Dplank Posted September 5, 2021 Report Share Posted September 5, 2021 I'm pretty new to location sound, and hoping someone can help me with some fairly fundamental set up questions... I am using a Sound Devices mixpre 10 with a Sony FX9. I am sending line level out of my mixer to the camera at +4dB. When I send -20dB tone to the camera, I am finding that I have to turn the faders on the camera to maximum just to set the tone on the camera to -20dB on the camera's VU meters, and not quite able to get there. In the audio set up menu on the camera, each channel has a user definable setting for "Input reference level". Previous sound men have set this variable to +4dB. In my research I have found information that seems to say that while professional line level is +4dB, professional reference level is 0dB. Could this be my problem? Should this setting on the camera be set to 0dB, and would that give me more headroom on the camera's faders? Or am I missing some other basic set-up information? Any help would be appreciated. Quote Link to comment Share on other sites More sharing options...
Rick Reineke Posted September 5, 2021 Report Share Posted September 5, 2021 I am not very familiar with the MP series, but the line output could be at -10dB, which would cause a low level feeding a +4dB input. The gain setting on the cam could be attenuating the signal as well. Quote Link to comment Share on other sites More sharing options...
Dplank Posted September 5, 2021 Author Report Share Posted September 5, 2021 41 minutes ago, Rick Reineke said: I am not very familiar with the MP series, but the line output could be at -10dB, which would cause a low level feeding a +4dB input. The gain setting on the cam could be attenuating the signal as well. On the mixpre series, the output is user definable in dB, rather than a mic or line preset... so I set it to +4dB Quote Link to comment Share on other sites More sharing options...
frankaudio Posted September 6, 2021 Report Share Posted September 6, 2021 I would set the input gain on camera to 5 and then send more gain from your MP to camera. Quote Link to comment Share on other sites More sharing options...
RunAndGun Posted September 6, 2021 Report Share Posted September 6, 2021 I was just on a shoot last week and the camera was an Fx6 and it was the same thing… Sent tone at line level to the cam from my 664 and had the cam pots turned all the way to 10(maybe they should go to 11…) and still couldn’t get enough level to “zero out”. Saw the reference level adjustment in the menu and that “worked”, but I’ve never seen that before on a cam when using line level, only mic. With my F55, it’s at +17(out of +99) to “zero out” and my VariCam’s are between 1/2 to 3/4 up on their pots. My C300, I think, is pretty much right in the middle at 5. So, it’s definitely the Sony(s) doing something. Quote Link to comment Share on other sites More sharing options...
Dplank Posted September 6, 2021 Author Report Share Posted September 6, 2021 10 hours ago, FrankH said: I would set the input gain on camera to 5 and then send more gain from your MP to camera. Would you mind explaining your reason for that recommendation? I guess what I am still wondering is, is "Input reference level" in the camera audio menu actually referring to a gain setting? Or is a reference level setting... which seems to me different from a line level setting. On the occasion that I mentioned originally, I did increase the output level from my mixer to +8dB so I could set the faders on the camera to bring the VUs up to -20dB to match the incoming tone... but is there a downside to outputting a signal from the mixer that is higher than professional line level? 5 minutes ago, RunAndGun said: With my F55, it’s at +17(out of +99) to “zero out” and my VariCam’s are between 1/2 to 3/4 up on their pots. My C300, I think, is pretty much right in the middle at 5. So, it’s definitely the Sony(s) doing something. Well I am glad to hear I am not the only one experiencing this. Regarding your F55 experience... do you mean that you had to set the output level from your mixer to +17dB? My experience with C300, with my mixer output set to +4dB, is the camera faders are at about 7 to match tone to -20dB. But the C300 doesn't seem to have the same "Input reference level" setting as the Sony. Interestingly, when using my 302 with the Sony FX9 I don't have this problem, and the faders on the camera are set to about 7 to match tone. But it seems like only the Amazing Kreskin could figure out what signal strength the 302 is outputting... the manual is bewildering to me. Quote Link to comment Share on other sites More sharing options...
Patrick Farrell Posted September 6, 2021 Report Share Posted September 6, 2021 19 hours ago, Dplank said: On the mixpre series, the output is user definable in dB, rather than a mic or line preset... so I set it to +4dB If I remember correctly, that menu is an output gain adjustment so "+4" means it is adding 4dB of gain to the output rather than providing a 4dBu reference level. The mixpre outputs are a nominal -10dBV so adding 4dB gets you to around -3.78dBu. You should make that setting about +12 which will get you pretty close to outputting 4dBu. Quote Link to comment Share on other sites More sharing options...
RunAndGun Posted September 6, 2021 Report Share Posted September 6, 2021 5 hours ago, Dplank said: Well I am glad to hear I am not the only one experiencing this. Regarding your F55 experience... do you mean that you had to set the output level from your mixer to +17dB? My experience with C300, with my mixer output set to +4dB, is the camera faders are at about 7 to match tone to -20dB. But the C300 doesn't seem to have the same "Input reference level" setting as the Sony. +17 on the camera, for the F55. It's all menu driven and doesn't have physical dials. I think there is "room for error" in the camera/mixer/cable system. I've seen the same camera set to different levels when used with the same model mixer(but not the same copy) and even same model cameras set to different levels when being fed from a single mixer. And from my experience, mixer umbilical cables and ends can sometimes play a roll in the equation, too. Quote Link to comment Share on other sites More sharing options...
Mungo Posted September 6, 2021 Report Share Posted September 6, 2021 Rare issue: There is an input level setting in the FX9 audio input menu. It works like a digital attenuator, so if you want to disable it, set it to +99. 1 hour ago, Patrick Farrell said: The mixpre outputs are a nominal -10dBV Yes, the MixPre series's outputs are far away from real line level. Quote Link to comment Share on other sites More sharing options...
Spin360 Posted September 7, 2021 Report Share Posted September 7, 2021 I've had the same issue, but with the PDW xdcam. Not inky that but also I couldn't put my peak levels at above - 10dB on the cam or it would completely distort. Which wouldn't be a problem for me, but I've had complaints that the "audio is too quiet". Any ideas? Quote Link to comment Share on other sites More sharing options...
Rick Reineke Posted September 7, 2021 Report Share Posted September 7, 2021 Quote - 10dB on the cam or it would completely distort. Which wouldn't be a problem for me, but I've had complaints that the "audio is too quiet" This would be a operating level mismatch, and is over-driving the input stage of the cam or recording device, for instance feeding a (nominal) +4dB to -10dB input, or in extreme cases, feeding line level to a mic level input.. a common issue on the DVinfo and DVX semi-pro audio forums. Quote Link to comment Share on other sites More sharing options...
Tim Norris Posted September 7, 2021 Report Share Posted September 7, 2021 On 9/5/2021 at 12:22 PM, Dplank said: I'm pretty new to location sound, and hoping someone can help me with some fairly fundamental set up questions... I have a MixPre-10 ll as a backup for my 688, or for those times when I might need to go out in a tippy boat in a flood or maybe hike up a mountain during a forest fire... a minimal kit with a boom and 2 channels of wireless. A confession... I have never actually used it on a shoot in the couple years I have had it, but it is ready to deploy if I must. I had to perform some setup and calibration of the MixPre-10 ll to have it match the output of my 688, a known and reliable device for me. The MixPre-10 ll does not seem to follow any traditional output standards. On the Sony XD ENG cams I have had experience with, the pots need to be set at around 1:00/2:00 to get -20db on the camera meter, with the 688 sending 1k tone at 0db at line level, hard wired to the camera. 'Lectrosonic wireless link/hop receivers are set to output +5db into the camera set at line level, with an appropriate mic level feed to the transmitters, to also read -20 db on the camera. With the C300 and most of the newer smaller Sony cameras, Sony Pro-sumer and good consumer cameras, setting the camera pot at the mid point "5" (there is a stop at this position) seems to give me proper results with the same 688 mixer setup. I believe the camera input pots should always be near the middle of their range. Using a third mixer (MixPre D - analog device) as a substitute for the camera, I was able to pre-set the MixPre-10 ll outputs to mimic my reliable 688. The TA3 outputs are set at line level, for a hard wire feed to a camera. The 'unbalanced stereo out' (mic level) feeds a pair of wireless transmitters for links/hops. When calibrating the MixPre-10 ll, I did not change the settings on the link/hop transmitters, receivers, nor the input pots on the 'camera substitute' mixer. The wireless links/hops are now interchangeable between my 688 and MixPre. I can swap from one mixer to the other without changing any settings, including those on the camera. I am fortunate to have a known and reliable mixer for this calibration. It would have been my desire that the MixPre series mimic the setup of common professional mixers, perhaps other more expensive Sound Devices mixers. I don't think the MixPre series was intended to be for professional users... but I think they can be if properly set up. I hope this makes sense and and is of some help. Good luck! Tim *The input levels on my wireless links/hops are essentially the same as they have been for years through generations of SD mixers going back to the 442, and my long retired Cooper CS 104. Because the output of each of these mixers was nearly the same as each of the others, I could use any of these mixers in place of my 688 without the need to re-calibrate settings. This is how it should be... or at least how I want it to be. Quote Link to comment Share on other sites More sharing options...
RunAndGun Posted September 8, 2021 Report Share Posted September 8, 2021 I think a big part of the issue with the current mixpre series, is that they are designed primarily as recorders and not to feed professional cameras or other devices. I think they could make good "Oh ***t" back-ups, but they're not your primary, especially for feeding cameras. Quote Link to comment Share on other sites More sharing options...
Dplank Posted September 10, 2021 Author Report Share Posted September 10, 2021 For anyone interested in this, I found this illuminating website dB conversion tool. It confirms Patrick Farrell's answer. Thanks again! http://www.sengpielaudio.com/calculator-db-volt.htm Quote Link to comment Share on other sites More sharing options...
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