Lectro line level input cable recommendation

While wireless microphone transmitters are normally thought of as being used with microphones, we often use them for line-level signals, such as when tapping into mixing board feeds or when using them as wireless “camera hops” to a camcorder. It has been determined that the previously recommended line input cable sometimes forced the transmitter limiters to work too soon and more often than Trew Audio recommends, particularly for dramatic dialog production, even when the transmitter’s input control was set to its lowest position.The new recommended cables (REM CALECXL3/5L & REM CALECTA3/5L) are wired so that the TA5 connector has the audio “+” through a 22K resistor to pin 5, then the ground and audio “-“ to pins 1 & 4. With this cable, the results described in the table below are achieved.

When standard line level signals are used, the transmitter input settings in the table cause the transmitter’s limiters to activate with a signal that is approximately 15dB above the 0VU reference level. It is the opinion of Trew Audio that these settings provide an ideal balance of overload protection, dynamic range, and signal to noise with the Lectronics wireless systems. It is also our opinion that during the peaks of normal conversational dynamics, settings that cause the occasional activation of the Lectrosonics limiters generally enhance the overall quality of dialog audio. But, as always, the ears of the professional operator should be the final judge.

It should be noted that the output levels of mixers can vary a bit, particularly between different brands. Therefore, for this and other reasons, the settings in the table below should be considered a starting point, then subject to the engineer’s discretion based on both technical criteria and personal preference.

(Thanks very much to Nashville sound mixers Matt Hamilton and Alex Altman for their help.)