The best audio?

Lynne Whelden · February 11th, 2012, 07:09 PM

Yes, that whole discussion on the forum was oriented around the wrong premise, of the camera not providing power to the mic. But the GP email states just the opposite. My experience seems to bear that out as well, because whenever I'd insert a mic into the jack, an electronic buzz would briefly result as the tip of the mic passed by the "hot" contact.
As for AGC, I've heard a lot of different gain controls over the years and if this is AGC, it's new to me. Why the rhythmic ticking? AGCs I've heard have more of a "breathing" nature that intensifies when nobody's talking. This was a constant churning or interference sound, not changing at all, not influenced whether I was talking into the mic or not. The ticking was always present along with the electronic interference.
That's what it sounds like to me...an electronic interference from the camera itself. For what it's worth, I'm reporting all of this to the GoPro customer support team. I asked them if this is a firmware issue or a mic issue.

Lynne Whelden · February 12th, 2012, 10:28 AM

I ran the same test using the same 3 mics today, just to verify my initial impressions. When listening to internal mic only, none of the sounds below are heard (except for a "kazoo-like" ringing that accompanies each word I speak into the mic, which by itself is bad enough).

Breaking down the electronic interference sounds:
1--there's a ticking sound present with all ext. mics except the Sony bluetooth
2-with all three mics, there's a high frequency hiss
3-with all three mics, there's a mid-range "gurgle," almost sounding like an idling scooter, or a dryer that's running.
4-the above sounds are injected into the sound track as soon as the rt. angle adapter (without any mics plugged in yet) is attached.

If I plug the mics directly into the camera, bypassing the adapter, the offensive sound is still there.

To cast a cynical eye upon all of this, when the instructions on the back of the camera warn the user about differentiating between audio recorded under 100 mph and above 100 mph, I suppose it's hard to take any audio output seriously. For the average extreme sports user, they're going to use a music track anyway. For those recording "sound," hearing gurgling (underwater), or hearing a voice (however broken up), is more than enough. Which leaves the rest of us documentary filmmakers out in the cold, with the only option being 2nd system sound with all its hassles for a long-form project involving hundreds of shots and hours and hours of footage.

One tantalizing and preliminary conclusion from the above is that the self-powered mic (the bluetooth) eliminates the ticking whereas the mics requiring power from the camera (the Olympus and the Sony 30) cause the ticking to occur. What to make of that, I haven't a clue.

Rick Hill · February 12th, 2012, 10:03 PM

I find this all very interesting. However I think it is a mistake to criticize the go pro on sound when you consider the intended applications.

It is a "sports" camera. The mic performs well with wind noise and underwater. The intended applications.

I would abandon the go pro in your quest since it is not the intended application. At least from an audio point of view.

At a minimum find a different audio recording solution.

Hart Boyd · February 13th, 2012, 06:23 AM

I had a chance to play with my Sony ECM-DS30P last night and I am getting different results that you. I started recording without the mic plugged in and then continued to talk as I plugged in the Sony ECM-DS30P mic. I took the recording and pulled it into Adobe Priemer and noticed right way that the volume levels were way lower than the Sony ECM-DS30P. I did not hear any clicking or anything noise just a lot lower of a volume. I will have to do some more testing with mic direction to get a true stereo recording with the Sony as my right and left was not at equal levels.

Lynne - It may be possible that you have a bad circuit in the camera and may want to test with another camera to confirm. It is also possible that you are hearing feedback in the way you are testing by using the HDMI connected to a TV to monitor your audio. What kind of seperation/distance do you have between your camera and TV?

Lynne Whelden · February 13th, 2012, 07:36 AM

I checked the HDMI cable, plugged it into a 2nd slot on the tv to see if that was the problem, moved the 6' cable around to make sure it wasn't crossing an electrical cable elsewhere causing interference...and it still sounds the same. (On closer listen, I would describe the "ticking" as 2 cycles per second, not 1 cps.)

I suppose it could be the camera but short of sending everything back (I'm 1/2 way through a 30-day trial period) and starting over, I don't know what else to do. At some point I'm probably taxing the patience of the seller...

This process of trying to figure out the source of the noise could be never-ending. (Is it the cable? The adapter? The mic? The camera? Cosmic rays?) I'd be more inclined to simply send the camera to GoPro and ask them if, in their opinion, the camera audio is "normal." If they would do such a thing, since by saying "yes" they'd be shooting themselves in the proverbial foot.

The lower volume may be the key...if you boost the volume up to what would be considered normal, that's likely where you'll hear what I'm hearing. Then too, I'm listening through speakers that are pretty good. If you're only hearing it through tiny laptop speakers, it may not be so obvious.

I realize the intended application for this camera is "extreme sports." Perhaps I'm wrong to lump backpacking into that category. But it still begs the question...why even put an ext. mic jack on the camera if audio wasn't to be taken (semi-) seriously? It seems as if their intended use for audio was as narration only, where the user is taking/shouting into a mic that's only 6" away. Under that circumstance, I suppose the audio's fine, either internal or ext. mic.
But for audio that's >5' away...(which I would classify as "natural sound") that's a whole other story!

Ian Newland · February 13th, 2012, 06:17 PM

As i explained to you on the Goprouser forum Lynne, the GoPro audio was optimized for loud sounds like car engines roaring close by. As soon as things go quite, up goes the AGC and the internal noises and noise floor increases. It's the same issue people have with the audio on the GH1. If you watch any Gopro produced video by Head Editor Abe Kislevitz, you will notice they hardly ever use the cameras audio. That's telling you something.

Lynne Whelden · February 14th, 2012, 07:47 AM

Here's the mystery of the ages then, Rambo, and I think others have touched upon it.

(1) Having done video for over 30 years now, I've come to assume that ext. mic ports are there to give you cleaner audio. Why then why would GP add one if it wasn't meant to do just that?

(2) Who's ever heard of a mic designed to pick up loud sounds but not quiet sounds? I've heard a lot of AGCs in my life, with their various responses and attack rates and all that, and GoPro's AGC, if that's what it is, is unlike anything I've ever heard. I don't hear any rise and falls, I only hear a constant noise floor that doesn't change whether I'm talking directly into the mic or talking 10' away.

The cynical me says this is audio not ready for prime time, in need of more tweaking before the next Hero release.

Ian Newland · February 14th, 2012, 06:09 PM

It's just not designed for what you had in mind.

Lynne Whelden · February 14th, 2012, 08:16 PM

Perhaps then it's a fitting eulogy to announce the results of the final mic, the cadillac of the plug-in powered mics, the Boss BA CS 10 at $80. (Drum roll please...)

Same as all the other mics...it couldn't resurrect the audio above the noise floor and the 2 cycle/sec ticks.
In the end, the built-in mic of the Hero 2 does the best of them all by managing to avoid this noise endemic in the ext. mic jack.

Hart Boyd · February 15th, 2012, 02:36 PM

Sorry hear that as I had hoped that at least on of them would work as I was not willing to purchase all of them. I only have the Sony and while the audio is low I am not hearing or seeing (video editor) any clicking sounds. I am still curious if your GoPro had a bad audio jack or circuit.

Warren Kawamoto · February 15th, 2012, 06:46 PM

I have a GoPro2, but would never think twice about using it's audio. Here's why. Go ahead and record something with it's built-in mic, then play it back. You'll hear a lot of artifacts in the audio, especially on the high end of the spectrum, as if it was recorded at a very low sampling rate. Hearing this, my conclusion is that even if you could connect the best microphone in the world to it, the audio will still sound poor because the problem isn't the microphone, it's the low sampling rate.

Lynne Whelden · February 17th, 2012, 06:15 PM

I'm still committed to walking this problem through all the way to a resolution. I sent the GP customer service people a (better) youtube link so they can listen to what I'm hearing.
Meanwhile, I sent the Boss mic back.
The other mics are still here for a few more days.
But GP seemed to suggest that if they are concerned enough, they might suggest I send the camera in for them to look at. We'll see.

February 11th, 2012, 07:09 PM	#31
Lynne Whelden Major Player Join Date: Feb 2003 Location: williamsport, pa Posts: 604	Re: The best audio? Yes, that whole discussion on the forum was oriented around the wrong premise, of the camera not providing power to the mic. But the GP email states just the opposite. My experience seems to bear that out as well, because whenever I'd insert a mic into the jack, an electronic buzz would briefly result as the tip of the mic passed by the "hot" contact. As for AGC, I've heard a lot of different gain controls over the years and if this is AGC, it's new to me. Why the rhythmic ticking? AGCs I've heard have more of a "breathing" nature that intensifies when nobody's talking. This was a constant churning or interference sound, not changing at all, not influenced whether I was talking into the mic or not. The ticking was always present along with the electronic interference. That's what it sounds like to me...an electronic interference from the camera itself. For what it's worth, I'm reporting all of this to the GoPro customer support team. I asked them if this is a firmware issue or a mic issue.

February 12th, 2012, 10:28 AM	#32
Lynne Whelden Major Player Join Date: Feb 2003 Location: williamsport, pa Posts: 604	Re: The best audio? I ran the same test using the same 3 mics today, just to verify my initial impressions. When listening to internal mic only, none of the sounds below are heard (except for a "kazoo-like" ringing that accompanies each word I speak into the mic, which by itself is bad enough). Breaking down the electronic interference sounds: 1--there's a ticking sound present with all ext. mics except the Sony bluetooth 2-with all three mics, there's a high frequency hiss 3-with all three mics, there's a mid-range "gurgle," almost sounding like an idling scooter, or a dryer that's running. 4-the above sounds are injected into the sound track as soon as the rt. angle adapter (without any mics plugged in yet) is attached. If I plug the mics directly into the camera, bypassing the adapter, the offensive sound is still there. To cast a cynical eye upon all of this, when the instructions on the back of the camera warn the user about differentiating between audio recorded under 100 mph and above 100 mph, I suppose it's hard to take any audio output seriously. For the average extreme sports user, they're going to use a music track anyway. For those recording "sound," hearing gurgling (underwater), or hearing a voice (however broken up), is more than enough. Which leaves the rest of us documentary filmmakers out in the cold, with the only option being 2nd system sound with all its hassles for a long-form project involving hundreds of shots and hours and hours of footage. One tantalizing and preliminary conclusion from the above is that the self-powered mic (the bluetooth) eliminates the ticking whereas the mics requiring power from the camera (the Olympus and the Sony 30) cause the ticking to occur. What to make of that, I haven't a clue.

February 12th, 2012, 10:03 PM	#33
Rick Hill Regular Crew Join Date: Aug 2008 Location: McHenry, Illinois Posts: 55	Re: The best audio? I find this all very interesting. However I think it is a mistake to criticize the go pro on sound when you consider the intended applications. It is a "sports" camera. The mic performs well with wind noise and underwater. The intended applications. I would abandon the go pro in your quest since it is not the intended application. At least from an audio point of view. At a minimum find a different audio recording solution.

February 13th, 2012, 06:23 AM	#34
Hart Boyd Regular Crew Join Date: Jan 2004 Location: Atlanta, GA Posts: 148	Re: The best audio? I had a chance to play with my Sony ECM-DS30P last night and I am getting different results that you. I started recording without the mic plugged in and then continued to talk as I plugged in the Sony ECM-DS30P mic. I took the recording and pulled it into Adobe Priemer and noticed right way that the volume levels were way lower than the Sony ECM-DS30P. I did not hear any clicking or anything noise just a lot lower of a volume. I will have to do some more testing with mic direction to get a true stereo recording with the Sony as my right and left was not at equal levels. Lynne - It may be possible that you have a bad circuit in the camera and may want to test with another camera to confirm. It is also possible that you are hearing feedback in the way you are testing by using the HDMI connected to a TV to monitor your audio. What kind of seperation/distance do you have between your camera and TV?

February 13th, 2012, 07:36 AM	#35
Lynne Whelden Major Player Join Date: Feb 2003 Location: williamsport, pa Posts: 604	Re: The best audio? I checked the HDMI cable, plugged it into a 2nd slot on the tv to see if that was the problem, moved the 6' cable around to make sure it wasn't crossing an electrical cable elsewhere causing interference...and it still sounds the same. (On closer listen, I would describe the "ticking" as 2 cycles per second, not 1 cps.) I suppose it could be the camera but short of sending everything back (I'm 1/2 way through a 30-day trial period) and starting over, I don't know what else to do. At some point I'm probably taxing the patience of the seller... This process of trying to figure out the source of the noise could be never-ending. (Is it the cable? The adapter? The mic? The camera? Cosmic rays?) I'd be more inclined to simply send the camera to GoPro and ask them if, in their opinion, the camera audio is "normal." If they would do such a thing, since by saying "yes" they'd be shooting themselves in the proverbial foot. The lower volume may be the key...if you boost the volume up to what would be considered normal, that's likely where you'll hear what I'm hearing. Then too, I'm listening through speakers that are pretty good. If you're only hearing it through tiny laptop speakers, it may not be so obvious. I realize the intended application for this camera is "extreme sports." Perhaps I'm wrong to lump backpacking into that category. But it still begs the question...why even put an ext. mic jack on the camera if audio wasn't to be taken (semi-) seriously? It seems as if their intended use for audio was as narration only, where the user is taking/shouting into a mic that's only 6" away. Under that circumstance, I suppose the audio's fine, either internal or ext. mic. But for audio that's >5' away...(which I would classify as "natural sound") that's a whole other story! Last edited by Lynne Whelden; February 13th, 2012 at 08:38 AM.

February 13th, 2012, 06:17 PM	#36
Ian Newland Major Player Join Date: Jan 2009 Location: Brisbane, Australia Posts: 319	Re: The best audio? As i explained to you on the Goprouser forum Lynne, the GoPro audio was optimized for loud sounds like car engines roaring close by. As soon as things go quite, up goes the AGC and the internal noises and noise floor increases. It's the same issue people have with the audio on the GH1. If you watch any Gopro produced video by Head Editor Abe Kislevitz, you will notice they hardly ever use the cameras audio. That's telling you something.

February 14th, 2012, 07:47 AM	#37
Lynne Whelden Major Player Join Date: Feb 2003 Location: williamsport, pa Posts: 604	Re: The best audio? Here's the mystery of the ages then, Rambo, and I think others have touched upon it. (1) Having done video for over 30 years now, I've come to assume that ext. mic ports are there to give you cleaner audio. Why then why would GP add one if it wasn't meant to do just that? (2) Who's ever heard of a mic designed to pick up loud sounds but not quiet sounds? I've heard a lot of AGCs in my life, with their various responses and attack rates and all that, and GoPro's AGC, if that's what it is, is unlike anything I've ever heard. I don't hear any rise and falls, I only hear a constant noise floor that doesn't change whether I'm talking directly into the mic or talking 10' away. The cynical me says this is audio not ready for prime time, in need of more tweaking before the next Hero release.

February 14th, 2012, 06:09 PM	#38
Ian Newland Major Player Join Date: Jan 2009 Location: Brisbane, Australia Posts: 319	Re: The best audio? It's just not designed for what you had in mind.

February 14th, 2012, 08:16 PM	#39
Lynne Whelden Major Player Join Date: Feb 2003 Location: williamsport, pa Posts: 604	Re: The best audio? Perhaps then it's a fitting eulogy to announce the results of the final mic, the cadillac of the plug-in powered mics, the Boss BA CS 10 at $80. (Drum roll please...) Same as all the other mics...it couldn't resurrect the audio above the noise floor and the 2 cycle/sec ticks. In the end, the built-in mic of the Hero 2 does the best of them all by managing to avoid this noise endemic in the ext. mic jack.

February 15th, 2012, 02:36 PM	#40
Hart Boyd Regular Crew Join Date: Jan 2004 Location: Atlanta, GA Posts: 148	Re: The best audio? Sorry hear that as I had hoped that at least on of them would work as I was not willing to purchase all of them. I only have the Sony and while the audio is low I am not hearing or seeing (video editor) any clicking sounds. I am still curious if your GoPro had a bad audio jack or circuit.

February 15th, 2012, 06:46 PM	#41
Warren Kawamoto Trustee Join Date: Nov 2006 Location: Honolulu, HI Posts: 1,435	Re: The best audio? I have a GoPro2, but would never think twice about using it's audio. Here's why. Go ahead and record something with it's built-in mic, then play it back. You'll hear a lot of artifacts in the audio, especially on the high end of the spectrum, as if it was recorded at a very low sampling rate. Hearing this, my conclusion is that even if you could connect the best microphone in the world to it, the audio will still sound poor because the problem isn't the microphone, it's the low sampling rate.

February 17th, 2012, 06:15 PM	#42
Lynne Whelden Major Player Join Date: Feb 2003 Location: williamsport, pa Posts: 604	Re: The best audio? I'm still committed to walking this problem through all the way to a resolution. I sent the GP customer service people a (better) youtube link so they can listen to what I'm hearing. Meanwhile, I sent the Boss mic back. The other mics are still here for a few more days. But GP seemed to suggest that if they are concerned enough, they might suggest I send the camera in for them to look at. We'll see.