Audio hiss at DVinfo.net

Evan Mann · October 8th, 2007, 04:34 PM

I imported an entire hour of footage using Vegas. I then took that and put it through Nero Vision 5. All the audio appears to have a hiss through it. Onboard mic is used.

Is this inherant to the onboard mic, or perhaps something Nero Recode induced?

Michael Jouravlev · October 8th, 2007, 04:45 PM

Haven't you listened to the sound when you were working on your project in Vegas?

Evan Mann · October 8th, 2007, 05:34 PM

Quote:

Originally Posted by Michael Jouravlev

Haven't you listened to the sound when you were working on your project in Vegas?

I didn't use Vegas for anything except pulling the footage off the camera. I needed to get the video out to the family (my daughter) and didn't have a lot of time to play around.

I just talked to a friend who has an HV20 who has done some re-mastering to DivX and I listened to some clips. He has the same hiss.

Matthias Krause · October 8th, 2007, 06:15 PM

The HV20 pre-amp sucks which is to be expected for a camera in this price range. The built-in mic sucks even more. If you want to manage the hiss you have to get a good external mic and a good pre-amp that allows you to turn the in-camera pre-amp way down. Than the hiss is pretty managable. Or you can shoot double system...

Evan Mann · October 8th, 2007, 06:21 PM

Quote:

Originally Posted by Matthias Krause

The HV20 pre-amp sucks which is to be expected for a camera in this price range. The built-in mic sucks even more. If you want to manage the hiss you have to get a good external mic and a good pre-amp that allows you to turn the in-camera pre-amp way down. Than the hiss is pretty managable. Or you can shoot double system...

I'm familiar with external mic's as I've researched some of those previously. But I'm not sure about the pre-amp's. How exactly does that mount up to the camera when using it? Does it add a lot of weight/bulk?

Slava Barouline · October 8th, 2007, 08:02 PM

You can try to use EQ in Vegas to remove the hiss

I have build a simple pre-amp some time ago - maybe I will give it a try with external mic

Deke Kincaid · October 8th, 2007, 10:05 PM

record in an empty room with no sound which will essentially be just the hiss by itself and then use that as a reference to subtract the hiss from your audio.

Don Palomaki · October 9th, 2007, 06:20 AM

One possible option that works with other Canon camcorders to reduce mic hiss is to use an external mic with a high output level, and use the MIC ATT setting. This usually reduces the noise floor, but relies on high mic output.

Another technique is to use manual audio level control. This can avoid the increase in hiss caused by AGC during quiet parts of the program material.

Allan Black · October 9th, 2007, 06:51 AM

Quote:

Originally Posted by Don Palomaki

One possible option that works with other Canon camcorders to reduce mic hiss is to use an external mic with a high output level, and use the MIC ATT setting. This usually reduces the noise floor, but relies on high mic output.

Another technique is to use manual audio level control. This can avoid the increase in hiss caused by AGC during quiet parts of the program material.

Agreed, and meter peaks up to zero, not -12 as the manual says which I've found is too low and can result in tape hiss.

The HV20 has a great limiter, on all the time. I was standing under some church bells on Rhodes when the things went off, the limiter grabbed them nicely without distortion too. Not a good recording but a good demo.
Cheers.

John Hotze · October 9th, 2007, 08:23 AM

Now that it's all said and done, go back & play the master tape with the camcorder and take the A/V output to an amp and listen to what you have on the tape. Don't forget to set the AV/Headphone to headphone in the setup. If you still hear a bad hiss, than you know it's on the master, but if you don't hear it than you can assume the problem lies in your capture application.

To me "hiss" is relative to what is in the normal audio stream. If most of the audio is speech, music, etc., & the his comes into play only during silent periods, than you can more than likely live with it a little easier. I think that everything folks have said about the poor preamp, mic, & post editing solutions are true but I still feel that the built in mic can provide adequate audio in many cases, such as family shoots of birthday parties, vacation, & other family events.

Of course adding a Beachtek and a $150 mic is going to produce better results but it is not necessarily appropriate for the typical family video being shot.

Matthias Krause · October 9th, 2007, 08:38 AM

"How exactly does that mount up to the camera when using it? Does it add a lot of weight/bulk?"
You could start with a Beachtek DXA-FX (http://www.beachtek.com/dxafx.html) which should work. You can mount it under your camera and it adds 16oz. Or you could use a Mixer like the SoundDevice 302 but then you'd have something else to carry and you are in a totally different price league. Both are overkill if you shoot only family videos. But I use my HV-20 professionally and the Beachtek should serve me well (on order...)

John Hotze · October 9th, 2007, 09:46 AM

My XLR-Pro from Signvideo is never separated from my camera. It may add a pound; I'm not sure. It mounts just under the camera and than the tripod mount is screwed into the bottom of the XLR-Pro & in turn slips onto the tripod as needed.

Over ninety percent of my shooting is live music concerts outdoors and shot using a tripod. I've even shot jams around a campfire with two mics giving me stereo. If I'm shooting a concert, I position a single mic on a stand directly in front of one of the speaker farms and run about a 50' XLR cable from the mic to my XLR-Pro.

If I'm shooting jams, such as above, around a campfire, I setup a couple mics each covering half or more of a semi-circle of accoustic instruments & vocalists. It comes out pretty nice. My XLR-Pro has a ground lifter, mic/line level input switches, mono/stereo switch, channel one & two XLR inputs and two aux channel inputs. The output of the adaptor plugs into the mic input on the camera. I always carry a couple mic stands, 2-25' and 2 50' XLR mic cables, and a couple $75 to $150 mics. I'm always on the look out and testing various mics to improve my audio capture. I still think the weakest link in the audio chain is the HDV audio format. Since I only shoot in HDV now, I live with it. I have been taking along my Zoom 4 audio capture device but I haven't fought through the hassle of trying to sync it with my video yet.

I would like to find a good portable solution for a 48 volt phantom supply so I could use condensor mics in the field. I also have a dual channel Asden wireless setup that can mount to the shoe of the camera (not dynamically). One channel is fed by a lavier mic and the other transmitter plugs directly into any mic with an XLR jack. This gives me a little extra flexibility but I still prefer the passive solution of using dynamic mics cabled to my XLR adaptor & not have to worry about so many battery changes.

Steve Boutin · October 9th, 2007, 12:38 PM

First, make sure the compressor is 'OFF' ( ALC) the ALC will bring the noise floor up when the incoming audio is low. Peak at about -3db. Just have some one stand in front of you, and yell loud, clap hands etc., adjust your input to -3db peak (try 0db also). Actually, the lower you record (-12db) the lower your noise floor will be. Adobe Audition, or an old version of Cool Edit Pro produces the best noise reduction results, Sound Booth should be the same if you want to manually remove the hiss. The preamp circuit in the HV20 is actually pretty good.

Evan Mann · October 9th, 2007, 06:17 PM

Would a moderately priced external mic (say $75 or less) provide me any reduction in hiss if used alone, or is an external pre-amp key to this equation?

I'm only shooting home video, but the hiss is rather annoying. My wife isn't going to want to have the extra bulk and weight of a pre-amp added, but an external mic wouldn't be that bad.

Steve Boutin · October 9th, 2007, 09:29 PM

The mic is usually never the cause of hiss. Try a cheap DYNAMIC mic (any non-powered mic) , borrow one or whatever, and see if you still have the hiss. If you do then it's purely electrical, and the mic is not the problem. I don't know how the HV20 is configured without the schematic. I don't know if you can bypass the internal preamp. If your just pluging a better preamp into the same noisy preamp, you're not going to solve the hiss problem.
I have not experienced any hiss problems with my HV20. If you are using proper recording levels, and bypassing the compressor, and still getting hiss then you might just have a bad circuit in your HV20. It's hard to troubleshoot something like this without seeing/hearing it.

Does the hiss stay at the same level all the time, or does it appear to rise if there is low or no incoming audio. If it rises, this would indicate the compressor gain too high.

October 8th, 2007, 04:34 PM	#1
Evan Mann New Boot Join Date: Aug 2007 Location: Orlando, FL Posts: 10	Audio hiss I imported an entire hour of footage using Vegas. I then took that and put it through Nero Vision 5. All the audio appears to have a hiss through it. Onboard mic is used. Is this inherant to the onboard mic, or perhaps something Nero Recode induced?

October 9th, 2007, 06:20 AM	#8
Don Palomaki Wrangler Join Date: Sep 2001 Location: Northern VA Posts: 4,488	One possible option that works with other Canon camcorders to reduce mic hiss is to use an external mic with a high output level, and use the MIC ATT setting. This usually reduces the noise floor, but relies on high mic output. Another technique is to use manual audio level control. This can avoid the increase in hiss caused by AGC during quiet parts of the program material. __________________ dpalomaki@dspalomaki.com

October 8th, 2007, 04:45 PM	#2
Michael Jouravlev Major Player Join Date: Jul 2007 Location: San Diego Posts: 209	Haven't you listened to the sound when you were working on your project in Vegas?

October 8th, 2007, 06:15 PM	#4
Matthias Krause Major Player Join Date: May 2007 Location: NYC Posts: 203	The HV20 pre-amp sucks which is to be expected for a camera in this price range. The built-in mic sucks even more. If you want to manage the hiss you have to get a good external mic and a good pre-amp that allows you to turn the in-camera pre-amp way down. Than the hiss is pretty managable. Or you can shoot double system...

October 8th, 2007, 08:02 PM	#6
Slava Barouline Regular Crew Join Date: Apr 2007 Location: Canberra, Australia Posts: 47	You can try to use EQ in Vegas to remove the hiss I have build a simple pre-amp some time ago - maybe I will give it a try with external mic

October 8th, 2007, 10:05 PM	#7
Deke Kincaid Regular Crew Join Date: Jul 2007 Location: Los Angeles, CA Posts: 26	record in an empty room with no sound which will essentially be just the hiss by itself and then use that as a reference to subtract the hiss from your audio.

October 9th, 2007, 08:23 AM	#10
John Hotze Regular Crew Join Date: May 2007 Location: Saint Louis, Missouri Posts: 129	Now that it's all said and done, go back & play the master tape with the camcorder and take the A/V output to an amp and listen to what you have on the tape. Don't forget to set the AV/Headphone to headphone in the setup. If you still hear a bad hiss, than you know it's on the master, but if you don't hear it than you can assume the problem lies in your capture application. To me "hiss" is relative to what is in the normal audio stream. If most of the audio is speech, music, etc., & the his comes into play only during silent periods, than you can more than likely live with it a little easier. I think that everything folks have said about the poor preamp, mic, & post editing solutions are true but I still feel that the built in mic can provide adequate audio in many cases, such as family shoots of birthday parties, vacation, & other family events. Of course adding a Beachtek and a $150 mic is going to produce better results but it is not necessarily appropriate for the typical family video being shot.

October 9th, 2007, 08:38 AM	#11
Matthias Krause Major Player Join Date: May 2007 Location: NYC Posts: 203	"How exactly does that mount up to the camera when using it? Does it add a lot of weight/bulk?" You could start with a Beachtek DXA-FX (http://www.beachtek.com/dxafx.html) which should work. You can mount it under your camera and it adds 16oz. Or you could use a Mixer like the SoundDevice 302 but then you'd have something else to carry and you are in a totally different price league. Both are overkill if you shoot only family videos. But I use my HV-20 professionally and the Beachtek should serve me well (on order...)

October 9th, 2007, 09:46 AM	#12
John Hotze Regular Crew Join Date: May 2007 Location: Saint Louis, Missouri Posts: 129	My XLR-Pro from Signvideo is never separated from my camera. It may add a pound; I'm not sure. It mounts just under the camera and than the tripod mount is screwed into the bottom of the XLR-Pro & in turn slips onto the tripod as needed. Over ninety percent of my shooting is live music concerts outdoors and shot using a tripod. I've even shot jams around a campfire with two mics giving me stereo. If I'm shooting a concert, I position a single mic on a stand directly in front of one of the speaker farms and run about a 50' XLR cable from the mic to my XLR-Pro. If I'm shooting jams, such as above, around a campfire, I setup a couple mics each covering half or more of a semi-circle of accoustic instruments & vocalists. It comes out pretty nice. My XLR-Pro has a ground lifter, mic/line level input switches, mono/stereo switch, channel one & two XLR inputs and two aux channel inputs. The output of the adaptor plugs into the mic input on the camera. I always carry a couple mic stands, 2-25' and 2 50' XLR mic cables, and a couple $75 to $150 mics. I'm always on the look out and testing various mics to improve my audio capture. I still think the weakest link in the audio chain is the HDV audio format. Since I only shoot in HDV now, I live with it. I have been taking along my Zoom 4 audio capture device but I haven't fought through the hassle of trying to sync it with my video yet. I would like to find a good portable solution for a 48 volt phantom supply so I could use condensor mics in the field. I also have a dual channel Asden wireless setup that can mount to the shoe of the camera (not dynamically). One channel is fed by a lavier mic and the other transmitter plugs directly into any mic with an XLR jack. This gives me a little extra flexibility but I still prefer the passive solution of using dynamic mics cabled to my XLR adaptor & not have to worry about so many battery changes.

October 9th, 2007, 12:38 PM	#13
Steve Boutin Regular Crew Join Date: Apr 2007 Location: Sarasota,Florida Posts: 36	First, make sure the compressor is 'OFF' ( ALC) the ALC will bring the noise floor up when the incoming audio is low. Peak at about -3db. Just have some one stand in front of you, and yell loud, clap hands etc., adjust your input to -3db peak (try 0db also). Actually, the lower you record (-12db) the lower your noise floor will be. Adobe Audition, or an old version of Cool Edit Pro produces the best noise reduction results, Sound Booth should be the same if you want to manually remove the hiss. The preamp circuit in the HV20 is actually pretty good.

October 9th, 2007, 06:17 PM	#14
Evan Mann New Boot Join Date: Aug 2007 Location: Orlando, FL Posts: 10	Would a moderately priced external mic (say $75 or less) provide me any reduction in hiss if used alone, or is an external pre-amp key to this equation? I'm only shooting home video, but the hiss is rather annoying. My wife isn't going to want to have the extra bulk and weight of a pre-amp added, but an external mic wouldn't be that bad.

October 9th, 2007, 09:29 PM	#15
Steve Boutin Regular Crew Join Date: Apr 2007 Location: Sarasota,Florida Posts: 36	The mic is usually never the cause of hiss. Try a cheap DYNAMIC mic (any non-powered mic) , borrow one or whatever, and see if you still have the hiss. If you do then it's purely electrical, and the mic is not the problem. I don't know how the HV20 is configured without the schematic. I don't know if you can bypass the internal preamp. If your just pluging a better preamp into the same noisy preamp, you're not going to solve the hiss problem. I have not experienced any hiss problems with my HV20. If you are using proper recording levels, and bypassing the compressor, and still getting hiss then you might just have a bad circuit in your HV20. It's hard to troubleshoot something like this without seeing/hearing it. Does the hiss stay at the same level all the time, or does it appear to rise if there is low or no incoming audio. If it rises, this would indicate the compressor gain too high.