These All Purpose Studio-Grade Condenser Microphones Combine Skillful Workmanship with a 1-Inch Gold Deposited Diaphragm for the Most Vivid Sound. There are a Variety of Optional Accessories available to Meet the Requirements of Almost all Applications and Settings.The CMH8A has a single Diaphragm with Fixed Cardioid Polar Pattern. There is no External Control Switch, but there is an Internal Low Cut Filter. The CMH8A has the Same Sound Quality as the CMH8B, Making it the Right Choice for those on a Limited Budget.