It has come up over and over again. A recurring problem unique to single-ear headsets equipped with 5-pin XLR connectors. Which pin should the one earpiece solder to? The answer to this question can vary depending on several factors including system design and the manufacture of the equipment that the headset is plugging into.

Equipment will often have the ability to alter their configurations to service a wide range of user's needs. That might include connectors for both 4-pin and 5-pin headsets, and the ability route signals to left, right or both ears. What is significant here is that the Headset not bear the burden of altering the performance of the equipment because this can lead to unpredictable performance for the individual user and expand to other users as well.

In the case of the RTS BP-325, the most common and simultaneously destructive condition to find is a 5-pin headset with pins 4 and 5 tied together. Shorting together the pins in the headset causes the earpiece amplifier outputs to also short together. This, in turn, causes the earpiece amplifiers to draw excessive current from the beltpack's internal power circuits which drastically changes the impedance and maximum audio level of the intercom channel. This manifests in the form of extreme levels of distortion and completely unintelligible audio for all users on that channel

The proper method of accommodating the need to hear both channels in a single ear headset is to set the internal jumpers in the belt pack to the MONO position.

It is important to note that in other types of equipment, it is possible that with pins 4 and 5 tied together, no unwanted side effects could occur. That is no excuse for allowing a headset, with such potential for damage, to float around a facility or production truck. Go the extra mile and investigate completely the ramifications of such a modification and pursue alternative alterations to accommodate the needs of the users.