Klangheim VU metering / mastering

domforr

Hi,

Can someone explain VU metering to me in basic English, so I can use it in a practical scenario? I've got some tracks all mixed and have just purchased the KLangheim VUMT metering deluxe and am now quite confused. When I place the meter over my entire mix (on the master channel) it seems to be peaking and hitting the red a lot. However, there's no peaking in my DAW and the tracks seem ok when rendered to MP3 or wav.

Am I supposed to be getting everything under the red when using the meter? And which of the many metering options in Klangheim is the one to use, as they all seem to offer slightly different interpretations of what a peak is?

Basically I need to make sure the tracks are good for mastering (even if do it myself using plugins) and that they aren't distorting/ clipping in whatever medium they're played in.

Any help gratefully recieved!

Thanks,

Dominic

spark240

Hi, what DAW are you using?....

domforr

Hi, Reaper, 64 bit on a mac.

colourofsound

Firstly - download manual for VUMT deluxe (pdf)

DAW metering is perfectly sufficient usually - but I've not used Reaper before. I'm interested to know what lead you to buy VUMT.

Does Reaper have it's own VU metering plugin you can compare it with?

Is pre-fader metering enabled? This often tricks me in Logic; this is the level of your audio before it hits your plugins.

EDIT: A quick googling around looks like VU metering is default in VUMT but DAWs will use RMS Peak Metering which will be more accurate. Its worth bearing in mind that 50% of the VU scale represents only 6db, which is why it might look extreme. Set VUMT to RMS and see if that is more consistent with your DAW.

Here is an article all about metering by Mastering Engineer Bob Katz - http://www.digido.com/index.php?option=com_content&view=article&id=21:level-practices-part-2-includes-the-k-system&catid=13:bob-katz&Itemid=89&fontstyle=f-smaller

Cirrus

Metering is a surprisingly complicated thing when you get into the nuts and bolts of it, and it's all to do with how we perceive the volume of steady sounds vs very short ones.

In the old, analogue days, all you had was VU meters that looked like what is modeled by the Klanghelm plugin. These work on the principle of showing the rms volume - which is not the maximum signal level, but the average signal level over a short period of time (usually some fraction of a second). They were calibrated so that 0vu showed the optimum signal level for that piece of gear - high above the noise floor, and low enough that there was headroom for quick, louder bursts - generally you'd have ~20dB extra above 0vu before the gear actually clipped. This was handy because it meant you could gain stage your signal chain to get optimum volume in each piece of gear your signal went through.

HOWEVER...

Because these were real needles with weight, they had inertia and momentum. So on some steady signals like guitars, bass, that sort of stuff, they had time to reach the correct position to show what the level was. On fast stuff like snare hits where the signal immediate ratches up and dies away, the needle doesn't have time to move all the way to the right before the signal's dropped off, so they tended to under-read, sometimes by quite a lot, on fast sources.

That said, our ears work in a similar way. If you ask someone to balance the volume of a distorted guitar and a snare drum, if you set them so they *sound* like they're the same volume to your ears, the snare will in actuality have muuuuch higher peaks.

People got used to working with VU meters. They knew that if you set them so, say, the vocals were at 0vu, the guitars were at -3, the snare was at -6... you'd have good signal levels with headroom to spare.

Then digital came along.

Suddenly the noise floor wasn't so much of a problem but clipping was a real concern because the signal sounded fine all the way up to clipping then suddenly sounded terrible. So the transition was made to peak meters, which show the absolute highest volume the signal gets to so that you could avoid the terrible clipping.

Which is fine, but now you're in a situation where if you balance a snare and a guitar to hit the same peak level, the guitar will be louder than the sun, with much much higher overall perceived volume and the snare will be almost inaudible. So in practical mixing terms, all peak level meters tell you is that you're not running out of headroom. They don't tell you anything about perceived volume, or about how loud the meat of the signal is - only the very short high volume bursts. To ram this point home, consider this; if you take your unlimited, uncompressed mix and normalise it to 0dBfs and compare it to a modern mastered, commercial release that also peaks at 0dBfs, the mastered mix will sound way louder despite not peaking any higher because the average volume is way louder.

The interface between the analogue world and the digital one is as a rule of thumb that if you plug analogue gear into your digital converter, a steady tone at 0VU on an analogue meter will = -18dBfs on your DAW's peak meter.

So it's perfectly possible to have a mix that's not peaking in your computer that would pin an analogue meter to the right at +3dBu, because all you need to do that is an average level of -15dBfs in the computer, which is perfectly achievable.

Now, a lot of plugins that model analogue gear expect a signal level in digital that would correspond to what you'd feed into the real analogue gear, if you had it. So if you put, say, an analogue modeled compressor like Klanghelm's (most excellent) MJUC on a track in your DAW, it would expect to see a signal that averaged around -18dBfs which corresponds to an imaginary 0vu in the plugin. If you feed it a hotter signal it will distort, if you feed it a lower signal it won't run as hard as it was designed to.

So the utility of a plugin like VUMT;

- It shows you what your digital signal would give you on analogue meters out in the real world, so you can calibrate your volume to hit your analogue modeled plugins at the right level.

- Likewise, it shows you your average signal level so if you sent your DAW signal out into real gear (say you want to mix through a real compressor, mixing desk, rack mounted reverb etc) you're sending a healthy volume out into the real world.

- VU meters give a more accurate reflection than peak meters of how your ears actually hear, so they're more useful yardsticks to show you how loud different signals sound relative to each other.

domforr

colourofsound said:

Firstly - download manual for VUMT deluxe (pdf)

DAW metering is perfectly sufficient usually - but I've not used Reaper before. I'm interested to know what lead you to buy VUMT.

Does Reaper have it's own VU metering plugin you can compare it with?

Is pre-fader metering enabled? This often tricks me in Logic; this is the level of your audio before it hits your plugins.

EDIT: A quick googling around looks like VU metering is default in VUMT but DAWs will use RMS Peak Metering which will be more accurate. Its worth bearing in mind that 50% of the VU scale represents only 6db, which is why it might look extreme. Set VUMT to RMS and see if that is more consistent with your DAW.

Here is an article all about metering by Mastering Engineer Bob Katz - http://www.digido.com/index.php?option=com_content&view=article&id=21:level-practices-part-2-includes-the-k-system&catid=13:bob-katz&Itemid=89&fontstyle=f-smaller

Thanks for the feedback.

Reaper doesn't have it's own meter plugin that I'm aware of - which is kind of why I thought I shoul dtry the Klangheim.

I also don't think it has pre fader metering - something that seems to cause much outrage on the forums.

When I play the track using RMS metering on VUMT it seems fine. When i play it with VU metering set it goes into the red on a regular basis - and when I have some mastering plugins on it's pretty much in the red all the time.

domforr

Cirrus said:

Metering is a surprisingly complicated thing when you get into the nuts and bolts of it, and it's all to do with how we perceive the volume of steady sounds vs very short ones.

In the old, analogue days, all you had was VU meters that looked like what is modeled by the Klanghelm plugin. These work on the principle of showing the rms volume - which is not the maximum signal level, but the average signal level over a short period of time (usually some fraction of a second). They were calibrated so that 0vu showed the optimum signal level for that piece of gear - high above the noise floor, and low enough that there was headroom for quick, louder bursts - generally you'd have ~20dB extra above 0vu before the gear actually clipped. This was handy because it meant you could gain stage your signal chain to get optimum volume in each piece of gear your signal went through.

HOWEVER...

Because these were real needles with weight, they had inertia and momentum. So on some steady signals like guitars, bass, that sort of stuff, they had time to reach the correct position to show what the level was. On fast stuff like snare hits where the signal immediate ratches up and dies away, the needle doesn't have time to move all the way to the right before the signal's dropped off, so they tended to under-read, sometimes by quite a lot, on fast sources.

That said, our ears work in a similar way. If you ask someone to balance the volume of a distorted guitar and a snare drum, if you set them so they *sound* like they're the same volume to your ears, the snare will in actuality have muuuuch higher peaks.

People got used to working with VU meters. They knew that if you set them so, say, the vocals were at 0vu, the guitars were at -3, the snare was at -6... you'd have good signal levels with headroom to spare.

Then digital came along.

Suddenly the noise floor wasn't so much of a problem but clipping was a real concern because the signal sounded fine all the way up to clipping then suddenly sounded terrible. So the transition was made to peak meters, which show the absolute highest volume the signal gets to so that you could avoid the terrible clipping.

Which is fine, but now you're in a situation where if you balance a snare and a guitar to hit the same peak level, the guitar will be louder than the sun, with much much higher overall perceived volume and the snare will be almost inaudible. So in practical mixing terms, all peak level meters tell you is that you're not running out of headroom. They don't tell you anything about perceived volume, or about how loud the meat of the signal is - only the very short high volume bursts. To ram this point home, consider this; if you take your unlimited, uncompressed mix and normalise it to 0dBfs and compare it to a modern mastered, commercial release that also peaks at 0dBfs, the mastered mix will sound way louder despite not peaking any higher because the average volume is way louder.

The interface between the analogue world and the digital one is as a rule of thumb that if you plug analogue gear into your digital converter, a steady tone at 0VU on an analogue meter will = -18dBfs on your DAW's peak meter.

So it's perfectly possible to have a mix that's not peaking in your computer that would pin an analogue meter to the right at +3dBu, because all you need to do that is an average level of -15dBfs in the computer, which is perfectly achievable.

Now, a lot of plugins that model analogue gear expect a signal level in digital that would correspond to what you'd feed into the real analogue gear, if you had it. So if you put, say, an analogue modeled compressor like Klanghelm's (most excellent) MJUC on a track in your DAW, it would expect to see a signal that averaged around -18dBfs which corresponds to an imaginary 0vu in the plugin. If you feed it a hotter signal it will distort, if you feed it a lower signal it won't run as hard as it was designed to.

So the utility of a plugin like VUMT;

- It shows you what your digital signal would give you on analogue meters out in the real world, so you can calibrate your volume to hit your analogue modeled plugins at the right level.

- Likewise, it shows you your average signal level so if you sent your DAW signal out into real gear (say you want to mix through a real compressor, mixing desk, rack mounted reverb etc) you're sending a healthy volume out into the real world.

- VU meters give a more accurate reflection than peak meters of how your ears actually hear, so they're more useful yardsticks to show you how loud different signals sound relative to each other.

Very informative thank you. So, on a basic level for a not massively technical song writer like myself, which meter should I be focusing on as my basis for a good overall level?  I'm a bit concerned that if I drop everything to meet the VU level and stay off the red, the track will lose a lot of energy and become a bit safe and dull. RMS or VU - or both?

spark240

Stick a limiter on your master bus to get the level back up..?

Cirrus

domforr said:

Very informative thank you. So, on a basic level for a not massively technical song writer like myself, which meter should I be focusing on as my basis for a good overall level?  I'm a bit concerned that if I drop everything to meet the VU level and stay off the red, the track will lose a lot of energy and become a bit safe and dull. RMS or VU - or both?

If you use the VU setting, calibrate it to -18, try to set your levels so the meter is around 0dbu, and just keep an eye on things and maybe turn tracks down so that your peaks don't go over, say, -10dbfs or maybe -6 for really loud peaks like snare drum, then you're probably going to be on the right track.

Then, operating within that framework, make the best mix you can. It's easy to bring the level up once it's finished.

domforr

Thanks all. Very helpful and I feel slightly more confident in approaching the mixes now.

shrinkwrap

I'm not convinced of any need for VU meters in Reaper unless you are experienced and know what they show.
Just rely on Reaper's master level meters. Don't let you peaks get higher than around -3 on that.
If you render to wav and later convert to MP3 the conversion process can push the peaks higher. (Lots of poeple advise to do it in a two step process)
Of course VU meters do look the mutt's nuts.

domforr

I used the VU meters on a track and just made sure nothing was going into the red and it seemed to improve the overall sound. Probably not much different from doing what you recommend as well, as I'm basically just lowering levels so they don't peak.