People say my voice sounds muffled!
Survivor + Catalyst Waterproof Case uses several small membranes to help waterproof your entire phone, including your microphone. To ensure your case's acoustics are working as designed, there are three main things you should check:
1. Double-check to make sure the iPhone is installed into the case correctly. The iPhone should be installed by sliding the bottom of the phone into the case so that it rests on top of the acoustic membrane. See page 36 of the manual for more instructions. Check that when you insert the iPhone it evenly compresses the foam padding at the bottom of the case. If you did not install it correctly, please take the phone out and let the foam padding come back into shape before re-installing your phone.
2. If you had the iPhone installed correctly, but the person on the other end of the call cannot hear you perfectly, you may have a pressure imbalance. This is easily solved by opening the charge door to allow the internal and external pressure to equalize (see video below). Any change in air pressure or air temperature can cause this type of pressure imbalance.
3. If you have just taken the case out of the water, you may have some water drops on the microphone port which could reduce the volume significantly. Simply use your mouth to blow the water out from the bottom microphone port in order to clear it.
For more details on these troubleshooting steps, see pages 36 and 48 of the Owner's Guide.