Sound Devices MixPre-6 II (second generation)

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rick.lang

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Sound Devices MixPre-6 II (second generation)

PostWed Jan 15, 2020 3:50 am

I’ve been running several shorter tests today and one test is still going for 4 ½ hours. They exhibit identical behaviour at 23.976 fps and 24 fps. Sometime after you jam sync, maybe five minutes or thirty minutes, there’s a difference of a single frame but that only happens once. After that it’s rock solid without any variation.
A fifteen minute experience can be identical to the 4 ½ hour test and that might be good all day. I think that’s decent, you just start the sync about twenty minutes before you need it, jam sync again when you see it slip a frame, and leave it good for the rest of the day or until break time and then resync.
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Re: Sound Devices MixPre-6 II (second generation)

PostWed Jan 15, 2020 1:27 pm

I sent the previous post to my Sound Devices support contact.
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Re: Sound Devices MixPre-6 II (second generation)

PostWed Jan 15, 2020 1:34 pm

This is pretty poor from SDs side.
It's a one of those things that should have been tested to death before release. :/
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Re: Sound Devices MixPre-6 II (second generation)

PostWed Jan 15, 2020 1:38 pm

I know. It usually slips in the first couple of minutes so amazes me it can be solid after that! Why three releases without nailing the solution?
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Re: Sound Devices MixPre-6 II (second generation)

PostWed Jan 15, 2020 6:55 pm

Kim Janson wrote:+1

If there is distortion when Second generation device is used for the playback but not when first generation device is used for the playback, it seems pretty obvious there is some problem with the second generation device.


"Turn down the volume."

"But it's so loud!"

"Then turn down the volume."

It's not the device when the operator would rather complain than just turn down the gain to compensate for a louder signal.
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Re: Sound Devices MixPre-6 II (second generation)

PostWed Jan 15, 2020 6:59 pm

Dmitry Shijan wrote:By the way i still don't know if headphones distortion noise problem exists in MixPre6II or MixPre10II.


I've encountered headphone clipping on neither.
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Re: Sound Devices MixPre-6 II (second generation)

PostWed Jan 15, 2020 7:02 pm

rick.lang wrote:Sound Devices has released version 6.0 for their MixPre recorders. This is very good news and hopefully resolved the Timecode jump with frame rates other than 23.976 fps.


It seems like it did. I did a recording where we used a Tentacle sync to jam the MixPreD6 II from then put the Tentacle on the camera, and the audio synced flawlessly -- though the user experience we had in Resolve lead us to believe initially that it had synced none of it. Needless to say, that lead to a pleasant surprise when I roughed out the first assembly.
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Re: Sound Devices MixPre-6 II (second generation)

PostWed Jan 15, 2020 7:50 pm

You may have a good point as I’ve only watched the meters. It may not present a sync problem on actual footage.
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Re: Sound Devices MixPre-6 II (second generation)

PostWed Jan 15, 2020 7:59 pm

rick.lang wrote:You may have a good point as I’ve only watched the meters. It may not present a sync problem on actual footage.


As long as it works reliably, I'm happy :)

It's an amazing sound mixer, but then so was its predecessor.
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Re: Sound Devices MixPre-6 II (second generation)

PostThu Jan 16, 2020 9:36 am

Rakesh Malik wrote:
Dmitry Shijan wrote:By the way i still don't know if headphones distortion noise problem exists in MixPre6II or MixPre10II.


I've encountered headphone clipping on neither.

Check this post for details about this problem:
viewtopic.php?f=2&t=97842&start=400#p573448
This problem was confirmed by SD tech support.
This problem don't exists in MixPre3/6/10 first gen.

Connect MixPreII as audio interface and playback provided test sounds from computer https://www.dropbox.com/s/e7idet23874sb ... o.zip?dl=0
Increase headphones volume during playback.
Depending of headphones impedance, you will start to hear distortion noise when headphones gain will reach 45-60.

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Re: Sound Devices MixPre-6 II (second generation)

PostThu Jan 16, 2020 3:10 pm

Further update on my testing of 6.0.0. I ran jamming Timecode from a Tentacle for 13 hours yesterday and no issue except for that early dropping of one frame. 24 fps tested. As mentioned earlier with Rakesh, this may not be a problem in a real video edit. We shall see. Sound Devices is investigating for me.
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Re: Sound Devices MixPre-6 II (second generation)

PostThu Jan 16, 2020 5:55 pm

Dmitry Shijan wrote:Check this post for details about this problem:
viewtopic.php?f=2&t=97842&start=400#p573448
This problem was confirmed by SD tech support.
This problem don't exists in MixPre3/6/10 first gen.


Still wondering about the procedure/answer to the following:

Mattias Murhagen wrote:
Dmitry Shijan wrote:
Mattias Murhagen wrote:
And to be clear then if you start lowering the computer output as you are increasing that headphone level amp with the knob;
distortion is still there even when the headphone amp is at "100" and the computer
sending signal is now lowered?


Yes, distortion is still there even when the headphone amp is at "100" and the computer sending signal is lowered.



And you stopped lowering it at a point where you were still getting the level you wanted on that music, just unfortunately with distortion, right?


I'm guessing the answer should be "yes", but just wanted to make sure.

I'd then also like to know how much you've lowered the computer output at that point.
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Re: Sound Devices MixPre-6 II (second generation)

PostThu Jan 16, 2020 7:19 pm

I get a feeling that this is related to either the 24 vs 32 bit or single to dual pre amp design.
Perhaps its different analog to digital amplification.
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Re: Sound Devices MixPre-6 II (second generation)

PostFri Jan 17, 2020 7:06 am

Did another test today. I jam synced the MixPre-6 II with the Tentacle and then immediately removed the Tentacle to see how well the MixPre would keep proper Timecode. It wasn’t long until there was the one frame slip but after 6 hours I plugged the Tentacle back in to Aux1 and the sync was still just that single missed frame.

This is good news as o now know I don’t have to dedicate a Tentacle to stay with the MixPre. So in a two camera shoot I can jam sync the MixPre and then leave both Tentacles on the Mini 4.6K and the BMPCC4K.

I think the next test I shoul do an actual recording to see if the dropped frame is real.
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Re: Sound Devices MixPre-6 II (second generation)

PostFri Jan 17, 2020 7:45 am

Thanks Rick for all the effort in testing.
We have ordered a MixPre-10 II and a Tentacle Sync Set at the end of December but haven't received the items yet. I will try to replicate your tests then with that device.
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Sound Devices MixPre-6 II (second generation)

PostFri Jan 17, 2020 9:09 pm

If you get different results, that will be most interesting. I hope your device is perfect.
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Re: Sound Devices MixPre-6 II (second generation)

PostTue Jan 21, 2020 7:11 pm

I finally did a test with a single clip over two hours long. I jammed the MixPre-6 II from a Tentacle Sync and then attached that Tentacle to my Blackmagic Pocket Cinema Camera 4K to force the camera to use external Timecode.

There was no dropped frame or drift within a frame! Good news.

I suspected that Difference of a frame that would show up on the MixPre Jam panel was bogus from something I observed. If I jammed the MixPre just removing the Tentacle would cause the one frame difference. But plugging the Tentacle back into Aux1, the Difference immediately went to zero without jamming again. Unplugging and replugging without physically jamming again repeatedly caused the one frame issue to appear and disappear. But it’s only a display issue, the actual Timecode recorded is solid.
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Re: Sound Devices MixPre-6 II (second generation)

PostTue Jan 21, 2020 7:41 pm

That’s sounds great Rick.
Thanks for the update.
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Re: Sound Devices MixPre-6 II (second generation)

PostTue Jan 21, 2020 8:25 pm

Rick, you are the man. Thanks so much for all the testing. Glad to know that the timecode with the footage all syncs up.
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Re: Sound Devices MixPre-6 II (second generation)

PostWed Jan 22, 2020 10:34 am

I will likely buy tomorrow used MixPre 10T, the price is about the same as MixPre 6 II.

I do not really need that many channels, the MixPre 6 II would have enough. I do like the balanced outputs on MixPre 10T.

Not to worry about clipping would be nice, but 24 bits should be plenty.

I think, without any proof, that the older version might actually have better sound quality. Has there been any tests about this?

What do you thing, is there some reason I should go with the MixPre 6 II
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Re: Sound Devices MixPre-6 II (second generation)

PostWed Jan 22, 2020 12:27 pm

Kim Janson wrote:I will likely buy tomorrow used MixPre 10T, the price is about the same as MixPre 6 II.

I do not really need that many channels, the MixPre 6 II would have enough. I do like the balanced outputs on MixPre 10T.

Not to worry about clipping would be nice, but 24 bits should be plenty.

I think, without any proof, that the older version might actually have better sound quality. Has there been any tests about this?

What do you thing, is there some reason I should go with the MixPre 6 II


I would purchase the MixPre-6 II unless you have an actual need for more channels or the two balanced outputs. There’s no point in the additional bulk and weight of the 10T unless you’re getting something useful in exchange. I would rather have 32-bit float than channels and balanced outputs that I don’t need. Has the two year warranty on the used 10T expired? If not, is it transferable and how much time is left? Sound Devices says that the Series II preamps are the same as Series I, and I am unaware of any reason to believe that the sound has deteriorated.

B&H, and perhaps other retailers, has been selling remaining stocks of the original MixPre-6 at a discount to the MixPre-6 II. Attractive if one doesn’t need the timecode generator or 32-bit float.
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Re: Sound Devices MixPre-6 II (second generation)

PostWed Jan 22, 2020 2:21 pm

Kim, the number of inputs might be a factor in influencing your decision. The MixPre-6 II has four XLR inputs but will record up to eight channels. I have already maxed out in terms of mic inputs. I use the MixPre on a mic stand so size isn’t that important to me.

I do think the 32bit audio is important as insurance. Programs such as Reaper will convert the 32bit to 24bit if needed. One day Resolve will have complete support for 32bit audio. When that happens, you’ll be glad you have the capability in the series II recorders.
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Re: Sound Devices MixPre-6 II (second generation)

PostWed Jan 22, 2020 3:01 pm

rick.lang wrote:I do think the 32bit audio is important as insurance. Programs such as Reaper will convert the 32bit to 24bit if needed. One day Resolve will have complete support for 32bit audio. When that happens, you’ll be glad you have the capability in the series II recorders.


Given that people have been successfully recording sound for decades without this feature, I don’t think that “important” is the right word. If one knows how to set levels properly, the feature is only significant in situations where sound levels are truly unpredictable. An example is recording thunderstorms, although even then one can record tracks at different levels. I think that the feature, in most cases, is principally useful for people who don’t know what they are doing.

Unlike Zoom’s implementation, at least Sound Devices lets one set levels for 32-bit. This is significant because it allows for repeatability. I do have a concern that this feature may retard learning good technique and promote sloppiness.

That said, I’d rather have 32-bit than channels, and the resulting additional bulk and weight, that I don’t need.

Edit: Clarified sentence on recording thunderstorms.
Last edited by robedge on Wed Jan 22, 2020 3:10 pm, edited 2 times in total.
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Re: Sound Devices MixPre-6 II (second generation)

PostWed Jan 22, 2020 3:08 pm

robedge wrote:I do have a concern that this feature may retard learning good technique and promote sloppiness.


I think the draw for 32-bit is especially strong for one-person shops where you're doing everything (lighting, camera, and sound) yourself. There are so many details involved in setup, and so many potential distractions (cutting your eye from the camera monitor over to the sound recorder to check levels) that removing any part of the equation can help. I'm sympathetic to the arguments for 32-bit even though I have no immediate plans to upgrade; I'm still using the original MixPre 6 and plan to stick with it.
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Re: Sound Devices MixPre-6 II (second generation)

PostWed Jan 22, 2020 3:17 pm

32bit audio is another tool I use as a one man band in uncontrolled situations and it makes some things easier while shooting. Agree it’s not necessary but it’s insurance.

Buying the Blackmagic Video Assist 12G 7” isn’t necessary but it’s another tool that provides insurance as well in addition to making several things easier in some situations.
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Re: Sound Devices MixPre-6 II (second generation)

PostWed Jan 22, 2020 3:23 pm

Brad Hurley wrote:I think the draw for 32-bit is especially strong for one-person shops where you're doing everything (lighting, camera, and sound) yourself. There are so many details involved in setup, and so many potential distractions (cutting your eye from the camera monitor over to the sound recorder to check levels) that removing any part of the equation can help. I'm sympathetic to the arguments for 32-bit even though I have no immediate plans to upgrade; I'm still using the original MixPre 6 and plan to stick with it.


I agree that it might be useful if there’s a preparation time or concentration problem. After discussing 32-bit with two major location sound vendors here in New York, who are not pushing the feature, I decided to stick with the MixPre-3. If I upgrade, it will be due to a decision to start recording ambisonic sound, but as interesting as ambisonic recording is, the practical applications are still mostly missing in action :)
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Re: Sound Devices MixPre-6 II (second generation)

PostWed Jan 22, 2020 3:27 pm

The warranty transfer is good point, I will verify if the 10T still has that.

The sound quality, I am just worried about the complicated calculations they make on sensitive domain, audio.

Even if the preamplifiers are same the DA converters are important also and how that data is processed. In this video, it is not really comparing sound quality, but there is some measurable differences on tonality depending MixPre 6 II recording levels. (starting at 8:00)



Does the MixPre have possibility to link multiple channels together internally and have them at different levels? This could come handy on the first generation devices on some occasions. One could of course make a cable that does this and the 10T has plenty of channels. If the 10T can do this internally then I am totally sold to it. Will then maybe move to 32 devices in couple of years when it is better supported by all SW.
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Re: Sound Devices MixPre-6 II (second generation)

PostWed Jan 22, 2020 3:50 pm

The manuals for the Sound Devices recorder is available online. Best if you have the time to read the manuals before buying. At least for the Series II. There is a feature that I haven’t needed to use, but you can mix down a channel you have recorded and fear it’s too hot.

I know you can link two channels to one mic and then you would lower the gain on one of the channels so sudden very loud audio is less likely to clip or just fall into a better level and not require the internal clipping logic to suppress loudness temporarily. Of course with 32bit recordings this may not be a concern and the limiters are not used as far as I know.
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Re: Sound Devices MixPre-6 II (second generation)

PostWed Jan 22, 2020 6:42 pm

Kim Janson wrote:Does the MixPre have possibility to link multiple channels together internally and have them at different levels?

Yes, you can set additionally different volume shift for each channel in Recording settings. So for example with MixPre6 you can record 2+2 channels (2 low gain and 2 high gain from same input). But just record stereo in 32 bit is waaaay simpler way to go.

Timecode generator and 32-bit float are the main reasons to go with II gen. During my 5 years field recording experience i got some odd real life moments when recording was totally damaged due unpredictable clipping or recorded at too low volume. I really hate to set levels when i need to operate quick. I also don't like to ask musicians to produce test singing before recording to adjust audio levels.
With MixPreII in 32 bit float those problems don't exists anymore. For stereo recording i prefer to operate in basic gain mode because it is way simpler to operate with single rotary pot and because i don't need that rather strange ultra fine gain+mix adjustment. Also i usually set single pot to adjust gain of both channels (1-2 linked). All this simplifies operation a lot and i in most cases i only need to think and worry about mics placement.

I can even live with slight headphones distortion problem during recording, but hope SD could fix it somehow...
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Re: Sound Devices MixPre-6 II (second generation)

PostWed Jan 22, 2020 8:51 pm

I know that it’s hard to clip when using the 32bit float option. But how good is it when it’s too low. Let’s say that you set the audio at -100db can you still raise it up to -24db and still have good audio will you introduce any noise?
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Re: Sound Devices MixPre-6 II (second generation)

PostWed Jan 22, 2020 9:00 pm

Chris Shivers wrote:I know that it’s hard to clip when using the 32bit float option. But how good is it when it’s too low. Let’s say that you set the audio at -100db can you still raise it up to -24db and still have good audio will you introduce any noise?


Perhaps others know better, but I haven’t seen any suggestions, including in Sound Devices videos, that 32-bit addresses that issue. If I’m wrong, I’d like to know.

The best that 32-bit can do is capture the full dynamic range of the mike, which Sound Devices does by using two converters. If the mike clips, so will the audio.
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Re: Sound Devices MixPre-6 II (second generation)

PostWed Jan 22, 2020 9:07 pm

Chris Shivers wrote:I know that it’s hard to clip when using the 32bit float option. But how good is it when it’s too low. Let’s say that you set the audio at -100db can you still raise it up to -24db and still have good audio will you introduce any noise?


I believe the noise floor in the new MixPre II series is -134 db. Your mic's own self-noise might be an issue, but I remember Curtis Judd did a demo where he recorded audio at a very low level and raised it up to -24 or -18 dbfs with no noise.
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Re: Sound Devices MixPre-6 II (second generation)

PostWed Jan 22, 2020 9:10 pm

robedge wrote:
Chris Shivers wrote:I know that it’s hard to clip when using the 32bit float option. But how good is it when it’s too low. Let’s say that you set the audio at -100db can you still raise it up to -24db and still have good audio will you introduce any noise?


Perhaps others know better, but I haven’t seen any suggestions, including in Sound Devices videos, that 32-bit addresses that issue. If I’m wrong, I’d like to know.

The best that 32-bit can do is capture the full dynamic range of the mike, which Sound Devices does by using two converters. If the mike clips, so will the audio.

On their video it said their dynamic range goes from -758dbfs to 770dbfs. They said nothing about it being mic dependent. Then again they was using $2000 mic to test lol.
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Re: Sound Devices MixPre-6 II (second generation)

PostWed Jan 22, 2020 9:16 pm

Chris Shivers wrote:I know that it’s hard to clip when using the 32bit float option. But how good is it when it’s too low. Let’s say that you set the audio at -100db can you still raise it up to -24db and still have good audio will you introduce any noise?

There is no any real reason to keep noise level at ultra low -100db and boost it in DAW. It will not produce less noise compare to normal recording. But if for some reason you need to record extremely like this this, 32 bit will sound way cleaner and way better than 24 bit.

I shared some tests in other thread viewtopic.php?f=21&t=101968&start=50#p571355 viewtopic.php?f=21&t=101968&start=50#p571546

"I done one more quick test with 32 bit sample files from SD website https://www.sounddevices.com/sample-32- ... wav-files/

1. I lower item volume to -150db (lowest possible volume in Reaper)
2. I render one file as 24 bit and another as 32 bit.
3. I open both rendered files in Reaper and Normalize them back.

After Normalize rendered 32 bit file looked 100% like original
After Normalize rendered 24 bit file was crazy distorted.

Next i repeat test with source item volume lowered to -130db and -100db, but even so 24 bit file show very visible distortion after normalize.

Next i repeat test again and again and only with source item volume lowered somewhere to -60 -70db (at these levels waveform start to became rather visible), rendered 24 bit file starts looks more less like original after normalize. But i can still notice some tiny digital noise pattern artifacts if look very close on spectre image.

Personally i see that 32 Bit Float allow to create huge volume adjustments not only during recording but also during any other workflow step and allow re-save truly lossless files 100% without any digital limits. Perfect archiving format."

"You may notice in older Curtis Judd's videos he discover that the normalized sound character is slightly different at different gain amplification levels.
My guess it is not because A/D converters, but because analogue circuits inside microphone body itself.

In 32 bit at any gain level we always capture all possible dynamic range of microphone and so we can always digitally normalize it without any loss. So when we provide more gain to microphone we actually provide more voltage to its circuit and so internal electronic components inside microphone reacts somehow to this voltage and adds some specific character to the sound.
When we provide less gain/less voltage to its circuit, the internal electronic components inside microphone reacts somehow in different way to this voltage and adds some other character to the sound (less bass, less warm in that video example)

So probably with 32 bit recorder we can shape the sound of microphone by experimenting with different gain settings and find which gain will produce better sound on specific microphone model for specific needs."
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Re: Sound Devices MixPre-6 II (second generation)

PostWed Jan 22, 2020 10:05 pm

When most people are recording 24bit, they try to keep their audio around -20 to -12 and try to keep peaks about -6.

When you’re recording 32bit audio, you’ll still get very good sound while recording mostly about -60 to -40.

In post both would normalize to -23 LUFs but the change working with 32bit is more dramatic to see. In Resolve the audio can appear to have little there, a line with some bumps and ripples but when normalized, looks ‘normal.’

I haven’t intentionally recorded lower than -60, but I know the option is there if that is all I can get. I always record above the noise floor unlike in Dmitry’s impressive test. I’m sure when you record in lower ranges, you’re going to want to use a proper mic so not as confident all mics will work at those low volumes. The big advantage of recording low levels is that you are not likely to have spikes that are going to clip in most situations.
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Re: Sound Devices MixPre-6 II (second generation)

PostWed Jan 22, 2020 10:18 pm

Chris Shivers wrote:On their video it said their dynamic range goes from -758dbfs to 770dbfs. They said nothing about it being mic dependent. Then again they was using $2000 mic to test lol.


As I understand it, the point of this technology, which involves using two converters, is to process more of a microphone’s range without the recorder itself clipping. In other words, if you clip the mike, you’re SOL. However, while I’ve tried to understand this technology, I’m sure not an expert and I’m not planning on stressing one of my mikes to find out :)
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Re: Sound Devices MixPre-6 II (second generation)

PostWed Jan 22, 2020 10:28 pm

Chris Shivers wrote:On their video it said their dynamic range goes from -758dbfs to 770dbfs...


That is the equivalent dynamic range of a 32bit signed floating point number. It is speculated that that might be the range of sound in the near vacuum of space at the low end and at the centre of a black hole or neutron star at the other end. So nothing we know of can record with that dynamic range AFAIK.
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Re: Sound Devices MixPre-6 II (second generation)

PostWed Jan 22, 2020 10:36 pm

rick.lang wrote:When most people are recording 24bit, they try to keep their audio around -20 to -12 and try to keep peaks about -6.


This is just a convention about headroom. In my view, if you know what your loudest sound is, there’s no need to follow it. Record producer/educator Kenny Gioia, if I understand him correctly, has argued that there is an optimum recording level because current digital hardware was patterned after analogue hardware, but as far as I know he’s the only person who says this. Even at that, he doesn’t endorse the above.

Here’s an example. Alex Knickerboker records sound effects. One of his recent videos (October 30, 2019) is about recording engine sounds for action movies. At 02:40, he talks about setting levels. He finds out what the loudest sound will be and records just below it. In other words, he ignores the above mantra and records hot. In my view, this is a breath of fresh air on a “rule” that has no apparent acoustic basis. It’s how I record myself. I’ve never had a problem doing this, and I’ve never heard anyone explain why I shouldn’t beyond repeating the mantra. Gioia at least gives a reason, but he seems to be in a minority of one on his theory.

“How to Record Engine Sounds for Hollywood Action Films”

Last edited by robedge on Wed Jan 22, 2020 10:46 pm, edited 1 time in total.
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Re: Sound Devices MixPre-6 II (second generation)

PostWed Jan 22, 2020 10:46 pm

Alex approach for sound effects related to inherently loud sounds will work well. I was speaking more from the perspective of live performances and narrative film where you tend to stay in a safe range that will allow you to pick up an unexpected low whisper or unexpected loud crash. When I’m shooting in those situations I don’t really know how quiet and how loud things will get. Actors often change from one delivery to another.
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Re: Sound Devices MixPre-6 II (second generation)

PostWed Jan 22, 2020 10:49 pm

rick.lang wrote:I was speaking more from the perspective of live performances and narrative film where you tend to stay in a safe range that will allow you to pick up an unexpected low whisper or unexpected loud crash. When I’m shooting in those situations I don’t really know how quiet and how loud things will get. Actors often change from one delivery to another.


Yes, that’s the headroom argument. Headroom makes sense in the circumstances you describe, but it doesn’t have an acoustic basis and it isn’t the “rule” that it is commonly made out to be.

For example, there’s no reason to do that if one is recording voiceover narration for a documentary, where one normally knows the dynamic range of the narration.
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Sound Devices MixPre-6 II (second generation)

PostWed Jan 22, 2020 10:58 pm

Correct! In fact I would record ADR at a higher level (if possible without adding gain). I don’t need to be so conservative the next time I do ADR or VoiceOver as that will be using the MixPre-6 II. Previous work was done with a borrowed Zoom H4/5n.

A slight aside, but normally the mic is at least a few feet away from an actor. But a radio broadcast host’s mic might be a few inches away. I’ve tested my Sennheiser MKH416 when it’s very close and the sound is pretty nice, much different. I should test my CM-4 mics that way. A very intimate sound because there’s no need to project one’s voice. Must use that for a ‘pillow talk’ scene!

First let me patent the technique so I can die rich.
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Re: Sound Devices MixPre-6 II (second generation)

PostWed Jan 22, 2020 11:27 pm

rick.lang wrote:I should test my CM-4 mics that way. A very intimate sound because there’s no need to project one’s voice. Must use that for a ‘pillow talk’ scene!

First let me patent the technique so I can die rich.


Marlene Dietrich beat you to the patent. Curious now - did she exploit proximity effect with whatever cardiods she used?
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Re: Sound Devices MixPre-6 II (second generation)

PostWed Jan 22, 2020 11:39 pm

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