can someone explain me the need for VU meter?

Discussion in 'Reaper' started by stav, Jun 22, 2024.

  1. boomoperator

    boomoperator Rock Star

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    In audioschool, I was taught that a VU meters' response resembles the human ear (slower attack, faster decay than a ppm meter).
     
  2. Lieglein

    Lieglein Audiosexual

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    This must have been either a long time ago, or not a good audio school (which is unfortunately more often the case than not), because the proper method to measure the level over the frequency spectrum now is LUFS.
     
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  3. eXACT_Beats_

    eXACT_Beats_ Audiosexual

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    True, if you want an overall average of the stem, but that's not the purpose of a VU meter.

    I've been told by a few different people that the VU meters that sounded best when they went deep into the red were often times poorly calibrated, and they were actually just touching the red. Other times, sounding good in the deeper red had to do with the tape, the machine, etcetera, but the most common scenario was that the VU meters were inaccurate and engineers never bothered to fix them since they knew where "the sweet spot" was and just aimed for that. Just second-hand information I got from people older than me; they could be blowing smoke, but it sounds legit.
     
  4. Pagurida

    Pagurida Platinum Record

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    VU Metering is an outdated measurement method that used to attempt to replicate human perception of loudness in the old days. Meantime (for more than 10 years!), there are measurement methods, e.g. according to EBU R-128, which measure loudness much more accurately. Different measurement values have also been defined there:

    "Momentary (M), using a sliding time window of 400 ms, best describes the instantaneous loudness;
    Short-term (S), using a sliding time window of 3 seconds, describes a more averaged, less event-dependent loudness of the past three seconds;
    Integrated (I), averaging the program from start to finish, describes the loudness of the whole program." [Wikipedia]


    It can be said that the modern measurement value Momentary (M) corresponds roughly to the earlier VU measurement, but is better adapted to reality. The use of VU meters is therefore only a nostalgic affair nowadays.
     
  5. boomoperator

    boomoperator Rock Star

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    Well this was some 30 years before LUFS was invented. Remember loudness? That was a knob on home audio equipment to boost lows and highs when playing at low volumes..
    Meanwhile, numerous recorders and mixing desks made by people smarter than me had VU meters, so I guess they had its purpose.
    But that was in the analogue era, nowadays my most trusted meters are these 2 flaps on the side of my head.
     
  6. Sinus Well

    Sinus Well Audiosexual

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    The meters on the tracks in Reaper measure Sample-Peak or LUFS-M/LUFS-S.
    A VU meter measures VU. It is a different tool. You can use VU Meters, but you don't have to.

    Software VU meters show RMS+3dB with an integration time of 300ms, modified by the ballistics of the needle. The output is therefore characterised by overshoots and a certain inertia.
    In addition, most VU meters use -18dBFS as a reference or their reference point can be adjusted accordingly. So you can think of these VU meters as a magnifying glass for average levels that have a high resolution around 0VU.
     
    Last edited: Jun 23, 2024
  7. Sinus Well

    Sinus Well Audiosexual

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    LUFS is not the "proper method". It is a newer, different method. With its own flaws, as with any other measurement method.
    I think people sometimes forget that meters are just tools. As long as you know the tool you choose an it helps you do your job efficiently, it's the proper tool.

    And as long as you don't work in post and have clear specifications regarding loudness, you don't even need LUFS. You can use it if it helps you, but you don't need it. You don't need VU, you don't need RMS, you don't need LUFS. All you really need is a max sample peak indicator. And even this can be ignored in some cases.
     
    Last edited: Jun 23, 2024
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  8. clone

    clone Audiosexual

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    It's the purpose of the thread. "Let's play the Best Answer Game!" about commonly misunderstood topics. Look at the OP's other created threads. What's funny is the replies like this is a question posed seriously, instead of "use search", "rtfm", and "lmgtfy" s.
     
  9. Lieglein

    Lieglein Audiosexual

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    Sure, if one likes to do wording complains: It's the technically standardized method to measure the level with the inclusion of the frequency spectrum over a specific time. :yes:
    It is not just "newer" in terms of time, or just "different" like a different eq. It is for the specified task in technical terms objectively better.

    But can also use a peak meter with 300ms ±10 % integration time to measure whatever. :dunno:

    Just don't fall for the fallacy that it measures "like the ear hears" or something like this. :excl:
     
    Last edited: Jun 23, 2024
  10. WillTheWeirdo

    WillTheWeirdo Audiosexual

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    Well I've always understood it to be...

    A VU meter mimics the way our ears perceive sound energy.
    A DBFS meter measures the peak level in digital form.
    A LUFS meter measures the RMS average of sound energy digitally.

    We often loose sight of the fact that sound is energy vibration in our atmosphere and many people smarter than us have created many different measurement methods over the years. Some like VU meters mimic they way we hear that sound vibrating the air particles around us, while other meters can show us phase, level average, level peak, db strength, and frequency strength.

    Every meter as a tool has value if calibrated used properly. I use digital meters daily working in digital and VU's every time my digital audio is converted into sound.

    As always to each their own tool choices.
     
  11. dkny

    dkny Platinum Record

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    As the old engineering adage goes: "VU stands for Virtually Useless".

    They are a relic from the old mechanical days, when it was the best we could do, and you learned how to work with them. Having the same thing in a DAW is really just a holdover from those old times - you may think it "looks cool", but reliable metering is much easier to do these days.
     
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  12. Pagurida

    Pagurida Platinum Record

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    You are obviously confusing manual loudness correction with loudness measurement.

    Because VU is cheaper to implement and satisfies the habits of some people.
     
  13. Haze

    Haze Platinum Record

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    Not much to add here as it's pretty much covered by previous answers.

    VU is more a specific type of measurement than a specific type of display. It's ironic that people speak of faking the hardware look of a needle then reference the hardware look of fake LED meters.

    A number of those fake LED meters can be set up to respond in various manners, LUFS, dBFS, PPU, VU etc so if you want to see a VU scale then it's perfectly possible to do so without resorting to needle displays.

    The usefulness of VU is precisely as has been touched on by previous posters, ie. gain staging. This is most useful in a hybrid setup as hardware is generally calibrated around 0dB VU.

    Eg. If sending a signal from a DAW to a hardware compressor, you are more likely to hit the sweet spot on the hardware unit where it responds most favourably at an average 0dB VU. The ballistics of a VU meter allows one to perceive the average easily as it is calibrated to be most sensitive around 0dB VU.

    It's worth noting here that mic pres behave in a similar fashion, rarely, if ever, will a mic pre perform at its best at 0 dBFS, non-linear distortion being introduced well before actual clipping is reached. The more budget the pre, the more limited the optimal clean operating range.

    Tip: Everyone with budget pres should test them by running clean sine waves through them at different frequencies and various levels, analysing the results. When the sine wave is the cleanest, that is where the gain should be set for recording with the least distortion. Most inexperienced users go wrong with this and attempt to hit close to zero, thinking that will reduce distortion when it doesn't work that way.

    In software, VUs are still very useful as many of the hardware emulating plugins are calibrated in the same manner so feeding them the right level of signal is very important.

    It's also the case that if you gain stage all the channel INPUT gains and following each insert to average 0dBVU that there'll be no clipping further down the chain, channel faders won't end up pushed lower, where gain changes become narrow and will sum to a more appropriate level for mix bus processing and mastering.

    Edit: Not much to add here he says... :rofl:
     
  14. Sinus Well

    Sinus Well Audiosexual

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    Yes, LUFS is objectively better suited to the specific applications for which it was invented. If it weren't, what would be the point of using LUFS? I don't think anyone would seriously disagree with this fact.
    Conversely, this does not mean that there are no examples of applications in which a VU meter would have no benefit or would even be preferable to a LUFS meter. As with all tools, the choice of tool is a question of the use case, the user's preferences and techniques.

    Well, when I automate the levels of my individual tracks in the editing process, I definitely favour VU over LUFS-M, which doesn't mean that I don't clearly prefer LUFS in other applications. But I could automate the level with the audio output muted just by looking at the VU meter and get an acceptable result. I can't say the same about Momentary LUFS, which is partly due to my long experience of using VU meters and partly due to the nature of the technical characteristics of the LUFS meter.
     
  15. Pagurida

    Pagurida Platinum Record

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    Yes, it tries to, but it doesn't reflect the human perception of loudness as accurately as a modern Loudness Meter.

    Correct, but there is also a more advanced measurement method that measures the true peak value (dB relative to True Peak Meter). It can display level peaks that may occur during digital/analog conversion, which a simple digital peak meter cannot.

    A Loudness Meter (Loudness Units relative to Full Scale Meter) measures the loudness of an audio signal, not just the RMS value. Loudness also implements a rating curve adapted to human hearing (K weighting, ITU-R BS.1770) and a threshold value detection (-70 dB gate).
     
  16. Pagurida

    Pagurida Platinum Record

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    I also understand that there may be situations where the gear environment is such that a VU meter is appropriate and fits perfectly into that particular measurement. However, as the general loudness meter, the VU Meter is no longer up to date.

    That's what I meant by some people's habits (not a criticism!:mates:).
     
    Last edited: Jun 23, 2024
  17. Sinus Well

    Sinus Well Audiosexual

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    Yes, like here. Just a small example to illustrate the differences.

    Random picked vocal. Audio muted.

    LUFS-M vs VU:
    Whilst LUFS represents the overall loudness quite well, VU is an excellent representation of the perceived dynamics of the performance. These big ups and downs in the VU graph is what I notice when I listen and what is important to me when editing performances.

    lufs-m vs vu.png

    So, this level edit based solely on the displayed VU level.
    Result: Not perfect (there are nuances that only the ear can determine), but 95% where I want to go with it. LUFS can't give me that because it displays the dynamics differently. LUFS is simply not made for this.

    vu automation.png



    Yes, agree 100% :wink:
     
    Last edited: Jun 23, 2024
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  18. eXACT_Beats_

    eXACT_Beats_ Audiosexual

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    Agreed. Like I mentioned, there's a difference between what you'd use gain staging in a mix for convenience, and what you'd want on your 2-buss/master. I know people of different generations who find one easier to use in a mix than the other due to what you succinctly described as "technical characteristics."
    With LUFS metering being more accurate, it clouds the fact that you don't have to be pinpoint accurate level-wise in a mix. Everything you're staging is going to be routed to busses, if not layers of busses, before hitting your 2-buss/master, which are better points where you might want to use LUFS instead of a VU. People forget you can turn things down anywhere in a mix.
    I'm the first to throw out oldhead keepsakes if they're no longer of any actual use, I just don't understand people's disregard for VU meters; it seems more like a mule-kick response to Boomer tools than a logical aversion to something that's no longer relevant.
     
  19. muse2love

    muse2love Producer

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    First because your eyes are deaf hearing...
    then... put what ever Sauce for loudness after with more modern Taste using the new LUFS Metering

    The reste is like...
    Velvet Underground

     
  20. eXACT_Beats_

    eXACT_Beats_ Audiosexual

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    This band clearly used single-coil LUFS in their guitars, and condenser LUFS for drum OH, that's why they sound amazing. :chilling:
    cowbell-lufs.png
     
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