I am using the S4. There are two ways to raise the volume. First, make sure you have increase the S4's volume by moving you finger over the right sensor on the S4. You will hear it say, volume level up, or something like that. Then there is also the bluetooth volume for the Iphone 4 when the device is connected. Raise and lower it using the volume buttons on the side of the phone. There is also a sensitivity level selection. Refer to the S4 user manual for how to do it. Also, make sure after you are saying, blueant speak to me, you say voice commands to activate the phones in built voice command system.