But a question for those that use earbuds plugged into the 20S: what are your experiences on the music's audio fidelity (given the audio is transmitted to the 20S over BT)?
Bottom line up front: You need to select your speakers by trying them out yourself as if buying speakers back in the day. What does it sound like to you? The Sena exceeds the basic bluetooth sample rate and should clearly support MP3.
Some specifications:
Target specification CD: CD audio Sample rate 16 bit 44.1 kHz is commonly used for music reproduction (16 (bits) x 44,100 (fs) x 2 (two channels in a stereo signal) = 1411.2kbps)
Bluetooth 4.1 audio specs:
http://soundexpert.org/news/-/blogs/audio-quality-of-bluetooth-aptx
Compression ratio: 4:1
Audio Format: 16-bit, 44.1kHz
Data Rates: 352kbps
Frequency Response: 10Hz to 22kHz
Algorithmic Delay: <1.89ms @ Fs 48KHz
Dynamic Range: 16-bit: >92dB
THD+N: -68.8dB
Sena 20s specs
Sample rate: max. 48 kHz (DAC)
Advanced Audio Distribution Profile (A2DP) supports MP3
https://en.wikipedia.org/wiki/List_...dvanced_Audio_Distribution_Profile_.28A2DP.29
Following from MPS source:
http://www.soundonsound.com/techniques/what-data-compression-does-your-music
Psychoacoustics is the study of how humans perceive sound. By middle age, few people can hear above 16kHz, and even young people with good hearing perceive these high frequencies far less efficiently. Perfect hearing is rated at 20Hz-20kHz.
Amazon offers MP3 files at 256kbps (it used to only offer 128kbps), and iTunes now offers AACs at 256kbps. The initial goal of MP3 was to produce 'acceptable' results when coding at 128kbps. That's a data reduction of over 90 percent, producing a file about an 11th the size of the raw 16-bit, 44.1kHz PCM file. MP3 lacks crisp high frequency and solid bass notes.
My conclusion: Get yourself a hearing test and see what your range is (don't wast money on speakers out of your range, they get very pricey with multiple drivers). Right now MP3 is about the best we're going to do based on file stoage for a good selection of music. Then check out several speaker's or earbuds meeting your range and sound good to you. Buy a BT system that supports Bluetooth 4.1 and ride