SGM-1X mic, too quiet, why??

robotriderdh

robotriderdh

Active member
I recently purchased an Azden SGM-1X microphone for filming with my GL2. I've got an XLR to 1/8th inch converter because the GL-2 has no XLR inputs. When using the SGM-1X, the sound levels claim that the audio coming in is properly balanced (the audio levels are no different than if i were to use the camera's mic), yet when reviewing the footage, the audio is almost inaudible.


I have done a few tests to see if I find the problem out or atleast narrow the possibilities.

-To prove that it was not the chord, I used a separate mic, and the audio was as it should be, proper volume and quite clear.

-To prove it wasn't the "ambient noise reducer" that was causing the problem, i simply recorded with it on and then off, noticicing no volume change.

-To prove it wasn't the GL-2's "mic att" function, i tried it on and then off, with no change (btw, what IS "mic att"?)

-To help prove it was in fact the mic, i recorded into garage band with the XLR to 1/8th inch converter cord (as used with the camera) and found the same volume problem. i made sure that the input levels for Line In on the computer were not the problem, as well.

-Finally, the mic is battery powered, and not phantom power, which the GL2 does not offer, so that is not the problem. the battery is properly oriented (positve/negative) and is brand new.




ANY IDEAS? This problem is bugging me like nothing else because i just purhcased it and have hardly been able to film at all due to its ineffectiveness. thanks so much!
 
does the level drop occur only when playing back the footage, or was it there on the `phones when you were recording in the first place? Also, have you checked both audio channels (ie. in stereo)? Depending on the way you're cable's wired you may only be sending the mic into one audio channel, meaning that if you try to listen to the wrong channel you'll just hear preamp noise and crosstalk.

When you say that the audio levels are "propperly ballanced" do you mean that the camera's audio meter is reporting a healthy signal? If so, remember that the metering options found on inexpensive AV gear are never as accurate as a good pair of headphones and an experienced set of ears.

The GL-2 is a pretty dodgy camera audio-wise, and most XLR to 1/8" cables aren't wired with that application in mind. I would strongly reccomend investing in a XLR to 1/8" adapter along the lines of Beachtek's DXA-2. One of those will clear up many of the issues that creep up in this sort of setup.

If you believe that the mic is at the root of the problem, take it back to where you got it and ask to check it on their equipment. Most dealerships will be more than happy to help.
 
SMuir said:
does the level drop occur only when playing back the footage, or was it there on the `phones when you were recording in the first place? Also, have you checked both audio channels (ie. in stereo)? Depending on the way you're cable's wired you may only be sending the mic into one audio channel, meaning that if you try to listen to the wrong channel you'll just hear preamp noise and crosstalk.

When you say that the audio levels are "propperly ballanced" do you mean that the camera's audio meter is reporting a healthy signal? If so, remember that the metering options found on inexpensive AV gear are never as accurate as a good pair of headphones and an experienced set of ears.

The GL-2 is a pretty dodgy camera audio-wise, and most XLR to 1/8" cables aren't wired with that application in mind. I would strongly reccomend investing in a XLR to 1/8" adapter along the lines of Beachtek's DXA-2. One of those will clear up many of the issues that creep up in this sort of setup.

If you believe that the mic is at the root of the problem, take it back to where you got it and ask to check it on their equipment. Most dealerships will be more than happy to help.
Click to expand...

i forgot to check the audio levels using headphones; i found that the audio in the headphones is exactly as it should be, and sounds reeeeally good!

- with respect to the proper audio levels, i mean that the audio levels on the GL2 read regular, as opposed to being far too little, which would correlate to the quiet playback level.

the audio levels being fine in the headphones bothers me... and makes me curious. what do you think the problem could possibly be? thanks so much for your help
 
-- forgot to mention: when using the headphones, the audio sounded great on both playback and during real-time review. i listened during playback with the headphones and all sounded good, and then unplugged them to find the speaker outputting terribly low volumes. this is truly frustrating. thanks again and again
 
So if you playback with headphones it sounds fine, but if you playback through the camera's built in speaker it's really low or silent? If that's the case, there's nothing "wrong"...

The cable you're using to connect your mic is meant to go into a mono balanced plug, while your camera is expecting a stereo unbalanced plug. (They look identical.) What ends up happening is the left and right channels in your camera are 180° out of phase, in other words they are exactly opposite of one another. You don't notice it in your headphones because each side is isolated. When the camera tries to combine them into a mono signal to output through it's speaker, though, they cancel one another out.

The cheapest option is to keep doing what you're doing, and then when you get your sound into a DAW or NLE just delete either the left or right channel (don't use an automated mono-summing function, or it will do the same thing the camera is.) The other option, which esentially does the same thing is to use a Beachtek like the one SMuir mentioned or Canon's own (slightly noiser) MA-300. They mount to your camera and accept XLR cables, so if you only plug one mic in it will only be recorded in the channel you plug it into, so you don't have to delete anything in post.
 
If Shawnmaddock's diagnosis is the case (and it certainly fits the symptoms), then you have nothing to worry about, as long as you can do without the on-camera speaker (the on-camera speaker being virtually useless as a diagnostic or evaluation tool). Just remember that you absolutely MUST delete one of the tracks in post-production (sometimes this opperation is called "take left" or "take right" in NLE software), and center-pan the resulting mono track. Otherwise, your videos will sound rather wide and spacey when played back on a stereo setup, and the dialogue will vanish altogether on a mono playback system (such as a small TV, portable video projector, or mono VCR).

The moral of the story is: always ensure that you're video's are mono-compatable. Here's an article about mono-compatability and phase cancellation: http://www.audiocourses.com/article1664.html.

One more thing to consider; some Beachtek models provide phantom power, and most electret condensor mics will deliver higher signal-to-noise ratios when opperating off phantom power rather than a battery. That, and a stereo XLR adapter would allow you to record dual-mono using a battery-powered mic and a Y-cable.
 
thanks sooo much, that helped a lot. after deleting the one track and duplicating it, it sounded correct and as clear as it should be. i really appreciate the help and the in-depth analysis from you both.

thanks again, so much
 
No worries, Robotriderh. Its good that you spotted the problem before you started editing the footage. When your cutting something on an NLE system and monitoring in stereo, its extremely difficult to spot this kind of an issue unless your specifically looking for it.

Before finalising a mix, always check that everything sounds alright when the left and right channels are summed.
 
You must log in or register to reply here.
Back
Top