PDX10P Sound Levels
 

Hi All
I just bought a new PDX10P and shot some test footage. I am happy with the results except for the audio levels. When using the XLR supplied mic on auto the sound level is unacceptably low. When set to manual I need to pump the level to maximum to get acceptable results, thus defeating the versatility of the manual level settings. The internal mics perforrm a bit better, sound level wise, both in auto & manual.
Is my camera defective, is the external mic supplied of bad quality or are all PDX10s performing that way? If they all perform that way what is the remedy? To adjust sound levels in post will take to much time and be too fiddly. If I use an external Senheiser, or similar, mic will the sound levels improve?
Regards from Oz.

I've seen a similar complaint here earlier but don't remember if it was resolved. I don't know what kind of stuff you're recording, but I have never tried shooting dialog with my PDX-10. I have used the mono mike on one channel while feeding the other from the sound board when shooting our operas.

After getting burned a few times with loud spikes causing distortion I tend to leave the channel from the house board on auto level. This seems to work reasonably well - when the sound guy feeds me a 0dB 1khz tone it registers around -15dB on the PDX-10 meter. I put the on-camera mike on manual and set it around the middle of the volume range which seems to give a comparable level.

But in post I do boost the levels, typically between 6 to 9 dB. The audio still sounds very clean with no objectionable background noise. If you don't want to do this, and if the levels seem too low then you might need a different sort of mike i suppose. Maybe someone else can recommend one?

Thanks for your comments Boyd.
Any sound recorded, dialog or general background sounds are very low. Never had that experience with any other camera and my conclusion is that there is something wrong with my PDX10.

> Any sound recorded, dialog or general background sounds are
> very low. Never had that experience with any other camera and
> my conclusion is that there is something wrong with my PDX10.

Make sure the hotshoe cable that connects the XLR module to the body of the camera is well seated. It's supposed to make an alarmingly loud click when it fits. I didn't get it right the first time and didn't work.

I have checked the hotshoe setting. Yes it does make a loud click and then watched the sound bars to see that the XLR is operational. If I play the tape from the camera straight to the TV or the Mac through FCE you can hardly hear the sound. I increased the level by 9db as Boyd suggested and burnt a dvd with seven minutes of my tests. The sound is good and clean. Is that how these cameras are supposed to operate?
Regards Spyros

Unless I am mistaken, a level of -12dB on digital video should equal a level of 0dB on analog equipment. Digital levels are intentionally held low as anything beyond 0dB causes clipping whereas analog equipment is more forgiving.

Audio is not really my thing.... Perhaps the audio forum would be a good place to ask this sort of question?

I did a quick check on the sound today and it seems that I have exactly the same "problem". The external mic is very low (specially in automatic), wheras the internal seems to be ok.. On the PD150 (same mic) the levels are higher. If you switch to manual, I got quiet satifying results, but the risk to peak over is quiet high

BTW: Unless you are recording from any other external source like some line (like Boyd on the Opera) or 'tie-mic' when performing ITVs, connect the external mic to have a "security source" or surrounding sounds would be a good idea, but

- is there a point to use the external mic only as the quality of the internal stereo mic seems to be quiet ok??
- is there any way to get the external mic on one track and the internal mixed up on the other? (guess no and I am dreaming here)

I'm sure you may already have checked this, but...

'INPUT LEVEL' switch on the XLR module: Is it set to 'MIC ATT'? Try 'MIC' if it is...

>To adjust sound levels in post will take to much time and be too fiddly.<

Hmmm. Audio is so often neglected and can make or break whatever you are trying to achieve. Whatever mics you use - cheap or exorbitant - it is, IMHO, worth putting aside plenty of time for audio. A touch of compression; EQ where needed and balancing the levels throughout really makes a difference.

Good luck, and my regards to Oz

K

I just did a few tests. If you can duplicate these it will tell you whether our cameras perform the same. As to whether these results are reasonable, that would probably be a better topic to discuss in the audio forum...

Using FCP I generated a 1khz tone. I adjusted my studio monitors so I had a Sound Pressure Level of ~85 db sitting at my normal distance. This was measured by my Radio Shack digital sound level meter set for C weighting.

Now I held my PDX-10 the same distance from the audio monitors, used the mono mike on input 2 which I set to automatic. Looking at the audio level display on the camera, it registered about -3 dB. Now I switched input 2 to manual mode and adjusted the gain until the camera display indicated -3 dB. That resulted in a gain setting of 5 clicks to the right of center (there are a total of 16 possible clicks right of center).

Do you have a meter and a tone source such that you can duplicate this test? Here in the US they're available at "Radio Shack" for $50, and would probably be a good investment since sound levels are a concern of yours.

Actually this test makes me feel pretty good and validates some things I'm already doing. When I record opera I use the sound board feed in one channel set for AUTO. I had the sound guy send me a 0dB analog tone and noted the auto level read about -15 dB. I put the mono mike on the other channel set for MANUAL with the gain in the center. I note that this gives a pretty comparable reading to the board feed during the show (eg -15 dB). Just now using my 85 dB 1 khz tone I tried setting the mike level at the center of the scale and saw the camera displayed an audio level of about -15 dB.

Anyway, from the very little that I know about audio, this seems reasonable and the sound quality of the camera sounds good to me. I also recall that when DV magazine reviewed the PDX-10 they singled out the audio as being especially good. I wouldn't think you'd want to draw too many comparisons to audio performance on the PD-150 since it's audio quality has been the subject of a lot of controversy. Perhaps they run the mike at a higher level to overcome a noisy preamp or something?

Hope some of this helps, and let me know if you can do a similar test.

thanks for this check,
I unfortunetaly can't perform a test like this, but it sounds really interesting. I do not want to compare the sound with the PD150 (had loads of problems, HISS etc), let's stick to our PDX10...
I am checking out these days more about the sound and therefore as well the levels, but I am not really worried about the low levels I must say. If in any case the levels seems to be too low on the XLR you always can level them manually, if you are using only one mic, then you can even have on track a bit lower and one track some more aggressive...
Kevin, I agree with you, Audio is really important, either the direct sound or the sounddesign in the post - for me it's 50 image / 50 sound, sometimes changing a bit concerning the project of course ;)

Something else to consider, are you running this mic to both channels or just one at a time. There is that setting that allows you to capture sound on both L and R (1 and 2) from the Ch 1 source. This may be affecting it but not likely. If it is then there is some sort of preamp issue there I would think.

The other thing to remember is, this is a shotgun mic and not an omni type hand mic. They have a tighter pattern and like a pair of binoculars or a spotting scope, they need to be pointed pretty accuratly at the subject matter. You probably know all that.

I don't know what the published sensativity is on the standard mic. Per the Full Compass web site, here are the specs from Sony on the ECM670. Per Sony this is the mic that ships with all DSR-PDX10 cameras.

http://external.fullcompass.com/ImageFromDB.aspx?imgid=1134&srctbl=doc

Check the pattern and sensativity for more clues. Seems OK though.

Sean

last weekend, i adjusted my pdx10's line 1 input to -12dB at 1KHz coming from a mixer. i set input to LINE levels.

now, my captured footage in FCP has very low audio levels. should i have used MIC levels?

does anybody have the right recipe?
thanks

juani

Juan, according to everything I've read you did the right thing. The concept of "very low levels" may be deceiving. What was the reading on the VU meter on the audio mixer. As I understand, it should read 0 dB at the same time as your camera reports -12 dB. Then the assumption would further be that as the sound engineer mixes the program he does so in a fashion that the loudest peaks read between 0dB and +3dB on his analog meter. Obviously if the mix level is low then your recorded level will be low.

I see that you're running FCP. The manual has a very good section (or at least I found it helpful) that discusses this topic. I'm running FCP 3, so it may be covered in a different section if you have a newer version. In my manual this is covered in "Final Cut Pro 3 User's Manual, Vollume 2: Editorial" See the topics in chapter 6 "Working with audio" which include:

Evaluating the audio in your program
Basic audio concepts
Setting proper audio levels
Settings that affect audio in Final Cut Pro

My feeling beyond this would be to raise the generic issue of "what are reasonable audio levels for DV" in the audio forum since I think the concepts would apply to almost any camera.

the audio on the PDX10 is very good, very clean.

BUT, it's low if you expect it to be used as a catch all mic.

The shotgun provided has a limited range and direction. Keep that in mind. A simple test would be to just put a larger and higher end mike, like a Sienheiser ME-66 and compare it with the supplied mike and you'll see what I mean.

So you may have to play around to find the optimal distance.

Messing around with the audio levels in manual would be good under well controlled conditions.

Messing around with the audio levels in manual would be good under well controlled conditions.

Ronald do you suggest using auto not manual sound?
I have tested the sound with a Senheiser connected through the mic input, that particular senheiser did not have XLR, and yes the sound was completely different and much louder. It picked up sound from a wider spectrum. Thanks for your input.

I can also confirm the low level of the supplied PDX10P mike on auto. Whilst the quality is good, the auto level is unacceptably low.

To me, this is a Sony design shortcoming (along with the 48KHZ stereo capture problem).

I found this out the hard way (my fault for not testing) after shooting a 100th Birthday celebration. I was using Ch1 to two channel.

Fortunately I was able to lift the level in post. I have since tried the manual settings and foumd they need to be almost at maximum.

I feel the auto level should be at least similar to the inbuilt stereo mikes.

Thanks Ron,
This was the answer I was looking for. The auto level is unacceptably low with the external mike supplied and yes on manual I too have to set the settings to maximum.
When I got the camera & tested it I thought there was something wrong with it. The dealer said that this is how the camera behaves and you have now confirmed that for me. Maybe it is a problem with the PAL models.
Regards

I have this XLR problem too and it is very difficult to check the audio level while shooting. The supplied Sony mic seems quite useless from this point of view, even with careful directional aiming.

I am afraid to use the manual adjustment in live shooting conditions as I sometimes cannot adjust down quickly enough if the live sound source suddenlyl changes.

I tried attaching a Sennheiser microphone ME-80 with a couple of different modules (shot gun and omni directional) using the XLR inputs (trying auto and manula) and the level was real low. I had to revert to the mini-jack to get a good level.

Oddly enough when I use my Comtek wireless mic, with the XLR connection for the receiver unit, I don't have any problems with the level. I'm not sure why this is so.

I thought it might be worth revisiting this thread since I just shot another performance using an audio feed from the house board. I am always paranoid about getting a loud spike that overloads (which ruined a couple nice shots on my VX-2000), so for the past year I always used the auto level setting. But after editing these tapes the sound levels seemed lower than necessary. For one thing, this means I can't make a Q&D dub on my DVD recorder without first capturing and then boosting levels.

So this time I talked to the sound guy and learned that the feed he gives me hardly ever peaks above 0dB on his board. So I set manual level on the camera to his 1 khz tone which registered 0dB on his meter. When I turned the volume up to the max on the PDX-10 it showed a reading of about -6dB. After quickly reviewing the tape it appears that the highest transient peaks are no greater than -3 dB and it sounds very good.

Just for safety I set the input for ch1+ch2 mono, and kept the other channel on auto. As I review the tape, the auto level seems to be consistently 8 dB lower than the manual level. I think the auto setting is merely a limiter since I don't see any compression or expansion when comparing the response of the VU meters on both tracks. Although it really doesn't seem to do anything since the levels never approach the point where limiting is needed.

Anyway, I'd have to agree that the sound levels on the PDX-10 are pretty low but as as practical matter it doesn't seem to create a problem for me. The fact to keep in mind is that when using manual adjustment at the max and line level input through the XLR's, an analog 0dB 1khz tone only registers about -6dB on the PDX-10. This same tone will register around -15 dB if you set the XLR for auto level.

Boyd,

The problem is not that the PDX10 records at low leves, the problem is the lower signal-to-noise (S/N) ratio. This is easily noticed when you try to boost the audio in post, and hear a higher background noise.

Btw, I am bit surprised that you use Auto levels!

One should use Auto or AGC levels as a last resort when recording controlled events, for instance when you don't have time to setup your gear.

And this is why:

1) One does NOT have control over the audio being recorded.

2) Recorded sound lacks dynamics and tend to sound monotone, that is because the Auto mode acts as a compressor (boosting for low levels, quiting high levels)

3) The PDX10's on-board AGC circuit is NOT the best quality piece of electronics. At best, it's a good limiter.

On the other hand, unpredictable events (receptions, sports, riots) can have unpredictable volume levels. In that case, AGC can save you from recording too hot of a signal and getting distortion. Besides, background noises are often considered a part of breaking events... that will be unacceptable for dialog.

I found, when using the XLR adaptor and its shotgun mic, that MIC levels gives me the "richest" sound. Adjusting a 1Khz tone @ -12dB is a pretty safe bet. The reason being is that the pre-amps work best in that region, i.e. they have a better linear response at that setting. Whereas using LINE levels, the sound becomes boring and noisier, at least to my perception.

The key is to find out what is the region where those pre-amps work best for your specific audio input. Namely, the region where they have a linear response with higher S/N ratio.

<<<-- Originally posted by Juan Parra : Btw, I am bit surprised that you use Auto levels!

Now that I've done a show and seen the full range in manual mode I will not be using auto anymore. When using my VX-2000 with Beachtek DXA-4 the levels from the same sound board feed were much "hotter" and resulted in distortion a couple times, making my gun shy. Opera has a pretty large dynamic range, from a soft aria to a huge chorus with full orchestra blaring.

<<<-- Originally posted by Juan Parra : 2) Recorded sound lacks dynamics and tend to sound monotone, that is because the Auto mode acts as a compressor (boosting for low levels, quiting high levels)

Certainly the case on my VX-2000, but as mentioned above, I don't see or hear this on the PDX-10 using line level. And if you read other posts on this topic people are complaining that Auto Level is too low, indicating that it doesn't do expansion.

<<<-- Originally posted by Juan Parra : The key is to find out what is the region where those pre-amps work best for your specific audio input.

In my case this seems to work best when I set a 1khz 0dB tone from the house board such that it registers -6 dB on my PDX-10. This way the really loud segments with chorus peak around -6dB and only a few brief transients hit -3dB. But more of a "normal" section of the opera is in the -12dB range. As you say however, it's best for everyone to experiment around and find the best combination for their specific application.

<<-- Now that I've done a show and seen the full range in manual mode I will not be using auto anymore. When using my VX-2000 with Beachtek DXA-4 the levels from the same sound board feed were much "hotter" and resulted in distortion a couple times, making my gun shy. Opera has a pretty large dynamic range, from a soft aria to a huge chorus with full orchestra blaring.-->>>

There you go, you seemed to have better pre-amps with the beachtech.

<<<-- Certainly the case on my VX-2000, but as mentioned above, I don't see or hear this on the PDX-10 using line level. And if you read other posts on this topic people are complaining that Auto Level is too low, indicating that it doesn't do expansion-->>>

Actually, I did a little more research on the AGC, and it seems it's just a hard limiter:

http://www.sounddevices.com/tech/pd150.htm

<<<--In my case this seems to work best when I set a 1khz 0dB tone from the house board such that it registers -6 dB on my PDX-10. This way the really loud segments with chorus peak around -6dB and only a few brief transients hit -3dB. But more of a "normal" section of the opera is in the -12dB range. As you say however, it's best for everyone to experiment around and find the best combination for their specific application. -->>>

Hmmm...you might still have room for improvement, since you seem to be working those amps in the non-linear region:

http://www.montagar.com/~patj/scan3.gif

Read this article:

http://www.dv.com/news/news_item.jht...se_feature1102

and see what I mean.

Hi Spyros. Just tried my wireless sony mic and had to put the levels up to maximum to get to -12db - then tries my Sennheiser ME66 and had to put the level done 2 or 3 notches below centre to achieve the same level - hope this helps