DSMC Fan 2.0 Kit - Audio Performance

[Phil Holland]

Well this felt like a Monday

So one of the things I've been seeing and hearing is how many folks who don't fully understand the new DSMC Fan 2.0 Kit and what it does. Another crazy thing is I've found recently when rigging up some cameras that some folks don't know about the new Adaptive Fan Algorithm. Which alludes to folks also not upgrading their firmware for some time. I'm now working with one major rental house to get all that cleared up because that's just nuts.

Onto the stuff. And this only relates to Red Epic Dragon.


Testing Details
- Audio Meters Used: Several Class 2 and Class 1 Meters, Brüel & Kjær 2250 was "the best one". Also utilized a Samsung S4 app which had impressive sensitivity.
- Meters were "on axis" to loudest potential point of the Bottom Fan.
- Variance Between Meters Readings = < 1dB (not really an issue)
- Room Size and Info: 5x8' Small Room, tile floors, no sound dampening.
- Tested 12", 3', and 5' distances. Measured from Focus Plane Mark w/ and w/out lens on.
- Roll Times Tested = 3, 5, 10 minute takes.
- Room Tone Measured at 26dB
- Room Temperature 78°


FAN MODE: Adaptive - Performance

** Adaptive Fan Mode uses an algorithm to adjust the speed of the Bottom Fan to try and maintain a user selected sensor operating temperature (this of course should match your Black Shade calibration temperature). A higher temperature may take longer for the sensor to heat up and start shooting. Lower temperature the opposite. Currently Red defaults the Epic Dragon Fan Mode using Adaptive at 65°, which is a good balance between start-up to targeted Black Shade sensor temperature and reasonably quiet camera operation. At 65° and 70° Red Epic Dragon is actually quieter than other cameras now.

Measured at 12":
- 55° - Typical Operating Range = 56-61dB
- 65° - Typical Operating Range = 40-46dB
- 70° - Typical Operating Range = 35-45dB


** I personally have been running at the default Adaptive 65° with the new fans lately. Initially I started at 70°, but I have switched as testing with standard shotgun microphones and recorders has produced decent results at that dB range. Know that you can squeak out a bit more of a quiet camera if necessary running at 70° though.

Default Adaptive 65° at notable lengths:
- 1 Foot = 40-46dB
- 3 Feet = 31dB
- 5 Feet = 30dB

** A note on fans. Some have noticed the new DSMC 2.0 Bottom Fan sounds different than the version 1.0 Fan. This is true. The 2.0 Fan is bigger, more powerful, and pushes more air through to cool the camera core and sensor faster. It can be potentially louder at moments (and we're talking minimal dB here), but will cool down the camera faster. The Bottom Fan itself is the most important part of the Adaptive Fan Mode as that is what is changing speed to adjust to various temperature levels.

** The DSMC Top Fan 2.0 Produces less noise than the Bottom Fan and is integrated with the algorithms though isn't as "blowy" as the new Bottom Fan when actively cooling. You will feel heat emanating from the Top Fan as warm air is pushed out. This is normal.

** Dragon does indeed run a bit warmer overall as a camera system. You will notice the camera body being warm to the tough. Also normal.


FAN MODE: Adaptive Preview Quiet Record - Performance

** Adaptive Preview Quiet Record allows you to specify a sensor temperature and "cut" the fan speed by a percentage range of 25-100%. You can also select a Post Record Delay of 10 seconds, 30 seconds, and 1 minute.

** In comparison to Adaptive mode at 65° which ran at 40-46dB, Adaptive Preview Quiet Record goes as low as 30dB at that same 12" measured distance. Which would be useful for extreme closeups while rolling dialogue for instance.


Audio Sample

I have previously recorded a sample of the new fans in action. I am quoting that post here as it's informative.

Alrighty. Finally had a moment to record a bit of a sample of what the fans sound like in "practical" use. Meaning with a decent shotgun mic and recorder that would be used on set.

Here's an MP3 file for you to download:
http://www.artbyphil.com/temp/reduser/phfx_DSMCFAN2pointOSounds.mp3

Details:
- Red Epic w/ Mysterium-X
- Fan setting = Adaptive @ 70°C
- Sennheiser MKH-416 Shotgun Mic (on boom pole)
- Zaxcom Maxx Audio Recorder/Mixer
- Increased sample by about 9.9dB to really reveal subtle sounds.
- Room size = 20x25-ish with a bit of reverb, matted floor mats on wooden panels.
- Room temperature = approximately 83-85° fahrenheit, no fans or A/C on to contaminate the sample.

There's been a lot of confusion regarding these fans, but hopefully this real world test clears up all that stuff. I've been shooting with the new fans installed and really it's a huge improvement.

As the audio sample states using the new fan algorithms and the new fans is where the increased performance is most noticeable.

Also, I should note based on my observations that on a typical shooting day the new DSMC Top Plate 2.0 acts somewhat like a heat sync and helps to dissipate/absorb heat.

One other tidbit. We tested a layered neoprene stack and foam with both plastic and aluminum backings to absorb and terminate sound a bit more. This typically cut 4-5dB off at 12". So if necessary that is possible. If you needs something super duper quiet (meaning generating no noise) at the moment a blimp would be ideal. The absorption stack we used was actually modeled off of what the Jacobson Soundblimps have been using for a long time now. If a full housing was made of this material with proper ventilation you would have a dead silent camera.


That's all my notes for now. I know a few wanted some hard numbers. Here they are.

Hope this helps.

 

[Stacey Spears]

** The DSMC Top Fan 2.0 Produces less noise than the Bottom Fan and is integrated with the algorithms though isn't as "blowy" as the new Bottom Fan when actively cooling. You will feel heat emanating from the Top Fan as warm air is pushed out. This is normal.

I am currently experiencing a louder top fan on my Dragon. When I take it out the top fan, the camera is quieter. Can you do a test in a quiet room with and without the top fan? Its a noticable difference when I am standing 3' in front of the camera.

 

[Alain M]

Thanks for the info Phil!

 

[Ivan Kovax]

Thanks Phil for putting the time and effort into doing this.

Unfortunately I do not think the issue is the levels of sound coming from the fan, but the nature of the sound. The previous sound was a more consistant sound analogus to background noise, whereas this fan (the front one especially) is much more distinct and mechanical sounding. It is just much more noticeable even at low levels.

Ivan

 

[Patrick Tresch]

Heat distroying the camera?

Heat distroying the camera?

At 65° and 70° Red Epic Dragon is actually quieter than other cameras now.

** I personally have been running at the default Adaptive 65° with the new fans lately. Initially I started at 70°, but I have switched as testing with standard shotgun microphones and recorders has produced decent results at that dB range. Know that you can squeak out a bit more of a quiet camera if necessary running at 70° though.

Hello Phil,

I'm also advocating the 70C° temp in adaptive mode but some people are concerned about the dammage caused to the boards with such a high temp. As Red never disclosed any infos about getting the camera so warm, and also perhaps because they don't have the long experience "feed back" (or camera sent in) running the Epic at this temp. I was wondering about your 2 cents as your closer to RED than I ;-) about running it at 70C° instead of the RED preset 65C°. There is a clear noise difference between 65 and 70 and noise is my only concern when shooting Epic.

If a full housing was made of this material with proper ventilation you would have a dead silent camera.

Yes!!! Great idea! Please ask RED to do it! I'm interested!


Patrick

 

[Patrick Tresch]

I am currently experiencing a louder top fan on my Dragon.

Hello Stacey,

You shoundn't hear a louder top fan than the new bottom fan. Don't forget the Epic is a dust eater. Have you tried to clean the air path and fans with Dustoff? I also often clean the fan blades with Q-tips. The front fan is easy to take off.

Pat

 

[Isaac Marchionna]

Thanks Phil for putting the time and effort into doing this.

Unfortunately I do not think the issue is the levels of sound coming from the fan, but the nature of the sound. The previous sound was a more consistant sound analogus to background noise, whereas this fan (the front one especially) is much more distinct and mechanical sounding. It is just much more noticeable even at low levels.

Ivan

While I really appreciate the effort that went into this test, I'm in violent agreement with Ivan, it's not the dB, but the mechanical sound is what becomes rather annoying to the ears.

 

[Phil Holland]

I agree it is a different sound and is "more mechanic". Though, to me it literally sounds more like film moving through a mag and doesn't bug me.

I was wondering about your 2 cents

I'm rolling at 65° as it's a more "consistent" sound in the dB range. I was running at 70° though for a while, but at peak ramp it's a audibly a larger gap.

I'm not experiencing the same "badness" though, but that's only due to the fact that on shoots we are using shotgun mics on boom poles and lavalier microphones on talent. Directional and omnidirectional. The 3 and 5 foot measurements with the default 65° have the sound falling in the soft whisper range and using a directional mic it's avoidable in the mix/recorder. Moar Omni setups I've had too.

Now if I was shooting within 12 inches of the focus plane and needed audio I would have a different opinion. I would also have different thoughts if I was attaching a microphone to the camera body.

For day to day production though and on the jobs that we have rolled audio this year it's been pretty good and even better than other cameras. So I'm a happy camper.

One thing I did test was simply attaching the mattebox and the little shield we devised and that cut out a similar 5-ish dB. So if it's mission critical building out a shield from the mattebox actually would make a bit of sense to me. But honestly I think more people are expecting camcorder-like performance from a digital cinema camera and none of the big guns on the market provide that.

Most commercials and movies I work on are focused on getting good audio on set that is either used or then referenced for ADR work after the fact. Just depends. ADR is pretty damn common though.

I think that's where the big separation is here. There's many folks who don't have issue with cameras even louder than this. And there's other folks who do. That's just the way things are I guess. Ideally it wouldn't make a sound at all and nobody would know you're in the room

 

[Patrick Tresch]

Most commercials and movies I work on are focused on getting good audio on set that is either used or then referenced for ADR work after the fact. Just depends. ADR is pretty damn common though.

You'r probably right, it's a cultural thing. Where I come from sound taken on set is king, ADR is not an option or it could come as a second choice for specific shots. I've also played around with a blimp and it fairly does the job. Have you any picture of your blimp?

Pat

 

[Randall Weatherington]

As a comparison, the Panaflex 35mm camera from Panavision has a 34-36 db A-weighted measurement in front of the camera with lens attached.
I am unable to remember whether the measurement was taken at 3' or 6', but it seems to me that 3' was usually the case.
Since it is used primarily with ADR productions, the sound department rarely had a problem with it.

 

[Phil Holland]

As a comparison, the Panaflex 35mm camera from Panavision has a 34-36 db A-weighted measurement in front of the camera with lens attached.
I am unable to remember whether the measurement was taken at 3' or 6', but it seems to me that 3' was usually the case.
Since it is used primarily with ADR productions, the sound department rarely had a problem with it.

At PV the 3' number is something that they have tested in the past. 6' makes sense too, but we didn't talk about it.

I based my testing range on averaging typical dialogue focal lengths, sensor size, and framing distances, but I'm weird like that.

You know the 12 inch measurement was really about that moment where you have an ECU on that eyeball and you direct it to "say something"

 

[Martin Stevens]

Thanks for this testing Phil. I really appreciate it.

Since the room that you performed your tests in was already at 26dB, I'm not quite sure how
to compare your results with other camera noise level specs. I keep wondering if they test their cameras
in a VERY quiet room, as in, say a room that is below 10dB etc.

 

[Phil Holland]

Thanks for this testing Phil. I really appreciate it.

Since the room that you performed your tests in was already at 26dB, I'm not quite sure how
to compare your results with other camera noise level specs. I keep wondering if they test their cameras
in a VERY quiet room, as in, say a room that is below 10dB etc.

If it's a published result by a manufacturer they tested it in a booth likely.

We could have used a large dampened vocal booth, but I'm not shooting in those conditions that often

I should add that most rooms float in the 25-40dB range depending on a variety of factors. 25dB is actually very, very quiet.

 

[Casey Green]

Hi Phil,

Thanks so much for the detailed write up...

Quick question. We noticed that our Element Technica 15mm LW adapter is not compatible with the new DSMC 2.0 bottom fan (since it protrudes out a bit more than the previous model).

Do you know if ET (now owned or merged with RED) plans on a revision of this accessory?

For our setups using this configuration, we sometimes need to install the old bottom fan to get around this, which, of course, offsets the usefulness of the new quieter fan algorithms.

I've asked RED, but so far, have not heard of an updated 15mm LW solution. WC has offered an extension for their legacy LW adapter and their newer version is extended, I believe. I'd think RED has plans for something compatible, but either I've missed the announcement of such a product or it is still in the works. Thoughts?

 

[Phil Holland]

Do you know if ET (now owned or merged with RED) plans on a revision of this accessory?

I don't know of anything, but I don't talk to the ET folks that regularly. I switched up to Red AKS a long while ago after my other 3rd party top plate and base plate caused me some rigging concerns when working on jobs with several cameras, hated my old arms too. The Red 15mm LWS works I know that much, but don't know if anything is in store for the ET item. I'd call up ET directly to find out for sure.

 

[Patrick Tresch]

For our setups using this configuration, we sometimes need to install the old bottom fan to get around this, which, of course, offsets the usefulness of the new quieter fan algorithms.

I wouldn't call the original bottom fan useless as algorithm works the same, the arlgorithm is based on the camera temp and not on what kind of fan it uses. The original bottom fan has a better noise response IMHO (silenter) the gain with the new bottom fan is that it can pump more air throught the air channel when used at speed higher than +-70% for fast cooling.

Pat

 

[Casey Green]

That is correct.

 

[Rob Castiglione]

Yes - old bottom fan has "friendlier" sound than the new one which is more obtrusive.

 

[Michael Tiemann]

Thanks for this testing Phil. I really appreciate it.

Since the room that you performed your tests in was already at 26dB, I'm not quite sure how
to compare your results with other camera noise level specs. I keep wondering if they test their cameras
in a VERY quiet room, as in, say a room that is below 10dB etc.

Below 10dBA is very, very hard to do, except in lab environments. But in recording studios (like mine), 20dBA is not an unreasonable expectation. Which is why we hear the fans of the brain and the Pro I/O module so clearly 8-/

 

[manoj paramahamsa]

Guys can you recommend which mode to keep for non sync sound films
because black shade calibration temp is not constant so my green T becomes yellow T often
is there a way to maintain it in varying exteriors shoot in sun light and shade?