HMC40 Audio 'hiss'

R

roeyscam

New member
I noticed in my new HMC40 that a rather annoying hiss existed in my headphones when using the Panny XLR adaptor. Thinking that it could be just in the jack, the hiss was later revealed in my footage. I wrote to Panasonic asking them if this was a normal defect in the model, or if my specific camera was bugged. They replied by saying, "they have never heard of this issue prior," and that I should take it in for service. So, I did. The service co. tested my camera against other HMC40s and discovered that it is common in all of them. While I tested and did my research before buying the camera, this issue never came up. My mistake was not testing the HMC40/XLR adaptor together, I assumed it would produce decent in-camera sound, but never anticipated such a problem. I realize the camera is cheap in comparison to more expensive counterparts, I figured in the smaller sensors and limited functionality for why it was priced so low -- but I guess audio is an issue too. The service co. said they didn't understand why Panasonic didn't make the issue known -- although we can all understand why. But they advertised the camera as having "professional audio" capabilities when the XLR adaptor is utilized. No camera can compare to the sound quality of independent audio devices, but a hiss!? Really!? Anyway, if any of you feel the same way, waste some time and take your camera in for service to have them tell you this, while Panasonic flips the bill under your warranty rights. Perhaps after so many unnecessary service visits by HMC40 owners, they'll change their practice.
 
Make sure if you have a mic that has it's own battery the phantom power is off or it will hiss. Also if it is a mic that has a small watch type battery make sure the battery is in the right way, if it is in the wrong way you will get a hiss. You did not give any info to the mic you are using as that might be the issue!! Hope it is a simple fix!!!!
 
Roeycam,

Before you condemn the cam, give us an idea of what you are recording, with what mics, at what distance from the source, and at what gain level. Any cam, and any recorder will have some hiss if you push it too far to get the levels up. For example, if you have a cam mounted mic and are 5 feet away, your audio will suffer no matter what. Now maybe you know what you are doing, but without any particulars, no one can help you.

FWIW, using your identical setup with a properly boomed hyper or shotgun, my HMC sound is decent for audio dialogue, with no particular hiss. Is it as good as a high end setup, no, but for dialogue for video it is plenty fine.

Grant
 
I think my anxiety got the best of me on this one. Mike, you're right, when using my Sony wireless lav I failed to recognize phantom power was switched on, which gave me that terrible hiss. Subsequently, I became sensitive to any sound the camera produced, even listening to the hum when no mic was connected to the adaptor. I have the Sony ECM-NV1 shotgun mic which works just fine when phantom is switched on. I think the service co. people refrained from calling me stupid or crazy or oversensitive. I appreciate the help. Please disregard my initial post.
 
roeyscam said:
I think my anxiety got the best of me on this one. Mike, you're right, when using my Sony wireless lav I failed to recognize phantom power was switched on, which gave me that terrible hiss. Subsequently, I became sensitive to any sound the camera produced, even listening to the hum when no mic was connected to the adaptor. I have the Sony ECM-NV1 shotgun mic which works just fine when phantom is switched on. I think the service co. people refrained from calling me stupid or crazy or oversensitive. I appreciate the help. Please disregard my initial post.
Click to expand...

Glad to hear it was an easy fix. I know I had the same issue the first time I hooked up my mic to the xlr adapter. It took a little playing around and then I learnd from my mistake. This forum is a great way to find fixes, I have learend from other's here and try to pass it on. If you do not have Barry's HMC book you may want to get one, it is like the bible for your camera.

Happy Shooting,
Mike
 
I use my HMC40 with the Beachtek DXA-2T, microphones Azden SGM-1X and Sony wireless UWP, and is fantastic
 
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AG-MYA30G Hiss

AG-MYA30G Hiss

Hmm, when I plug in headphones to my hmc40 and have my Panasonic AG-MYA30G xlr adapter in, I hear a noticeable level of hiss without even plugging in a microphone. Does this happen to everyone else as well?

I hear hiss whether it is on line/mic, phantom or not.

Something wrong here, or is there just a certain level of noise present for everyone?
 
Obi..,
Is the hiss in your footage or only in live monitoring? I don't have this cam but many cams have fairly poor circuits for live monitoring.
 
Audio Hiss

Audio Hiss

I did a quick test yesterday and the the hiss certainly seemed to be apparent on the footage when I attached a Sennheiser MD 46 to the panasonic adapter. I then made a recording with the same mic attached to my pmd661 field recorder, which was much quieter. (I'm going to do a less rushed test tomorrow though)


However, it might not be the adapter, it might be the camera. When I plugged in an 1/8inch to xlr cable in the mic input on the hmc40, I heard the same level of hiss. (Again before plugging in a microphone)


To be fair, when I plug in my headphones to my pmd661 recorder and listen there before plugging in a mic, there is a small amount of hiss present as well. You really have to turn up the headphones to hear it though.

Am I just expecting too much from consumer level circruity?

I'm going to take a guess that nobody would hear this hiss when I'm actually recording dialogue, but knowing this, I may just want to go double system from now on...
 
There is a bunch of hiss being introduced by the AG-MYA30G and it is being recorded. (At least on mine)

Here is proof. (30mb .wav file)
http://www.sendspace.com/file/pt3nnc


I recorded this, and encoded straight to a wav file using VLC.

I started with AG-MYA30G unplugged from camera. Switches on the AG-MYA30G in following position - Mic/Mic - Att Off - 48v off - ch select 2 - Volume 0 L&R and Mic ALC off in Record Setup
here is the timeline of the test

0:00 Internal mic only, level all the way down at -30.
0:15 Plug in AG-MYA30, no mics attached settings as above
0:30 Plug in stereo XLR mic both L/R
0:45 Turn on 48v on only ch 2, noise increase ever so slightly
1:00 Raise volume on both channels to 3 o'clock (lots of room noise but hiss does not go away and might even increase slightly)
1:15 Lower volume to 0
1:30 48v off
1:45 Unplug mics
2:04 Unplug AG-MYA30G
2:25 Plug AG-MYA30G back in
2:42 end

The times to pay most attention to are :15, 2:04, & 2:25 when the AG-MYA30G is plugged in and unplugged. There are no mics atached at that point, no phantom on, and nothing turned on/off or plugged in after that makes the initial hiss go away.

I was hoping the hiss would diminish once mics were plugged into the AG-MYA30G but the above test proves that is not the case.
Any sugestions would be GREATLY appreciate. I have a gig coming up where I need to put lavs into the AG-MYA30G and this might be a deal breaker for the AG-MYA30G. I guess I can adapt down and use the 1/8th mic input for the lav but eeesh, why did I even buy the AG-MYA30G then?


ps.. Hi Everyone.. First Post, long time lurker.. sux it has to be about this... :(
 
Truth is, this camera + adaptor produces more background noise than higher-end cameras. While I realize my initial mistake, having phantom switched on with my Sony wireless UWP (a lesson I fail to grasp apparently), the HMC40 is not for people with sensitive ears. I tested this in my PD170, leaving phantom switched on caused the Ss' to sting and the Ps to pop, but no hissing in between. Plain and simple we're getting what we paid for. But there are solutions to this problem: recording sound out of camera is one, or, using EQ/compressor in post to reduce its presence. I never used an XLR adaptor before, so I can't compare. Built-in XLR ports, in my experience, never had this issue. However, and I'm trying to find it again, I remember reading an article about the fixed gain levels in the HMC150, which has built-in XLRs, are set much higher than Panasonic's other pro models. I wonder if the 40 is set to a similar level, and if the 150 produces the same hiss. Anyway, some find the hiss acceptable, others don't. I am with the latter. Remember your experience and use it for your next acquisition.
 
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roeyscam said:
Plain and simple we're getting what we paid for.
Click to expand...

Uhh.. REALLY?

I paid thousands of dollars for my camera and XLR adapter. I believe that puts it firmly in the category of a camera that should have useable XLR ports. ESPECIALLY when you have to pay extra for the XLR. My office is filled with various XLR equipped audio equipment that cost a fraction of what the HMC40 did and they all have silent inputs. Including several $99 Kodak 1080 HD Cams with stereo mic inputs that have a MUCH cleaner sound than the HMC40.

IMO the audio quality of the HMC40 is totally inexcusable especially considering what it costs.
 
Jim Cooper said:
Uhh.. REALLY?

I paid thousands of dollars for my camera and XLR adapter. I believe that puts it firmly in the category of a camera that should have useable XLR ports. ESPECIALLY when you have to pay extra for the XLR. My office is filled with various XLR equipped audio equipment that cost a fraction of what the HMC40 did and they all have silent inputs. Including several $99 Kodak 1080 HD Cams with stereo mic inputs that have a MUCH cleaner sound than the HMC40.

IMO the audio quality of the HMC40 is totally inexcusable especially considering what it costs.
Click to expand...

Jim,
Consider what you're getting for the price: though small, 3MOS sensors that are capable of magnificent imagery, scene file settings, 1080 24p, AVCHD, a decent Leica lens, waveform monitor, syncro scan, user buttons, focus assist, 7 gamma curves to choose from, portability, etc., but you must already know what the camera is capable of -- for $1700. I agree with you that not having "usable" XLR ports sucks royally, especially since you paid more to have that option. Complain to Panasonic, they seem to disagree. It's obvious they cut corners to make this camera more affordable -- relative to other models with similar capabilities. I, like you, am annoyed with the discovery. But, for my purposes this camera works best for the price, and there are solutions to the problem you too can agree with. If not, sell it. Or save your bones for something better, such as the AF100. I'm sure we'll find something wrong with that one too.
 
Gweilo66 said:
Any HMC80 owners have noisy audio inputs?
Click to expand...

The audio quality on my HMC80 is quite good, certainly fine for the field interviews and such that I normally use it for. I generally use it with either a Sennheiser G2 wireless setup, or an ME66 or MD46 (dynamic) mic plugged in directly. The preamps are about as clean as I've encountered in any previous camcorder or VCR I've used, although certainly not as good as in a first-rate external mixer. I would be comfortable using them for any of the ENG, event or industrial/educational projects this camera is designed for, but (as with almost any camcorder) I'd want to use at least a good outboard mixer, and maybe my Tascam HD-P2 recorder, for top-quality music recording or dramatic dialog work. That's as much as I would expect from any small camcorder and I am fully satisfied with the HMC80's performance in that respect.

The AC3 audio compression is probably at least as big a factor in the overall sound quality as the preamps, and does discourage me a little bit from using the HMC80 for critical audio applications. But it wasn't really designed for that anyway, and it's not an issue in 95% of the work I do.

- GDS
 
Thanks for commenting ,Greg.
So I wonder if there is more than just a difference in connectivity between the two cams.
 
Gweilo66, the main difference (and you probably already know this) is that on the HMC80, the balanced XLR inputs are a standard, built-in part of the camera and not in an optional external box (that must then plug in through the unbalanced inputs) as with the HMC40. I don't know for a fact (although I have designed some audio circuitry in a past life), but not having to pass the audio through the mic preamp and connectors designed for unbalanced mics may have made it possible for Panasonic to optimize the levels, shielding, etc. better on the HMC80, or perhaps eliminate a noisy gain stage. I suspect most of the electronic components used are pretty much the same at the part-number level, but they may be hooked up and tweaked differently.

- GDS
 
Gweilo66 said:
What model $99 Kodak?
Click to expand...

http://www.bhphotovideo.com/c/product/641078-REG/Kodak_8796062_Zi8_Pocket_Video_Camera.html

(I have 3 and love them as crash cams, bike cams, bar cams, sure they are what they are but what they are for the $$ is pretty awesome. Almost disposable)

I was stretching a bit to make a point. The Zi8 has unbalanced stereo inputs natively. But an unbalanced stereo mic plugged into that cheap-o thing comes out MUCH cleaner than a stereo balanced XLR mic plugged into the HMC40.

IMO the hiss introduced by the AG module makes it unusable. Never thought they are passing the balanced inputs through the unbalanced circuitry. Guess I assumed (oops) that since they had the forethought to include the AG plug, they also had balanced circuitry for it under the hood.


harumph

IMO anyway... ;)
 
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