Pro Line Level
In professional line level audio, the reference level is commonly set at +4dBu, equivalent to approximately 1.228V. This level is the standard signal strength used among professional audio equipment. Balanced transmission is generally employed for pro line level signals, utilizing TRS (Tip-Ring-Sleeve) or XLR connectors. Balanced transmission offers higher noise immunity and improves signal accuracy. Pro line level is designed to operate without signal loss even at distances of 100m and with a 600-ohm impedance. Through impedance matching, it minimizes signal loss, ensuring accurate signal transmission even at 100m distances.
Consumer Line Level
Consumer line level is primarily used in home audio equipment and generally operates at a voltage level of -10dBV, approximately 0.316V. Unbalanced signal transmission is primarily used at this level, often using RCA cables, TS cables, or 3.5mm connectors. These signals are commonly used for short distances (about 3m or less), and they are designed to transmit at a sufficient RMS voltage to avoid signal loss.
Considerations for Compatibility
There is approximately an 11.78dB level difference between +4dBu and -10dBV, so additional equipment or settings may be needed for compatibility. Some professional audio equipment provides input/output ports that can accommodate consumer level signals.
Summary
Pro line level and consumer line level are designed for different applications and requirements. Pro line level is suited for high-impedance and long-distance transmission, using balanced signal transmission. Consumer line level is optimized for short-distance unbalanced signal transmission and is relatively less expensive to manufacture.