Adventures In Audio

Virtually Useless? Hear what VU meters can really do for you in the studio

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Avoid BottomFeeder Populists:  My PC advises me NOT to download the TB Pro exe.

Eric Newhuis:  I feel like modifying my few (real) VU meters with a circuit witha reset button that shows me the max gain reached to see if I've oversaturated something I didn't quite hear, so I can crank the gain up further to make sure everything is saturated. :D j/k that A.I. animation is creapy and I never want to see it again. Forgive me I am a drummer...and don't use Google. Use Freespoke.

Eric Rosenfield:  That AI women is real creepy

PreWar:  I used to use them in the old days of analog. And their pretty cool….fun to ride them on the edge…..

cholky milk Mirage:  paul mcartneys brother teaching mixing.

Tuff Kaya:  1:21 All the horror

N8oR:  Wouldn't a VU metre just be used on the master output as opposed the individual tracks?

Victor Seastrom:  Did you look exactly like Paul McCartney when you were young? I gotta think so...chuckle

Lerssi Larsson:  Dad had one in his Corolla -69 50 years ago. Wondering why not a RPM meter?

Al Rude:  Zero dBm was originally 1mw across 600 ohms or .775v which was defined by Bell Telephone. A typical VU meter was calibrated for zero at Line Level which was equal to +4 dBm or 1.23v across 600 ohms. VU [Volume Units] meter was calibrated for optimum display of RMS levels with the ballistics of the meter defined and calibrated for broadcast use. I still like to use VU meters across my stereo buss to gage my mix density. I'm old school, guilty as charged.
BTW: Ampex 456 standard bias reference level was 250 nW/m [nano Webbers per meter] with "Elevated" bias being 370 nW/m typically used for 30 IPS operation for Ampex 456. The higher fidelity of 30 IPS operation was better high frequency response and lower noise at the loss of a half octave of low frequency response. The 370 nW/m standard was pretty common in studios by the late 80's. 250 nW/m was used for 15 IPS in broadcast. 185 nW/m was the Ampex "original" standard for older tape formulations and 7.5 IPS. I really don't miss tape, I was the guy that had to maintain the tape machines in both broadcast and multitrack studios. And no, I don't think tape sounds better, it's a sound quality that we're used to.
Early in my broadcast engineering career I was called into the Air studio by a DJ due to a "clicking sound" in his headphones when he had the microphone on-air. I quickly determined that he was running the mic so hot the RCA console VU meters were banging hard against the end stop making a loud click. Not so good for analog meters and in fact I noticed that the pointers were bent from repeated abuse. While the station processing prevented overmodulation of the transmitter, I found that the DJ actually liked the sound of the mic preamps being over driven. "Sounds more intense." he remarked. In those days a limiter for the mic channel would have been expensive and it would have involved a major rewiring of the console. No insert patch points on broadcast consoles. It was a Album Oriented Rock station.
I've been a professional broadcast and studio engineering since the mid '70's. I currently run a live capture audio/video service and mixing/mastering/editing services.

William Palminteri:  Hello.
This -18 dB 'standard' is ridiculous. I build my own analog V.U. meter plugins and I subscribe to 0 V.U. being exactly that.
As you well know, there is no 'soft clipping' in the digital domain. Therefore my overload LED comes on at 0 dBs.
If I see that LED blink, I crashed.
Why record at -18 dBs and give up 3 bits of data and settle for 78 dBs of dynamic range ?
No need to remind me that I'm a reactionary hardass who still records like it's 1961.
I could go on for days about how these kids think that the -18 dB thing is for the benefit of 'soft clipping' plugins, etc.
All I know is that if we went 'into the red' in the old days, there were 'consequences'....
Once again, a most enjoyable presentation, thank you !
Bill P.

William Palminteri replies to William Palminteri: @Audio Masterclass All of those unused bits are following me into old age, I'm afraid !

Audio Masterclass replies to William Palminteri: I absolutely agree but with the one exception that -18 dBFS, when quoted, is usually meant to be a 'round about' level to aim for, not peak. But it does seem that it's widely regarded as peak which, as you say, wastes 3 bits. Coming from analogue myself, waste is just plain wrong. Shame we can't donate those unused bits in some way. DM

felipousismix:  It's my understanding that -18 dBFS = 0 VU (EBU) and -20 dBFS = 0 VU (SMPTE), for Post.


Audio Masterclass replies to felipousismix: -20 isn't the problem. I have documentation on that. I'm still looking for the definitive source of -18. It must be somewhere but finding an authentic document that links -18 dBFS with 0 VU has so far been difficult. DM

Majik Glustik:  So, volume units are to audiologists as scale rules are to draftsmen? Have I followed well?

Arjan van Vught:  Funny the Max comparison ;-) yes, I am Dutch

Tellit Liketis:  I think this guy is really Paul McCartney

ashwadhwani:  The VU became popular to enjoy 80's discobeat music ;)

1donniekak:  Depending on gear quality channel eq changes with volume.

Society Of High End Audio:  HI. Greeting from farEAST

Audio Masterclass replies to Society Of High End Audio: Hi back, thank you for your visit. DM

Flow the River:  I always wanted to learn about VU meters from Sir Paul McCartney, thank you for making my dream come true.

Editing SECRETS revealed! replies to Flow the River: In Penny Lane the studio meters show VU
of every signal that the tape will ever know
compatibility can come and go
at 4 dBU

Lonetrack:  I love your investigative, objective attitude toward the subject. A lot of audio people on YouTube get lost in the "mojo" stuff.

Editing SECRETS revealed! replies to Lonetrack: Least nostalgic vintage gear discussions on Youtube!
Everyone else: It's so old fashioned, crunchy and warm! Just like Mum and Dad's living room!
Audio Masterclass: Toss out that old inaccurate junk, you nincompoops of all ages!

Victor Mihai:  turtle from the grave!

Rupert Erskin:  Right on. Thanks for sharing.

Anthony Jackson:  Fabulous explanations. Thank you from an old tape devotee.

Mark Williams:  Betty is eerily realistic

Jay01:  Hi Paul!

Carter William Humphrey:  Also, since you brought it up: origins of -20dBFS or -18dBFS. Sony went with -20dBFS = +4dBu, Matsushita (TAD, Pioneer, Panasonic) went with -18dBFS=+4dBu. I believe SMPTE codified -20 and EBU codified -18? You'd think they could have fought this out in Japan over 2dB, but nobody did.

Carter William Humphrey replies to Carter William Humphrey: @Audio Masterclass Dig through Matsushita Electric, now called the Panasonic Company. I would suspect the Sony 1630 would be the origin story of -20dB.

Carter William Humphrey replies to Carter William Humphrey: @Audio Masterclass Dig through Matsushita Electric, now called Panasonic Industries.

Audio Masterclass replies to Carter William Humphrey: Thank you for your input. Yes, the manual for the Sony 1630 gives -20 dBFS for +4 dBu. As for minus 18 - I'm still searching for the document that specifies this. DM

Carter William Humphrey:  I can only speak for the U.S.A., but since you brought it up: Ampex created the standard of 185nWb/m, aligned to 0VU. By the time I was in school, in the 80's, most music multracks were using "elevated" alignments at 250nWb/m, so called "+3dB" (which is actually +2.6dB over 185nWb/m, but that's a whole other can of worms!). Film still stayed at 185nWb/m. Then came the newer tape formulations (Scotch 996, Ampex 499), and it settled at (most of the time) 355nWb/m or so-called "+6dB over 185nWb/m" (which is actually +5.5dB over 185Wb/m).

There is your largely historical knowledge for the day from somebody who aligned way too many tape machines!

Carter William Humphrey replies to Carter William Humphrey: @Audio Masterclass Yep, that's the other can of worms. Fun fact, Magnetic Reference Laboratories (MRL) was founded by guys from Ampex.

Audio Masterclass replies to Carter William Humphrey: Thank you for your input. I have a document somewhere in my chaotic library that says the Ampex standard was measured at 700 Hz, so the level on tape at 1 kHz was around 180 nWb/m. But what's a quarter of a decibel between friends? DM

Mr. Lowery:  It is kind of creepy with the AI girl but I still subscribed to your channel! LOL

Really Nice Audio:  wow what serendipity, I am currently restoring a B77 and about to embark on a VU driver circuit for my latest saturation device. Great info!!

Walter Kopatz:  Excellent, very interesting. Thank you

Vilg∆x Records ♪:  Why i the visual indication changes while I insert VU in the track vs The Master Bus. Eg; Solo Kick shows 0VU
But then the Same solo kick in Master Bus VU shows more or else numbers.

Audio Masterclass replies to Vilg∆x Records ♪: Pan law probably. If you pan a track centre, the level in the left and right meters will be 3 to 6 dB lower than in the channel. DM

Emiel333 Official:  Isn’t it in the AES handbook? (-18dBFS=0dB VU). Great video. Besides the awesome knowledge, thumbs up for the excellent video quality.

Emiel333 Official replies to Emiel333 Official: @Audio Masterclass I thought it’s referenced by the AES, but I’m not sure. The Sony A6600 is an amazing camera. Oh btw, I’ve subscribed to your channel.

Audio Masterclass replies to Emiel333 Official: I'll see if I can find that reference. Regarding the video quality, that I think is down to the camera (Sony A6600) and the lights. I just sit there. DM

Guilherme Lima:  great video. I like to calibrate my VU meters using a reference track. then can also split the frequencies to have total control on what i'm monitoring. then can make the adjust and keep control based on what know that is good.

Steve L:  Why so bad mouth about VU meters. We should mix with our ears, not our eyes. VU meters serve a certain purpose in mixing, but don't need to be bad mouthed as "useless"

Remy David:  Understanding why a VU meter, works the way it does. With its rise and fall times, what they are. You can be certain. All of your peaks are, up to 15 DB, beyond. What the VU meter can display. And so when creating an average standard, operating level. There were 3 schools of thought. Rank amateur beginners. Dangerous newbies. And skilled professionals. Thus! We got, 3 different, 0 operating standards. Of -18. For the rank amateur beginners. -14 for the intermediate clueless wannabes. And -12. For those of us who know how to keep our levels in check. Before we try to record them.

And so that's how the different, average operating levels were established. This provided for, 18 DB of distortion free headroom. For the rank amateur beginners. 14 dB's of headroom for the intermediary clueless enthusiasts. And 12 DB of mostly unnecessary headroom. For the professionals that know how to, track an instrument or singer, properly. And can get a better sound. That is cleaner and more well defined. By pushing the analog to digital converters. Two greater limits. And getting your money's worth out of them! As they don't like to convert, low volume level, nondescript sounding, signal sources. For the utmost definitive blasé sounds you will get. When not adequately energizing your analog to digital converters to their fullest extent. But nobody ever teaches you that. They teach you that they clip when you go too far at the input. So make certain you don't. And you can record at hotter levels. Where it will sound bigger and fuller. Because you're not wasting, 8-12 bits of your converter. All on headroom. And still wondering. Why all of your recordings and mixes sound like a wet blanket over limp noodles? And how to get your precious, pillow sound a little warm present and alive sounding.

I always love these stupid rhetorical technical, idiot discussions. That really have no bearing whatsoever. On delivering a fine sounding recording. Because there is no standard. The standard is, don't go over, 0 dB FS. And, pump, Pump, PUMP IT UP! Don't be afraid! You not going to get killed! There is no, 0 dB FS police. And Jesus will forgive you. I might not?

It's all in how much headroom? You want to buy yourself. And if you've tracked really well. And committed with, EQ, dynamic range limiting and De-essing. But wait! After that. You want some downward expansion. Kind of like a gate. But without slamming the door fully closed. That stops the door from closing entirely. And let's some of the sound through you preset. So it ducks it down but doesn't turn it off. And is much more natural sounding for vocals. Where you want a gate. That slams the door closed and off. On drums, particularly. Or to, Key a gate. Against another instrument. To turn another instrument on and off or up and down. By the other source. A cool engineering trick I've used. Bob Clearmountain has also used. Lots of people have used. Since 1972. The Allison Research, KEPEX-500 a.k.a. the famous KEPEX-1. Later replaced by the Valley People, KEPEX-II. After he divorced Allison or Allison divorced him? But I digress. It's a cable programmable expander. That uses no computer. It's analog. And has been around for 51 years. As I have some of those. 9 to be exact. And also a few, DBX similar versions. But certainly not the same. And cannot be used in the same way. But sort of. You can get by. But not the same.

Now when it comes to the limiters in use. There are so many. All will work. Some differently from others. Such as RMS versus Peak, detectors. And adjustable attack and release times. And side chaining, capabilities.

And the one thing really not mentioned here. Is, how the VU meter can, fuzzy up, your sound. With plenty of, measurable and audible, Inter-Modulation Distortion. When you connect a VU meter. Directly across the outputs. As has been done since the beginning of, vacuum tubes. And within the meter. There is what we call a, 4 diode design, Bridge Rectifier. And it makes the best Guitar Fuzz Pedals, also! And you just put that across your output. And you get all of that distortion for free! And it sounds like garbage! It sounds like a meatgrinder.

And so it actually affects your sound when you have a VU meter. Unless you include a, IC chip, op amp, meter buffer amplifier, circuit. Then it imparts no distortion. But most people just connect that raw meter across their audio. LMAO! What a bunch of Maroons! And they all think they want the best sound! But they really don't know what the hell they are listening to? Because they never had to, design, build, troubleshoot, install, maintain, anything! They just got their parents to, pay to play for their children. And whoever's parents spend the most money on their children's audio equipment, wins! A stick on Goldstar for your, for head. And your official, Zero-dB FS, authentic gingerbread cookie! They are going fast! That must be slowed down to, 44.1 kHz. In order to make it into the Saturday morning cartoon lineup! Collect all 5! Milani Trump, standing by to receive your MFT's, as payment. As she wants to get her husband back. All of him. And will ship you, an official, White House Trump Big Mac. Which must be received while bent over. And will only take a mere moment. Of your money.

One day… Fish will learn. How to swim upside down. And we will be in real trouble.

billybob thornton:  yea someone noticed this guy is a Paul McCartney clone.

Thomas Hambrecht:  We digitize old tapes, audio cassettes... and see these VU meters of these devices every day. But I'm glad I don't have to use any of these pointer instruments in my DAW.

MATT FRESHA Lab One:  Asked ChatGPT... something quite interesting regarding the connection:

Q) where does 0VU = -18dbfs come from?

A) The relationship between 0VU and -18dBFS (decibels relative to full scale) comes from the calibration standard for analog audio equipment, which was later adapted for digital audio.

In analog audio equipment, 0VU (Volume Unit) is the reference level for audio signals. It represents the level at which the equipment is operating at its optimal performance, and is typically set to correspond to a certain voltage level in the equipment's circuitry. For example, in the United States, the standard reference level for 0VU is +4 dBu, which corresponds to a voltage of 1.23 volts.

When digital audio was introduced, it became necessary to establish a reference level for digital signals that would be compatible with the existing analog equipment. The standard that was adopted was -18dBFS, which is equivalent to 0dBu in the analog domain. This level was chosen because it corresponds to the highest level that can be represented by a 16-bit digital signal, which was the standard for many years.

So, in summary, 0VU corresponds to a certain voltage level in the analog domain, while -18dBFS corresponds to the highest level that can be represented by a 16-bit digital signal, which was the standard for many years. The two levels are related through the calibration standard for analog audio equipment.

Editing SECRETS revealed! replies to MATT FRESHA Lab One: @MATT FRESHA Lab One ChatGPT must have had some training material that discussed 0 dB and also 18 dB, some that discussed 0 dB and also 16 bit audio, and some that discussed 0 dB and metering. Its copy and paste assembly mixed and matched and maybe paraphrased fragments that are similar in the word match analysis tree but refer to different concepts. Another example of how large model "AI" is not actually intelligent at all, a useful generator of fresh combinations but an unreliable guide to the truth.

MATT FRESHA Lab One replies to MATT FRESHA Lab One: Yeah but the question was where does 0vu Vs -18dbfs originate from. 16bit audio for sure has 96db of range, and can see now where chatgpt mangled the response. Good call

Editing SECRETS revealed! replies to MATT FRESHA Lab One: As usual ChatGPT proclaims a mix of fact and word-salad fantasy as totally authoritative. A 16 bit digital signal without dithering can represent from 0 to -96 dB FS, not merely 18 dB. The highest level that can be represented by a 16 bit linear digital word is 0 dB Full Scale by definition.

Audio Masterclass replies to MATT FRESHA Lab One: Yes this is very interesting. Half of the paragraphs are correct. DM

Max Carola:  One last thing. Many people that own the AX plugin from Waves already have a nice VU meter, just put the "process" to 0 and it's a very nice VU meter with almost perfect ballistics.

Max Carola:  Regarding the numbers... I loved the Ampex 456 that allowed +6bB above the standard 250nW or 320nW. And we could choose the 499, +9bB from 250nW or 520nW. That helped a lot with the analogue tape enemy, the NOISE... I personally was for the 456. I never liked the crunchy high end of the 499. And as soon I could get rid of the tape completely (in 1994, I sold my beloved Otari MTR90), I did.

Max Carola:  In the digital age's infancy, Sony set their machines to -21dBFS as 0vu, considering that a highly dynamic percussion could have up to 26dB of peak-to-average difference. Soon that was considered too much in the 16bits digital world, and the new common point was -16dBFS for 0vu. But pioneers of standardization pushed for a standard -14dB as 0vu. That was good for a mixed master but not a valid DAW reference since it required too careful gain staging to avoid mistakes. So a good compromise was -18dBFS, and nearly all the DAWs complied to that. I analysed many of the best CD masters of the '90s and nearly all of them had a 0vu at -12dBFS. That was before the loudness war become tragic. I still head to that while mixing and then push to a CD "standard" -9dBFS when delivering listening passes. That helps reducing the request for revisions quite a lot. Still, I deliver a -12dBFS master to the mastering engineer, when I don't do the mastering myself (That is a budget matter, since I prefer to have a new pair of ears to master my mixes)

Nick Wallette replies to Max Carola: Huh... I didn't know any of this, and found that a typical "normalized" mix would be hard in the red at nominal -18dBFS. That being rather unhelpful, I settled on -12dBFS because it's enough margin that, if my mix is averaging around 0dB, it should have decent dynamic range without clipping, and without being so low that I run out of headphone amp gain on a laptop or phone when playing it back.

I had no idea what fundamental rule of the ancients I was violating by deviating from the default (which I assumed was there for a reason), but it worked for me, so I risked my audio club reputation on it anyway.

Daniel Denholm:  You shouldn't be doing any gain staging unless the recorded level is very low. By the time you've summed 20-40 tracks you'll be hard pressed to keep that from clipping the stereo bus input.

Editing SECRETS revealed! replies to Daniel Denholm: It would be nice for him to do a video on floating point audio

Adrian Yañez:  More please

mpasistasyalanci:  Nice, I'm sick with the mentality of sticking to a number just because. The examples and the history behind the VU is great. Personally I gain stage with a bit of guitar chain mentality, reduced on the saturation level and more precise. Like when the instrument hits a pedal, that another one .... all that the preamp and then to the power amp... In that occasion you make your sound by gain staging between different characteristic devises wit ''color'' in mind.This happens with any non linear device that we find also in our world, from mic to preamp, to every non linear plugin in your chain even the first one etc. For example I use sometimes a Pultec plugin as the first non linear plugin in my master bus (after a stock reaeq for gain staging without moving all the faders). in this occasion I push the levels by how much I want to''saturate'' the specific mix I work .I still use visual indication thought cause psychoacoustics is a b;[ch

Chuck Gibson:  what does this mean for world peace?

Editing SECRETS revealed! replies to Chuck Gibson: We're only 4 dB away from achieving it as long last. All it takes is for the USA to switch to metric and invert its distribution polarity.

Sandwich Breath:  Excellent short post! I use the Klanghelm VUMT for my master bus during rough mixing to ensure I have enough headroom for my final mix, and use it during my final mix to ensure the same for mastering. I also use it on the pre-mastering tack and post mastering tracks to compare levels. It's a gem of a plugin!

James Williams:  Excellent, thanks!

Norman Love:  Just an FYI, I got nothing out of that, as I understood nothing of what you were saying. Over my head. (why is there no over my head emoji?) I've been producing music for only 6 years though, so I just learned about Gain Staging and started using it, like a year ago. But you read out the ANSI standards? That seems like a waste. There's thorough, and there is overkill my friend.

Editing SECRETS revealed! replies to Norman Love: It's a vintage-loving nitpickers channel. Try looking up the K-meter as a useful reference for recording, mixing, and mastering.

Greg Giorgio:  Standard Pro Tools Meters go from dark green to light green at -14. If you peak there your average will be -18. No need for a VU. Also, it's kind of funny - all this talk about gain staging.. the modern style of recording is defined by distortion.

Enjneer:  Your AI is sexy nightmare-fuel

Albert Batchelor:  It's in alot off manuals to plugins. The signal hitting -18dbfs when going into most plugins is idea. Especially for the plugins simulating analog gear. That's the only place I've actually.seen it written🙂👍

Michael Holland:  Our Studer 2" 24-track machines were at 240 nW/m back in the day, using Ampex 456 tapes, Zomba company policy for in-house studios

Michael Holland replies to Michael Holland: @Audio Masterclass yes, +4dBu/0VU. This was in the '80s and '90s, for some context, and clients ranged from full orchestras to rock, pop, R'n'B and hiphop artists.

Audio Masterclass replies to Michael Holland: I'm presuming for +4 dBu / 0 VU? I'm always pleased to hear actual use cases. DM

Karma Mechanic:  VU meters are essential. And marijuana is essential to appreciating VU meters.

U-Recken Dacru/Tree of Life:  I also use the this VU…but for me and for the style I’m
Producing I only worry about gain staging the post processed Kick which is the hardest hitting element of each track, this way I get consistent mixes and can use hardware emulations care free, never clipping in digital ones as well…you can also get away with -12 and don’t clip the mixbuss..thx for the vid❤

Trekster:  So you haven't really showed why in the digital world we should care about VU meters. If you did show it, I certainly missed it.

Audio Masterclass replies to Trekster: The answer is assistance with gain staging. VU meters are not necessary but you can find a number of YouTube channels promoting their use. This is something I will cover in future, possibly not on YouTube but I'll announce it here when ready. DM

hozaifa sayed:  Excellent!!

Ronin1973:  The VU meter was definitely necessary for setting up analog tape: level, bias, EQ were important especially if you had 2" tape coming in from another studio and you're trying to overdub. The big secret weapon was the factory test tape that consisted of 1kHz, 100Hz, 10kHz etc tones to align the playback heads.

mixc8 replies to Ronin1973: I still record to tape! LOL and your correct.

Steven Jackson:  Our dBVU measurement system goes back to telephony, the 300ms rise time is the aural equivalent to image persistence that allows us to use a 25/30Hz frame rate in motion pictures. This 'slow' rise and fall time allows us to approximate the perceived volume level of a signal rather than the peak level, which is almost useless outside of the capture medium. The importance of VU metering is that it allows us to match perceived loudness on the short term, this is very difficult with peak metering and LUFS metering is too slow as it's purpose is different again.

I would argue that the 'harsh' sound of digital is 50% due to peak metering not being a representation of how we hear and 50% opening the industry to people who don't understand the electronics behind their systems and not a product of the medium itself.

The 'operating level' of audio equipment was based on dBm, 0dB = 1mW and with a 600ohm load this equates to 0.775V RMS or 0dBU. This is a measurement of power transfer between two devices and is related to voltage and impedance.

We then see the term 'Line Level' which is defined as +4dBu, this is NOT operating level of our audio equipment, but the transmission level of the telephone lines. Engineering standards allowed for a maximum of 4dB drop in signal along the line, and as signal can always be easily terminated, signals were boosted by 4dB to account for potential loss as amplification at source is the least noisy way to amplify.

BUT because the audio equipment being used in telephony was being sequestered for recording studios, their output meters were calibrated to 0VU = +4dBu and so that stuck for the studio.

Now when we transfer to tape, we usually had 14dB headroom above this +4dBu level (remember the 0dBu operating level, this was to allow for 18dB headroom above that).

And now transferring to digital, this 18dB headroom in tape set the standard of +4dBu = -18dBFS and most of our professional digital consoles still conform to this.

To allow for a minimum of 18dB headroom above +4dBu we need a rail voltage that will allow for at least +22dBu, or 14V, but manufacturers attempted to maximise this headroom by increasing rail voltage and we saw consoles start using 18V rails which gives +24dBu max.

This has given us the confusing competing standard of +4dBu = -20dBFS because the important part of the standard is having the same voltage leaving the console in the analogue domain after processing. Yamaha is an example of this, their supply rails are 0dBFS = +24dBu

Anthony Egan:  Talking about Analogue inputs, and then using AI robot to speak , don't cut it for me

J G:  Which is why you should use Dorrough meters...

iBeatsbyJunius:  Maybe -18 dbfs is the humans ear translation for an internal sweet spot. While making it easy on ourselves, we default that sweet spot starting at 0 VU, like some sort of foundation to being with. 🤷

JEWLER DA ROCKET:  Great video, how did you do that girl AI please?

Audio Masterclass replies to JEWLER DA ROCKET: Betty would tell you herself, but she doesn't know. DM

A.Sweden:  I always thought VU meters were there to look cool?!

Chris Colon:  I trust you

Bon Tempo:  Forgive me but i just landed here and it immediately struck me that you remind me of Paul McCartney !

Louis Alfred III:  The techs at our studio when aligning a sony digital with our analog consoles would have an oscillator that output a sine wave at 0 db rms not peak and the machine was aligned to -18 or -20 (engineer preference) and those meters in the machine were peak and the outputs coming back to the line in vu meters read 0 vu. As far as today is concerned I would think the whole “vu thing 0db rms thing” matters only if your plugin really models analog gear and its characteristics and idiosyncrasies. Other than that yeah maybe useless.

Ian Mac:  thanks for the great info!

Audio Masterclass replies to Ian Mac: You're welcome. DM

Music Factory Studios:  The -18 dbfs equals 0 VU comes from the argument Rupert Neve & Neve Senior Engineer Jeff Watts had with CBS in America so they defined the DBu scale in the West to bridge the gap of 600 ohms in Britain and 150 ohms in America. Rupert has a video on his channel talking about it from about 10 years ago its called "Creation of the dBu standard level reference". But most Analog designers took this -18dbfs=0VU from the late 60s and made it a standard for most outboard equipment. It was to have a clear standard world wide (or at least in the western world during the cold war). Now remember VU isn't the same as a sample peak or RMS it is measuring (Volume Units) which is a voltage based reading. Cranesong has a free pdf called "Volts to dBu to VU Comparison". The reason the VU takes 300 milliseconds to adjust to the audio is that was found to be the time it takes for the human ear to hear most transient dissipation from initial attack to silence. (think of a hand clap in a room). So VU meters were meant for tracking as a way to get the correct level going to the recording medium weather thats analog tape or digital Tape or hard disk recording. For mixing they don't really serve a great purpose other than for calibration of analog gear such as compressors and other effects to match the console VU, but they are very handy for setting levels on a console or mic preamps/channel strips during recording. Great video and I thought I would pass on what I have learned about VUs over the years and where they came from. Cheers!

Music Factory Studios replies to Music Factory Studios: @Audio Masterclass No you are right but I'm on the hunt to find out where it came from you've sparked my interest.

Audio Masterclass replies to Music Factory Studios: @Music Factory Studios Thank you for your input, which brings us more understanding and perhaps some more leads to follow. If I plumb the depths of my memory 40 odd years I remember in relation to the Sony 1600 (pre 1610 and 1630) I overheard someone say you had to drive it from a power amplifier to reach full scale on the meter. I think this might have been figure-of-speech but it would make sense to take advantage of all of the headroom of a typical mixing console it would be used with. The manual for the 1630 advises aligning -20 on the meter to +4 dBu so we still don't have a definitive source, pre-EBU R68-2000, for -18. The hunt goes on. DM

Music Factory Studios replies to Music Factory Studios: @Audio Masterclass
I would venture to say no one really cared about db Full Scale until 1980 when the Sony Dash and rainbow book systems made it something you needed to care about. Remember "Red Book" CDs that were the standard for CD mastering? That was Sony standardizing digital audio from the studio to the consumer. Prior to the Sony Dash system, digital recording was RARE and only the top stars in music could even consider playing with digital audio, and it was mostly relegated to digital sampling and very short bursts of digital recording, like the Fairlight. But Sony's Dash system covered everything from Tracking and mixing all the way up to tools like the Sony Dal-1000 the first lookahead brick-wall limiter I remember. I asked Paul Frindle where the scale came from since he was around and in the highest levels of pro audio back then. Paul built the first true digital mixing console for studios for Sony's Oxford company (now sonnox) in the late 1990s and before that he worked for SSL and designed the SSL G+ EQ. I asked him and he said Sony because DASH was the first true digital multitrack machine and was widely adopted by the US and Europe in the 1980s through the 1990s. This allowed Sony to make the rules and Sony standardized digital audio as we know it today. Paul said that DBFS only mattered in the digital domain but he's not sure where the actual DBFS scale was originally calculated, America or Japan, but it was Sony who developed it since they invented the standardized way digital audio was recorded and played back. DASH encompassed both recording and playback of digital audio. Later on the ADAT & DAT machines would bring the digital standard to even smaller studios, using the same DBFS scale pioneered by the Sony Dash system. So someone at Sony in Japan correlated the work done by Rupert Neve and CBS and calculated what that was in terms of DBFS for the new Red Book quote "DASH" standard. I'm sure their name is lost to time but now you have me very curious to find out!! Cheers! 🎶🌡

Audio Masterclass replies to Music Factory Studios: Thank you for your input but although the video you mention - - covers dBu, it doesn't mention dBFS so there is still a missing link. EBU R68-2000 covers -18 dBFS but I suspect there must be something that predates this. DM

ak5:  Well ,I've learned something - old school knowledge is the best - cheers! 👍👍👍

All Valley:  Redbull, boooooooo

Örn Leifsson:  Betty is scary.

chris harbin:  Ok, so a question: I don't know if I missed it, or it's just fake news, but I've heard that VU's are not good for drums. Is that a myth (in which I'll just giggle) or is there something to it? (which I really would like more theory on that)

Editing SECRETS revealed! replies to chris harbin: @chris harbin My browser crashed while I wrote another version of this, sorry if it's a duplicate.
There are free K-meter plugins you can use to watch the levels in and out of your DAW.
The most important thing in digital audio is to not clip the loudest parts.
You could record the drummer's heavy bashing at around -10 and still have some headroom if the drummer gets extra excited.
This will mean your signal to noise specs aren't perfect, but with good converters, recording a 24 bit file, that's not much of an issue these days. Your listeners' ears will still be ringing from the drummer's loud parts when you get to the quiet part, right? 🙈 If there's some distracting noise on the drum tracks, put a noise gate on them.

chris harbin replies to chris harbin: And while I have you, what would be a recommendation for drums? Lately I'm using Live (yes, the session view and muckin' around mostly lol) TTBOMK, it doesn't really have anything other than the meters (and that Klanghelm that was a great cheap VU) Frankly, I use SD3 which really doesn't have anything that "clips" much if at all (or electronic stuff which again, I can tame pretty easily) but just in case.

chris harbin replies to chris harbin: @Editing SECRETS revealed! Thanks so much for that knowledge. Yeah, I should have figured that out.

Editing SECRETS revealed! replies to chris harbin: VU specification smooths out the meter response. It was designed for use with tape recorders and standards for analog broadcast transmitter levels. The meter doesn't instantly pop up when there's a loud sound, it gradually moves up a bit while a loud sound is sustained. Useful to see an average level of a sustained instrument like a singer, trumpet, violin etc. but useless to prevent clipping on an instantaneous peak. For checking recording levels you need an instant response meter that will highlight if even two samples in a row stay locked at full scale, proving you've clipped the signal into a square wave. Once you have a clip-free signal recorded, using a VU while you mix can show how listeners will perceive the overall volume level of whatever signal the VU observes - whether a selected track, group, bus, or the whole mix - while smoothing away the wildest extreme volume fluctations out of the meter reading.

chris harbin:  I'm really glad that you mentioned the Klangham virtual VU meter. When I was using Studio One rather exclusively, that one is good too. But lately, I've really been getting into Live and though I think there is a way (I can't figure it out though) to use that VU in other hosts, the Klangham looked great and was cheap. So now almost every channel get the Klangham and it's really nice. (I like the "neon" skin best ;) )

Kári replies to chris harbin: Klanghelm, as in helmet ;)

King Jus replies to chris harbin: @Ramt33n I also love the neon skin!!

Ramt33n replies to chris harbin: Same same here!

Mr. Richard :  Lol. Had me chuckling straight out of the box. Paradise Lost.

Reno Mellow:  The -18db rule comes from the nominal alignement level of audio interface that embed preamp and ADC. The manual let you know this alignement. Example, for a RME fireface, in the manual you can read : input level For 0dbs at +4dbu = 13dbu. That means that 4dbu = 1.23 volt = 0Vu = -9dbfs.

Each audio interface has his own alignment but, at times we mixed on large console plugged in adc/dac, it was pretty standard to align the max +22dbu of the analog console to 0dbfs and so having the 4dbu = -18dbfs...

Eric Newhuis replies to Reno Mellow: You had me at RME. :) I am still learning the ropes of TotalMix.

U-Recken Dacru/Tree of Life replies to Reno Mellow: Interesting!

Pat McGuire:  I can also highly recommend Sleepy-Time DSP Mono/Stereo FREE VU meters! 😉

Self-Law:  Thanks Paul.

Gunther Mampaey:  Some mixers did only use VU meters to mix their projects on analog mixconsoles. Source: Sunset Sound Studios, LA, a minority of them of course. Btw, some should use more a VU instead PPM meters, because of making their mixes too loud.

Frank Frank:  Just by coincidence I looked up the word "sag" just before I clicked on this video. I came away with two key definitions 1)drooping of the amp power supply voltage in response to large transient signals and 2) Your face.

Audio Masterclass replies to Frank Frank: Haha that's so funny when people insult how I look. It shows they haven't much to say. DM

Robert Matichak:  I always preferred peak (ppm) meters over vu meters wether on a console or tape machine. No need to adjust your level based on the type of signal ie: -10 to -7 for percs like tamborine and so on ….
vocals can go to + 2 or 3 vu. With ppm just aim for 0.
Great video

tony:  Good stuff melody man.

TripleBeam:  May I ask where you found that lady .. im guessing it's A.I text to speech .. but I need a girlfriend and someone to tell me I'm sexy and my mixes are amazing.. so I'm gonna need the location I can find her... or the cat gets it 😺🔫

Matt Rausch:  I seem to recall being taught 180 nW/m in recording school. But there is no hard and fast rule to that, just thought that was interesting.

Matt Rausch replies to Matt Rausch: @Audio Masterclass Hey I remembered something correctly from school!? Great content, very much appreciated that you are sharing your wealth of knowledge!

Audio Masterclass replies to Matt Rausch: 185 nWb/metre at 700 Hz was Ampex level, which becomes 180 nWb/m at 1 kHz. Source - MRL. DM

Nat Love:  I’m new to this channel. Looks like Paul is back from the “dead”!

spidif:  Great discussion

Jim Shaw:  VU Mewters -- what we used when we had nothing better. Today, we have better.
But VU meters are like milled metal faceplates and solid metal knobs, audiophiles love eye candy. You can sell a 2000 dollar amplifier for 6995 if you add big blue VU meters.
Ask McIntosh...

J G:  wtf am i watching!!!!!!

J G replies to J G: too stoned for this shit

walthaus:  Being a Broadcast Audio Engineer educated in Europe but working in the US, it took me about 30 seconds to find this..."that the European Broadcasting Union (EBU) Technical Recommendation R68-2000 and the Society for Motion Picture & Television Engineer (SMPTE) RP 155 – 2004 operating practices are based on two different audio reference levels, namely –18 dBFS1 and –20 dBFS respectively"

-RECOMMENDATION ITU-R BS.1726-Signal level of digital audio accompanying television in international programme exchange -

That translates to +4dBu (or whatever other analog reference level is being used with 0dBu being more common now) being the equivalent of those digital audio reference levels depending on where you work, and 18 or 20 dB of "headroom" respectively when it comes to broadcast audio. This assumes that your analog I/O has a maximum level of equal or greater than +22 or +24 dBu ( or +18 or +20 dBu if 0VU equals 0dBu)
In music mixing there aren't any of those standards, only streaming platform loudness standards measured in LUFS, LKFS or some proprietary standard. If you work in those areas it makes perfect sense to set your digital reference level to -14 or -12 dBFS, resulting in louder mixes deflecting properly on your VU while having less "headroom". A VU set to -14 dBFS tracks nicely with a mix compliant with streaming loudness standards ( -14 to -16 LUKS/LKFS)

Audio Masterclass replies to walthaus: Yes R68-2000 seems to be the one thank you. It doesn't mention VU but I guess that it's implied. DM

Delta Whiskey Bravo:  Great info, thanks much. I use those Klanghelm Vu meters in my DAW on every track, I only have 4 tracks now. It's my Livestream project.

Valomat:  Is this Paul McCartney's younger brother?

Hinton Instruments:  The physical size is also part of the VU meter spec. The little ones on Revox B77s and other gear are non-standard.

The level that a tape machine is calibrated at depends on the tape being used. It used to be 185nWB/m2, but as tape improved it was raised and the meters were used to calibrate to the test tape at a different VU level to compensate. The meters were calibrated to a test tape being played and then the record level was adjusted to read 0VU with a line reference level. This is where +4dBu (pro) and -10dBV (domestic) come from which many people believe is the signal level, but the signal can easily be 10dB above this. VU meters on mixers were calibrated to match the recorder(s) even though they had over 20dB headroom.

Zbyszek Olko replies to Hinton Instruments: @Hinton Instruments I don't care if you call it calibration or max output set at the factory. If a manufacturer publish the specs (what is not so obvious these days) they are mostly true.

Hinton Instruments replies to Hinton Instruments: @Zbyszek Olko Audio interfaces are not calibrated, they are just nominal +/- a few dB.

Zbyszek Olko replies to Hinton Instruments: ​@Hinton Instruments Simple. If your audio interface is eg. +20dBu full scale then +4dBu is at -16dBFS.

Audio Masterclass replies to Hinton Instruments: @Hinton Instruments Thank you for your input. You're jogging my memory somewhat and a quick look at MRL's literature reminds me that they offered IEC calibration tapes in 200 nWb/m and 320 nWb/m versions, as well as 250 and 355 which I don't remember at all. 185 nWb/m I seem to remember having some connection with 'Ampex level' and also Dolby level was 185 nWb/m. It all seemed to make sense at the time but I think we are better off now with fewer things to worry about. Especially tapes that arrived encoded with Dolby but no tone. DM

Hinton Instruments replies to Hinton Instruments: @Audio Masterclass There was what a tape manufacturer recommended for their tape type, what the producer "preferred" and what reference tape you happened to have. This involved doing a log calculation to determine the dB difference on the VU. In practice there were 5 common flux densities in common use giving 25 combinations to set the VUs to. If you were lucky there was a little chart printed on the tape box.

A commercial studio would have to recalibrate their multitracks to the tones tape a client brought in if the session was started in another studio, but 2T master machines would only need recalibrating if the tape type was changed as that tended to use a new tape each mixdown.

The most important thing now is to match analogue clipping to digital clipping and the audio interface maximum levels need to be known. A lot of interfaces can take over 22dBu, but some can't. There is no need to observe SMPTE/EBU recommended 0VU levels if you are recording electronic sources that can't output more than +19dBu. When you are recording you can choose whatever headroom that is appropriate to maximise snr, when you are transferring media you should provide the levels required. The clue is in "SMPTE/EBU"--broadcasters don't want to have to change their levels for every track.

The most difficult thing now is finding a source of +4dBu @ 1kHz to calibrate your meter levels. A computer is not a good source as you can't calibrate the interface. Your 0dBFS is not necessarily the same as anyone else's.

George Ogrady:  Some like it loud as some dont

George Ogrady:  What point if cont use your volume

George Ogrady:  Try vu they mess up board re soildering prosound

david keller:  Betty has beautiful........"Eyes"

david keller replies to david keller: @Editing SECRETS revealed! That would be peaking

Editing SECRETS revealed! replies to david keller: "The signal level is supposed to be up here, Buddy"

Paul Stubbs:  Interesting, I have a meter on my PC's audio out, (a physical one, no emulation) I kind of thought of it as a VU meter (it has a VU type scale) I zeroed it to your meter to see how it compares - no comparison, yours is way faster!
I hooked it up in an attempt to balance the various audio track used for a church service, with very limited success.
All your early samples were lucky to hit -4, however the extra, 'could get blocked' track went to +1!
What was most surprising was an ad that popped up mid video, it held the needle to an almost constant 0 to +1, any less movement would be your test tone. Now if all my church hymns had that dynamic range, aligning them would be so much easier - although there would be a great pile of rumblings from the parishioners.
In my chain is also a Behringer desk, it's bargraph meter had your 0dB as -10, and all your sample tracks tickling the -4 db LED, so obviously something is going on between your DAW and what's popping out of YouTube into the USB input on my Behringer DX2000USB mixer.

Wild Weasel:  Thanks for using the B77 image from my insta reel. 😉

Audio Masterclass replies to Wild Weasel: Hi thank you. I believe I credited this correctly in the description but if anything needs changing please let me know. DM

Dr Broncanuus:  VU meter means Volume it's getting serious between Betty and

Dr Broncanuus replies to Dr Broncanuus: @Editing SECRETS revealed! true but Betty and I are on the same wavelength

Editing SECRETS revealed! replies to Dr Broncanuus: Something about her really peaks your interest? Be careful, sometimes love hertz.

Alejandro Lobos Kunstmann:  Since the day I started taking sound staging seriously, everything started sounding magical. All plugins worked as i expected.. Bliss. Before that, I was dumb to treat digital as analog (Where I started), warming the sound as close to 0dBFS without clipping as possible. I just didn't get it. I did that for about 20 years. What a shame. I started working on bad converters like E-mu cards and "Soundblasters" in 1996-97. I never had the opportunity to work with DigiDesign Protools, or ADAT, or DAT! In the 90s, for me, it was all 1/4'' Tascam 32s, Portastudios, and such. I used to warm the tape. The transition to digital was extremely painful for me (still is). I long to go back to analog, but seeing tape machines literally disposed of, and now worth thousands, tens of thousands aches me. Plus maintenance. Nope. I'm so glad I learend soundstaging. Best of both worlds.

Rivermint Official replies to Alejandro Lobos Kunstmann: Thank you for your insight.

Jorge Neri replies to Alejandro Lobos Kunstmann: I saw myself in you comment. I did the same, but not for so much time. And when I realized about the digital realm gain stage, it changed everything. Also I have used soundblaster from 1998 until early 2000, when I got an E-MU card.

senor coconut:  thanks for this - i was wondering what my otari mtr90 mk3 was doing when i compared exactly the sine wave to a kick drum)

senor coconut replies to senor coconut: @Audio Masterclass that what i did but i wasnt really aware of the slowness of VU meters, so i was surprised when i tested it) very useful information also about the clip light!!

Audio Masterclass replies to senor coconut: You're welcome. I would say judge your kick by the sound - drums can sound better with a little tape 'warmth'. DM

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Thursday April 20, 2023

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David Mellor

David Mellor

David Mellor is CEO and Course Director of Audio Masterclass. David has designed courses in audio education and training since 1986 and is the publisher and principal writer of Adventures In Audio.

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