In an audio interface or any other, there are three main types of inputs. They are Mic, Line, and Instrument level inputs. Their utilities and the instruments that you can pair them with differ. In this article, our motive is straightforward. And that is to provide that governing differences between Mic, Line & instrument level inputs.
There are a lot of different inputs and outputs on an audio interface. But our focus here is to dive deep into the differences of various information universal to all the audio interfaces.
First, look at the diagram below that I just created. It will give a fair idea of the different dB ranges in which each input signal lies.
Different types of signal levels in an audio interface
From the above image we can infer that:
- Mic level signal is the weakest.
- Line level input is strongest after speaker level.
- Instrument level input signal lies between mic and line input levels.
| Feature | Mic level | Instrument level | line level |
| signal level | -60 dB to -40 dB | -30 dB to -10 dB | -10 dB to +4 dB |
| signal strength | weakest | b/w mic & line level | strongest |
| cables required | XLR | 1/4″ TRS | 1/4″ TRS |
| Instruments used | condenser or dynamic mics | Keyboards, drums, compressors, mixer | guitars, basses |
Mic Level signal in audio interface
[Also check: Top 15 things to consider before buying an audio interface!]
The mic level signal is the weakest of all signals present in an audio interface. It is one of the primary reasons why a mic level input requires a signal amplification of some kind.
Preamps increase the voltages of mic level recordings to amplify the mic level signal. These preamps increase the voltage and gain levels of the audio recorded by mic-level inputs. The primary motivation behind amplification is to bring the mic level signal to the line level.
E.g., Audio Interfaces, Mixers, or Amplifiers.
The preamp quality becomes very important, and if the preamps are of poor quality, they make a lot of noise when you increase the gain or voltage of the weak input signal. It is one of the fundamental reasons that mic preamps should be made healthy by manufacturers.
Some preamps provide clarity, while others add a bit of color.
In conclusion, we can say that the mic level input signals are the weakest of all.
[Also check: Audio interface setup diagrams to connect MIDI, mics, guitars, monitors, mixers and other studio gear!]
Line level signal in audio interface
Various studio pieces of equipment accept a line-level input like delays, EQs, compressors, and keyboards.
You must have heard that there are two standard voltages for line-level inputs. It is around -18 dB for consumer level, and for studio-grade audio gear, it is +4 dB.
The +4 dB signals are much more robust and are great for studio gears to accept and further work with the audio signal.
But nowadays, some audio interfaces are equipped with a switch to change the input levels as per convenience. This feature allows you to connect both consumer-level and professional-level audio gear.
Speaker level signal in audio interface
A speaker level signal is a signal that gets amplified using amplifiers. The monitors connected to the interface are an example of a speaker-level signal.
The input audio coming from the audio interface to studio monitors is amplified to a very high degree using amplifiers.
The power required to drive these speakers depends upon the size of the monitors. Large monitors require higher voltages, while small monitors require much fewer voltages to operate.
Instrument Level signal in audio interface
The thing with instrument level or Hi-Z inputs is that they produce a high impedance audio signal. For this reason, these high impedance inputs need a relatively high impedance input.
Most of the audio interfaces under $500 have almost two high Z or instrument level inputs. Let’s see what you can plug into these high Z inputs.
A typical example of a high impedance instrument is an electric guitar. The pickups found in electric guitars have very high impedance levels, which a mic or line-level inputs cannot handle.
Solution: Convert high impedance unbalanced signal to low impedance balanced signal
Only “High Z” or “INST” input on an audio interface or a mixer manages a high impedance audio signal from the guitar.
In addition, DI boxes or Direct Injection Box also do the same task. A DI box converts a high Z signal to a low Z signal.
An audio interface that is best for guitar recordings is the IK Multimedia AXE I/O. It has features that no other audio interface has, like an inbuilt tuner, AMP OUT, which eliminates the need for DI Box, external pedal switches, Z-tone, a button for active and passive pickup, and a free bundle of plugins worth $1000.
The reasons to convert high Z to low Z are:
- Noise is reduced,
- The signal can be transmitted over longer distances.
As you can see from the diagram above, Instrument level voltage is stronger than Mic level signal but weaker than line-level signals. Therefore, it lies in between the mic and line-level signals.
What is difference between Mic level and Line level?
As you upgrade your audio interface, the mic preamps really get great in terms of audio quality that allows a producer to record studio grade sound. Also, the gap between mic and line level is filled by amazing quality sound converters.
[Also check: Best high end audio interfaces for studio grade recordings]
The only obvious differences between mic level and line-level inputs are:
- Instrument compatibility,
- Signal strength,
- And whether amplification is required or not!
As you may have understood by now that the signal strength is weakest in mic level audio and comparatively high in line level. The audio signal coming from mic level input is converted to line level with the help of Pre-Amplifiers. Then, the audio signal is heard by a listener on either a studio monitor or a headphone.
[Also check: Highly portable audio interfaces perfect for touring musicians! ]
What is the difference between instrument and line level?
The significant difference between instrument level and line level is of impedance carried by the input. The instrument-level inputs have high impedance and are fit for use by high Z instruments.
Furthermore, the voltage range of the instrument level audio signal is between mic and line level. Most of the audio interfaces under $200 will provide you a good quality mic preamp, high impedance, and line-level inputs.
[Also check: Best audio interface under $200 that provide a well all round performance!]
Conclusion
We discussed Mic, Line & Instrument level inputs in an audio interface. In addition, we saw the various differences between them. These were related to instruments that can pair with the inputs, cables and a few technical aspects.
Again, feel free to refer the table and mention any cool fact that is not listed above.
However, if you are a music producer who is willing to buy a perfect audio interface, I highly recommend reflecting back on your budget, studio gear and future requirements.
Leave a Reply