jgbsound Posted September 6, 2015 Report Share Posted September 6, 2015 Howdy Gents, So I have a new shiny S3 console and am re-calibrating my speakers for film reference? (85 C spl). So I mapped 6 tracks in ProTools to discreet channels for the 5.1 field and inserted Pro Tools tone generator, set it to pink noise to start the process. By default, the tone generator sets the tone level to -20db (for headroom?). But if I truly want to work at the 85db reference level, shouldn't I set the tone generator to 0? By doing this wouldn't that more accurately reflect the meximum 85spl I need to dial my monitors to? Am I thinking about this the wrong way? Thanks for any guidance you can give me! John Quote Link to comment Share on other sites More sharing options...
jozzafunk Posted September 6, 2015 Report Share Posted September 6, 2015 I'm not an expert but that's the way the test tones are provided ( at -20dBFS ) so I I've always assumed that's the way to play them down. In saying that 85dB C SPL is way too loud for me - unless you're in a stage this is going to blow your head off - I work to a non-standard 75dB and that's still too loud in the loud bits, but then so is the theater - and it has been translating nicely. Quote Link to comment Share on other sites More sharing options...
CraigF Posted September 6, 2015 Report Share Posted September 6, 2015 Am I thinking about this the wrong way? yes, you are think the wrong way what you need is band limited pink, pink nose with HP at 500 and LP at 2000 (aka Dolby Pink) this helps eliminate room modes from effecting the measurement level so 1 channel set to 1 output, SG set to -20dB Pink, EQ3 with LPF set to 500 & HPF set to 2k measure the SPL for that channel, trim to 85 dB slow C change the output for the next speaker repeat setting the SG to 0 would make you calibration 20 dB to low / you mixes would be ~20 dB low Quote Link to comment Share on other sites More sharing options...
Jay Rose Posted September 6, 2015 Report Share Posted September 6, 2015 -20 dBFS is the nominal ("dialog") level. That's what should come to 85 dB. FWIW, it's also common in smaller rooms to work at 82 dBSPL C. Measure at the listening/mixing position. And in case it wasn't clear, you're measuring one speaker at a time. Quote Link to comment Share on other sites More sharing options...
minister Posted September 6, 2015 Report Share Posted September 6, 2015 (edited) So I have a new shiny S3 console and am re-calibrating my speakers for film reference? (85 C spl). Congratulations!How big is your room? Why are you calibrating to 85dBC? Is your room the size of a small Theater or larger? If so, go ahead. If not, like it's the size of a typical control room, you should be at 76 or 79dBC. So I mapped 6 tracks in ProTools to discreet channels for the 5.1 field Good. and inserted Pro Tools tone generator, set it to pink noise to start the process. Stop right there! The PT Pink genny is off by as much as 2dB. Download the pink noise from here: http://thedubstage.com/links/ Don't use Band-limited PINK UNLESS you have Bass Managed speakers. For Full Range, full PINK is required. Are you mixing for theatrical? Or DVD/Home? Because the cal is different. for Theatrical, the Surrounds are 3dB down from the Screen Channels (so they sum to 1 "channel" of level in the back). For the Home, it is equal SPL all the way around. HOWEVER, you need an RTA to calibrate the Sub which should be +10 IN-BAND above the Screen Channels. This ends up being around 91dBC on an SPL meter assuming 85dBC. Edited September 6, 2015 by minister Quote Link to comment Share on other sites More sharing options...
jgbsound Posted September 6, 2015 Author Report Share Posted September 6, 2015 I'm mixing for theatrical, mostly. Minister, I see the settings you mentioned in the Dolby Production Guidelines. And thank you for the link to the appropriate band limited pink noise, a.k.a. Dolby Pink. I'm in a smaller mixing room (it's a 15x12' mix room ) so I would calibrate to the lower level I'm assuming. Makes sense now considering you are setting reference relative to nominal dialog levels. I'm pretty sure this is what I did before, the last time I calibrated the entire system. I have been doing the initial SPL measurement with my Sound Level Meter.. This is a good starting point! I'll pipe up if I have any additional questions? Thank you one and all! John Quote Link to comment Share on other sites More sharing options...
jgbsound Posted September 6, 2015 Author Report Share Posted September 6, 2015 One additional note I am using band limited speakers (the primary 5 speakers frequency response is 30kHz to 54Hz). I also am using an LFE for the low end. Quote Link to comment Share on other sites More sharing options...
minister Posted September 6, 2015 Report Share Posted September 6, 2015 (edited) How things translate to rooms with 10,000 cubic feet of room volume and above from your room will be a bit of an art. It is hard to say exactly if it should be 76 or 79, but I would start with 79 to see how it translates. And, the reason you set it lower in a smaller room has to do with how "loud" things sound in a smaller room vs the same SPL in a bigger room, not nominal dialogue levels. I also am using an LFE for the low end. What does this mean? LFE is Low Frequency Effects. It is a channel, not a speaker. Are you using a Sub-Satellite system? If your speakers go down to 54Hz, where is your crossover? If you have a Bass Managed (Redirected) system -- and I am assuming you know what that means -- you use Band Limited Pink. Otherwise, if you simply have a speaker in the front that goes down to 54 but you are not not using Bass Redirect, use full pink. What monitor controller? Edited September 6, 2015 by minister Quote Link to comment Share on other sites More sharing options...
John Blankenship Posted September 7, 2015 Report Share Posted September 7, 2015 What monitor controller? What monitor controller(s) do you recommend? Quote Link to comment Share on other sites More sharing options...
minister Posted September 7, 2015 Report Share Posted September 7, 2015 What monitor controller(s) do you recommend? For surround? Bass Managed? Film work? They are all a little different, fitting different applications. If you need Bass Managed, then Blue Sky. If you don't, I like the Passive SM Pro Controllers. They make a 5.1. Not Bass Managed. For film work, the standard for a long time was the MartinSound MulitiMAX. I have one of these in my film mix room. Not bass managed. For high-end, Cranesong Avocet (Not Bass Managed) or Trinnov (options are there wit these). Quote Link to comment Share on other sites More sharing options...
John Blankenship Posted September 7, 2015 Report Share Posted September 7, 2015 Thanks. Quote Link to comment Share on other sites More sharing options...
jgbsound Posted September 8, 2015 Author Report Share Posted September 8, 2015 Just curious: is there any inherent advantage to a hardware based Bass Management System, or software such as Waves 360 or others (i think there's also one called Spat?). Quote Link to comment Share on other sites More sharing options...
CraigF Posted September 16, 2015 Report Share Posted September 16, 2015 Bass Management is part of the room's B-Chain calibration Using a software option presents the possibility of shipping files that have it baked into the files Quote Link to comment Share on other sites More sharing options...
Glen Trew Posted September 16, 2015 Report Share Posted September 16, 2015 -20dBfs is the accepted 0VU reference for original dialog recording. I am assuming that the accepted VU reference for the mix of a final product is the same as mastered music, which is -12dBfs. If this is, indeed, the case, the calibration 0VU reference for final mix would be -12dBfs, not -20dBfs. This would explain why 85dB would be painfully loud with a 0VU reference of -20dBfs, which would be 8dB louder than when using a 0VU reference of -12dBfs. Glen Trew Quote Link to comment Share on other sites More sharing options...
minister Posted September 17, 2015 Report Share Posted September 17, 2015 (edited) -20dBfs is the accepted 0VU reference for original dialog recording. I am assuming that the accepted VU reference for the mix of a final product is the same as mastered music, which is -12dBfs. If this is, indeed, the case, the calibration 0VU reference for final mix would be -12dBfs, not -20dBfs. This would explain why 85dB would be painfully loud with a 0VU reference of -20dBfs, which would be 8dB louder than when using a 0VU reference of -12dBfs. Glen Trew Sorry Glen, this is misleading.... Theatrical alignment in US has been, since the 70's: Electrical alignment : -20dBFS 1kHz Sine = 1.23vRMS = 0 VU = +4dBU. For Room Calibration: -20dBFS RMS PINK = 0VU = 85dBC per Screen Channel in a room having a volume of 10,000 cubic. -82dBC per surround. and +10 IN-BAND for the Subwoofer (measured on an RTA) Aligning a Music Mastering suite for -12dBFS= 0 VU has ZERO to do with theatrical alignment. Mix of the final Theatrical product is -20=0VU. When mixing a film, you calibrate, then MIX BY EAR. So if it is PAINFULLY LOUD, like a piece of full scale music, then turn it down. it's simple. Yes, it's true, you would not play a Full Scale Mastered Music piece at that level, it would be painfully loud. For smaller rooms, an alignment should be 79dBC or 76dBC for translation to larger rooms (with X-Curve). Edited September 17, 2015 by minister Quote Link to comment Share on other sites More sharing options...
Rick Reineke Posted September 17, 2015 Report Share Posted September 17, 2015 I use the Blue Sky calibration test files for the occasional audio post project. However.. while BS states the full bandwidth pink noise file is -20dBFS, (mono) it indicates -11.3dBFS on my DAW meters.(which are know to be accurate). Quote Link to comment Share on other sites More sharing options...
minister Posted September 18, 2015 Report Share Posted September 18, 2015 I use the Blue Sky calibration test files for the occasional audio post project. However.. while BS states the full bandwidth pink noise file is -20dBFS, (mono) it indicates -11.3dBFS on my DAW meters.(which are know to be accurate). PINK noise is measured as -20dBFS RMS. You are measuring PEAK. Yes, it is approximately -11 PEAK. But you don't align Sound Pressure Level using PEAK. Quote Link to comment Share on other sites More sharing options...
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