Audio issue question at DVinfo.net

Steve Rosen · January 15th, 2006, 07:58 PM

This is probably a general HDV comment/question, but I'm using an H1 so I'm posting it here.

In one of my first posts in this forum I suggested that HDV may turn out to be a transitional acquisition medium, not because of the picture quality or the GOPs or the compression - but because of the compromises that were made in the audio recording specs.

Recap: I am producing a documentary for television about an artist for which I've received a grant. I have shot SD footage in the past few years of this woman with several cameras - DSR300 and XL2. I am finishing the majority of the shooting with the H1 so I will have an HDV master for future venues.

I am currently editing a trailer to apply for a finishing grant, using material from all three cameras. The audio from the H1 sounded fine to me (which I commented on previously) until I began mixing it yesterday with the SD audio. Side by side, the X1 material sounds tinny, almost like a transistor radio.. it's not THAT bad, but it isn't comparable...

My question is, since I'm not a soundman, what audio filtration in FCP can someone (who's experienced this problem) suggest that will bring out the best quality of what I have?

FYI: All of the audio, SD and HDV, were recorded in the same artist's studio with a Sennheiser 416 on a pole - optimum placement. I am editing in an SD timeline in FCP 5.0.4, currently on a G4 1.25 dual.

Shannon Rawls · January 16th, 2006, 03:31 AM

That's interesting Steve.
I wonder if it's the MPEG1L2 that's doing that, or is it the pre-amps in the camera.

Only way to test it is to record some music from a CD player via rca or xlr connections. One time in HDV mode and one time in DV mode. Slap 'em on a NLE timeline like vegas or in a audio program like Soundforge and then compare the waves and the sound. If they are identical....then it's the pre-amps that's giving you that skinny sound. If one sounds better then the other....then we know it's the format.

That would be a cool test. Especially if the results were posted so we can hear for ourselves.

Also, maybe the sound isn't skinny, but rather the DV recorded audio you have is nice and fat?? What camera was the DV footage recorded with?

- ShannonRawls.com

Steve Rosen · January 16th, 2006, 09:49 AM

Shannon: Good suggestion and I will try something of the kind, although I'm limited at the moment to FCP software and Soundtrack - which should be sufficient though.

The other audio mostly comes from the Sony DSR300, an excellent camera that I still have but seldom use because it's 4x3... Some is from the XL2, which is also excellent by comparison to the H1. That makes me think it can't be the pre-amp, because I would assume (and I could easily be wrong) that Canon wouldn't have cheapened up the audio processing on a successive, and more expensive, camera... Steve Rosen

Pete Tomov · January 16th, 2006, 10:09 AM

Shannon, I tought you said that it is possible to record uncompressed audio using the console software?

Pete Bauer · January 16th, 2006, 12:24 PM

I'm not using the Console Software presently, so can't state with certainty. But I'm pretty sure I remember that it can record in DV as well. If you do that, you'll get PCM audio per the DV spec. Of course, if you want to be recording live video in HDV, that doesn't help much.

Alister Chapman · January 16th, 2006, 12:30 PM

Is your H1 set to record 2 or 4 channels of Audio? If it is set to 4 channels in HDV mode the bit rate is halved to 192Kb per pair of channels compared to 2 channel mode where the pair of channles are 384kb. In DV mode the sampling is reduced to 32k in 4 channel mode and this does sound "tinny".

Steve Rosen · January 16th, 2006, 12:39 PM

Nope, two channels.. never would use four...

January 15th, 2006, 07:58 PM	#1
Steve Rosen Major Player Join Date: Dec 2005 Location: Monterey, California Posts: 895	Audio issue question This is probably a general HDV comment/question, but I'm using an H1 so I'm posting it here. In one of my first posts in this forum I suggested that HDV may turn out to be a transitional acquisition medium, not because of the picture quality or the GOPs or the compression - but because of the compromises that were made in the audio recording specs. Recap: I am producing a documentary for television about an artist for which I've received a grant. I have shot SD footage in the past few years of this woman with several cameras - DSR300 and XL2. I am finishing the majority of the shooting with the H1 so I will have an HDV master for future venues. I am currently editing a trailer to apply for a finishing grant, using material from all three cameras. The audio from the H1 sounded fine to me (which I commented on previously) until I began mixing it yesterday with the SD audio. Side by side, the X1 material sounds tinny, almost like a transistor radio.. it's not THAT bad, but it isn't comparable... My question is, since I'm not a soundman, what audio filtration in FCP can someone (who's experienced this problem) suggest that will bring out the best quality of what I have? FYI: All of the audio, SD and HDV, were recorded in the same artist's studio with a Sennheiser 416 on a pole - optimum placement. I am editing in an SD timeline in FCP 5.0.4, currently on a G4 1.25 dual.

January 16th, 2006, 03:31 AM	#2
Shannon Rawls Major Player Join Date: Nov 2003 Location: Los Angeles, California Posts: 853	That's interesting Steve. I wonder if it's the MPEG1L2 that's doing that, or is it the pre-amps in the camera. Only way to test it is to record some music from a CD player via rca or xlr connections. One time in HDV mode and one time in DV mode. Slap 'em on a NLE timeline like vegas or in a audio program like Soundforge and then compare the waves and the sound. If they are identical....then it's the pre-amps that's giving you that skinny sound. If one sounds better then the other....then we know it's the format. That would be a cool test. Especially if the results were posted so we can hear for ourselves. Also, maybe the sound isn't skinny, but rather the DV recorded audio you have is nice and fat?? What camera was the DV footage recorded with? - ShannonRawls.com __________________ Shannon W. Rawls ~ Motion Picture Producer & huge advocate of Digital Acquisition.

January 16th, 2006, 12:24 PM	#5
Pete Bauer Wrangler Join Date: May 2003 Location: Eagle River, AK Posts: 4,100	I'm not using the Console Software presently, so can't state with certainty. But I'm pretty sure I remember that it can record in DV as well. If you do that, you'll get PCM audio per the DV spec. Of course, if you want to be recording live video in HDV, that doesn't help much. __________________ Pete Bauer The most beautiful thing we can experience is the mysterious. It is the source of all true art and science. Albert Einstein Trying to solve a DV mystery? You may find the answer behind the SEARCH function ... or be able to join a discussion already in progress!

January 16th, 2006, 12:30 PM	#6
Alister Chapman Inner Circle Join Date: Dec 2005 Location: Bracknell, Berkshire, UK Posts: 4,957	Is your H1 set to record 2 or 4 channels of Audio? If it is set to 4 channels in HDV mode the bit rate is halved to 192Kb per pair of channels compared to 2 channel mode where the pair of channles are 384kb. In DV mode the sampling is reduced to 32k in 4 channel mode and this does sound "tinny". __________________ Alister Chapman, Film-Maker/Stormchaser http://www.xdcam-user.com/alisters-blog/ My XDCAM site and blog. http://www.hurricane-rig.com

January 16th, 2006, 09:49 AM	#3
Steve Rosen Major Player Join Date: Dec 2005 Location: Monterey, California Posts: 895	Shannon: Good suggestion and I will try something of the kind, although I'm limited at the moment to FCP software and Soundtrack - which should be sufficient though. The other audio mostly comes from the Sony DSR300, an excellent camera that I still have but seldom use because it's 4x3... Some is from the XL2, which is also excellent by comparison to the H1. That makes me think it can't be the pre-amp, because I would assume (and I could easily be wrong) that Canon wouldn't have cheapened up the audio processing on a successive, and more expensive, camera... Steve Rosen

January 16th, 2006, 10:09 AM	#4
Pete Tomov Regular Crew Join Date: Sep 2005 Posts: 106	Shannon, I tought you said that it is possible to record uncompressed audio using the console software?

January 16th, 2006, 12:39 PM	#7
Steve Rosen Major Player Join Date: Dec 2005 Location: Monterey, California Posts: 895	Nope, two channels.. never would use four...