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-   Sony TRV950 / PDX10 Companion (https://www.dvinfo.net/forum/sony-trv950-pdx10-companion/)
-   -   PDX10P Sound Levels (https://www.dvinfo.net/forum/sony-trv950-pdx10-companion/30186-pdx10p-sound-levels.html)

Ron Bird August 17th, 2004 03:56 AM

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.

Spyros Sideratos August 26th, 2004 04:15 AM

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

Roger Garcia August 27th, 2004 06:57 PM

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.

Boyd Ostroff October 10th, 2004 07:40 AM

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.

Juan Parra October 10th, 2004 11:06 AM

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.

Boyd Ostroff October 10th, 2004 12:17 PM

<<<-- 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.

Juan Parra October 10th, 2004 04:09 PM

<<-- 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.

Harvey Shiner October 11th, 2004 05:15 AM

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


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