what’s the difference between line, instrument and microphone levels

2/20/12 Whatʼs the Difference between Line, Instrument and Microphone Levels?

1/6www.audiorecording.me/whats-the-difference-between-line-instrument-and-microphone-levels.html

Audio Recording HomeAbout meMy Works

ContactResourcesSitemap

Search

Search

Popular ContentTips on buying a mixer for home recordingBest & most popular (DAW) Digital Audio Workstation Software of 2011Selecting a Microphone for Home Recording13 Important Factors in Computer Audio RecordingSong Mixing Software Recommended for Audio Recording BeginnersASIO vs. WDM: Best practices in Modern Home RecordingHow to use a parametric equalizerBest Microphone for Vocal Recording- Tips and GuidesHome Studio Recording and Mixing Studio Setup Acoustic DesignAdobe Audition Compressor Tutorial: Implement Dynamics ProcessingCheapest 24-bit/96KHz USB Audio Interface and DAW for Windows 7

Recent PostLaney AH200 Review and Usage Tips for Live Band & RecordingBeginner FAQ on Audio Interface Preamps, Analog gears and DI BoxesCopy Karaoke or Minus-one from YouTube or DVD player to ComputerReaper DAW Tutorial and Getting Started Quick Guide for BeginnersMP3 Watermark: How to Implement Audio Watermarking and BenefitsNotion3 Mixer Console Tutorial6 Most Proven Hit Songwriting TipsAdding Reverb to Vocals: Best Practices and Processing SettingsHow to Build a Recording Studio using Digital Audio Workstation MethodMusic Rights for Film – Short Guide to Independent film makers

Get InvolvedMusic Production Help Q&A Write for Us

Post CategoriesAudio Mastering TutorialMusic Mixing



Music PublishingReaper DAW TutorialsRecording and Mixing DrumsRecording EquipmentRecording Tips

PagesHomeAbout meMy WorksTerms&DisclaimerServicesContactResourcesSitemap

ArchivesSelect Month

Subscribe

Enter your email address:

Subscribe

Delivered by FeedBurner

Share, Follow & Support Us Love this post?Help us share.Thanks.

5Like

1



by: EMERSON MANINGO on October 18, 2011 in Recording Equipment

What’s the Difference between Line, Instrument andMicrophone Levels?

Haveyou encounter recording equipment like an audio interface or audio mixer with inputs or outputslabelled as “Line” or “Instrument” and even “Microphone”? For example see the two images below:

Image credits: Focusrite Audio Engineering

In the first image, you see 2 inputs with label “Mic-Line-Inst”; this implies that it can acceptmicrophone, line and instrument level inputs. Then in the second image, you see a label called “Lineoutputs”, this means that the output is at line level and should connected to equipment requiring linelevel signals.

So what are Line, Instrument and Microphone levels? Beginners in home recording often ignore theimportance in knowing the difference between line, instrument and microphone signals. But these thingsplay a BIG role in achieving quality recording in your studio. Things associated with poor recordingsuch as noise, hiss, weak signals, unintended distortion or clipping and tonal shifts are caused by thelack of understanding between line, instrument and microphone levels.

The first difference is the voltage level

The first difference between line, microphone and instrument are the voltage levels. In a microphonelevels; the output voltage is not the same as the line level voltage or instrument level voltages.In a microphone, there is a transducer that converts sound vibrations into electrical energy. The result isan induced voltage which is VERY low (within ~2millivolts). This low and very weak voltage cannot



be used by other recording equipment or components in the signal chain. If you attempt to plug amicrophone to an input requiring line level signals, then the resulting signal will be noisy or containinghiss. It is because the input assumes it is already pre-amplified which in this case it’s NOT since theoutput is still in microphone level voltages.

To make the microphone level usable by other components in the recording signal chain with reducednoise/hiss, it should be pre-amplified. This is where you should be using a “microphone pre-amplifier”.A microphone pre-amplifier applies a very high gain to amplify the very weak microphone signals (~2millivolts) into a line level signal. Once amplified, this signal can now safely be plugged into any inputsrequiring line level signals.

On the opposite if you attempt to plug a line level signal into an input requiring ONLY microphonelevels, then you will get distortion. It is because the input signal is already highly amplified and pluggingthis input level again into a microphone input (which has a pre-amplifier on it) will further drive thesignal level into intense levels causing distortion.

On the other hand, instrument level voltages (those that are coming out of the guitar pickups) havehigher voltages compared to microphone levels but still less than line level voltages. It still needs to bepre-amplified.

Two types of Line Levels: PRO level and Consumer Level

OK so you now clearly understood microphone, line and instrument levels. So if you see input requiringline level signals, then you should feed that with a line level input right? Not so fast; this is wherebeginners in home recording can still commit some mistakes. There are two types of line levels that youshould know which are very important.

First, there is a “consumer line level”. This is defined to have a line level equal to -10dBV. dBV is avoltage measurement relative to 1 volt. Converting this to equivalent voltage level that you canunderstand and relate:

dBV = 20log (Vlevel)-10 = 20log (Vlevel), solving for Vlevel which is the consumer line level voltage:Consumer line level voltage = 0.316 volts, this voltage is in RMS measurement.

Second, there is a “pro recording line level”. This is equivalent to a voltage level of +4dBU. dBU is avoltage measurement relative to 0.775 volt. Converting +4dBU to equivalent voltage level:dBU= 20log(Vlevel/0.775)+4=20log (Vlevel/0.775), solving for Vlevel which is the pro- line level voltagePro line level voltage = 1.23 volts

So you have seen that there is a big difference between a consumer level and pro line level voltages.Consumer line level voltages are commonly seen in non-professional audio recording equipment such ashi-fi equipment and CD players. Pro line level voltages are used by professional recording gears likerecording pre-amps, etc.

Best practices when dealing with line, instrument & microphone levels

Below are some of the best practices you can implement in your home recording to get the bestrecording quality when working with any types of voltage levels.

1.) You will get a poor recording signal if you plug -10dBV equipment (a consumer line level) into an



MP3 to Music SheetConverter: Understandingthe Conversion ProcessOne of most difficult andseemingly impossible task isconve...

Adobe Audition PitchCorrection Tutorial-TuningRecorded Audio TracksThis is a tutorial on how toimplement pitch correction inA...

Microphone ImpedanceMatching to get the BestRecording SignalMost beginners in homerecording do not understand theimpor...

How to Easily Convert yourPC into a Recording Studio?Today, it is not hard to create arecording studio right in ...

input requiring +4BU (pro recording equipment). To avoid this mistake, make sure you understandingthe output and required input levels for signal compatibility. You can often get this information from themanual or ask the equipment manufacturer.

2.) Do not ever plug microphone directly to line inputs. A line input assumes that the signals are alreadyamplified. As a result, you will get a noisy output from the microphone because it’s not pre-amplified.

3.) Use balanced XLR inputs in the mixer for plugging the microphone. This will ensure that themicrophone signal will go to the pre-amplification stage. For example this is the screenshot of theBehringer Xenyx manual:

Image credits: Behringer Xenyx Manual

4.) Understand what type of line input is required (is it consumer level or pro-level inputs). Again referto the equipment manual for the specifications.

5.) Guitars with active pickups can be plugged directly into line level inputs provided they have anoutput voltage of 1.75volts (which is greater than the pro-line level required voltage of 1.23 volts).When in doubt, contact the guitar pickup manufacturer and verify.

6.) Guitars and bass with passive guitar pickups cannot be plugged directly into a pro-line level input(such as in the mixer) because they have output voltages less than the required level. You need to plugthe guitar input into the pre-amp input of your mixer or audio recording interface.

7.) A good way to assess whether you are connecting the right input-output combination of your gearsis to look at the level meter of audio interface, in DAW or in the hardware mixer. For example, notusing XLR input for connecting dynamic microphone to the mixer and plugging it directly to the lineinput will get a very low recording signal level (because it is not being passed into pre-amplificationstage) with much hiss and noise (as you increase the trim or main output volume). In this case, the levelmeters will barely move and the signal is not good.

Related posts:

Name (required)

what’s the difference between line, instrument and microphone levels

Documents