Immediately upon the introduction of the Collins S-Line the industry recognized the popularity of these units. Other traditional OEM manufactures looked for add on products that enhanced and took market advantage of the S-Line. The DX Engineering Speech Compressor was one of these products. This device compressed the audio from the microphone into a smaller bandwidth. When properly adjusted a few additional dB of intelligence can be delivered in single sideband mode of operation. These devices from day one should have been designed with a fixed output level. Today we still hear the operator who thinks "more is better" and we can not understand him because his compression level is to high. These units add value to the earlier series S-Line transmitters making these units more desirable than the units without this device.