I have notice a buzzing or humming like noise in the background when listening to music. I found that it the same way when listening to noise on apps and games. the problem might not be the adapter because i experience the same thing with the included
It's probably a sound card problem. You should check in with T-Mobile
The LG Spectrum is a 4G LTE (700MHz) phone with dual-band EV-DO Rev. A (850/1900MHz) and 802.11b/g/n Wi-Fi. It also works as a 4G mobile hotspot for up to 10 devices simultaneously. On a rainy day in NYC, (which can sometimes affect data performance), I saw download speeds averaging 5 to 9 Mbps down and 6 Mbps to 9 Mbps up over LTE; we've seen download speeds as high as 16Mbps with another LG Spectrum. Voice quality was mixed, with a crisp tone in the earpiece and plenty of gain, although it distorted at the top settings. Transmissions through the mic were clear, with minimal street noise outdoors, although the tone was on the warm (read: slightly muffled) side. Reception was fine, but the phone heated up a bit during longer calls and while charging.
Calls sounded fine through an Aliph Jawbone Era Bluetooth headset ($129, 4 stars). Voice dialing worked well over Bluetooth, but the speakerphone was weak, with a tinny voice timbre and considerable distortion at the top volume setting. The 1830mAh battery was good for a solid 8 hours and 41 minutes of talk time; given that result, expect about three and a half hours of solid 4G LTE data streaming. If that's not enough, you can swap the pack out for an optional 3040mAh battery.