Hello!
I've been using RMS buddy is my to-go rms-readout plugin lately, but strangely enough i noticed that the readout seems to be about -3dB off? Does anyone know why this is occurring? I've compared it with TT dynamic range meter on a 20 rms pink noise signal and it confirmed the issue :/
screen cap : http://postimage.org/image/u93x600uz/
the test sound : http://kiwi6.com/file/2x5sajhlfx
Any help or explanation of this issue would be greatly appreciated.
Best regards, Mike[/img]
RMS buddy wrong readout ?
-
- KVRian
- 588 posts since 23 Mar, 2010 from Canada
RMS buddy is giving me the same readout as Voxengo Span and Sony Sound Forge.
-
- KVRer
- 2 posts since 5 Aug, 2008
This is not an error, but rather is a difference in metering standards. You will find that in Span there is a +3 option as one of its scale choice (DBFS, DBFS+3, K-12, etc). IIRC, it has something to do with when measuring a sine wave - is the peak and average measured as the same or as 3db different.
-
- KVRAF
- 16797 posts since 8 Mar, 2005 from Utrecht, Holland
+1 on metering standards. It depends on where you put the zero dB reference.
If zero is defined as a sine wave with max amplitude, then a square wave with the same amplitude will measure as +3dB.
If zero is defined as a sine wave with max amplitude, then a square wave with the same amplitude will measure as +3dB.
We are the KVR collective. Resistance is futile. You will be assimilated. 
My MusicCalc is served over https!!
My MusicCalc is served over https!!
-
- KVRer
- Topic Starter
- 5 posts since 11 Jul, 2011
Thanks for the explanation guys! You're amazingBertKoor wrote:+1 on metering standards. It depends on where you put the zero dB reference.
If zero is defined as a sine wave with max amplitude, then a square wave with the same amplitude will measure as +3dB.
So, is which one is more commonly used and well, more standardized ? Would be great to know so while reading guides with RMS values stated in them i won't be 3dB off.
-
- KVRian
- 1075 posts since 16 Jun, 2007
Their have been complaints about how TT Dynamic Range meter gets it's results measuring the crest factor rather than the true loudness range. There's a good article with an accompanying video on the Ian Shepherd Mastering site about the different meters here.
One that is worth checking out that isn't mentioned on that page (it wasn't out when it was written) is Melda Production's free MLoudnessAnalyzer.
Hope that helps.
One that is worth checking out that isn't mentioned on that page (it wasn't out when it was written) is Melda Production's free MLoudnessAnalyzer.
Hope that helps.
-
- KVRAF
- 14739 posts since 19 Oct, 2003 from Berlin, Germany
Sorry, but MLoudnessAnalyser, just as any EBU Loudness Measurement, is just plain nonsense to use while mixing.
While mixing, I recommend using a digital peak meter (also known as sample peak program meter, or SPPM) and(!) a VU meter according to the ANSI C16.5-1942/British Standard BS 6840/IEC 60268-17 standard calibrated to -18dBFS = 0 VU. Take a dive into my KVRmarks and read the post regarding "using analog equipment".
And this clears the question with the +3dB shift and whether or not to use it - along with the different calibration with either Sine Wave or Square Wave (calibration is usually done with Sine's at 1kHz). The shift is really only important while mastering, especially in use with a weighting filter pre-measurement. Plain RMS measurement however doesn't use any shift and mostly goes by 300ms - the same a s the VU Meter.
Additional:
RMS Meters and VU's don't use any weighting filter (A, C, K, etc).
EBU R-128 uses a modified K-weighting filter (also known as R2LB)
The bx_meter can be setup to your needs (A, C, K filter)
The K-System doesn't use any filter, but is shifted by 3dB
Specific meters like TT Dynamic Range (or bx_meter for that matter), EBU Loudness Metering, K-System and ITU 1770.1 are really only for mastering/broadcasting purposes.
Though I have to admit, the video by Ian Shepherd is an interesting and somewhat informative watch (he leaves out a lot of info regarding the weighting filter pre-measurement). But I'd focus on the basics rather than the whole iceberg.
While mixing, I recommend using a digital peak meter (also known as sample peak program meter, or SPPM) and(!) a VU meter according to the ANSI C16.5-1942/British Standard BS 6840/IEC 60268-17 standard calibrated to -18dBFS = 0 VU. Take a dive into my KVRmarks and read the post regarding "using analog equipment".
And this clears the question with the +3dB shift and whether or not to use it - along with the different calibration with either Sine Wave or Square Wave (calibration is usually done with Sine's at 1kHz). The shift is really only important while mastering, especially in use with a weighting filter pre-measurement. Plain RMS measurement however doesn't use any shift and mostly goes by 300ms - the same a s the VU Meter.
Additional:
RMS Meters and VU's don't use any weighting filter (A, C, K, etc).
EBU R-128 uses a modified K-weighting filter (also known as R2LB)
The bx_meter can be setup to your needs (A, C, K filter)
The K-System doesn't use any filter, but is shifted by 3dB
Specific meters like TT Dynamic Range (or bx_meter for that matter), EBU Loudness Metering, K-System and ITU 1770.1 are really only for mastering/broadcasting purposes.
Though I have to admit, the video by Ian Shepherd is an interesting and somewhat informative watch (he leaves out a lot of info regarding the weighting filter pre-measurement). But I'd focus on the basics rather than the whole iceberg.