely your headphone drivers just have a lot of peaks and dips in the response, and in other casesBT headphones either have strong bass or the amp circuit applies an EQ effect, because the target market aren't exactly looking for measurements to compare these BT headphones to something like a Sonus Faber Stradivari Homage.
Is that I am getting an issue of degradation of music quality: from high quality, the music is reduced its quality to fit with Aptx, then it is transmitted to my phone?
Degradation is there
but I'd worry more about the hardware, and then worry about the source files (or in this case avoiding compression) only after you have better audio hardware.
In other words get a better DAC-HPamp and headphones. Note though that there will always be compromises with headphones in general vs speakers in much the same way that the price for an optimally performing speaker system is higher (ie a dampened room; instead of just low noise floor, you need to worry about reflections). So for one even if a certain headphone measures with good bass response some people find the bass weak for at least two reasons: they don't realize they have a high enough noise floor (I mean just because you don't worry about reflections doesn't mean the noise floor isn't a problem) and they're comparing these to speakers where the bass emanates through a room and hits the listener's whole body. Getting that kick in the chest from a good speaker system heightens the perception of the bass response vs just plain hearing the bass.
Do I really need such high quality music for my current devices?
No. But unless you're using a battery powered device that can have the downconversion process make the CPU drink up the charge, you want to free up cores and RAM on a desktop computer that is running the downconversion, just keep those files as they are that way when you upgrade your headphone system they're already there.
