ignition wrote:I got a generic aux cable to link my echo to my soundbar, but the sound quality was far inferior to using Bluetooth. Don't really understand why though, and not sure if a 'higher quaility' cable would've made any difference.
It's to do with the different signal types. The echo itself is a digital machine and will output a digital signal. Audio from the 3.5 jack is analouge. So the Echo passes the digital signal that it creates through a digital-to-analogue converter (DAC) and then you plug your analogue aux cable into the 3.5 jack. With the bluetooth signal it just stays digital.
The reason for the difference is that digital is binary (0s&1s) and therefore either is or isn't. So if your digital signal isn't being picked up by the audio equipment you just won't hear anything (you might but it will be broken up). Analogue sends the signal in a wave form and the wave form is subject to all kinds of interferences, just like when you tune your radio to the correct wavelength. You can tune it in to somewhere around the correct frequency and you'll hear something but it won't be perfect untill you get the wavelength perfect. All kinds of silly things can make a difference with analogue audio. The quality of the hardware, the shielding of component parts and cable from electical noise, the quality of the cable used, the solder or weld quality and resistance between the connecting electrical components etc.
It's trial and error finding out where your weak link is but the first port of call for most people is the cable as this is the cheapest and easiest to replace without buying new output or receiving hardware. If possible I would just connect over bluetooth the whole time if you're happy with the audio quality and it does what you need it to do.