The model 649B features the exclusive Electro-Voice Acoustalloy® diaphragm. This nonmetallic diaphragm withstands high humidity, temperature extremes, corrosive effects of salt air, and severe mechanical shocks. It is practically indestructible with normal use.
The 649B is equipped with two specially designed accessories intended to increase the usefulness and mounting convenience of the microphone: a newly designed lavalier cord assembly and a belt clip. The lavalier cord assembly is supplied attached to the microphone, ready for use. Note that the flexible plastic cord adapter may be removed from the microphone, if desired, by firmly pulling it over the front of the microphone. Alternately, it may be pushed free of the microphone and allowed to slide down the cable, the neck cord being retained separately for future use. In this case, the cord adapter will be retained permanently and cannot be lost since it cannot escape from either end of the cable. (In the event the cord is misplaced, an ordinary shoe-string may be employed after simply tying a knot in each end.)
The belt clip, when used in conjunction with the lavalier cord assembly, provides effective control of cable placement and prevents unwanted mechanical noise from being transmitted up the cable to the microphone. After inserting the cable in the clip as shown in Figure 1, simply attach it to the belt at one side. It may also be clipped over the edge of a pocket.
A protective pouch is also provided to shield the microphone from filings, airborne magnetic particles, and dust when not in use.