-
MixPre-D and Windows 7?
-
Craig,
Nice graphics!
You’re missing what I’m saying about calibrating the mixer to the camera. For just a moment, forget everything you know about the topic and begin afresh.
The idea is to calibrate the camera meters to the mixer meters so you don’t have to look at the camera meters to know exactly what level you’re sending to the camera. Setting 0 tone from the mixer to -12 will result in clips if you use the entire headroom of the mixer because it goes to +20. I’m the audio guy. I can’t and don’t want to be watching audio levels on a camera. I want to watch them on my mixer.
Having said that, yes, you want audio to peak somewhere above -12 and 0 on the camera. But I don’t want to keep looking at camera meters while I run audio.
As for the dynamic mics, yes they are less sensitive than condenser mics and require more gain from the preamps.
Regards,
Ty
Want better production audio?: Ty Ford’s Audio Bootcamp Field Guide
Ty Ford Blog: Ty Ford’s Blog -
Thanks Ty. I do feel I understand you and I follow this advice exactly with all my prosumer level cams. But on the HV 40s I’m finding that if I calibrate the camera so that 0 tone is about -20 (again no indication of where that is exactly) then when we are recording soft spoken talent the levels are too low. On the mix pre-d their voices do not exceed 0 unless I turn the gain up to 3 o’clock or more.
Again if I calibrate 0 tone to -12 you still do not need to look at the cam meters but rather just know the modified range on the mix pre d meters – about 0 (-12) to + 6 (about -4) (-12 the only thing with a mark)
[Ty Ford] “Having said that, yes, you want audio to peak somewhere above -12 and 0 on the camera. But I don’t want to keep looking at camera meters while I run audio.”
Just to be be clear here: when you say ‘peak’, do you mean where every spoken line peaks or just the loudest lines during a shoot – that is the occasional spike where you have left enough headroom so as not to clip?
Let me put this another way: I’m doing a sound test with a talent. “Read me your first line at a comfortable level as if you were performing.” The talent gives me their first line. Where should that test read on the mixer? My understanding if I calibrated 0 tone to -20 would be about +4 to +16 on the mixer. If the talent projects well and is more animated and has some excited louder lines, I leave them more headroom. If they are quiet and even in their delivery I start at a higher base level.
Mac Pro, macbook pro, Imacs (i7); Camcorders: Panasonic AG-HPX170/AG-HPX250P, Canon HV30/40, Sony Z7U, VX2000, PD170; FCP 6 certified; write professionally for a variety of media; teach video production in L.A.
-
Ty, just another quick word of thanks for your help on this issue–much appreciated!
-
Craig,
Unless you know where -20 is, you really can’t say where 0 is. Calibration is not done on an elastic scale, It’s doesn’t stretch and shrink. It is what it is.
If your peaks are lower than you think they should be then what you think -20 is on the camera is probably wrong, and too low.
Peaks are defined as different from RMS. (root mean squared). RMS is also described as average. You must select RMS and Peak as the meter reading on the 302 so you see both the lower RMS and blank spaces then the peak reading above that. You need to pay attention to the peaks to prevent clipping. If you’re mixer is set to only read RMS then it will seem very low. If you try to make it read higher by turning up the gain, then the peaks you’re not seeing on the meter, will clip.
These peaks are not just from people talking louder, they are the peaks that happen in normal speech. I’m thinking you may not have your meter set to the correct setting and are seeing only RMS or VU and not peak.
Regards,
Ty Ford
PS: tone doesn’t really have peaks the same way human voices do, it’s a continuous sine wave.
Want better production audio?: Ty Ford’s Audio Bootcamp Field Guide
Ty Ford Blog: Ty Ford’s Blog -
David,
Happy to be of service! 🙂
Regards,
Ty Ford
Cow Audio Forum LeaderWant better production audio?: Ty Ford’s Audio Bootcamp Field Guide
Ty Ford Blog: Ty Ford’s Blog -
Ty,
Please be patient. You’re my go to guy when it comes to sound. Not trying to be thick.
My 302 mixers are set for combo peak.
When I use the 302 I use it with a camera that has a -20 indicator and that is what I use for 0 tone calibration.
I try to record voices from +4 to +12.
I think I’m following your lead here. Right?
——–
The consumer cams do not have a mark for -20 but they do for -12. I calibrate the cam to a couple of joy stick clicks below -12.
The mix pre-d with soft spoken female voices and dynamic mikes need to have the input gain control at about 3 o’clock to start metering above zero on the mix pre-d’s meters.
What do you use as a target range when you capture sound both on the mixer and on the camera’s meters?
What would be the low end of the sweet range?
If Canon says that the meter should read only OCCASIONALLY above -12 then what is acceptable below -12? Are they right?
If I play back footage where the camera’s meters are consistently reading below -12 I find I need to turn up my monitors amp to the point where I’m adding noise to the signal. This doesn’t seem right to me.
I think the sweet spot is a bit above -12 and a bit below 0. Is the sweet spot for range more like a bit above -20 and a bit above -12? If so I’ve been doing it wrong and need better playback equipment.
Mac Pro, macbook pro, Imacs (i7); Camcorders: Panasonic AG-HPX170/AG-HPX250P, Canon HV30/40, Sony Z7U, VX2000, PD170; FCP 6 certified; write professionally for a variety of media; teach video production in L.A.
-
Craig,
Yes, combo, so you can see the peaks and the RMS!
I think there are two combos on the SD meters.nI like the one that shows a space between the peak and the RMS. It’s interesting that the size of the space varies depending on the voice. Each person has a slightly different peak to RMS ration and you can see it with this metering system.
I set my limiters at about +14 and try to hit peaks between +12 and +14, just tickling the limiter, making the Sound Devices limiter light blink slightly and occasionally. Camera limiters are usually pretty nasty so I don’t use them.
The Sound Devices limiters are designed to gracefully catch voice peaks and still sound very good. This means that their attack time is a little slower. Because of that, very quick sounds like hand claps and the click of a three ring binder clicking open or closed sneak through the limiter, That’s why aiming for +14 is a good idea. It gives you 6 dB of extra headroom before clipping.
I have clipped on a three ring binder, but since it’s just one CLICK, it didn’t sound bad. Applause, OTOH, can sound pretty nasty if creates a lot of clips over time.
Z’at make sense?
Regards,
Ty Ford
Cow Audio Forum LeaderPS: and remember some of the cameras have “soft front ends.” The PD 150 and PD 170 (and later HDV versions) come to mind. I think they designed them using a -10 Consumer Line Level instead of a 0 Pro Line Level, because I always have problems trying to calibrate my mixer to them if I use line instead of -10 or Mic level output from my mixer. I can calibrate them with tone, but I can’t get peaks past +10 or +12, everything over that clips and I hear splatter in my Sony MDR7506 headphones.
PPS: If you’re using low-ball headphones, you can end up in trouble because you can’t really hear what’s going on. The Sony MDR7506 are great for clarity. They are a little peaky on the bottom and top, but not in a bad way.
Want better production audio?: Ty Ford’s Audio Bootcamp Field Guide
Ty Ford Blog: Ty Ford’s Blog -
Thank you Ty,
Best forum on the cow for a prosumer level generalist like me.
I feel when all is said and done I have more or less been following your lead and mirror your practices with the possible exception that consumer level cams are not designed to adhere to this standard practice and experience must dictate a compromise of sorts. I am slowly moving away from using them. Money makes the world go round.
Just a couple of more basics:
1) I understand your target levels +12/+14, but what would you consider to be the lowest acceptable peak level on the SD mixer?
Assuming I am calibrating correctly, 0 tone to -20, then if a talent drops to 0 for a sentence of two, they would be at -20 on the camera input which I find way too low. The camera manuals talk about -12 being a upper end target which implies that below -12 is a preferred average RMS, but do not mention an unacceptably low level. I have used -12 (on cam) as the lowest acceptable peak. I’m going to check what +12 (on mixer) equals on my cams that do have -20 marks for calibration.
2) Is there any such thing as a conversion chart or program or formula that lets you translate the mixer level to the camera level?
3) What do you make of these quotes form the 302 manual:
These seem to mirror the camcorder manuals advice that from -20 to -12 (on the camcorder meters is the
target range for recording. Not sure what to make of this.“Yes, combo, so you can see the peaks and the RMS! I think there are two combos on the SD meters.nI like the one that shows a space between the peak and the RMS. It’s interesting that the size of the space varies depending on the voice. Each person has a slightly different peak to RMS ration and you can see it with this metering system.”
Yes I’ve noticed this and never gave it much conscious thought but subconsciously my reaction was how evenly the talent delivered their lines. A large gap indicated sudden attacks (have no idea if my audio vocab is technically correct – have I mentioned that audio standards are the most confusing of any multi-media discipline?)
I set my limiters at about +14 and try to hit peaks between +12 and +14, just tickling the limiter, making the Sound Devices limiter light blink slightly and occasionally. Camera limiters are usually pretty nasty so I don’t use them.
That would be ATT (attenuation on or off in the camera settings?) And yes they are worthless. If the audio peaks into the 0, or even a touch below, the distortion is horrid.
The Sound Devices limiters are designed to gracefully catch voice peaks and still sound very good. This means that their attack time is a little slower. Because of that, very quick sounds like hand claps and the click of a three ring binder clicking open or closed sneak through the limiter, That’s why aiming for +14 is a good idea. It gives you 6 dB of extra headroom before clipping.
Understood and in more disciplined (on one production/one shot at a time shoots it has been what I aim for. In more circus evironments, I ask students to leave a bit more headroom – +8 to +12 as a target with +4 as a base.
I have clipped on a three ring binder, but since it’s just one CLICK, it didn’t sound bad. Applause, OTOH, can sound pretty nasty if creates a lot of clips over time.
Z’at make sense?
Yes it does and really a high frequency very short peak for what is more or less a sound effect doesn’t really bother the audicene all that much. It’s a low rumbling raspy distortion that really gets on their nerves. And of course straining to hear dialog is a complete drag too.
Some of the cameras have “soft front ends.” The PD 150 and PD 170 (and later HDV versions) come to mind. I think they designed them using a -10 Consumer Line Level instead of a 0 Pro Line Level, because I always have problems trying to calibrate my mixer to them if I use line instead of -10 or Mic level output from my mixer. I can calibrate them with tone, but I can’t get peaks past +10 or +12, everything over that clips and I hear splatter in my Sony MDR7506 headphones.
Yes when I first began we were using the shure mixer and I was beyond frustrated that I couldn’t get good levels on my 150 170 cams. I tried to learn to manually set the line level out to match the camera but shure tech support kinda told me not to mess with the little internal switches) I ended up learning to go in mic level and bought some xlr attenuation plugs for some sources and leaving more headroom and the frustration waned but the audio on these cams were seriously flawed. The weak link of otherwise great cams. The XL2 was a better and its soft focus (so called film look) was quite nice with studio lights in the mix) but the 170s were just incredible available light run and gun cams. Truly perfect for students, reporters, the web, docs, etc.
PPS: If you’re using low-ball headphones, you can end up in trouble because you can’t really hear what’s going on. The Sony MDR7506 are great for clarity. They are a little peaky on the bottom and top, but not in a bad way.
They are the only headphones I give students. At your advice, been using them for years. Hate the coiled cable. Personally find the ear pads a touch too small, and the pads get worn out too fast with student handling. The little exposed wires that go into the speakers always worries me – but I’ve been using them for years and other than the coiled cables becoming more and more streached out and some reversed coils that I can not learn to unknot they have been a workhorse and accurate what you hear is what you get headphones.
Mac Pro, macbook pro, Imacs (i7); Camcorders: Panasonic AG-HPX170/AG-HPX250P, Canon HV30/40, Sony Z7U, VX2000, PD170; FCP 6 certified; write professionally for a variety of media; teach video production in L.A.
-
Craig,
1. If you’re a sound recordist you get the mic closer or ride gain on the mixer unless the ambient noise change becomes obvious. Otherwise, noise reduction or ADR.
2. If you calibrate the mixer to the camera as I have suggested, this is not necessary.
3. I peak in the orange with occasional peaks in the first red LED.
Ty Ford
Cow Audio Forum LeaderWant better production audio?: Ty Ford’s Audio Bootcamp Field Guide
Ty Ford Blog: Ty Ford’s Blog -
Again thanks Ty,
1) Yes we do both of these. I teach talent with hand held mikes and boom operators to work with the audio tech to get a good level and a good quality before we start shooting.
2) understood though in any given shoot you might have sudden changes in levels. If for example there was a line with horrible distortion and you had the option, you would reshoot. The occasional low level that say dips to 0 or -4, can be boosted in post. But at what level would you say best to reshoot? Remember I’m using student talents and student audio techs. Not someone with your skill. I’m just surprised to read in the manuals that 0 (-20 on the cam) is a target level.
3. So you disagree with both Canon and Sound Devices manuals, as do I, or am I misreading what they are saying?
Thanks again Ty. Just surprises me that at this point in time that the camcorder companies are not addressing audio with the same competitive spirit that they are evolving visual acquisition. For example, the headphone amps on even fairly expensive video gear is really awful. They add so much noise to the signal that you think you have a problem with your mikes. So it’s hard to monitor your incoming audio. Play it back and it’s fine. We use a snake cable into the 302 and I tell the students to just switch to RTN to make sure that the camera is receiving the signal. Then switch back to the 302s headphone amp so you can actually judge audio quality. You would think also that the camcorders would have a RTN output nearer the xlr inputs so the snake cables didn’t need to have a built in splitter. Which by the way doesn’t always reach the headphone out or gets in the way of some other function on the camcorder.
Mac Pro, macbook pro, Imacs (i7); Camcorders: Panasonic AG-HPX170/AG-HPX250P, Canon HV30/40, Sony Z7U, VX2000, PD170; FCP 6 certified; write professionally for a variety of media; teach video production in L.A.
Reply to this Discussion! Login or Sign Up