Testing a device like the E3 is always a challenge since it is both USB/Bluetooth DAC and amplifier, so I will be testing this on a pair of speakers and headphones and ear buds to test the audio fidelity and amplification.
Marshall Major Headphones
When it comes to analog headphones these are my favorite, I use them for all my mobile devices and I already love the sound quality. When connecting them to the E3 and tethering the E3 to my phone through the Bluetooth/NFC I was amazed at what the E3 is capable of. The first thing that you notice is how much better it makes everything sound, the clarity and fidelity that the E3 provides is nothing short of amazing. Suddenly you find yourself noticing minor things in the music that you have never heard without it that enriches the song you are listening to. In addition to the excellent sound quality that Sound Blaster has become known for the amplification abilities are incredible. I would have to say it is 2 to 3 times amplification over what your mobile device is able to, so much so that you can practically use your headphones as speakers.
Luxa2 Groovy Duo & Samsung ear buds
The Speakers I tested with the Sound Blaster E3 were a pair of Luxa2 Groovy Duo wireless speakers. As with the Marshall Headphones I found that everything sounded richer and more detailed. I was also able to turn up the volume higher than what the built in controls on the speakers. I would also like to warn you because the amount of amplification the E3 is capable of allows you to crank things up and could cause long term damage to your speakers, headphones and or hearing loss.
During the testing I decided to use the pair of ear buds that came with my Samsung phone and while the audio quality was improved it was unable to handle additional amplification from turning up the volume beyond what the phone normally provides. This is not a fault with the E3 but the ear buds themselves, but in reality with ear buds if you were able to increase the volume your almost guaranteed hearing loss.
The Bluetooth receiver on the E3 is always discoverable, as long as the E3 is turned on and the LED lit up it is functioning. So there is no need to push any buttons to connect your mobile device and it is possible to connect multiple devices. However only one device can be playing at a time and if you tell another to play it cuts off the first. During testing I tested it with a Samsung S3, S4, Asus TF700T and a laptop running Windows 8.1. The sound quality was always crystal clear with all of the devices I tested, there was no noticeable lag that I could detect while listening to music and watching movies. The range was exceptional and I was able to leave my phone on the charger and I was free to walk around the house and do chores and this included going between floors without any noticeable degradation.
Using the controls built into the E3 there are buttons to play, pause, accept calls, forward, back and volume through the Bluetooth wireless connection