EX3, SD 442 and settings

[Ron Wilk]

Although this topic may have been addressed elsewhere, a search has failed to reveal anything relevant, so, here is my question:
I am new to the SD 442/EX3 combination and am not clear on the recommended camera audio settings vis-a-vis the recording of a relatively hot signal. I have experimented with a COS-11 lavaliere (48v PH Pwr'd) and have found that in order to record a decent signal, the camera's audio input setting (manual) has to be placed at its maximum (camera audio settings at factory default) and the 442 set so that the meter occasionally just enters the red zone (+4-6db with meter set at factory default).
Question: While I understand that some variation of adjustment will be required with the use of different mics, have I missed something in regards to the EX3 and or SD 442 audio settings?
Thank you in advance.

[Karl Lohninger]

To get your gain stages correct you've got to send 'tone' to the camera and - with an ex3 (=digital device) you should set it at -20 at the camera end.
You set your mixer so that your get a nice level without distorting it - really depending what kind of material you're going to record. If voice, then just make them peaks not higher than, let's say -6db. I personally run rather hot levels, but a) it's kind of a habit from old days and b) I know what I'm doing.
Set the 442s limiter accordingly and you're safe, voila. You'll never over modulate the ex3.

[Ron Wilk]

Originally Posted by Karl Lohninger

...You'll never over modulate the ex3.

Thank you for your reply. What about changing the EX3's input trim, thereby increasing its sensitivity? I've read elsewhere that there may be some advantage in doing so(in the case of low level input), however, the EX3 manual seems to indicate that it's only effective in "mic" mode but does that mean that the levels can only be adjusted in "mic" mode or that that changes to these levels will only be effective in said mode?
Thanks again.

[Karl Lohninger]

Ron, maybe I don't understand the question correctly. If you send 'tone' which is by definition 0db out of the 442 (this is 'line level' !) then you adjust gain on the EX3 (line input !) so that you have a reading of -20 db.

That's your setting. Level changes if you switch mikes or whatever are now only on your mixer. Put a tape on the gain pot on the camera so it doesn't change.

Don't forget to monitor via return from the camera out of the 442 or depending on the setup directly out of the camera.

What that the question?

[Ron Wilk]

Originally Posted by Karl Lohninger

Ron, ... What that the question?

In part. I had already done the adjustment with tone from the 442 but I found that in order to place the mike level into the -20db range I had to increase grain to the max. My question regarding trim was in relation to the latter but on a whim, I changed the trim thereby allowing a greater degree of gain latitude with the mike in question.

I suppose my confusion arose from a statement in the EX3 manual that seemed to suggest that the trim was only active in "Mike" mode but as it turns out, the switch must be placed in "mike" mode to make adjustments but the effect of change appears to be relevant in "line" mode as well.

[Jerry Merrell]

I have a few basic questions about these recommendations.

The EX3 has mic inputs labeled: "mic", "mic+48V" and "line". When receiving a line-level signal from my SD 302, I have been setting the EX3 to "line" (per Ty Ford's "Audio Bootcamp Field Guide", page 40). The EX3 trim can not be adjusted when set to "line". To avoid distortion, I try to have peaks ranging from -12db to - 6db on the mixer and also set the mixer's limiter just in case .

I understand that digital recorders don't like audio levels > 0db. Are you recommending trimming the EX3 to -20 db primarily to avoid distortion or is there some other reason for this setting? Also is there some kind of trade-off in signal quality when you set the camera's audio trim below 0 db?

Jerry

[Ron Wilk]

Originally Posted by Jerry Merrell

I have a few basic questions about these recommendations.

The EX3 has mic inputs labeled: "mic", "mic+48V" and "line". When receiving a line-level signal from my SD 302, I have been setting the EX3 to "line" (per Ty Ford's "Audio Bootcamp Field Guide", page 40). The EX3 trim can not be adjusted when set to "line". To avoid distortion, I try to have peaks ranging from -12db to - 6db on the mixer and also set the mixer's limiter just in case .

I understand that digital recorders don't like audio levels > 0db. Are you recommending trimming the EX3 to -20 db primarily to avoid distortion or is there some other reason for this setting? Also is there some kind of trade-off in signal quality when you set the camera's audio trim below 0 db?

Jerry

Hi Jerry:
When it comes to the Ex3 and audio, I am quite the neophyte, however, I will try to answer your questions within the confines of my limited knowledge.
1. Your are correct when you state that the trim cannot be adjusted while in "line" mode but by switching to "mic" mode one can make changes to the trim and then switch back to line. With the factory default setting of 41, I found it necessary to increase the gain to 10, the maximum, in order to record a signal hot enough to produce good quality audio when connected to my SD 442 (line out to line in). By changing the trim to 47, however, I was able to record the same signal level but with the gain just a hair above "5," thereby allowing for further leeway in gain if necessary. I am not certain if the trim adjustments are supposed to be effective while in line mode but it seems to work nevertheless.
2. As for the -20db statement, that is point at which (on the EX3's audio meter), or at least close to which, the EX3 seems to record good, clean, full sounding audio but I must admit that I have been pushing the level peaks to somewhere between -20 and -10 for a hotter signal that seems to provide fuller sounding audio with the mikes that I have in my kit.
3. In re your question, "Also is there some kind of trade-off in signal quality when you set the camera's audio trim below 0 db?" I will have to defer to someone with greater expertise than I possess.
Hope this helps,
Ron

[Steve House]

I think there's a lot of confusion about what this -20dB level setting is all about. -20 is an alignment level, not a recording level. It's not relevant to the levels you see when recording program. Instead it's a setup adjustment, aligning the meters on the camera and the mixer so when you look at the mixer meter you know what the camera is recording. You send a 1kHz tone coming from the mixer at 0VU on the mixer's meters. With a sinewave tone, peak reading and VU reading meters register the same. You set the mixer to send tone to the camera reading 0VU on the mixer meters, equivalent to an output of 0DBu. With the 442 default settings, this is with the output level control at its detent (actually the output level knob doesn't vary the tone level but the detent is unity gain so everything lines up). You adjust the camera levels so you see -20dBFS on the camera meter. When you switch off the tone and record program, you adjust the MIXER's faders so the average level is in the yellow zone just tickling the red on the MIXER'S meters. This should give you average levels on the camera meters with speech of around -10dBFS. I like to have the 442 in its VU/PPM metering mode - you'll see a single dot indicating the average signal level in VU and higher on the scale above it the dots representing the signal's peak level. The difference between the two will corrspond roughly to how far above -20 the camera's peak-reading meters will be indicating when recording program. The mixer's limiters are set by default at +20dBu. Since you set 0dBu (0VU) at -20 dBFS, the limiter kicks in just as the camera level tickles 0dBFS. Some mixers prefer to reduce the limiter level to between +17dB to +18dB to an increased safety safety margin for peaks, setting it so the limiter on the mixer kicks in when the camera level is hitting -2 or -3dBFS.

Just to make it intersting, SMPTE says 0VU = +4dBu. The 442 default meter calibration, OTOH, is 0VU = 0dBu. (You can change it in the menus if you want the meters to be SMPTE. You can also change the tone output level to +4 or whatever other level you want if you feel compelled to.) If you really want to go by the book, you'd align 0dBu tone to -24dBFS on the camera, not -20, but I think this is needlessly low. The only time it really matter what level TONE is at is in the final broadcast deliverables.

[Ron Wilk]

Thank you, that was an excellent and well received explanation.

[Jerry Merrell]

Thanks, Steve.

[Ron Wilk]

I have been experimenting with the SD 442 and EX3 and so far, with the microphones that I have available at the present time (cos-11, RODE NT2, ntg3, nt4, Royer 121) was surprised by the absence of any significant audible difference between the mic-SD442-EX3 combination vs the same mic's connected directly to the EX3.

Am I missing something other than the mechanical advantages of (off camera audio adjustments, various ins and outs, etc.) the 442 or does the EX3 have better than average audio capabilities?

[Karl Lohninger]

Ron, no matter what you put in front of the ex3 (or any other camera) is just that. Your signal in the end has to go through the built-in audio circuitry. If you want to compare you'd have to compare via headphone out of your 442 and the headphone return from the camera though that still won't give you the correct results as headphone amps seem always to be a weak point.
In other words, you can't expect 'better' sound just by putting a mixer in front of a camera.
Chances are, that even delivering line level via a mixer the signal is still going through the (attenuated) mic pre-amp stage in your camera.
What a mixer does in first line is, yes, mixing. Then there's signal distribution (where the 442 really excels with all it's direct outs and numbers of different outputs, be it for comteks, double system recordings etc etc), and then there's the option to nicely monitor your incoming signals and correct/adjust gain stages during a take. Things you can't do with just plugging a mike and headphones into a camera.

[Ron Wilk]

Originally Posted by Karl Lohninger

Ron, no matter what you put in front of the ex3 (or any other camera) is just that. Your signal in the end has to go through the built-in audio circuitry. If you want to compare you'd have to compare via headphone out of your 442 and the headphone return from the camera though that still won't give you the correct results as headphone amps seem always to be a weak point.
In other words, you can't expect 'better' sound just by putting a mixer in front of a camera.
Chances are, that even delivering line level via a mixer the signal is still going through the (attenuated) mic pre-amp stage in your camera.
What a mixer does in first line is, yes, mixing. Then there's signal distribution (where the 442 really excels with all it's direct outs and numbers of different outputs, be it for comteks, double system recordings etc etc), and then there's the option to nicely monitor your incoming signals and correct/adjust gain stages during a take. Things you can't do with just plugging a mike and headphones into a camera.

Hello Karl:
Your analysis makes sense vis-a-vis "the chain being as strong as its weakest link."
I made my comparison by importing the resultant files into FCP and auditioning via my studio monitors/BlackMagic Eclipse. If I had used my intellect rather than my eyes (perusing posts on various forums) I probably would have waited before purchasing the 442. There have been numerous posts that alluded to the improvement of audio quality with a mixer such as the 442 but in the end, you are correct, the sound quality is only as good as the device recording it. Well (deep sigh), that said, there are other advantages to the 442 but I suspect as well that there will be occasions where I will feel comfortable dispensing with the extra bulk and weight of the mixer.

[Steve House]

Originally Posted by Ron Wilk

Hello Karl:
Your analysis makes sense vis-a-vis "the chain being as strong as its weakest link."
I made my comparison by importing the resultant files into FCP and auditioning via my studio monitors/BlackMagic Eclipse. If I had used my intellect rather than my eyes (perusing posts on various forums) I probably would have waited before purchasing the 442. There have been numerous posts that alluded to the improvement of audio quality with a mixer such as the 442 but in the end, you are correct, the sound quality is only as good as the device recording it. Well (deep sigh), that said, there are other advantages to the 442 but I suspect as well that there will be occasions where I will feel comfortable dispensing with the extra bulk and weight of the mixer.

Well, the sound can be better with the mixer in the sense that you have more control over the variables such as better limiters to help handle situations where the sound level varies considerably, better high pass filters to reduce wind and handling noise, more input channels with better controls and metering, that sort of thing. But there is nothing you can put upstream from the camera or recorder that will compensate for serious deficiencies in the recording device's circuitry. Now if you were using a camera where the line level inputs actually bypassed the (perhaps noisy or otherwise lacking) mic preamps, as is often the case, you could get an improvment because you'd actually be replacing the lower quality camera mic preamps with the higher quality mixer preamps but as I understand it the EX1 doesn't do that. But there are lots of cameras or recorders you might use in the future where going to a line input does indeed bypass the built-in mic preamps. So IMHO your 442 is still a good buy.

I do wish manufacturers of prosumer cameras included better block diagrams, etc, so you could know for sure ahead of time what you're dealing with.

[Ron Wilk]

Hello Steve:
I appreciate your input and agree with you in regards to the absence of full disclosure but that said, the EX3's audio is reasonably good but would be perhaps some modicum better if it were possible to bypass its preamps.

My comment about the 442 purchase was more of a timing issue but I have no doubt that it will prove increasingly more useful as the days go by. And since I do possess a digital recorder (Tascam HD-P2, albeit, not of SD quality) I could simply synch to the camera and record to it from the SD 442.
Thanks again for your thoughtful comments,
Ron