Hiss in the footage from the cameras

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daniel.v

Member
I have shot a documentary over a few months using first the HVX200 and a Sennheiser 416 that belonged to a friend, and then a HPX-170 and an equal mic (brand new) I bought for myself.

Now I'm reviewing the material I notice a mic hiss in basically all the footage. It only becomes more noticeable when you turn the sound up a bit.

Perhaps an amateur wouldn't really notice this hiss, but for me it's really terrible, specially considering how much I paid for all my gear.

I didn't record the audio low, the dial was usually at twelve 'o clock, perhaps a bit less, because there were usually sudden bursts of loud noise.

I don't have anywhere else to plug my Sennheiser in to test, but I have a couple of cheap XLR mics. When I plug them in on the 170 I get the exact same amount of hiss, so I assume it must be coming from the camera.

Also, when I turn the volume all the way down on the mics I still get a bit of hiss.

Are the cameras known to have hiss? I trust the Sennheiser mic more than I do the Panny cameras to be honest, since these mics have been used in major motion pictures for years now, and two different (but same model) mics were used. And according to what I heard the 416 is known to have very low self-noise.

I'm sure I'll be able to manage because as it is a cinema-verite documentary not-perfect audio is somewhat acceptable, but I'm planning a short film now and I just can't have this hiss!

Does this basically mean that recording sound in-camera is not acceptable for reasonably professional narrative work?

What's happening?

PS: I am monitoring the audio with a Sennheiser HD202 headphone.
 
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have you viewed the footage on anything other than the camera? The heaphone circuits are usually pretty noisy.
 
I first noticed it in FCP.

I get it both using the headphones (the same I'm using on the camera) and on the computer's speakers.

It's a low and constant "mic hiss".

When there is a lot of noise going on you don't really notice it, but when there is silence you can clearly hear it.

What's the correct level to usually leave the mic on the cameras? Was leaving it at twelve 'o clock too low?

Or maybe this is what audio is supposed to sound like and I'm just too demanding?

I just thought that a 1K plus mic should be noise-free.
 
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Daniel,
I too have found the HVX to employ poor pre-amplification. Lots of noise on mine as well. Most amateurs will not notice it, but after working with Wunder Audio, Presonus and Avalon mic pres in the studio, the HVX audio sticks out like a sore thumb.

Did you check your cable? If you drop a leg on a balanced cable, you will loose atleast 5db. Compensation on the trim pot will increase the noise floor.

Also, you should always set your level for each mic and for each sound source. 12 o'clock is not the 'one-sized-fits-all' setting. based on your second post, it could just be that your input trim was too low and you didn't record audio hot enough to saturate above the noise floor. Remember, the HVX is digitally sampling the electrical signals comming from your mic at 16bit, 48k. Proper gain levels are not just important to reduce the noise floor. It is also important to use up as much bit depth as you can (aim for peaking at around -12 to -8).


Jason
 
Thanks for the thoughtful reply Awakened.

Glad to see I'm not alone in noticing this shortcoming from the cameras.

My cable was of good quality (don't remember the brand) BRAND new from BH.

Maybe you are right and I didn't record the sound as loud as I could. We shot guerrila style with only two people (Brothers Maysles style, you might say) but the person with the mic didn't have any mixer in them or anything.

So I guess I should be monitoring it at all times to see if the audio's always in the latter part of the bar, right?

Thankfully while it's a bit noticable it's not a dealbreaker, since the whole thing's supposed to have an "organic" feel to it.

BUt I don't know, I think I'm gonna invest in a Sound Devices recorder/mixer pretty soon if the sound is this bad.

At least for narrative stuff, it seems necessary.

The only thing that holds me back is that I intend to get an S35 Scarlet soon and if the sound in that camera is good enough I'd much rather to have the sound already synced with the image.

When you have 40+ hours of documentary stuff manually syncing audio should be a *****.
 
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I have been using and HVX200 for several years and never had that kind of problem. MAke sure the rear channels are not being monitored (internal mic on the rear channels) Also make sure that you are setting the mic sensitivity properly in the recording setup menu. If you are recording low level stuff with the "pad" on it will be 10 DB noisier than necessary.
Good luck.
 
Daniel,
In post you can roll off the highs or boost 2.5k to add mid range (that is, for human voices). I have a line level wireless lav and also use a mixer on occasion to input line level into the camera. Sadly, I have not noticed a big difference in sound quality. I think my ears were spoiled in the studio.


Jason
 
ksteiger said:
I have been using and HVX200 for several years and never had that kind of problem. MAke sure the rear channels are not being monitored (internal mic on the rear channels) Also make sure that you are setting the mic sensitivity properly in the recording setup menu. If you are recording low level stuff with the "pad" on it will be 10 DB noisier than necessary.
Good luck.
Click to expand...

The mic sensitivity was set to -50db.

What do you mean by the "pad"? The rear channels are channels 3 and 4?

At first I recorded with the internal mic on as well as the external, afterwards I it was just the external. Same results.

I'll try to fix it in post, but I honestly don't see anything wrong with what I did, as far as I can tell it seem to be an issue with the cameras themselves.

Later in the shoot I start recording things a bit higher, and while the voices distinguish themselves better from the "hiss", it's still there.

What worries me is that if I have to increase levels on ANYTHING, the hiss is just gonna show too much. I hope that the fix Awakaned suggested helps a bit. Does Soundtrack Pro (I'm on a Mac with FCP) have a hiss remover that works? I heard the Audition has one and it works fairly well.

Is Barry around to give us his 2c on this?

If I did something wrong by all means tell me, because I'd rather admit that I'm the one at fault rather than the cameras.

EDIT: What I am noticing is that my Sennheiser headphone (which is cheap) has a bit of hiss of itself. When I use my (also cheap) Sony headphone I can still hear the hiss, but it doesn't seem to have its own hiss as the Senneheiser phone.

My guess is the Sennheiser phone has some sort of gain in it, because I get a lot more volume using the same level.

Still, there is a noticeable mic hiss using whatever phones and the speakers in the PC.

I honestly find it surprising that this issue hasn't popped up here before, for me it's far worse than any lens wiggle for example.
 
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I usually roll a few seconds of gate noise and remove it through careful adjustment in Adobe Audition, and depending on the case I may re-introduce some noise to keep things from getting hollow.
 
Hi Dniel

How do the wave files look in your timeline? Are they big and fat looking, filling up the clip or small and mellow not taking up much of the range? You can "display waveforms" in FCP, and should leave that on. Then you can see what's happening to some extent. If they are low, then you are in the hiss range, but if you get your signal up over the hiss, when you turn it down your hiss will turn down as well.

It is very helpful to use a mixer like the Sound Devices MixPre to get that signal strong and at line level. Setting the camera at line level will lower the hiss right off the bat. The MixPre has nice limiters too, so you could pump the volume with a safety net if something loud happens unexpectedly.

As for the hiss removal. I suggest you find an audio buddy who knows what he/she is doing and has a good plug-in. The effects in FCP/Soundtrack are clunky, and not as good as they need to be. (Man, if FCP only had the audio functions of Vegas it would be perfect...) Hiss removal needs to be dealt with in moderation. You can really make a track sound unnatural if you over do it. But with something from iZotope, or Waves you can really make a difference and save the day. Remember that Audio is as, if not more important than video in things people are watching. They will forgive some cruddy IQ as long as they can hear everything clearly, and the music sounds great. But put an amateur audio track with a beautiful visual and people will change the channel.


On a more personal note: What are the opinions of others on the audio of this HVX200 camera? I'm in the market and doing research. Are we dealing with uncompressed audio here? I'm not fond of HDV's compression. Are the preamps clean? Is hiss a known issue like it is with the Sony PD170/VX2100?

Chad
 
Chad, The HVX records 4 seperate tracks of 16bit 48khz audio (when recording in HD formats). Definitely not 'uncompressed' but decent quality. I have found the HVX's pre's to be a bit noisy. Nothing too unsettling if the gain structure is staged properly. Some HVX's dealt with a known issue called "the beep". A pulsing tone that seems to line up with the flashing led of the P2 cards. Most people did not have the problem. I believe Panasonic fixed the ones who did.
If you are any sort of an audiophile, you will not like the HVX's pre's very much. Are they worse then a VX2100? No. Just not all that one could want. Remember, it is a $5000 camera...
Its also worth noting that the HVX always records the internal mic to two tracks and records the XLR inputs to two other tracks if assigned. There is no way to record 4 separate audio tracks inputted to the HVX, even though DVCPROHD supports it.


Jason
 
Thanks for the Info Jason.

My VX2100 was way too hissy for me, so I got the Greg Winter mod to totally bypass any internal preamps, and now I get DAT quality audio. I suppose if I used my MixPre with the HVX it would push down the hiss. I was just wondering if te HVX was considered "very good" "Good" "So-So" or "Bad" as far as audio quality goes. It sounds like they are "so-so" to "good".

Anyone else have any audio opinions on the old HVX? or any P2 cams?

Thanks again.

Chad
 
Thanks for the replies guys.

Chad, currently I don't have the resources for a mixer (I am absolutely certain I need one though) because my next purchase has to be a professional tripod, I still use a prosumer tripod that gives me a lot of headaches.

My waves sometimes are not so high on FCP, at first I think I did record a bit too low, but as I said, it's not a dealbreaker, just something I'll to try to fix a bit in post.

By "line level" you mean you somehow only start recording sound from a certain level and you leave the hiss "out" of the recording? I don't know what that is, sorry.

Is this mixer worth it? I mean, could I use this with a feature film, is it durable, can you use it when you import/export footage, etc?

Does a Sound Devices recorder has a built-in mixer? Because I remember those being 1,3K or something, perhaps its better to stretch and get one of those, even if I sometimes use it only for the mixer.
 
daniel.v said:
Thanks for the replies guys.

Chad, currently I don't have the resources for a mixer (I am absolutely certain I need one though) because my next purchase has to be a professional tripod, I still use a prosumer tripod that gives me a lot of headaches.

My waves sometimes are not so high on FCP, at first I think I did record a bit too low, but as I said, it's not a dealbreaker, just something I'll to try to fix a bit in post.

By "line level" you mean you somehow only start recording sound from a certain level and you leave the hiss "out" of the recording? I don't know what that is, sorry.

Is this mixer worth it? I mean, could I use this with a feature film, is it durable, can you use it when you import/export footage, etc?

Does a Sound Devices recorder has a built-in mixer? Because I remember those being 1,3K or something, perhaps its better to stretch and get one of those, even if I sometimes use it only for the mixer.
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Hi Daniel

"Line Level" is a setting you can choose on some cameras or mixers, and also on some cameras. Some cameras are mic level only. For example my VX2100 has an input with a switch to choose between "Mic" or "Line" level. On "Mic" the preamp is louder in order to push up the level if you plug a mic straight in. On line level, the preamp is lower (and the noise is lower) for when you plug in a line level mixer that is louder than a mic.

Many mic level mixers, like beachtek, don't amplify the volume of the mic. At their loudest they are the same volume as the mic plugged into them, and the volume knobs only turn down from that point. On the other hand, line level mixers, like my Sound Devices MixPre, are at line level, and actually amplify the volume of mics that are plugged into it. Another mixer, the juicedLink, can switch between "Line" and "Mic" level to accomodate whatever camera they are plugged into. The Canon HV20 camera input is "Mic" level only, so you either use a beachtek, or a juicedlink set to "mic", but a sound devices won't work as it would sent too hot of a signal to the camera and distort. Again the MicPre is line level only.

Also the Sound Devices MixPre is a mixer only, not a recorder. You can get one for 665.00. You can get a 2 channel JuicedLink mixer with phantom power (to run pro mics) for 300.00.

Here's the juicedlink youtube page with tips, and a link to his site where you can order one. They also sell juicedLink at B&H.

http://www.youtube.com/user/juicedLink


For a feature film I suggest you use a camera with line level inputs, so you can use a good mixer and keep the noise level down. That is, to have a better "signal (sound) to noise ratio". The higher your signal, the less you hear the noise. There are also recorders you can use that are much cheaper than the Sound Devices recorders. That way no matter how bad your camera audio is, you get a nice clean recording. I use the Edirol R4-Pro. That's a little expensive at 2,000.00. But there is the R-44 also that goes for around a grand.

http://www.bhphotovideo.com/c/produ...4_R_44_Solid_State_Four_Channel_Portable.html


Nobody said it was going to be affordable! So you do what you can, and hope to get the best quality out of the gear you have. As far as tripods go you can get a Manfrotto set of legs and maybe a 503 fluid head for 300.00 - 400.00 bucks. Tripods are very important, as is your audio. Audio is big! Bad audio will render your movie unwatchable, so give 'till it hurts. Then give some more.


Good luck!

Chadfish
 
Thanks for the great reply again. =)

You have convinced me, I'm probably going to pick up the JuicedLink mixer as soon as I can, does it get the job done? I mean, practically no hiss at all? What does it do besides that, are there limiters and such?

Now, assuming I don't have a mixer yet, using the mic in the LINE mode will give me less noise? I just want to try to avoid this hiss right now as much as I can with the basic gear I've got.

I understand there is some inherent noise, but I just find it too damn high.
 
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daniel.v said:
Thanks for the great reply again. =)

You have convinced me, I'm probably going to pick up the JuicedLink mixer as soon as I can, does it get the job done? I mean, practically no hiss at all? What does it do besides that, are there limiters and such?

Now, assuming I don't have a mixer yet, using the mic in the LINE mode will give me less noise? I just want to try to avoid this hiss right now as much as I can with the basic gear I've got.

I understand there is some inherent noise, but I just find it too damn high.
Click to expand...

Hi Daniel

JuicedLinks don't have limiters sadly. (Though his line of units changes, so ask him) If you watch the vids on his youtube page you can hear a comparison between it and a beachtek, and possibly a MixPre as well. You can email specific questions to Robert at juicedlink through his site, or his youtube site. He answers everything in detail. I have only used mine a little with an HV20, and it's pretty good, but I have not done anything critical with is as it's only for backup, or secondary. YOu just have to listen to your levels (there are no meters either) to see if clipping will occur. Just do tests outside of the real shoot.

Plugging in a Mic to the camera: A mic is at "mic" level. So you don't plug it into a camera set to "line" level. Use "mic" level. If you set it at line you will turn down the hiss, but also turn down the signal to an unusable range, and then when you turn it back up in post you will have all the noise and more.


{{{{EDIT}}}} About hiss. It's not the juiced link as much as it's your camera that makes the hiss. What camera do you have? Is it a consumer cam with a little a/v input? Chances are it will be somewhat hissy, but the idea is to get your signal up as far above the hiss as possible.
 
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I used both an HVX200 and and an HPX-170.

That's what bugs me, these cameras are supposed to have better audio than what I'm getting, to be honest.
 
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Forgive me for not reading this entire thread (in a hurry), but: the Panasonic cameras record 4 channels of audio. Your senn mic was probably using one or two of those channels. The other channels may be empty, but when they're brought into Final Cut, they produce a soft "hiss" when you listen to all your audio channels together. Try to delete or mute the two channels in Final Cut that do NOT include your dialogue track. That may quiet things down considerably.

In other words: your mic may have been fine, but you're listening to noise on the empty channel.
 
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