Audio ref. level on HD100 at DVinfo.net

Paul Jefferies · October 24th, 2006, 06:38 AM

Hi,
Could someone clarify something to me re: HD100 audio ref. level -
It is preset to -20dB, I'm assuming this is the optimal level for HDV
however, am I right in saying that, if you are recording in DV mode, you should set the level to -12dB?
The reason I ask is that we shot something yesterday in DV mode and the recordings were too low (we used auto levels)
or is it somehow due to the way "auto" works on the HD100?

John Doran · October 24th, 2006, 09:53 AM

good question paul

we will await the reply
jon

Bill Ravens · October 24th, 2006, 10:24 AM

I beleive HDV is specced to use -20dB as a nominal level, at least according to Steve Mullen. What this means is that you want to keep your record level between -26 and -12 dB, leaving headroomm for dynamic transients. The lower the reference level, the higher the actual sound level. The HD100 also has a setting for the sensitivity of the mike used. There are two settings, -50 and -60 dB. You can get a higher mike output by using the lower setting, i.e. -60 dB.

Jiri Bakala · October 24th, 2006, 04:27 PM

Broadcast digital reference is -20dB.

John Doran · October 25th, 2006, 02:28 AM

so is it -20 for hdv and -12 for dv shooting

john

Werner Wesp · October 25th, 2006, 02:31 AM

Actually it is more like this:

In professional and broadcast use it is usually set to -20 dB to create more headroom. Also, professionals are deemed to work with better sound equipment, so the fact that the dynamic range itself is smaller (because it only goes to -20 dB) won't be a huge issue.

For home and consumer use, the lever is standard -12 dB. Here is a smaller headroom, but obviously a wider dynamic range, which is important to make sound recorded with inferior (amateur) equipment useful.

This goes for DV and HDV as well. consumer miniDV is usually set to -12 dB, where miniDV on the professional miniDV camcorders from JVC is set to -20 dB (or -18 dB as a specific requirement for BBC broadcasts as I remember correctly)

Brian Drysdale · October 25th, 2006, 03:34 AM

I suspect this might go back to VU and peak level meters. Broadcasters (in the UK at least) have used PPM (Peak Programme Meters) on which the zero level tone was set at -8 db below peak level. This has been transferred to digital (on which you can't go over 0) so that the zero level reference tone is recorded at -20db, you peak your audio at -12db and you have 12 db of headroom.

In broadcasting, using a peak level meter voices (unless they're shouting) usually peak at around - 6db. That would be around the - 18 db on the meter in the JVC.

On VU meters people often use a reference tone that lined up on the 0 on the meter.

Basically don't use - 20 db as your audio peak level, use -12 db. DV is also a digital format and on the broadcast cameras -20 db ref tone level is used.

BTW The 1000 Hz Reference Tone is used to line up the audio throughout the process. When you're editing you set the tone so that it plays back at -20 db on the video player, so at everything in the audio chain is lined up to play at the correct levels.

If you've got a mixing desk that lines up to - 8 db below your peak level on a peak reading meter, 4 on a PPM (the peak is 6, each unit equals 4 db). It's important that everything in the audio chain is lined up correctly, otherwise you can end up with incorrect levels.

Be careful of mixing peak meters and VU meters, you can end up with low levels doing that.

Unfortunately, the JVC has a rather confusing arrangement on it's V/F audio level bars.

October 24th, 2006, 06:38 AM	#1
Paul Jefferies Major Player Join Date: Nov 2005 Location: Croydon, England Posts: 277	Audio ref. level on HD100 Hi, Could someone clarify something to me re: HD100 audio ref. level - It is preset to -20dB, I'm assuming this is the optimal level for HDV however, am I right in saying that, if you are recording in DV mode, you should set the level to -12dB? The reason I ask is that we shot something yesterday in DV mode and the recordings were too low (we used auto levels) or is it somehow due to the way "auto" works on the HD100?

October 24th, 2006, 09:53 AM	#2
John Doran Major Player Join Date: Jun 2005 Location: belfast, northern ireland. Posts: 210	a good question paul we will await the reply jon

October 24th, 2006, 04:27 PM	#4
Jiri Bakala Major Player Join Date: Apr 2004 Location: Kelowna BC Canada Posts: 706	Broadcast digital reference is -20dB. __________________ www.ascentfilms.com

October 25th, 2006, 02:28 AM	#5
John Doran Major Player Join Date: Jun 2005 Location: belfast, northern ireland. Posts: 210	sound presets so is it -20 for hdv and -12 for dv shooting john

October 24th, 2006, 10:24 AM	#3
Bill Ravens Join Date: Nov 2001 Location: santa fe, nm Posts: 3,264 Images: 10	I beleive HDV is specced to use -20dB as a nominal level, at least according to Steve Mullen. What this means is that you want to keep your record level between -26 and -12 dB, leaving headroomm for dynamic transients. The lower the reference level, the higher the actual sound level. The HD100 also has a setting for the sensitivity of the mike used. There are two settings, -50 and -60 dB. You can get a higher mike output by using the lower setting, i.e. -60 dB.

October 25th, 2006, 02:31 AM	#6
Werner Wesp Major Player Join Date: Aug 2005 Location: Belgium Posts: 497	Actually it is more like this: In professional and broadcast use it is usually set to -20 dB to create more headroom. Also, professionals are deemed to work with better sound equipment, so the fact that the dynamic range itself is smaller (because it only goes to -20 dB) won't be a huge issue. For home and consumer use, the lever is standard -12 dB. Here is a smaller headroom, but obviously a wider dynamic range, which is important to make sound recorded with inferior (amateur) equipment useful. This goes for DV and HDV as well. consumer miniDV is usually set to -12 dB, where miniDV on the professional miniDV camcorders from JVC is set to -20 dB (or -18 dB as a specific requirement for BBC broadcasts as I remember correctly)

October 25th, 2006, 03:34 AM	#7
Brian Drysdale Inner Circle Join Date: Feb 2006 Location: Belfast, UK Posts: 6,143	I suspect this might go back to VU and peak level meters. Broadcasters (in the UK at least) have used PPM (Peak Programme Meters) on which the zero level tone was set at -8 db below peak level. This has been transferred to digital (on which you can't go over 0) so that the zero level reference tone is recorded at -20db, you peak your audio at -12db and you have 12 db of headroom. In broadcasting, using a peak level meter voices (unless they're shouting) usually peak at around - 6db. That would be around the - 18 db on the meter in the JVC. On VU meters people often use a reference tone that lined up on the 0 on the meter. Basically don't use - 20 db as your audio peak level, use -12 db. DV is also a digital format and on the broadcast cameras -20 db ref tone level is used. BTW The 1000 Hz Reference Tone is used to line up the audio throughout the process. When you're editing you set the tone so that it plays back at -20 db on the video player, so at everything in the audio chain is lined up to play at the correct levels. If you've got a mixing desk that lines up to - 8 db below your peak level on a peak reading meter, 4 on a PPM (the peak is 6, each unit equals 4 db). It's important that everything in the audio chain is lined up correctly, otherwise you can end up with incorrect levels. Be careful of mixing peak meters and VU meters, you can end up with low levels doing that. Unfortunately, the JVC has a rather confusing arrangement on it's V/F audio level bars.