What Does a VU Meter Do and Why It Is Essential For a Great Mix

By | February 2, 2015

In the modern times of digital music, we have many sophisticated metering options available to us. Sometimes these modern meters can be a bit “too much” in visual and numerical information. The solution: let’s go back in time and look at the VU meter. You might be wondering: “What does a VU meter do and how can I use it to make my music any better?” Well, read on to find out…

What is a VU meter?

The VU (volume unit) meter is not a gain reduction meter which are seen in compressors, even though they look similar. VU meters are not peak meters either, such as the ones found in every DAW’s mixer.

StereoChannel VU-meter by Sleepy-Time DSP

StereoChannel VU-meter by Sleepy-Time DSP

VU meters were originally designed for the analog world to visualize the average volume of a signal. That’s right, a VU meter displays the average volume or loudness of the signal that’s sent through it.

VU meters are very slow, so they don’t respond well to quick transients. For this reason, VU meters don’t show available headroom like peak meters do, where the headroom is clearly visible under zero dB.

What does it show then? Let’s continue…

Why would I need a VU meter in my music?

As said before, a VU meter shows the average loudness of a signal. It shows the energy and intensity of the music. In mixing, a VU meter shows the actual level of the mix.

One of the purposes of a VU meter is this: it’s healthy to have some kind of “borders” when mixing music. The 0VU can be thought of as the border. But it’s not an absolute limit. It’s fine to go a little bit beyond 0VU, as it doesn’t “hurt” the mix in any way. Go too much, and your mix could suffer. Generally, 2-3VU could be considered as the very limits.

The 0-3VU range is what should be considered as the limits.

The 0-3VU range is what should be considered as the limits.

The VU meter can be calibrated so the end result of the music achieves the loudness or average volume that is desired.

Personally, I use a VU meter on the stereo mix bus on every mix I do. As a result, my music has more consistency in sound levels and average loudness; my mixes are at the same volume level every time and have similar, punchy dynamics.

A VU meter needs to be calibrated to get the right results.

How to calibrate a VU meter correctly?

In order to calibrate a VU meter, we need to decide a nominal operating level which will equal to 0VU on the meter.

In StereoChannel, the nominal level is found by clicking the small drop-down menu button. All VU meters have the same function.

In StereoChannel, the nominal level is found by clicking the small drop-down menu button. All VU meters have the same function.

In the digital world, a healthy signal level is about -20dB on the peak scale on average. There can of course be peaks above -20dB, but to play safe, keep those peaks under -6dB. So think of -20dB as the average level of any sound signal.

Let’s say we would send a pure sine wave gain-staged to -20dB on the peak scale, through a VU meter. The VU meter’s needle would stay at 0VU if calibrated to a -20 nominal level. The sine wave always stays at the same volume level, so it’s a good example.

If you calibrate your VU meter to a nominal level of -20 or -18, you will always have a nice amount of headroom and your mixes will never clip, causing unwanted digital distortions.

The VU Meter In Action

Don't pin the needle, just make it "dance" around 0VU.

Don’t pin the needle, just make it “dance” around 0VU. Photo Credit: PSYJAZZPOP via Compfight cc

The point here is to calibrate a VU meter for the stereo mix bus, and adjust the individual faders so the VU meter’s needle would be “dancing” around 0VU. Do that, and you’re already on the other side.

Of course, as a smart mixing engineer you would have gain-staged each instrument individually in the beginning of a mix, according to the rules of the VU meter, and letting no channel peak above -6dB on the peak scale. You can gain-stage each instrument to the nominal level of -20, which is the same level used in calibrating the master bus VU meter.

Note that transient-rich, high frequency and fast material doesn’t necessarily even move the needle on the VU meter at all. Don’t worry about it as it’s completely normal. Sustained sounds such as bass will respond nicely to the VU meter, because they have so much energy. As I said before, the VU meter has a very slow respond time.

It’s important to use a peak meter together with a VU meter for best results. If you use both correctly, you’ll get a killer gain-stage and mix.

I pulled a recent mix of mine to FL Studio. As you can see, the VU meter looks as it should, and the track has 10dB of headroom, which can be seen from the peak meter on the right!

I pulled a recent mix of mine to FL Studio. Since I mixed it at a nominal level of -20, the VU meter looks as it should, and the track has 10dB of headroom, which can be seen from the peak meter on the right!

VU meters are very handy for judging bass levels of your mix. Let’s say you have a kick, bass and drums mixed together nicely, the meter moving around 0VU. Then you decide to bring in the sub bass full of the very lowest frequencies.

In your room, you don’t really hear the sub bass because of bad acoustics or too small speakers. What you do notice though, is that the stereo bus VU meter’s needle is now pinned all the way to the right, and this is a clear sign to back off the sub bass. So use the VU meter as an aid.

The other advantage a VU meter has it ensures your mixes will have enough headroom for mastering, because like I said, it sets the “limits” for the level of your mix. If you let the VU meter help you and mix to 0VU at a -20 nominal level, you will have a nice, healthy mix with at least -6 to -10dB of headroom. The mastering engineer will thank you.

Even though you don’t see the available headroom on the VU meter, it doesn’t matter. When calibrated correctly, you’ll be swimming in safe waters. You can always double-check using a peak meter.

Awesome, VU Meters Rock!

Photo Credit: Daniel Dreier via Compfight cc

Photo Credit: Daniel Dreier via Compfight cc

VU meters are great tools from the analog era – and a gift for us digital musicians. It’s so easy on the eyes as well, and who wouldn’t dig such analog vibe in their sessions than what a simple VU meter brings?

Learn VU meters, live with them for a while and see how it behaves towards your music and you’ll begin to understand it.

Produce great-sounding music by having a VU meter as your friend!

Leave all comments below and I’ll make sure to get back to you.

(Psst… Check out the great free MonoChannel and StereoChannel plug-ins from Sleepy-Time DSP.)

-JP

What do you think about the VU meter? Did you only use a regular peak meter before? Did you know about different metering options? Let’s discuss!

10 thoughts on “What Does a VU Meter Do and Why It Is Essential For a Great Mix

  1. Kyle

    Great info here. I’ve done some sound recording and VU meters are great to have for a variety of reasons. Thanks for the post.

    Reply
    1. JP Post author

      Yes, they are indeed. Great for setting up the input gain for recording instruments, and of course mixing. No worries there!

      Reply
  2. Paul

    Interesting stuff – I’ve seen that meter several times when I’ve recorded in professional studios, but now, having my own home studio, I just rely on everything inside of Logic (which is the platform I use to record). This is an interesting read.

    Reply
    1. JP Post author

      Thanks Paul. Yeah, VU meters are everywhere in pro studios, especially in the mixing consoles. Anyone can get by by peak meters (such as those in Logic), and VU meters are a great option, both for recording and mixing, and also mastering.

      Reply
  3. Ian

    Hi, I was just searching the internet for some sound equipment that I am after and your site popped up. As far as VU meters go, in my opinion they are great for an instant visual feedback on what you are trying to produce. They can help balance sound and make sure that certain noise levels (bass, treble etc) are not to high which could overshadow other parts like vocal or instruments. Thanks. Ian.

    Reply
    1. JP Post author

      Hi Ian, thanks for the comment. Indeed, VU meters are great for instant visual feedback on any signal or instrument. They are especially great for sound-staging before recording or setting up a mix.

      Reply
  4. Adrian

    Hey JP,

    Thanks for the info on VU and Compressor. Will you be posting any info on EQ anytime soon?

    Thanks
    Adrian

    Reply
    1. JP Post author

      Hey Adrian,

      Glad you liked my VU and compressor articles! An EQ article should be coming out at some point. Is there any specific info you’d like to know about equalization?

      -JP

      Reply
  5. Mick Lamm

    Hi
    I’m using Studio One v3 as my DAW. I play a steel string acoustic guitar into a Duet 2 then into my DAW. I’ve recently started using the VU meter from Klanghelm. I calibrate it to -16. When I record I make sure the needle just hits 0. However on the peak level meters in my DAW the levels are up around -6dbFS. I thought that by calibrating to -16 on the VU meters I should be seeing my peak meters averaging around -16 but they are going much higher. Any advice around this would be much appreciated.
    Thanks
    Mick

    Reply
    1. JP Post author

      Hi Mick,

      The reason why VU meters don’t react to peak levels properly is because they are very slow. VU meters are good for measuring the overall energy of the signal. Don’t worry though, it’s okay to have peaks in your recordings, just make sure they stay well below 0dbFS. For example, a VU meter doesn’t necessarily react well to a transient-rich hi-hat line from a drum kit, but it will show the average loudness of a fat bassline really well, because a bass has so much more (sustained) energy which is picked up by the meter.

      When you calibrate your meters to -16, it means the average level of your signal will hover somewhere around -16, shooting off peaks above and below it. Remember, the VU needle is too slow to react to sudden peaks.

      The best method is to use both VU and peak meters. Use peak meters as a safety net to make sure, ideally, no peak goes above -6dbFS. Hope this helps.

      -JP

      Reply

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