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Speaker calibration tutorial for students
Old 29th July 2013
  #31
Gear Maniac
 

Sorry, you've been given the wrong information which is very worrying. I stand by RMS as the reference:
http://www.dolby.com/uploadedFiles/A...UserManual.pdf

As you can see in the linked document (page 5-5), Dolby specifies to line up with the meters of your film console at 0 VU and VU metering is equivalent to RMS ITB, not peak. They even make a point of being careful about the ballistics and mention the potential error of lining up using peaks rather than VU/RMS meters.

-20 (or -18 depending on where you are) is calibrated to be the average level (hence RMS) of your sonic energy across the frequency spectrum (hence pink noise) measured in dBSPL, C weighted, slow response at the listening position.
Old 29th July 2013
  #32
Gear Head
 

Brent, I was told by Dolbys consultants (and others in this industry) to use Peak not RMS.

I know the advices from the document above. It's the same I got from Dolby in their document called "Dolby 5.1 Production Guidelines", which they provide to us mixers.
The AL is 0VU = -20dBFS. For me it doesn't make sense to use RMS in that case, because everything digital is firstly related to Full Scale and being measured as Sample Peak. Digital RMS measurement is totally different so it should be specified exactly what ballistics the RMS meter has to have. But there is no such information so it's likely to be peak reading.

Maybe it is and always was RMS. That would mean that some studios and cinemas are wrong calibrated because these Dolby guys which are advising to use Peak are working out there!

So it would be great to hear of some more experiences with this, preferable from colleagues from other large mixing stages please.
Old 29th July 2013
  #33
Gear Maniac
 

Ok, lets just ignore the dolby documentation and still hold up the anecdotal quote from one of their reps. How about Thomlinson Holmans 5.1 surround sound up and running - AFAIK still an expert book on the topic?
Page 84
A problem creeps in with the use of noise signals however, they show a strong and time varying difference between their rms level and peak level. The difference can be more than 10 dB. So which level is right? The answer depends on on what you are doing. For level setting we use the rms level of the noise, both in the electrical and acoustical domains. Peak meters, therefore, are not useful for this type of level setting.

If you play back the dolby pink file or the blue sky file most folks use for calibrating pro rooms you will see its level move all over the place due to its decorrelated, random nature. Hence rms metering and vu meters are historically used.

Again, the video is intended for Film students and first timers to get them in the ballpark (without having to chase up dolby or blue sky files) and teach the fundamentals this is not a textbook guide for a professional space, if you run a dub stage hopefully you know the stuff Ive omitted for the sake of brevity and clarity for beginners.
Old 29th July 2013
  #34
Excuse the [somewhat noobish] question - I'm just starting out. What if you're in a temporary location while finding a rental and have to primarily mix with headphones. Is there anything you have to look out for then? How do you achieve the same effect?
Old 16th December 2013
  #35
Gear Maniac
 
clark_savant's Avatar
 

Thanks for the video
Old 19th June 2014
  #36
Here for the gear
 

Thanks for sharing useful post.
Old 31st January 2015
  #37
Gear Head
 

Sorry for digging up an old thread but I found it very helpful for me as an up-and-coming mixer for film and TV.

To continue on topic and changing the direction a bit - do people use well mixed reference stuff before starting to mix their own projects? For example do you listen to a well mixed TV program or a part of a film to kind of adjust your ears to a well mixed material before starting to mix your own stuff if you get what I mean?. A bit like people use reference material when mixing and mastering music.

Thanks!
Old 18th February 2015
  #38
Here for the gear
 
Jonathan Jenkins's Avatar
Yes, reference material can be very useful - but it must be the correct type; just be aware of the differing dynamic range between, TV, DVD, and cinema mixes. I find it useful to at least listen to some well-recorded narration or dialogue if I have to use a room I haven't mixed in for a while.

cheers,

Jon.



Quote:
Originally Posted by tv_engineer_lnd View Post
Sorry for digging up an old thread but I found it very helpful for me as an up-and-coming mixer for film and TV.

To continue on topic and changing the direction a bit - do people use well mixed reference stuff before starting to mix their own projects? For example do you listen to a well mixed TV program or a part of a film to kind of adjust your ears to a well mixed material before starting to mix your own stuff if you get what I mean?. A bit like people use reference material when mixing and mastering music.

Thanks!
Old 18th February 2015
  #39
Gear Head
 

Quote:
Originally Posted by Jonathan Jenkins View Post
Yes, reference material can be very useful - but it must be the correct type; just be aware of the differing dynamic range between, TV, DVD, and cinema mixes. I find it useful to at least listen to some well-recorded narration or dialogue if I have to use a room I haven't mixed in for a while.

cheers,

Jon.
Top tip, thanks J!
Old 17th June 2015
  #40
Lives for gear
 

This link seems bad.
Is there another place to see the tutorial?

Quote:
Originally Posted by Brent_in_Sydney View Post
It seems like we get questions about how to mix for film/tv a lot in here, funny that. The most common misunderstanding I see is how to calibrate a home studio to 79 to set up the gain structure in the edit from the beginning.
I just made this simple video tutorial to help students wrap their heads around speaker calibration. Hope its useful.
Speaker Calibration tutorial | ProToolsProfessional.com
Old 21st June 2015
  #41
Gear Addict
 
jjeffers's Avatar
 

Quote:
Originally Posted by theom View Post
This link seems bad.
Is there another place to see the tutorial?
Same. Not much point in keeping the thread stickied if the link to the info is dead.
Old 21st June 2015
  #42
Gear Addict
 

Older Gearslutz posts can't be modified. Here's another link: https://vimeo.com/22735507
Old 16th December 2016
  #43
007
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007's Avatar
 

I'm trying this by using an SPL meter app on my iPhone and the pink noise generator in Logic, set at -20 RMS on output.
I slowly crank the gain up on one monitor, with the meter in the sweet spot at ear level, and it gets insanely loud with the meter barely hitting 55-60dB!
I can't imagine cranking another 20dB to bring this up to 79db!

I believe I have everything set correctly, 'slow response', 'c-weighted', etc.
This is in a smallish room - sound mixing for a tv program.

I downloaded a different SPL meter and getting the same results.

What am I overlooking?
Old 25th December 2016
  #44
Lives for gear
 

Same problem here... 79 db is crazy loud in an average size room
Old 26th December 2016
  #45
Gear Addict
 

I wouldn't trust a smartphone microphone for calibrating, but it won't be 30 dB off.. Hows your analog chain, what interface do you guys use, does it have a -10dBv or a +4dBM output level? what kind of monitors, same question for input level..
Old 27th December 2016
  #46
Lives for gear
 

I have a real sonometer, not a smartphone application. I can calibrate to 64 db max, otherwise it 's too loud. My interface is an audient id22 and speakers are Adam A7. Both are connected with rca unbalanced cable. Maybe that's the reason why it seems so loud in my room? ( i plan to buy mogami balanced cable )
Old 1st February 2018
  #47
BTW the link to the tutorial from the OP is broken.
Old 24th March 2018
  #48
Lives for gear
 

If you're mixing for TV don't calibrate to 79dBSPL.
Normalize content to your target level (-23/-24 LUFS). Play that content with unity gain.
Adjust monitor gain to comfortable level.

Then import reference pink and measure one speaker. This is your reference level to calibrate all speakers to.

Done.
Old 12th October 2018
  #49
Gear Maniac
 

About distance to speakers and roomsize:
Is there a faq about dimensions and distances regarding SPL somewhere on the interwebs?
We have several rooms that we would like to try recalibrating.
Old 12th October 2018
  #50
Gear Nut
 

Quote:
Originally Posted by kosmokrator View Post
If you're mixing for TV don't calibrate to 79dBSPL.
Normalize content to your target level (-23/-24 LUFS). Play that content with unity gain.
Adjust monitor gain to comfortable level.

Then import reference pink and measure one speaker. This is your reference level to calibrate all speakers to.

Done.
Hi! How do you go about normalizing the content, simply raising the volume and take it through a metering program? or how do you do it?

Do you know if there is a place where you could download well mixed material somewhere as reference-content or do you just use one of your own mixes and normalize?

Thank you Kosmokrator!
Old 12th October 2018
  #51
Gear Maniac
 

There are several meteringplugins that will do the job.
We use Izotope Insight for metering, and RX loudness Control to get the final mix to hit -23 precisely.

Try to stay between 20 and 27 lufs, at a comfortable level, and you should hit around -23 lufs on a standard tv mix.
Old 12th October 2018
  #52
Gear Nut
 

Quote:
Originally Posted by tha_lode View Post
There are several meteringplugins that will do the job.
We use Izotope Insight for metering, and RX loudness Control to get the final mix to hit -23 precisely.

Try to stay between 20 and 27 lufs, at a comfortable level, and you should hit around -23 lufs on a standard tv mix.
Oh yeah thank you, I got that! I am using WLM Plus and it works perfectly.
I was just wondering what Kosmokrator meant by normalizing content to your specified LUFS, for example -16 for web, and then calibrate your monitors using the normalized content.
Old 12th October 2018
  #53
Gear Guru
 

Quote:
Originally Posted by pettah93 View Post
Oh yeah thank you, I got that! I am using WLM Plus and it works perfectly.
I was just wondering what Kosmokrator meant by normalizing content to your specified LUFS, for example -16 for web, and then calibrate your monitors using the normalized content.
It's pretty much exactly what he wrote. You find something that represents the type of work you do and is nicely balanced and even. When he writes "normalize" he simply means that whatever that material is averaging using LUFS you make sure it's set to whatever you have to deliver, meaning -23LUFS for TV in Europe or -16LUFS for the web perhaps. So if that source content is already at -23LUFS when you import it you'll boost the level to -16LUFS (i.e. boost 7dB) if you're delivering for the web and that's your desired target level.

Once you've done that you leave your signal chain in the DAW at unity and adjust your monitors so that it feels right to you. At this point you have a reference level so that when you're mixing your own material later if it ends up sounding as loud as this reference mix (with monitoring chain at unity) then you should be pretty much at -16LUFS. So you've got your reference level set.

(obviously be careful with peaks as you boost that first source if that's what you end up doing)

What he then wrote was that you should then switch to noise and pick one speaker as the reference and make sure they all measure the same at the listening position. This is done to make sure you're getting the same level from all of your speakers, it's not about the reference level at this point.

Makes sense?
Old 12th October 2018
  #54
Lives for gear
 

Quote:
Originally Posted by mattiasnyc View Post
It's pretty much exactly what he wrote. You find something that represents the type of work you do and is nicely balanced and even. When he writes "normalize" he simply means that whatever that material is averaging using LUFS you make sure it's set to whatever you have to deliver, meaning -23LUFS for TV in Europe or -16LUFS for the web perhaps. So if that source content is already at -23LUFS when you import it you'll boost the level to -16LUFS (i.e. boost 7dB) if you're delivering for the web and that's your desired target level.

Once you've done that you leave your signal chain in the DAW at unity and adjust your monitors so that it feels right to you. At this point you have a reference level so that when you're mixing your own material later if it ends up sounding as loud as this reference mix (with monitoring chain at unity) then you should be pretty much at -16LUFS. So you've got your reference level set.

(obviously be careful with peaks as you boost that first source if that's what you end up doing)

What he then wrote was that you should then switch to noise and pick one speaker as the reference and make sure they all measure the same at the listening position. This is done to make sure you're getting the same level from all of your speakers, it's not about the reference level at this point.

Makes sense?
Couldn't have said it better.
Old 12th October 2018
  #55
Gear Nut
 

Quote:
Originally Posted by mattiasnyc View Post
It's pretty much exactly what he wrote. You find something that represents the type of work you do and is nicely balanced and even. When he writes "normalize" he simply means that whatever that material is averaging using LUFS you make sure it's set to whatever you have to deliver, meaning -23LUFS for TV in Europe or -16LUFS for the web perhaps. So if that source content is already at -23LUFS when you import it you'll boost the level to -16LUFS (i.e. boost 7dB) if you're delivering for the web and that's your desired target level.

Once you've done that you leave your signal chain in the DAW at unity and adjust your monitors so that it feels right to you. At this point you have a reference level so that when you're mixing your own material later if it ends up sounding as loud as this reference mix (with monitoring chain at unity) then you should be pretty much at -16LUFS. So you've got your reference level set.

(obviously be careful with peaks as you boost that first source if that's what you end up doing)

What he then wrote was that you should then switch to noise and pick one speaker as the reference and make sure they all measure the same at the listening position. This is done to make sure you're getting the same level from all of your speakers, it's not about the reference level at this point.

Makes sense?
Thank you so much for your help, it really makes sense now! It means a lot!
Old 13th October 2018
  #56
Gear Guru
 

Quote:
Originally Posted by pettah93 View Post
Thank you so much for your help, it really makes sense now! It means a lot!
Det var så litet så.....
Old 17th October 2018
  #57
Gear Maniac
 

So... back to my question ;-)

About distance to speakers and roomsize:
Is there a faq about dimensions and distances regarding SPL somewhere on the interwebs?
We have several rooms that we would like to try recalibrating.
Old 17th October 2018
  #58
Gear Guru
 

I don't know of such an FAQ.

But since you measure levels at the listening position why do you need it?
Old 18th October 2018
  #59
Gear Maniac
 

Good question. I have seen roomsize been mentioned several times as a factor for what kinds of spl one should be working in, but no proper (as far as my limited understanding) guide on how it should affect the monitoring.
Old 7th November 2018
  #60
Lives for gear
 
Airon's Avatar
Quote:
Originally Posted by bcslaam View Post
BTW the link to the tutorial from the OP is broken.
He placed it on Youtube at the same time. Here you go:
Speaker calibration for film/tv sound mixing
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