I've seen a couple complaints regarding this particular vibrator, some involving the vibrator unit either being a solid hum while playing music. Also I've seen complaints about its weak vibes unless you turn up the unit. Because I bought it direct from the Ohmibod website I could not properly write a quick review here, so here's what I found to fix. The so-called 'freedom cord' does not properly transmit bass, so the sound will be louder, less clear, and quite frankly, quite aweful. Simply buy a nice headphone splitter, and connect it to your music player, to your headphones, and to the freedom cord which you connect to the vibrator. Now your music will be much higher in quality, and the additional power will allow you to turn up the music so the vibes are stronger because it requires more electricity to power them. This is especially true if you use some nice headphones vs earphones or in-ear phones. To solve the solid vibes when a song is being played, try turning down the music a bit. There is a rather bizzare sweet spot where you will turn it down and it will be much more responsive to the bass, if not exact response. Thats it. Good luck. less