Audio hiss

Mat Cain

Mat Cain

Member
I confess I am not the sharpest tool in the shed and I am not used to larger cameras like the 300. I hardwire into the channel 1 xlr input to connect with my AT lav mic... I am running it in with phantom power but getting a lot of hiss.

I am worried that I am missing something because at this rate I am gonna need to load all the audio into an audio program and try to cut out the hiss. This can't be right... I have no audio issues with my little Canon XH-A1's.

I have adjusted several settings but I either get the hiss or nothing at all.

I wondered if perhaps the hiss was worse due to monitoring the inactive channels but even when I bring the footage into the computer and I dump the other channels it still sounds poor.

So hopeful I am just a bonehead that has missed something obvious. Anyone have any pointers or other advice?

Thanks,
Mat
 
The audio part is not where the 300 shines is my experience. I use a sennheiser MKH416 which is a reasonable mic but I have to turn up the both pot meters and the master level almost at max to get a -12 dB output on the audiometers. The input is just not very sensitive. Concerning noise don't judge it using the earphone output on the cam since it is very very noisy, in the recorded footage it is much better.
 
Are you using mic or line settings on the input. Mic will be much hotter. Line is used with a mixer which can add more gain.

I assume your lav is phantom powered, is the 48v phantom switch on for that channel.

How close is your mic to the talent? Since your using a lav, I assume close, but placement need to be within a about a foot. If it is more, you will lose performace very quickly.

If your signal is just to weak to get the gain down on the cam and reduce the preamp noise, you will probably want to add a mixer.

Grant
 
MIC setting
Phantom is on
all within 1 meter

input of the HPX is just weak as I already stated 5 months ago in another tread but that is not problem of the pesrson who started this thread.



ggrantly said:
Are you using mic or line settings on the input. Mic will be much hotter. Line is used with a mixer which can add more gain.

I assume your lav is phantom powered, is the 48v phantom switch on for that channel.

How close is your mic to the talent? Since your using a lav, I assume close, but placement need to be within a about a foot. If it is more, you will lose performace very quickly.

If your signal is just to weak to get the gain down on the cam and reduce the preamp noise, you will probably want to add a mixer.

Grant
Click to expand...
 
The lav placement is normal... I am coming in to channel 1 on the back - it is phantom power. I don't want to babysit the audio - I just want to plug it in an let the camera handle it. I do notice a lot of hiss in the headphones but I also notice it on my computer. When I play out to a tv it isn't as noticeable but I don't understand why it isn't cleaner. I realize that I could use a mixer but I didn't want to do that - and I don't think that I should have to in order to get clean sound.

Anyone else have any suggestions?

Thanks,
Mat
 
Well all I can say is that I have 30 years broadcast TV and film experience mainly in audio and dubbing and have not found any problems with the HPX 301.

Ok the headphone amp can be a bit noisy but the inputs are fine and what I generally hear is what I get in the edit, choosing the right headphones may be the key as I find that my MDR-V700's work best for level and noise floor.

The MDR-7506 or the small walkman cans are not as good, as for mic's I use all sorts of dynamics to high end radio mic's and condensor's and they are all acceptable for broadcast use.
 
I'm curious if the original poster is using a hard wired lav with it's own battery for power and also adding phantom power from the camera.
 
Cees Mutsaers said:
MIC setting
Phantom is on
all within 1 meter

input of the HPX is just weak as I already stated 5 months ago in another tread but that is not problem of the pesrson who started this thread.
Click to expand...

Cees-I don't have a 300 but I do have an hpx170 and dvx100b. In the recording menu, is the audio set to -50db or -60db? -50db will give you more signal (higher level) which means you have to turn the pots down to keep the signal from blowing out.
 
I will add that using an old sony ECM55 lav was quite noisy but it was the mic and not the camera.

As also said you can adjust the gain in the menu's but I have not found that I have needed to do that.
 
RicFic said:
I'm curious if the original poster is using a hard wired lav with it's own battery for power and also adding phantom power from the camera.
Click to expand...

The original poster is using a hard wired lav with no battery with phantom power. I suppose I can try using a battery with mic rather than the phantom power.

any other suggestions? I am seriously all ears. I have also tried different XLR cables... no difference. I'll keep experimenting...

Thanks for all of the help thus far.

Mat
 
Usually the battery option is not as good as cam power. I know you said you had used this lav with a Canon, but have you tried any different mics? Have you tried another input channel on the 300, maybe it (the input) is faulty.

Do you have the option of a mixer to boost the signal? At least that might help isolate the problem.

Grant
 
Keep in mind - it isn't that I am not getting high enough levels. I am getting the audio - just with a bunch of hiss. I am gonna try some different options today. I honestly need to come through the manual a little but more as this camera is totally new to me. Hopefully there is just something I am missing. I'll keep you all updated. Thanks for everyones help thus far.

Mat
 
ok - after playing with it some more I think it is a level issue. I am not getting high enough levels I think... The meter is maxing out at -18db it is never going beyond that... isn't that a bit low? I think I need more volume.
 
I also agree with RicFic to try switching the audio menu from -50 to -60, or the other way that it is currently. I thought that the -50 made it LESS sensitive, with less hiss. I know that I switched mine from -60 to -50, and it sounds fine now.

Who is the woman squeezing your face? :-)
 
Ok - So I have been using channel 1 or 2 out of the back of the camera and I have been having all of this hiss problem... So I decided to plug the mic into the front XLR input and everything changed. The hiss went away and I got higher levels - it went from -18 to about -10 to -12. I checked playback on the monitor and it was like night and day.

I looked back through the setting but I don't see any difference between the front input and the back... I am starting to get concerned that there is a problem with channel 1 and 2 at the rear of the camera. I would like to feel good that my problem is solved but it isn't... Why can't I get audio from the rear of the camera?

I have gone through the settings again and I see nothing out of order can anyone tell me what I must be missing?

Mat
 
that is 8 year old daughters hands reaching over the couch - I took the picture of myself with a rebel 450
 
I just checked the manual, and I think my last reply is the right one - In the audio menu, the default setting of the front mic level is set at -50db, and the rear inputs default to a setting of -60... (That explains hearing a volume difference in the front.) Try setting the audio menu "R.MIC CH1 LEVEL" (and CH2) to -50db and then it should sound better. It's worth a try.
 
I have set the rear channels at -50 as well and it is a bit better. But what I am experiencing out of the front mic XLR is MUCH better. The hiss is gone and the level is where it should be. when I go back to the rear jacks it all falls apart again - even with the settings at -50db. I am either missing something very obvious or my 300 might have some problems. Any other thoughts?

Can you possible run through the audio settings in the menu and list them here to see if mine match - perhaps the audio settings on the side as well to be sure I am monitoring things properly?

Thanks
Mat
 
Mat, Mat, Mat...

Yes, since you asked - one more suggestion. Get a real soundperson involved on your shoot ($250-$400), at least until you get the hang of the camera. By your statement "I don't want to babysit the audio" suggests...

You must, always, 100% of the time, especially on the feature you plan to do, monitor and improve the audio constantly. That's a no brainer. Especially if you do not have a soundman, it is up to you, the DP, to monitor the audio. Can you imagine going into post and you then realize you messed up the audio? The 300 doesn't mess it up, it is always user error. People who aren't looking at your camera, the audio gear, the settings, the connections, they can't trouble shoot your hiss. It is very easy to mess up audio which is why it requires "babysitting" 100% of the time.

Perhaps offer a soundman dinner or beers to help you initially set up the audio portion of the camera, should just take a half hour. Or, if you didn't buy it from a box house, bring it in to the people who sold it to you and ask them to go through, step by step, the audio set up. I get the impression from your posts that you don't like reading the owner's manual, no offense.

I understand not going through the mixer, when I do 1 man bands I don't use the mixer because it slows me down and adds variables (switches, settings, etc.) that can make audio worse when going solo.

The last time I had hiss I immediately raised the mic cable a foot off the floor and it was GONE, probably because there were wires and utilities in the floor of the skyscraper's offices. And I could rattle off about 15 other hiss causing situations. If I have a buzz or hiss and I can't immediately rectify it, my standard response is to go wireless.

So in sum, none of these dvxuser members, no matter how helpful they want to be, is going to solve your hiss successfully. It's this simple: Get a soundman, at least to initially run you through full size rigs' audio set up.
 
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