Instruct: Classify Amazon reviews into positive or negative sentiment
Query: good size, fast pairing but low volume

I bought this device 2 days ago and the first 2 hours it performed nicely. Cell phone to cell phone calls were fine, synchronization was excellent with my Motorola black razor and it even allowed me to use the voice names I had recorded in the cellphone to make calls with voice recognition, just by pressing the big blue button in the speaker phone.The problems began later, when suddenly the volume started getting very low in some calls. Since this device is for car use, the speaker should be bigger. This defeats the whole purpose of a "speaker phone" because yes, sometimes the audio is loud, but I've had phone calls with my wife from her office and I have to pick up the device and put it in my ear in order to listen.I will return my device tomorrow.