Audio Quality

Mike Banks · September 23rd, 2007, 04:36 PM

I must say that when I plug a good Neumann mic in to my A1 it sounds very good. Maybe not as good as it's possible to get but still very good. Matching the mic may be the issue?

:)

Mike

Bill Pryor · September 24th, 2007, 07:51 AM

I use mostly a Sennheiser MKH60 and it sounds great too.

Michael Blieden · October 14th, 2007, 04:59 AM

After reading everyone's suggestions here, and using my A1 on a few more jobs, I'm now quite comfortable with the sound quality when the Mic Att setting is turned on. Thanks all.

Now there's a new problem. Either I never noticed it before, or it never existed before, but when my shotgun (Rhode) is mounted in the shotgun mic clip I hear siginificant hum coming from the camera motor. It took me quite a while to figure out where the hum was coming from actually, but as soon as I took the shotgun out of the mic clip, the hum was gone. I can recreate the hum by simply touching the microhone to the body of the camera. I know that the rubber gaskets inside the mic mount should dampen those vibrations, and if I simply lay the microphone in the clip but don't tighten the screw, then I don't hear the hum. But as soon as I turn the screw to provide enough tension to keep the mic in place, then I hear the hum again.

I have solved this problem by using a shock mount in the hot shoe, but I'd hate to think that my shotgun clip is no good to me any more. Has anyone experienced this?

Peter Jefferson · October 14th, 2007, 05:24 AM

The mount is a mount only, not a dampener as I found out the hard way. Then again, there are no rubber sprockets to separate the mic from the cam.

I had to use some soft foam tape to mount my mics (K6 ME64/66) and it has helped a bit but the mount itself does nothing to stop any camera noise from being picked up.

Does anyone know of any solutions to the on cam mic mount? Such as mounts with proper sized threads and placement of those threads?

Jim Bacus · October 14th, 2007, 08:51 PM

Quote:

Originally Posted by Don Palomaki

Dummy plug (open circuit) inserted in the MIC jack (to disconenct internal mic)

what does this mean? does the A1 leave its internal mic on unless you plug both xlr inputs? I thought it was xlr or internal only- but never both....sadly...

Mark Fry · October 15th, 2007, 04:02 AM

Quote:

Originally Posted by Jim Bacus

what does this mean? does the A1 leave its internal mic on unless you plug both xlr inputs? I thought it was xlr or internal only- but never both....sadly...

In the XH-A1, the moment you choose XLR inputs in the audio menu, the built-in mics and the 3.5mm mic socket are switched off, regardless of whether you plug anything into the XLR sockets. However, when the XLR inputs are not selected, the internal mics are live unless you plug something into the 3.5mm mic socket. Having the choice of internal mics or balanced XLR inputs is pretty useful (compared to e.g. Sony FX7/V1 where you have to choose when you buy the camera) but it is an either/or choice per shot.

Don Palomaki · October 15th, 2007, 08:05 AM

As you tighten the screw on the mic mount, it compresses the rubber damping material. The more it is compressed, the less damping it provides, and the more vibration is transmitted to the mic. In general, the best damping performance is provide when the external mic is loosely held by the clamp.

Don Palomaki · October 15th, 2007, 08:10 AM

Quote:

Dummy plug (open circuit) inserted in the MIC jack (to disconnect internal mic)]

what does this mean? ...

Means that you can disconnect the internal mic without enabling the XLR input jacks by inserting a 3.5mm stereo mini phone plug (with nothing connected to it) in the mic jack. This will result in no sound being recorded to tape, so mainly it serves testing purposes.

Michael Blieden · October 22nd, 2007, 05:02 PM

Quote:

Originally Posted by Don Palomaki

As you tighten the screw on the mic mount, it compresses the rubber damping material. The more it is compressed, the less damping it provides, and the more vibration is transmitted to the mic. In general, the best damping performance is provide when the external mic is loosely held by the clamp.

Don,

This is very true. Last night I performed a test with two different but very common shotgun mics, each screwed firmly in place on the mic mount. In fact, they were very likely screwed in too securely. All the same, I'm going to share my results. I used the Rhode NTG-1 and the Sennheiser MKH 60 (P48).

I ran the audio from my XH A1 directly into my computer, so that I could record the camera's audio signal while the camera was 1)recording, 2)in pause, and 3) in power save mode.

If you are listening with headphones, you will hear that the Rhode mic picks up much more hum from the camera motor. That being said, I don't know exactly how to interpret the results of this test. I almost always use a shock mount for shotgun mics anyway, and I've recorded lots of audio with my Rhode and I've always been happy with the results.

The simplest conclusion I can draw is to follow Don's advice and avoid clamping down too hard on the mic.

To hear my results go here:

http://www.theclawproductions.com/test/MicMountTest.mov

Andrew Rowe · October 29th, 2007, 07:40 PM

Microphone positioning is a MUCH more significant factor than the A1's noise floor.

A couple of the posts here suggest that the A1 doesn't record PCM sound. It does - when you are recording SD video - and just as well as other camcorders of its ilk.

It's impossible, as someone else mentioned, to tell the difference between PCM and the slightly compressed audio of the HDV format. But it's also true that any compression will be exaccerbated in post by further compression (for broadcast or for the internet). I don't think this is a big deal though - the audio compression of the format certainly won't ever be as apparent to the ears as the video compression of HDV is to the eyes! (Of course, if you were shooting for TV broadcast, you'd probably be filming in SD anyway, so the sound would be PCM in the first place.)

I don't think the A1 is particularly noisy when correctly set up. It's probably not advisable to record onto a camcorder for anything intended to be played loud through, say, cinema speakers - but for TV and PC playback, it's not bad at all.

The only thing I really dislike about the camera's audio is the peculiar insensitivity of the line inputs, and the counter-intuitive gain pots.

Bill Pryor · October 29th, 2007, 08:31 PM

I agree--the damn pots are backwards.

Paul Joy · October 30th, 2007, 10:44 AM

Quote:

Originally Posted by Andrew Rowe

A couple of the posts here suggest that the A1 doesn't record PCM sound. It does - when you are recording SD video - and just as well as other camcorders of its ilk.

I didn't know that, I used my camera to record some voice over a couple of weeks back and although I think the sound was great (using a Sen MKH-416) it's useful to know that selecting SD mode would have helped too.

Thanks for the tip

Paul.

Petri Kaipiainen · October 30th, 2007, 12:20 PM

To clarify: when shooting SD the audio is DV standard 16 bit 48 kHz sample rate uncompressed pcm wav, better than CD in theory.

When shooting HDV the audio is compressed to MP2 at about 1:5 ratio. This is the unfortunate side effect of fitting (near) HD data to a miniDV tape. This is the same with all HDV cameras.

For critical HDV work use external audio recorder at 16/48 (or 24/48 and convert to 16/48 for edit).

About hiss: you have to listen to clean sample to judge the real quality of the audio. Often camera headphone amplifiers are noisy, as are PC based edit systems. Connect the camera to TV and hifi stereo system to hear what the audio on tape is really like.

Don Palomaki · November 23rd, 2007, 04:42 PM

For Jeff Johnson's reference.

http://www.dvinfo.net/conf/showthread.php?t=89879 provides information on noise levels.

Eric Casper · November 24th, 2007, 12:31 AM

just a question. i am new to the whole video filming thing(just got an XL1 last week), and the processes that are used here. i joined up here in dvinfo.net and have been soaking up as much info about DV filming as i can. when it comes to sound i have a couple questions....

why does anyone attach a mic to a camera?

i have been doing Audio recording as far as music for about ten years now. a couple of those years analog and the rest digital recording with Pro Tools and Cubase. granted its two different worlds, and from the sound of it the tolerances of quiet that you need in recording music is different from the tolerances of quiet you need in recording Video. attaching a microphone to something that has any moving mechanical parts whatsoever sounds crazy. even loosely attached. i suppose if that does the job thats cool. just sounds odd.

why does everyone record sound to the camera?

unless i am wrong when you run all of the sound right to the camera its recorded along with the video. imbedded in with the MPEG4 or on the MiniDV(in my case). i suppose if people are just using one mic on a pole, or attached to a camera, its not much to worry about. but if you are using multiple mics to capture better sound, and perhaps ambient noise, wouldnt it be better to record it to separate tracks on another audio device? that way each microphone track could be altered in post. perhaps one mic track needs a noise gate/limiter because of one instant where the sound redlined, or its too quiet/loud, or needs different compression levels, or really anything. i have never tried syncing audio to video so maybe therein lies the answer why its recorded straight to the camera. but i would imagine avid/protools does a good job of syncing sound.

i guess i am used to putting five mics around a room to record a guitar amp and tweaking the sound of all five to get something distinct. all of that nonsense isnt neccessary in the filming. still it would be nice to record serveral digital tracks and have the option of doing whatever you needed to sound later instead of recording two or more mics through a mixer to a camera where you lose track individuality.

these are the ramblings of a newbie so if they dont make sense or i am way off on something i apologize now.

September 23rd, 2007, 04:36 PM	#31
Mike Banks New Boot Join Date: Apr 2007 Location: Oxford, UK Posts: 19	I must say that when I plug a good Neumann mic in to my A1 it sounds very good. Maybe not as good as it's possible to get but still very good. Matching the mic may be the issue? :) Mike __________________ http://www.RecordProduction.com http://www.RecordProduction.smugmug.com

October 14th, 2007, 04:59 AM	#33
Michael Blieden New Boot Join Date: May 2007 Location: Los Angeles Posts: 15	sound update - good news and a new wrinkle After reading everyone's suggestions here, and using my A1 on a few more jobs, I'm now quite comfortable with the sound quality when the Mic Att setting is turned on. Thanks all. Now there's a new problem. Either I never noticed it before, or it never existed before, but when my shotgun (Rhode) is mounted in the shotgun mic clip I hear siginificant hum coming from the camera motor. It took me quite a while to figure out where the hum was coming from actually, but as soon as I took the shotgun out of the mic clip, the hum was gone. I can recreate the hum by simply touching the microhone to the body of the camera. I know that the rubber gaskets inside the mic mount should dampen those vibrations, and if I simply lay the microphone in the clip but don't tighten the screw, then I don't hear the hum. But as soon as I turn the screw to provide enough tension to keep the mic in place, then I hear the hum again. I have solved this problem by using a shock mount in the hot shoe, but I'd hate to think that my shotgun clip is no good to me any more. Has anyone experienced this?

October 15th, 2007, 08:05 AM	#37
Don Palomaki Wrangler Join Date: Sep 2001 Location: Northern VA Posts: 4,488	As you tighten the screw on the mic mount, it compresses the rubber damping material. The more it is compressed, the less damping it provides, and the more vibration is transmitted to the mic. In general, the best damping performance is provide when the external mic is loosely held by the clamp. __________________ dpalomaki@dspalomaki.com

November 23rd, 2007, 04:42 PM	#44
Don Palomaki Wrangler Join Date: Sep 2001 Location: Northern VA Posts: 4,488	For Jeff Johnson's reference. http://www.dvinfo.net/conf/showthread.php?t=89879 provides information on noise levels. __________________ dpalomaki@dspalomaki.com

November 24th, 2007, 12:31 AM	#45
Eric Casper New Boot Join Date: Nov 2007 Location: Harrisburg PA Posts: 19	hmm just a question. i am new to the whole video filming thing(just got an XL1 last week), and the processes that are used here. i joined up here in dvinfo.net and have been soaking up as much info about DV filming as i can. when it comes to sound i have a couple questions.... why does anyone attach a mic to a camera? i have been doing Audio recording as far as music for about ten years now. a couple of those years analog and the rest digital recording with Pro Tools and Cubase. granted its two different worlds, and from the sound of it the tolerances of quiet that you need in recording music is different from the tolerances of quiet you need in recording Video. attaching a microphone to something that has any moving mechanical parts whatsoever sounds crazy. even loosely attached. i suppose if that does the job thats cool. just sounds odd. why does everyone record sound to the camera? unless i am wrong when you run all of the sound right to the camera its recorded along with the video. imbedded in with the MPEG4 or on the MiniDV(in my case). i suppose if people are just using one mic on a pole, or attached to a camera, its not much to worry about. but if you are using multiple mics to capture better sound, and perhaps ambient noise, wouldnt it be better to record it to separate tracks on another audio device? that way each microphone track could be altered in post. perhaps one mic track needs a noise gate/limiter because of one instant where the sound redlined, or its too quiet/loud, or needs different compression levels, or really anything. i have never tried syncing audio to video so maybe therein lies the answer why its recorded straight to the camera. but i would imagine avid/protools does a good job of syncing sound. i guess i am used to putting five mics around a room to record a guitar amp and tweaking the sound of all five to get something distinct. all of that nonsense isnt neccessary in the filming. still it would be nice to record serveral digital tracks and have the option of doing whatever you needed to sound later instead of recording two or more mics through a mixer to a camera where you lose track individuality. these are the ramblings of a newbie so if they dont make sense or i am way off on something i apologize now.

September 24th, 2007, 07:51 AM	#32
Bill Pryor Contributor Join Date: Jan 2003 Location: Kansas City, MO Posts: 4,449	I use mostly a Sennheiser MKH60 and it sounds great too.

October 14th, 2007, 05:24 AM	#34
Peter Jefferson Inner Circle Join Date: Apr 2003 Location: Aus Posts: 3,884	The mount is a mount only, not a dampener as I found out the hard way. Then again, there are no rubber sprockets to separate the mic from the cam. I had to use some soft foam tape to mount my mics (K6 ME64/66) and it has helped a bit but the mount itself does nothing to stop any camera noise from being picked up. Does anyone know of any solutions to the on cam mic mount? Such as mounts with proper sized threads and placement of those threads?

October 29th, 2007, 07:40 PM	#40
Andrew Rowe Regular Crew Join Date: Jan 2007 Location: London, UK Posts: 39	Microphone positioning is a MUCH more significant factor than the A1's noise floor. A couple of the posts here suggest that the A1 doesn't record PCM sound. It does - when you are recording SD video - and just as well as other camcorders of its ilk. It's impossible, as someone else mentioned, to tell the difference between PCM and the slightly compressed audio of the HDV format. But it's also true that any compression will be exaccerbated in post by further compression (for broadcast or for the internet). I don't think this is a big deal though - the audio compression of the format certainly won't ever be as apparent to the ears as the video compression of HDV is to the eyes! (Of course, if you were shooting for TV broadcast, you'd probably be filming in SD anyway, so the sound would be PCM in the first place.) I don't think the A1 is particularly noisy when correctly set up. It's probably not advisable to record onto a camcorder for anything intended to be played loud through, say, cinema speakers - but for TV and PC playback, it's not bad at all. The only thing I really dislike about the camera's audio is the peculiar insensitivity of the line inputs, and the counter-intuitive gain pots.

October 29th, 2007, 08:31 PM	#41
Bill Pryor Contributor Join Date: Jan 2003 Location: Kansas City, MO Posts: 4,449	I agree--the damn pots are backwards.

October 30th, 2007, 12:20 PM	#43
Petri Kaipiainen Major Player Join Date: Apr 2007 Location: Espoo Finland Posts: 380	To clarify: when shooting SD the audio is DV standard 16 bit 48 kHz sample rate uncompressed pcm wav, better than CD in theory. When shooting HDV the audio is compressed to MP2 at about 1:5 ratio. This is the unfortunate side effect of fitting (near) HD data to a miniDV tape. This is the same with all HDV cameras. For critical HDV work use external audio recorder at 16/48 (or 24/48 and convert to 16/48 for edit). About hiss: you have to listen to clean sample to judge the real quality of the audio. Often camera headphone amplifiers are noisy, as are PC based edit systems. Connect the camera to TV and hifi stereo system to hear what the audio on tape is really like.