Reading VU Meters & I/O Level

[John GleasonParticipant]

Kaleb, if PT shows the signal going to the compressor at 0 VU and the compressor is only getting the signal down -3.5 VU, then you might need to increase the output level on your interface. Once the compressor input shows 0 VU, then lower the compressor output to 0 VU. At that point, if PT doesn't show 0 VU coming back from the compressor, then adjust the input level on the interface to bring PT back to 0 VU. Then everything is happy.

0 VU is a pseudo-maximum, and many record 3 or 6 db lower (depending on the track) to give them some headroom so your preferred recording level is probably fine. Are the -11.4 and -16 readings from a loudness meter?

John

[Kaleb TreacyParticipant]

Yeah that's the thing though, I can't increase the output to my inserts on my desk. That's all done VIA my DAW. The insert points only have 2 switches to engage the insert and to return it back to the DAW, everything else is done through firewire digitally. So I'm in a bit of a pickle. I could just gain it down to 0VU once and not touch it again even though adding the insert bumps it up another 2.6VU. That'd make the compressor sit around -.5 which's ideally what you were saying you tend to aim for right?

They sure are. Just your normal DB meters. The kick that I was talking about previously was one that I recorded when I was new to this, aiming for -6dbs, hence why it was clipping going to the compressor. But yeah now I peak around -18 so it's all good.

Kaleb

[John GleasonParticipant]

Kaleb, I have neither a firewire interface nor Pro Tools, so someone else who has both of those may be able to offer some suggestions,

It sounds like your only issue is that signal boost when you insert the compressor. What are the readings when you lower the output of the compressor until PT shows the same level signals going into and out of the insert?

Also, what does the input meter on your compressor read with the Input Threshold fully clock-wise and PT set at 0 VU going to the insert?

John

[Kaleb TreacyParticipant]

That's no worries. I thought I'd tell you what I'm running anyways incase it could help a little.

Yeah I just tried it without connecting the compressor and it didn't bump up that 2.6db. I turned the output down 3 and it's fixed it. VU's reading -1.8 on both the input and output. There's only an output meter, no input.

Kaleb

[John GleasonParticipant]

Sounds like you've got it set! Good luck and enjoy your outboard gear (I'm a "knob" fan since I find it difficult to adjust a plug-in with a mouse while I'm focused on listening carefully or watching something else!).

John

[Kaleb TreacyParticipant]

Cheers buddy! Learn something new everyday. I really appreciate it!

[Steve HoggartParticipant]

The difference between +4dBu and -10dBV [or to simplify "+4" and "-10"] is 11.79dB

If you set your unit to -10dB you’re effectively giving the signal a boost of 10dB there by a hotter/larger signal the idea is to reduce noise. The +4dB position is expecting a big loud signal.

As far as VU’s Aim for 0dB as this is optimum level for the internals of the bit of kit to work at.

[Warren HuartKeymaster]

Thanks Kaleb for the great question and thanks everyone for responding so well! You ALL Rock! Have a marvellous time recording and mixing, many thanks Warren P.S Steve great technical answer!

[Joe Salyers SalyersParticipant]

Ok I think this may help 0 on a VU Meter is -18 on a DAW digital full scale meter when your hardware is set to +4 (I know it's confusing) if you're VU meter reads 0 and your return DAW meter reads anything above/below -18 when calibrating your gear with a 1 Kilohertz (1000 hertz) test tone you need to set the calibration correctly for the analog equipment's VU metering. Here is how to do that take a signal generator most DAW's have one built in and set the output of the generator plugin to -18 send that signal out of your interface into your analog gear. Some gear will have a calibration knob or screw some may not if it does use a screwdriver to set the signal coming into your VU to 0. If it does not take a mental note on how close to 0 it is and compensate the offset accordingly. RMS, K-12, K14, K20, Peak, EBU,R128, PPM and loudness metering are not the same as VU so we have to use the analog standard when calibrating analog equipment. TB Pro Audio has a free VU meter for all DAWs so jump over to their website and grab it it also does other metering types this way you can check that the outgoing signal from your hardware is reading correctly coming back into your DAW with a VU plugin because a VU meter can go bad so it is best to double check and hey it's a free metering plugin. Also the difference between +4 (1.23Vrms) and -10 is you should always use +4. -10 is for consumer equipment.only use -10 if a +4 option is not available on the hardware. Granted some hardware may allow for higher headroom but 0VU = -18 Digital is the best way to be in the safe zone. If you want to drive your gear hard go ahead there are not rules and it might sound quite nice but the VU needs to be calibrated correctly so you get the best possible results for your clients and yourself. Here is the link to the free VU meter Have a great day Ya'll!! http://www.tb-software.com/TBProAudio/mvmeter.html

• This reply was modified 6 years ago by Joe Salyers Salyers.
• This reply was modified 6 years ago by Joe Salyers Salyers.
• This reply was modified 6 years ago by Joe Salyers Salyers.

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