The Party is Definitely in this Bag! Fydelity stereo bags have a built-in amplifier and speakers that let you listen to music without headphones. Fydelity bags connect to most any Bluetooth Device. Bring your beats to the streets or just bust some jams with your friends while "Listening Outside the Box". SPECS: INPUT: Bluetooth OUTPUT: Maximum 10000 milliWatts Signal to Noise Ratio: 60db Frequency Response: 150HZ ~ 20KHZ Amp Input Sensitivity: 200mV/150 ohm (at 1KHz) Channel Isolation: 40db Distortion: 1.