In this article we cover some of the basics of line level and mic level outputs.
-
What does line level mean?
-
How is line level different from microphone level?
-
How is professional line-level different from consumer line-level?
-
What about aux level?
-
What are signs that you need a different audio input?
-
What device to I need?
What does line level mean?
A device that operates at line level either has a very strong output signal, or only functions properly when you feed a very strong signal into it. Examples of line level outputs include mic preamps, mixers, soundboards, the "line out" of an amp, and some effects-loop "send" jacks.
While it varies from device to device, typically line level is in the region of 0 dBV (1.000 volt). See professional line-level v. consumer line-level for more of a rabbit hole.
How is line level different from microphone level?
A mic-level or microphone-level signal is the voltage amount that comes out of a microphone when someone speaks into it, typically just a few ten-thousandths of a volt. Of course, this voltage varies in response to changes in voice level and and in the talker-to-mic distance. But the signal is still quite small relative to line-level.
Microphone level is in the region of -60 dBV (0.001 volt) to -40 dBV (0.010 volt), or just a fraction of line-level.
How is professional line-level different from consumer line-level?
Even though you might be using a line-level input or output, turns out it's more complicated than that. You need to know if you're using a professional line-level or a consumer line-level.
Professional line level is generally thought of as a signal whose level is at +4 dBu (1.23 volts or significantly higher). Signal-processing equipment and professional mixing consoles are examples of professional line level equipment.
Consumer line level is generally thought of as a signal whose level is at -10 dBV (0.316 volts). CD players and DVD players are examples of consumer line level equipment.
What about aux level?
You may also encounter jacks marked "aux," or auxiliary. Aux-level inputs and outputs are found on many kinds of equipment, including DVD player, tape recorders, CD players, and some computer sound cards. Aux-level is near to line-level, but aux-level inputs and outputs are nearly always unbalanced, using RCA connectors or 1/4" phone plugs. Microphones will not operate properly if connected to aux inputs.
What are signs that you need a different audio input?
Generally speaking if you send an instrument-level signal into a device that needs line-level input, you will get weak sound and probably extra noise as you increase the signal to compensate. If you send a line-level signal into a device that's meant for instrument or mic-level input, you will get distortion.
What device do I need?
1) To go up in dBV
You can boost microphone level signals up to line level signals. Mixers are the most popular piece of equipment. A mixer will not only boost a microphone level signal, but it will also combine multiple signals together into a single output. There are also devices called Mic preamplifiers or Mic-to-Line amplifiers. These are available as single-channel or multi-channel devices.
2) To go down in dBV
You can reduce, or attenuate a line level signal down to a microphone level signal, using our iPhone-Mic-Line Level Adapter for an 1/8" plug, Mic-Line-Plus Adapter for monitoring, or our Mic-Line-Pro Adapter for a 1/4" plug.
We also have dynamic microphone adapters, ECM (batteryless) microphone adapter cables, and line level to mic level adapters for DSLR cameras.
Mic-Line: -20dBV
Mic-Line Plus: -17 dBV
Mic-Line ECM: 0 dBV
Mic-Line Dynamic: Corner Frequency of 60 Hz
Not bored yet?
See the attachment below for a detailed explanation of the difference between dBu, dBv, and dBV, or have fun with this dB and voltage calculator.