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Craig Alan
levels sd302
on May 3, 2011 at 1:11:02 am

As Ty said on 4-9

0 dB tone leaving the mixer should be set at -20 dB on the camera of you are using any of the current location audio mixers like any of the Sound Devices mixers. You then (as the manual says) run audio levels on the mixer up to about + 14 on the mixer meters, which means they will hit about -6dB on the camera.

Ty, Can't find this passage in the manual even searching in the pdf version. Would like to since it would be a great teaching aid.

My question is this: The limiter kicks in at +16. As far as I can tell this is preset at the factory and can't be changed???

The LEDS go from +12 to +16. At what level on the SD302 do you consider the sweet spot to keep levels? I would imagine it depends on the recording device and what it prefers? For example, I have one camera that sounds best when on the camera's meter it reads just over -12. Another is a little more forgiving and allows up to a tad over -6 before any distortion is heard.

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; Camcorders: Sony Z7U, Canon HV30/40, Sony vx2000/PD170; FCP certified; write professionally for a variety of media; teach video production in L.A.


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Ty Ford
Re: levels sd302
on May 3, 2011 at 3:19:51 am

Hello Craig,

"as far as I can tell", so you didn't read the manual? The 302 manual is aways online

PAGE 12:

Output Limiters
In addition to the limiters on each input channel, the 302 has a software-controlled
Output Limiter. Output Limiters are used to prevent overloading of recorders, cameras, and wireless transmitters connected to the 302. The Output Limiters on the 302 use an optoisolator-based peak limiting circuit. The Output Limiter threshold is set in the Setup Menu. The Output Limiter can be set in one of two positions, Link or LIM.

PAGE 20

Output Limiter Adjustment
Output limiter thresholds are adjustable between +4 dBu and +20 dBu in 1 dB increments. The threshold level is shown on the lower (right) meter string by illuminating LEDs. Because LEDs are spaced every 4 dB, a combination of flashing and solid adjacent LEDs indicate limiter levels between the numbered LEDs. Factory default is 20 dBu. Each press of the battery button or meter brightness control changes the threshold by 1 dB. Three possible LED indications show threhold value:
• Single solid LED - actual value indicates threshold. • Flashing LED next to a solid LED - indicates that the threshold is one dB above or below the
solid LED value. • Two solid LEDs - threshold value is even number value between the two indicated values.

My Advice: Set the limiter for +10 and tickle the read at +12. That should cause readings of -8 on the camera.

If you have a camera that won't take audio to 0 dB without distorting. That's a broken camera. Cameras do break. Values of components change. When that happens, calibration accuracy goes out the window for video and/or audio. What cameras do you have that can't take up to 0dB?

Regards,

Ty Ford

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Craig Alan
Re: levels sd302
on May 3, 2011 at 6:43:10 am

Thanks Ty,

‘"as far as I can tell", so you didn't read the manual?’

I did, but not with complete comprehension, I gather.

I was referring to input limiters:

Input Limiters +18 dBu threshold
“There is no user-selectable adjustments to the Input Limiter’s threshold or its envelope.”

The Limiter LED above each fader indicates input limiter kicking in, right?

My Advice: Set the limiter for +10

So you are referring to output limiters set to +10?

“and tickle the read at +12. That should cause readings of
-8 on the camera.”

“+ 14 on the mixer meters, which means they will hit about -6dB on the camera.”

And that is assuming you set tone 0db to -20db on the camera.

Please Ty dummy this down. If you were riding levels at +12, why would you limit output at +10? Factory default is 20 dBu. Wouldn’t that be 0 db on the camera? Wouldn’t that make sense?

If you have a camera that won't take audio to 0 dB without distorting. That's a broken camera. Cameras do break. Values of components change. When that happens, calibration accuracy goes out the window for video and/or audio. What cameras do you have that can't take up to 0dB?

The Sony PD150/PD170 would record with distortion below 0.

On the Canon HV30/40 I would say -6 would be a better upper limit than 0. Above that and a notch below 0, I hear distortion.

But these are just my observations. I have not run any hard tests. Though other end users report similar results.

One more question Ty, though I will set the output limiters as you suggest – if the input is limited to +18 doesn’t that mean the output does not exceed this limit?

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; Camcorders: Sony Z7U, Canon HV30/40, Sony vx2000/PD170; FCP certified; write professionally for a variety of media; teach video production in L.A.


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Ty Ford
Re: levels sd302
on May 3, 2011 at 11:34:25 am

I was referring to input limiters:

Input Limiters +18 dBu threshold
“There is no user-selectable adjustments to the Input Limiter’s threshold or its envelope.”

The Limiter LED above each fader indicates input limiter kicking in, right?

>> Exactly! I was talking about the output limiters


My Advice: Set the limiter for +10

So you are referring to output limiters set to +10?


>> Yes.

“and tickle the read at +12. That should cause readings of
-8 on the camera.”

“+ 14 on the mixer meters, which means they will hit about -6dB on the camera.”

And that is assuming you set tone 0db to -20db on the camera.

>> Yes.


Please Ty dummy this down. If you were riding levels at +12, why would you limit output at +10? Factory default is 20 dBu. Wouldn’t that be 0 db on the camera? Wouldn’t that make sense?

>> You want to limit before you get to 0 dB on the camera because that limiter is not fast enough to catch sounds with quick transients like hand claps and the snap of a 3-ring binder.


If you have a camera that won't take audio to 0 dB without distorting. That's a broken camera. Cameras do break. Values of components change. When that happens, calibration accuracy goes out the window for video and/or audio. What cameras do you have that can't take up to 0dB?

The Sony PD150/PD170 would record with distortion below 0.

On the Canon HV30/40 I would say -6 would be a better upper limit than 0. Above that and a notch below 0, I hear distortion.

But these are just my observations. I have not run any hard tests. Though other end users report similar results.

>>When you do make sure the mixer is set to read peak and not just rms. It's those sneaky peaks that may get you.

One more question Ty, though I will set the output limiters as you suggest – if the input is limited to +18 doesn’t that mean the output does not exceed this limit?

The attack time set on the limiters is not fast enough to catch sounds with quick transients (per above). It's set to catch most of the human voice quite gracefully. Leaving a little safety space to catch the spill of what gets past the limiter is a good idea. That's what I use the top 6 to 8 dB on the mixer for.

Regards,

Ty Ford

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Craig Alan
Re: levels sd302
on May 3, 2011 at 1:24:28 pm

Got it. Wow so basic. The SD302 manual seems to imply that the input limiter really protects from distortion and doesn't let you modify it. But you're saying neither limiter can do this fast enough for quick changes in input levels? So although it works there is a time lag in its effectiveness. Therefore if you set the threshold lower it will kick in sooner and more or less do the job intended by a higher level.

Most of my learning came from trial and error in controlled studio style shoots using a shure mixer. Everything went smooth until we were in run and gun situations and all equipment was left as is. Then, as you mention, we would end up with hits of distortion. So I adjusted by riding the inputs lower. Now the shure did not have the user friendly output limiters that the SD has. I called shure with help setting the defaults by modifying the little switches inside the unit. But the tech guy told me to leave it alone and just suggested to calibrate to lower readings on the sony. I'd be curious though if the sony indeed distorts at levels lower than 0. It seemed that way in playback. Regardless, I would need to boost the levels in post adding even more noise to the already noisy preamps. I switched to the Canon xl2 for events. Better lens better sound but not as friendly for mixed light low light situations.

All that said, would your suggested settings change at all using a Ki Pro for audio capture? Or are these setting pretty universal?

OSX 10.5.8; MacBookPro4,1 Intel Core 2 Duo 2.5 GHz
; Camcorders: Sony Z7U, Canon HV30/40, Sony vx2000/PD170; FCP certified; write professionally for a variety of media; teach video production in L.A.


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Ty Ford
Re: levels sd302
on May 3, 2011 at 1:46:05 pm

Got it. Wow so basic. The SD302 manual seems to imply that the input limiter really protects from distortion and doesn't let you modify it. But you're saying neither limiter can do this fast enough for quick changes in input levels? So although it works there is a time lag in its effectiveness. Therefore if you set the threshold lower it will kick in sooner and more or less do the job intended by a higher level.

>>The input limiter is designer to keep the front end of the mixer from being overloaded by momentarily loud sources.

>>The output limiter is there to protect what you are sending to.

Different jobs, both important.

Most of my learning came from trial and error in controlled studio style shoots using a shure mixer. Everything went smooth until we were in run and gun situations and all equipment was left as is. Then, as you mention, we would end up with hits of distortion. So I adjusted by riding the inputs lower. Now the shure did not have the user friendly output limiters that the SD has. I called shure with help setting the defaults by modifying the little switches inside the unit. But the tech guy told me to leave it alone and just suggested to calibrate to lower readings on the sony. I'd be curious though if the sony indeed distorts at levels lower than 0. It seemed that way in playback. Regardless, I would need to boost the levels in post adding even more noise to the already noisy preamps. I switched to the Canon xl2 for events. Better lens better sound but not as friendly for mixed light low light situations.

>> The distortion hits you were hearing could have been due to peaks either at the input or output that the Shure never caught or reported. Was it one with an analog meter?

All that said, would your suggested settings change at all using a Ki Pro for audio capture? Or are these setting pretty universal?

I have no experience with a Ki Pro. If you see audio levels on it, then set your tone out at 0 dB on the mixer and make it -20 on the Ki Pro. Test it and see. BTW, on the 302 the limiter threshold light is the LAST light on the meter scale. I think it winks yellow when the threshold is crossed. When recording boom and lav on the same person, split the output limiter because each mic hears slightly differently.

Regards,

Ty Ford

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Craig Alan
Re: levels sd302
on May 3, 2011 at 4:18:13 pm

Get it got it good. Not a huge difference in how I've been doing it but the output threshold will be set lower and therefore allow me to run the fader a tad higher. Less chance of "distortion hits."
Win win. Thanks Ty.

OSX 10.5.8; MacBookPro4,1 Intel Core 2 Duo 2.5 GHz
; Camcorders: Sony Z7U, Canon HV30/40, Sony vx2000/PD170; FCP certified; write professionally for a variety of media; teach video production in L.A.


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Craig Alan
follow up levels sd302
on May 3, 2011 at 6:07:21 pm

Sorry Ty,

I've set the output limiter at +10. At that setting, unless I'm not setting some option correctly, the LEDs will not illuminate beyond +4. The +10 was set by getting both +8 and +12 to glow solid (page 16). Instead the LIM at the end of the row illuminates meaning the limiter kicks in. So how can I ride the fader at +12? It is reading about -10 to -8 on the Sony z7u.

OSX 10.5.8; MacBookPro4,1 Intel Core 2 Duo 2.5 GHz
; Camcorders: Sony Z7U, Canon HV30/40, Sony vx2000/PD170; FCP certified; write professionally for a variety of media; teach video production in L.A.


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Ty Ford
Re: follow up levels sd302
on May 3, 2011 at 6:59:33 pm

Fascinating. Call Sound Devices and see what they say. They may have changed the engineering in the 302 to not be the same as the 442.

Or, something else..:) You have the meters set to read peak and RMS, right?

You're using voice, nit just tone, right?

But you get my drift on leaving some room at the top, right?

Regards,

Ty

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Craig Alan
Re: follow up levels sd302
on May 3, 2011 at 11:04:17 pm

Hi Ty,

Well I'm getting more used to the set up menu. I reset it to factory default in case I screwed something up. Reset to +10. Checked my tone out to -20 on cam. All good. LEDS won't read above limiter thershold. While monitoring with headphones it sounds good and the camera's meters are at a -10 -8 which is good. I wrote customer support to see if I can have the LEDs reflect the levels as if they are not being limited. It might be an option.

OSX 10.5.8; MacBookPro4,1 Intel Core 2 Duo 2.5 GHz
; Camcorders: Sony Z7U, Canon HV30/40, Sony vx2000/PD170; FCP certified; write professionally for a variety of media; teach video production in L.A.


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Ty Ford
Re: follow up levels sd302
on May 3, 2011 at 11:49:15 pm

Craig,

Remember I said only some audio sneaks past the limiter. Audio with very quick limiters. I don't even know if the meters register it on the mixer. I have see camera and mixer levels differ after calibration. That indicates that either something is sneaking through the mixer, or there is a non-linearity in the metering.

Regards,

Ty Ford

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Craig Alan
Re: follow up levels sd302
on May 4, 2011 at 6:06:18 pm

Ty,

User error again. Sort of. Though unless it's mentioned on some other page, the manual does not indicate this: The knob that controls headphone monitoring options also controls the LED monitoring options. So, if I switch to "1" rather than ST I can ride the level as you suggested at 12 even though the limiter is kicking in at 10. The problem with this is I want to use a breakout cable with RTN so that I'm headphone monitoring from the camera headphone out not the mixer headphone out.

Is there a way of having the best of both, or do we just toggle back and forth? This will get very difficult with three inputs. I'm working with sound devices support on this.

But here's the thing. If we ride the input levels at +12 and apply an output limiter at +10, that means the output signal almost always has the limiter applied. Is this best practice? I mean the LIM is always lit?

OSX 10.5.8; MacBookPro4,1 Intel Core 2 Duo 2.5 GHz
; Camcorders: Sony Z7U, Canon HV30/40, Sony vx2000/PD170; FCP certified; write professionally for a variety of media; teach video production in L.A.


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Ty Ford
Re: follow up levels sd302
on May 4, 2011 at 6:28:37 pm

But here's the thing. If we ride the input levels at +12 and apply an output limiter at +10, that means the output signal almost always has the limiter applied. Is this best practice? I mean the LIM is always lit?

Remember I said it depend on the nature of the transients. Fast transients will sneak through the limiter.

I set my 442 limiter at +14, with only 6 dB of headroom to +20 (0 dB on the camera). When I tried setting the 442 limiter to +20 or +18, I got "overs" on the camera from audio that sneaked past the output limiter.

You said your cameras were incapable of handling full scale audio, so I dialed it back for you to +10 limiter with +12 peaks. Regardless, you need to test this before committing on a shoot.

Regards,

Ty Ford

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Craig Alan
Re: follow up levels sd302
on May 4, 2011 at 7:21:13 pm

Oh Oh Oh. That was for the pd170. I would say that +14 limiter out and +12 levels IN would make sense.

But I still want to know how to use the LEDs for input monitoring and the headphone for camera headphone out monitoring using the RTN IN on the mixer with a breakaway cable at the same time.

Isn't that common practive to want to hear what the camera is recording while using the mixer's meters to adjust levels on the fly?

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; Camcorders: Sony Z7U, Canon HV30/40, Sony vx2000/PD170; FCP certified; write professionally for a variety of media; teach video production in L.A.


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Ty Ford
Re: follow up levels sd302
on May 4, 2011 at 8:02:44 pm

Craig,

yes. Whenever possible you want to listen to the camera headphone output through the return.

Page 4.

14. Headphone Selector Switch
Sets the signal source sent to headphones. Options include: input PFL 1, 2, 3; left output bus; right output bus; Mono (summed left and right); STereo master; RTN - stereo monitor return; MS-mono; MS-stereo; RTN-MS.

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Craig Alan
Re: follow up levels sd302
on May 4, 2011 at 8:40:49 pm

Right. And if I set it to RTN the LEDs switch to output levels not input levels and certainly not individual input levels.

OSX 10.5.8; MacBookPro4,1 Intel Core 2 Duo 2.5 GHz
; Camcorders: Sony Z7U, Canon HV30/40, Sony vx2000/PD170; FCP certified; write professionally for a variety of media; teach video production in L.A.


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Ty Ford
Re: follow up levels sd302
on May 4, 2011 at 8:57:17 pm

I don't know if the LDs switch or not, but that would be pretty obvious to see.

The 442 can be set to do that, but the default is NOT to.

Regards,

Ty Ford

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Craig Alan
Re: follow up levels sd302
on May 4, 2011 at 9:36:07 pm

Thanks. I'm going to try to work this out with Sound Devices. If not, it's a feature request. All that said, the meters look fine on the Sony and they sound fine on input, on output, and monitoring from the Sony.

And although I'm kinda back to where I started, it is with a lot better understanding of how the mixer works.

OSX 10.5.8; MacBookPro4,1 Intel Core 2 Duo 2.5 GHz
; Camcorders: Sony Z7U, Canon HV30/40, Sony vx2000/PD170; FCP certified; write professionally for a variety of media; teach video production in L.A.


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Craig Alan
Sound Devices Response
on May 4, 2011 at 9:45:59 pm

On a forward note, whenever you are sending signal to a camera and want more headroom, use the setup menu and add a few dB of output attenuation. Using the limiter is not a proper way of setting levels. The limiters are only (and should only be) used as a safety net for clipping. If one can maintain good input levels, have the limiters active and never hit them in a full day of production, the limiters were used properly. With a proper method of gain staging this is 100% possible.


Back to the original question: It is always best practice to mix with the ears and not the eyes. If you want to see the PFL signal on the meter, you will want to hear them too. So, the options are:


1) The monitor switch will tell the HP what to output and the meters what to display OR
2) The monitor switch will only send the selected signal to the HP and the meters will always stay on ST.


There is no way to see a signal being metered on the LED and not be able to hear it unless that signal is the ST output with the limiter attenuation applied. With proper gain staging applied to the signal flow, this works perfectly every single time. If you camera' audio circuitry is easily overloaded, apply output attenuation and monitor the 302 output. Use the camera return as a momentary reference and return to monitoring the output of the 302. This is the most effective way of controlling the signal.


The final option would be to plug your HP directly into the camera. This way you could do what you are wanting to. Not recommended though.

OSX 10.5.8; MacBookPro4,1 Intel Core 2 Duo 2.5 GHz
; Camcorders: Sony Z7U, Canon HV30/40, Sony vx2000/PD170; FCP certified; write professionally for a variety of media; teach video production in L.A.


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Ty Ford
Re: Sound Devices Response
on May 4, 2011 at 10:18:25 pm

Um, Craig, what's your source for this?

Ty

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Craig Alan
Re: Sound Devices Response
on May 4, 2011 at 10:39:50 pm

Sound Devices Tech support

I gather you have some issues with it?

What is the difference between the limiter and output attenuation?

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; Camcorders: Sony Z7U, Canon HV30/40, Sony vx2000/PD170; FCP certified; write professionally for a variety of media; teach video production in L.A.


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Ty Ford
Re: Sound Devices Response
on May 5, 2011 at 1:27:27 am

Craig,

Given your questions, I knew it wasn't your thoughts. I would have given attribution if I had posted it.

I tickle the limiter with occasional vocal peaks, but I'm usually peaking about +14.

Regards,

Ty Ford

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Craig Alan
Re: Sound Devices Response
on May 5, 2011 at 2:17:31 am

Ty,

I thought the title of my post and the previous post that I was contacting them implied the source.

In any case, do you agree with what they are saying?


What is the difference between the limiter and output attenuation?

OSX 10.5.8; MacBookPro4,1 Intel Core 2 Duo 2.5 GHz
; Camcorders: Sony Z7U, Canon HV30/40, Sony vx2000/PD170; FCP certified; write professionally for a variety of media; teach video production in L.A.


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Ty Ford
Re: follow up levels sd302
on May 4, 2011 at 9:49:15 pm

Craig,

It's not a circle, it's a spiral. :)

Regards,

Ty Ford

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