XLR auto input level on the V1 at DVinfo.net

Piotr Wozniacki · February 26th, 2007, 06:19 AM

Do you guys also find the auto input level for the supplied shotgun too low on the V1, or is it just me?

Jiri Bakala · February 26th, 2007, 10:27 AM

Not at all. Are you using manual or auto setting? Also, what level is the input set to - Mic or Line?

John Cline · February 26th, 2007, 10:29 AM

The shotgun supplied with the V1 has a fairly low output anyway. I generally use an Audio Technica AT-825 stereo microphone. The 825 always had plenty of output to get decent levels near 0db on my PD150, but on the V1 with automatic gain, the 825's peak levels hit at around -20db.

The audio section of the V1 is a disappointment. Besides the gain issue, it is noisy regardless of input level.

John

Piotr Wozniacki · February 26th, 2007, 11:14 AM

Quote:

Originally Posted by Jiri Bakala

Not at all. Are you using manual or auto setting? Also, what level is the input set to - Mic or Line?

Of course the input is set to mic, and I'm asking about auto settings. It seems to provide very low sound; is it normal? Do most of you set in to manual and crank it up?

Timo Mukari · February 26th, 2007, 11:28 AM

I noticed this too, the supplied mic gives quite low signal on auto. The Rode mic gives clearly higher level.

Jiri Bakala · February 26th, 2007, 02:59 PM

In auto settings I would expect the peaks to be around -20 dB and since the meters don't have units it's impossible to know for sure where they are hitting. Maybe someone with the HVR-M25 deck could confirm this. I would guess that the peaks are in the correct vicinity and with the camcorder I had here, they were certainly not low. However, if you expect -12 dB or even higher, than perhaps the levels are a bit low but -12 dB is a consumer level and all professional equipment uses -20 dB as a nominal volume giving the recording a lot of headroom.

Piotr Wozniacki · February 26th, 2007, 03:28 PM

Jiri, in fact when I play clips in Vegas, the audio monitor shows peaks at around -20dB. I didn't know this level is standard for professional camcorders; thanks.

The Canon A1's internal mic is operating much louder, though.

Martin Saxer · February 28th, 2007, 02:59 AM

Quote:

Originally Posted by John Cline

The audio section of the V1 is a disappointment. Besides the gain issue, it is noisy regardless of input level.
John

John,
would you say it's much worse than the on the PD150? Would you be able to post an audio sample of the two?

Martin

Bob Grant · February 28th, 2007, 06:02 AM

Well with the camera in auto the levels are way lower than say the PD150 in auto and I'm pretty certain that out of the box they both use the same mic.

As for setting the level to -20dB, that's kind of a bad thing to be doing, you're reducing your headroom and on these cameras that's a really bad move as the noise floor is pretty high and adding gain to mpeg audio is also a bad move.
What happens in all these cameras with the Audio Ref level st to -20dB in Auto is the AGC limits the peaks to -20dB, not the average, which is where the -20dB things comes from.

Tradionally in the land of analogue audio the VU meters were set to read 0 VU at -20dB, actually that was -16dBm as 0dB was +4dBm. That gave you 20dB headroom between average and peak program. This doesn't really work so well in the digital domain with peak reading meters and DV and things get much worse with HDV where adding any gain in post exposes the limits of the encoding .
We change all our DV cams where possible to set the reference level to -12dB, that gives us 8dB more S/N which sure doesn't go astray. This helps if the cams are run with AGC on and doesn't make any difference with AGC off when you ride the gain and watch the meters as the meters display peak and are unaffected by the reference level setting.

February 26th, 2007, 06:19 AM	#1
Piotr Wozniacki Inner Circle Join Date: Aug 2006 Location: Poland Posts: 4,086	XLR auto input level on the V1 Do you guys also find the auto input level for the supplied shotgun too low on the V1, or is it just me? __________________ Sony PXW-FS7 \| DaVinci Resolve Studio; Magix Vegas Pro; i7-5960X CPU; 64 GB RAM; 2x GTX 1080 8GB GPU; Decklink 4K Extreme 12G; 4x 3TB WD Black in RAID 0; 1TB M.2 NVMe cache drive

February 26th, 2007, 10:27 AM	#2
Jiri Bakala Major Player Join Date: Apr 2004 Location: Kelowna BC Canada Posts: 706	Not at all. Are you using manual or auto setting? Also, what level is the input set to - Mic or Line? __________________ www.ascentfilms.com

February 26th, 2007, 02:59 PM	#6
Jiri Bakala Major Player Join Date: Apr 2004 Location: Kelowna BC Canada Posts: 706	In auto settings I would expect the peaks to be around -20 dB and since the meters don't have units it's impossible to know for sure where they are hitting. Maybe someone with the HVR-M25 deck could confirm this. I would guess that the peaks are in the correct vicinity and with the camcorder I had here, they were certainly not low. However, if you expect -12 dB or even higher, than perhaps the levels are a bit low but -12 dB is a consumer level and all professional equipment uses -20 dB as a nominal volume giving the recording a lot of headroom. __________________ www.ascentfilms.com

February 26th, 2007, 03:28 PM	#7
Piotr Wozniacki Inner Circle Join Date: Aug 2006 Location: Poland Posts: 4,086	Jiri, in fact when I play clips in Vegas, the audio monitor shows peaks at around -20dB. I didn't know this level is standard for professional camcorders; thanks. The Canon A1's internal mic is operating much louder, though. __________________ Sony PXW-FS7 \| DaVinci Resolve Studio; Magix Vegas Pro; i7-5960X CPU; 64 GB RAM; 2x GTX 1080 8GB GPU; Decklink 4K Extreme 12G; 4x 3TB WD Black in RAID 0; 1TB M.2 NVMe cache drive

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February 26th, 2007, 10:29 AM	#3
John Cline Major Player Join Date: Oct 2002 Location: Albuquerque, New Mexico USA Posts: 333	The shotgun supplied with the V1 has a fairly low output anyway. I generally use an Audio Technica AT-825 stereo microphone. The 825 always had plenty of output to get decent levels near 0db on my PD150, but on the V1 with automatic gain, the 825's peak levels hit at around -20db. The audio section of the V1 is a disappointment. Besides the gain issue, it is noisy regardless of input level. John

February 26th, 2007, 11:28 AM	#5
Timo Mukari New Boot Join Date: Nov 2006 Location: Oulu, Finland Posts: 20	I noticed this too, the supplied mic gives quite low signal on auto. The Rode mic gives clearly higher level.

February 28th, 2007, 06:02 AM	#9
Bob Grant Trustee Join Date: Nov 2005 Location: Sydney Australia Posts: 1,570	Well with the camera in auto the levels are way lower than say the PD150 in auto and I'm pretty certain that out of the box they both use the same mic. As for setting the level to -20dB, that's kind of a bad thing to be doing, you're reducing your headroom and on these cameras that's a really bad move as the noise floor is pretty high and adding gain to mpeg audio is also a bad move. What happens in all these cameras with the Audio Ref level st to -20dB in Auto is the AGC limits the peaks to -20dB, not the average, which is where the -20dB things comes from. Tradionally in the land of analogue audio the VU meters were set to read 0 VU at -20dB, actually that was -16dBm as 0dB was +4dBm. That gave you 20dB headroom between average and peak program. This doesn't really work so well in the digital domain with peak reading meters and DV and things get much worse with HDV where adding any gain in post exposes the limits of the encoding . We change all our DV cams where possible to set the reference level to -12dB, that gives us 8dB more S/N which sure doesn't go astray. This helps if the cams are run with AGC on and doesn't make any difference with AGC off when you ride the gain and watch the meters as the meters display peak and are unaffected by the reference level setting.