| To be fair, I haven't recorded any soundclips, and there aren't any good/useful ones on the net that I know of. It's precisely because it's such a subtle effect- most of the time switching on a compressor you will hear one of more of these three things:
1) "hey my signal just got noisier"
2) "hey my signal just got louder"
3) "hey my preamp isn't clipping as much"
Sometimes, depending on the specific comp and your settings and the input signal from your bass, you may also hear other qualities, such as the ones I describe in my reviews like loss of lows, loss of highs, extra sustain, fatness, etc. But TBH most of those qualities would be hard to effectively hear from an MP3 or Youtube clip due to the signal degradation.
When you listen to the soundclips provided by makers/vendors of compressor pedals, invariably it's some guitar guy playing a slick lick with no pauses between notes, and cut or faded at the end so you don't hear the noise afterward. This can show a nice fat present tone with minimal dynamics, but they never do an A/B, and it never reveals the amount of noise between notes or the irregularities that may occur with different attack/release times.
IOW I do think at some point in my life, if I'm ever financially "comfortable" again (not seeming likely), it would be worthwhile to record some hi-res WAVs of the all the compressors at a range of settings, with a range of input levels, engaged/disengaged, and with a broad array of playing techniques including rests. Frankly that level of complexity and obsessiveness is what would be required IMO for any compression audio clips to be worth anything to anybody. | 
