I am at a point of either throwing my mic against the wall or waiting until someone here can point me in the right direction.

I am definitely having a sound problem - I am not sure if it is caused by the camera or the mic itself. About 1.5 years ago, I was getting a loud hiss when the camera was plugged into an AC outlet. I took the mic and camera to a music shop and they pointed me to an impedence transformer that seemed to do the trick. Well, 1.5 years later and now I am getting that hiss even with the impedence transformer. Logic says it is my mic, but I am wondering if it could also be my camera. My mic has tele and normal. On tele, the hiss is really loud and somewhat unusable. On Normal, it is fine because the noise only comes from the end of the mic (although the volume is considerably lowered).
So my questions is this - can a mic break down from use and cause the above problems? Does this sound typical for mic degradation? Does this maybe sound like an audio problem with the camera (pana 852)?

Thanks in advance from a man on the edge...

Did you check battery or phantom power supply?

Is it only when you've got the camera plugged in to AC power? I think it's because that isn't grounded power. My friend had the same problem when we tried to take an aux send from his sound board to his laptop - the PA buzzed when he had the laptop running on AC but as soon as he went to batteries, it was fine.

I guess I should have been clearer. The impedence transformer did the trick and fixed it. But low and behold 1.5 years later, it is back - just wondering if a mic would degrade this way.

The camera has no phantom power. The mic is double AA powered - XLR output.

In my experience it is the microphone. I owned one of these for about 2 days, tested it numerous ways and still received an unacceptable amount of hiss. I took it back and purchased an Azden SGM 1X. Much quieter.

Well , I discovered this whilst testing things - when I plug the mic into my camera, there is a loud sound - it comes right through the headphones, even when the mic is not on - therefore I wonder if it is a bad connection or something that is causing this? If this is the case, I guess I need a new mic. I am going to try and connect another mic to it in a shop and see if this causes the same problem, if the hiss is gone, I guess the mic's gotta go. It will be a shame, $150.00 down the drain.
Any other ideas on how to test this?

Well , I discovered this whilst testing things - when I plug the mic into my camera, there is a loud sound - it comes right through the headphones, even when the mic is not on - therefore I wonder if it is a bad connection or something that is causing this? If this is the case, I guess I need a new mic. I am going to try and connect another mic to it in a shop and see if this causes the same problem, if the hiss is gone, I guess the mic's gotta go. It will be a shame, $150.00 down the drain.
Any other ideas on how to test this?

It could be that the jack on the camera has gone bad, One of the reasons that those little 3.5mm miniplugs aren't used much of pro equipment is they're just plain too fragile to stand up to hard repeated use and it's very common for them to fail after a lot of plugging and unplugging. If you have or can borrow a mixer or other audio amplifier that will accept the mic, plug it in there and while wearing headphones see if you can hear the hiss. Wiggle the wire where it connects to the mic and also where it connects to the plug and see what happens. If everything is okay there you've ruled out the mic being the culprit and it's time to look at the camera side of things.

Consumer cameras often have very marginal audio and inexpensive mics are inexpensive for a reason - it could be that with a couple years experience you're starting to hear more critically than you used to and equipment flaws that didn't bother you then are starting to annoy you.

I did an audio test :

http://dvstuff.250free.com/audiotest.mp3

The three setting all in sequence and as follows :
1) tele mode with the apex 175 - giving me the most problems, background hiss
2) normal mode (sound isolated to the end of the mic) - quieter
3) just the camera's onboard mic (snapping fingers)

If this sounds normal, please let me know, if not at least I have a better idea of which way this thing is going.

Thanks

I did an audio test :

http://dvstuff.250free.com/audiotest.mp3

The three setting all in sequence and as follows :
1) tele mode with the apex 175 - giving me the most problems, background hiss
2) normal mode (sound isolated to the end of the mic) - quieter
3) just the camera's onboard mic (snapping fingers)

If this sounds normal, please let me know, if not at least I have a better idea of which way this thing is going.

Thanks

Clicking your link says "hotlinking not permitted"

Interesting, it works with mozilla firebird ,but not IE.
How about this :

http://dvstuff.250free.com/audio.htm

Click on the audio link.

I listened to your clips. Although I'm only listening through comp. speakers I can hear the noise you describe. I experienced the same thing with the tele mode being much noisier than the cardoid mode which wasn't that good either. I thought it was my camera at first too, but turned out to be the mic.

yeah, I am starting to guess that it why I am having the problems. going to take it to a sound guy tomorrow, hopefully he can sort it out.

yeah, I am starting to guess that it why I am having the problems. going to take it to a sound guy tomorrow, hopefully he can sort it out.

Try another mic. If it doesn't hiss you have your answer.


Regards,

Ty Ford

I'm also hearing a signifigant AC hum in the two clips from your mic that is not present with the camera-only clip. The "tele" position of the mic does seem to have less bass response and emphasize the sibilance more than the normal but these old ears aren't hearing a lot of hiss - playback through an Echo audio interface and listening with Sony MDR7506 phones. Would like to hear a version with less speech so can hear the system noise better.

Why don't you see if you can borrow a Beachtec or proper matching transformer and repeat your tests.

What is the 'proper matching transformer'?

What is the 'proper matching transformer'?

According to what I was able to find on the web about it, the MT-50 that you said in a previous message that you had is to match a low impedance source to a high impedance input. I believe that it is intended to match to a much higher impedance than is the mic input on your camera. Its output is TS instead of TRS and it doesn't block the DC bias I expect is on your camera's mic jack. Something like the Shure a96f or a purpose built adapter from someone such as Trew Audio that Ty mentioned in his comments would probably give better results IMHO.

Thank you, I am going to look into that today. The Impedence transformer I bought from a music shop, I thought they might know what they are doing, but again this is camera tech and not music, so maybe it could have been a mistake easily overlooked.

Thank you, I am going to look into that today. The Impedence transformer I bought from a music shop, I thought they might know what they are doing, but again this is camera tech and not music, so maybe it could have been a mistake easily overlooked.

That may not be the source of the hiss you're hearing but it couldn't hurt to try it. The hum I hear under your sample clips made with your Apex mic yet the fact that it's not there on the clip recorded with the in-camera mic tells me there's noise being picked up between the mic and the camera while the "thin" quality in both Apex clips could be due to an impedance mismatch distorting the frequency response, bolstering my theory about the transformer. It's certainly worth experimenting to see what happens.

How can I find out the impedence that my camera is looking for so I can match it up to the mic? It is a pana 852...

How can I find out the impedence that my camera is looking for so I can match it up to the mic? It is a pana 852...

Should be in the manual - it probably wants to have a low to medium impedance mic connected to it.

Unfortunately, I could not find it in the manual. I have email Pana and hope they get back to me about it. I wanted to phone, but I was on hold for about 20 minutes, paying the long distance charges...

Unfortunately, I could not find it in the manual. I have email Pana and hope they get back to me about it. I wanted to phone, but I was on hold for about 20 minutes, paying the long distance charges...

LOL - "Customer Service" is fast becoming an oxymoron like "Jumbo Shrimp"!

lol! Aint that the tooth.
I am looking thru the manual again, I will see what comes up. Thanks for all your help and support Steve.,

lol! Aint that the tooth.
I am looking thru the manual again, I will see what comes up. Thanks for all your help and support Steve.,

I downloaded a copy from Panasonic's website and all I could find was the a rated sensitivity of -60db but nothing about expected input impedance. Still, the camera is certain to be expecting expecting an unbalanced mic to be plugged into it. They will typically have an impedance of 150-300 up to 600 or so ohms. The line matching transformer that you have, with the XLR to 1/4 mono, is usually low impednace on the XLR side at 47,000 to 50,000 ohms on the output side. (Look on the transfomer, it should be labeled.) I'm not an expert and I might just be wandering around in the woods here - but I'm confident enough to think it merits an experiment or two to see if changing the way you connect the mic to the camera cleans up the audio.

The xformer I'm talking about is <$40 from BH Photo ... http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=154878&is=REG&addedTroughType=search

Got this message back from Panasonic :

Thank you for your email.

In regards to the mic input on the camera all that is listed for it is
the sensitivity which is -50 DB. In the case of the camera a 4Ohm
impedance mic should be just fine in the device so long as it has the appropriate
adaptor to physically fit in the device.

Best Regards,
Panasonic Canada Inc
Customer Care Centre
SM

Got this message back from Panasonic :

Thank you for your email.

In regards to the mic input on the camera all that is listed for it is
the sensitivity which is -50 DB. In the case of the camera a 4Ohm
impedance mic should be just fine in the device so long as it has the appropriate
adaptor to physically fit in the device.

Best Regards,
Panasonic Canada Inc
Customer Care Centre
SM

4 ohm?!?!?!?!?!?!?!?!?!?!?!?!?!?!?!?!

I am guessing it is
40 Ohm,

I am guessing it is
40 Ohm,

Even that seems awfully low. The generally accepted definitions are low impedance 150-600 ohm, medium impedance 600-10k ohm, and high impedance >10k ohm. Most good mics seem to lay in the 150 to 600 ohm range while super-cheap consumer mics like the $15 Radio Shack varieties can sometimes run 1.5k or higher. I'm betting they're recommending either 400 ohm or 4 kilohm.

I emailed them back about this, and your response - but I haven't heard anything yet Steve. Hoping by next week!

RE: Panasonic, you have encountered the incompetence and willingess to pull facts and advice out of the air that is typical of well-meaning customer service people. Because of the nature of the circuits they feed, cam mic jack inputs are relatively high; typically around 15K. Personally, I've never seen one spec'd at below 5K.

Equivalence between mic output impedance and cam input impedance is not the ideal. That would deliver the most power, but not the most voltage. Cam mic input circuits are voltage driven. You want the impedance of the mic to be on the order of about 1/10 or less of the cam input. That way most of the voltage developed by the mic is dropped across the cam input, not the mic innards. So any mic in the range of 150 to 600 ohms should be fine. The matching transformer that Steve mentions can help a bit with signal level because as it steps up the impedance it also steps up the voltage.

I think of hiss as electron traffic noise occuring at the molecular level in conductors and electronic components. It's often high when oxidation occurs in connections that are made between surfaces in contact, or at high resistance points like connections that are almost broken. Well chosen materials and designs in minimize it. If the mic and the cam aren't inherently noisy, it could be cheap or faulty cables. If all else fails, SoundSoap is pretty good at removing such noise.

Anyone is capable of a brain fart.

Ty Ford

Thanks Fred,
But I still need to find out exactly the Ohms right? I think what they sent me was a misprint - the 4ohms...just waiting for Customer Services to get back to me on that one...

Thanks Fred,
But I still need to find out exactly the Ohms right? I think what they sent me was a misprint - the 4ohms...just waiting for Customer Services to get back to me on that one...

Leo, whether it was a misprint or not, why not just get one of the Shure transformers I suggested or get a Beachtech and try it? If the hiss is still there (and I didn't hear a lot of of what I think of as hiss in the samples you posted, maybe just my geezer's ears losing the very high response or high frequency loss from it being posted as MP3s, but what I heard was 60 cycle hum and somewhat pronounced sybilance on the esses in the tests from the Apex, both absent on the recording from the internal mic) - you can always return it to the store and instead try a different mic. And remember too, whether this mic is faulty or not, several of the Beachteks also supply phantom power, opening up a gaggle of high quality mics as future options that right now you can't take advantage of.

Are you here in Canada? I ask because Apex is a sister company of Yorkville Sound, both owned by Long & McQuade which is a major chain of music stores across Canada - don't know how much distribution they have down in the States so since you have an Apex mic I just thought there might be a good chance you might be near to a Long & McQuade store. And that's relevant because unlike some of the mail-order places that don't allow returns on mics, at least their store near here in Burlington Ontario doesn't have a problem with returns or exchanges of recording gear or with you taking your camera and an adapter into the store, plugging mics you're considering into it, and making some test recordings on the spot. I would do that instead of sending emails back and forth to Panasonic hoping they give you some useful information.

Leo,

I listened to your clip, but only through the PC speakers. I scanned through the thread, but did not see if you'd tested the camera sans microphone.

I'm assuming you edit your video on an NLE? What kind of audio software do you have? On the PC, I had Syntrillium's Cool Edit 2000, which they sold out to the Borg (A-dopee) which renamed it Audition which I now have.

If you can, record a "silent" track with you cam, plugging a mic cable or even just a plug with no connection into the mic jack. Import (capture) this into your audio software. If it's like the above programs, it will have the option of a spectral view. Take a look. Your "silent" track will show noise, the noise of the audio circuit.

Both mentioned apps have an noise filter that will take a sample of audio, in this case, the noisy "silent" track, and make an exact template from it. Apply it to the track and hey! presto! the noise is gone. It's an invaluable tool to save potentially good tracks from the crapper. BTW, once you have this "filter", save it. Apply it to all audio tracks recorded with this equipment.

If the noise is indeed in the mic, well, it's harder to deal with. If you try to do the same exercise but with the mic plugged-in and as silent a situation as you can create (mic wrapped in pillows in the dead of night?) you may come up with another useful profile, tailored to the mic plus circuit.

As the recent victim of a bad mic, I sympathize with your plight. If nothing else, sell it to somebody with less critical hearing.

Frankly, I think everyone with the means to create such a filter should do so, one for each piece of equipment.

I will record the silent track when I have a chance, thanks for checking it out for me.
Steve, I will look into that. I hope someone around here carries the Shure model. Thanks for sticking by me!

Finally got an answer to my ohm question, not specific, but better then nothing :

Generally, microphones can be divided into low (50-1,000 ohms), medium (5,000-15,000 ohms) and high (20,000+ ohms) impedance. Most consumer camcorder microphones are rated low-impedance. Please make sure the microphone you select is between (50-1,000 ohms).

What do you guys think?

Yes. Most pro mics are between 40 Ohms and 250 Ohms.

Ty Ford