NEW UPDATED Room Calibration for Film and TV Post

[abluesky]

Hello Georgia

Send me an e-mail and I will put you in contact with our VP of Sales. I have already forwarded your contact info to him.

[email protected]

Cheers!

[dr sound]

Well it's been 1 year since I originally posted the links and it's been used by many of you out there. There's hasn't been an answer from Dolby on the previous links (that have expired since they redid their website) so I will e-mail them again and post it when I get an answer.
Take Care,

[bigears]

In small rooms, I believe Dolby tends to recommend calibrating to 79db, with surrounds dropped 2 to 3 db.

The "Dolby:" noise is not really proper pink noise, so that could be throwing things as well.
And of course you only want to use an SPL meter with a VU meter...

Another thing to take into account is that the 96 i/o is factory preset to -14db headroom. Without some carefull planning it is difficult to set it up in the dubbing universe.

charles maynes

Hi Charles and other readers,

Just setting up a 5.1 set of BlueSky System 1 for a dolby SR mix

Im in a small room so your comment caught my eye

Im wondering if you could elaborate a bit on the Dolby noise or where I might download it, I thought it was just pink noise?
Blue Sky have their own noise too which can be down loaded off their site!!

also Im not sure what you mean by the -14db headroom

Im playing out of a protools rig

[bigears]

I appreciate Marti's honesty and clarity on this issue

I have the radio shack DIGITAL meter

"huh???" !!!!!!!
(a sharp intake of breath by everyone!!!!!!!!)

Hands up who can hear a difference of 00.1 decibels?

OK.

Isnt that why we measure in decibels?

;-)

logarithmic, exponential.......

[bigears]

So I wonder how Georgia got on with the Blue Sky speakers?

[Dan Worley]

one other note about the level being extremely hot for you when mixing music using film calibration. If you calibrate a room as discussed here you also have to understand that you are mixing from a minimum of 15 feet from the monitors.. so if you are calibrated at 85db, mixing music at full 0 dbfs AND your sitting a couple feet from a set of near field monitos it IS going to hurt.

Question: If the SPL measurements are taken at the mix positions, why would it be louder just because the music mixer is sitting closer to the monitors?

I think what happens is that when music mixers start seeing their meters under a certain level (like, -.01 dBFS ), they start freaking out and turn down the monitors and push up the faders.

I've been mixing music with calibrated monitors (usually 77dB SPL) for a few months now and I very much enjoy it--though it did take me awhile to get used to it. I got the idea from Bob Katz' book on mastering audio. Mastering engineers really appreciate it, as the mixes tend to end up with a much greater dynamic range and not as high peaks, which gives them more room and freedom to do their work.

Regarding 85dB SPL; I mix _some_ songs using that reference level, but I sure wouldn't want to play a hyped-up commercial CD over a system set to that level. Not, as you say, sitting four or five feet away. Ouch!!! I think it would hurt even at fifteen feet away.

I'm a little confused about using -20 dB RMS pink noise and calibrating to 85 dB SPL. I thought there was a 2dB error made in the early SMPTE RP 200 document and that the pink noise level was changed to -18 dB RMS. Can anyone shed some light on that for me? Maybe I didn't quite understand what I read.

Thanks for the helpful topic.

Regards,

Dan Worley

[pindebraende]

In small rooms, I believe Dolby tends to recommend calibrating to 79db, with surrounds dropped 2 to 3 db.

charles maynes

Hi there

Just curious!
What is the minimun size for a room, when mixing surround?

Thanks

Pindebraende

[dr sound]

There is no minimum. There are issues with acoustic problems in very small room that divide into themselves (10x10 etc). If your talking about movies and having Dolby come to Printmaster, the room needs to be Dolby certified. They have a list of requirements. By the way, my room is Dolby certified. I will have pictures up in the next few days.

[dr sound]

Dan,
The reference of 85 SPL is for mixing Movies. It is not for mixing music unless that music is intended for a Film or TV show. There is NO standard reference level for Music. With Film and Video there is up to a 20 db headroom. In Music, people mix it to .1 db of digital zero. That is 20 db louder than the reference level for Films! That means when a music cue is played in a calibrated "Dub Stage", it is playing back at 105 SPL!
If your Mixing for Film make it 85 spl "C" weighted slow.If your Mixing for TV make it 82-79 SPL.

[Dan Worley]

Dan,
The reference of 85 SPL is for mixing Movies. It is not for mixing music unless that music is intended for a Film or TV show. There is NO standard reference level for Music. With Film and Video there is up to a 20 db headroom. In Music, people mix it to .1 db of digital zero. That is 20 db louder than the reference level for Films! That means when a music cue is played in a calibrated "Dub Stage", it is playing back at 105 SPL!
If your Mixing for Film make it 85 spl "C" weighted slow.If your Mixing for TV make it 82-79 SPL.

Yeah, I'm aware of all that, Marti. But calibrated monitor levels are starting to gain some popularity in music mixing and mastering now. I think it's a good thing. And yes, you can use 85 SPL for music mixing and get a great sounding mix without blowing your ears out. The mastering engineer takes it from there and usually masters calibrated to 77 SPL (14 dB of headroom). I took to it right away, even after fifteen years of doing it the other way. I usually mix with my monitors set to 77 SPL. It all depends on the song and what dynamic range it has.

I know you don't have time, Marti, but here's an article for anyone interested. This is the guy that turned me onto it.

Because of a 2-dB error in measurement, was not the SMPTE 200 RP Standard changed from -20 dBFS RMS pink noise to -18 dBFS RMS pink noise in order to keep the popular 85 SPL number? That's what I thought I read, but everyone still keeps using -20 dBFS RMS and 85 SPL. It's complete anarchy!

Hope things are going well for you there at the dub stage.

Regards,

Dan Worley