View Full Version : External mic arrangement


Renton Maclachlan
August 27th, 2012, 04:03 AM
You may be interested in the arrangement I've made for using an external mic with myGoPro

Chris Harding
August 27th, 2012, 04:59 AM
That's neat Renton

It, of course, wouldn't be totally waterproof any more but would certainly protect the camera in a light drizzle...What mic are you intending to plug in there??

Chris

Renton Maclachlan
August 27th, 2012, 05:34 AM
Hi Chris.

The case is totally waterproof...though obviously not for underwater (though it could be - I won't try it!), and the mic will not be protected. The right angle jack is a tight fit in the rubber gromit.

Just ordered a couple of elcheapo mics off ebay ...be interesting to see how they go...

Sony ECM-DS70p Mini Microphone Mic for Skype iChat MD | eBay (http://www.ebay.com/itm/Sony-ECM-DS70p-Mini-Microphone-Mic-for-Skype-iChat-MD-/360291535002?pt=LH_DefaultDomain_0&hash=item53e30c889a)

Mini 3.5mm Flexible Microphone Mic For PC Laptop Skype MSN Internet Telephony | eBay (http://www.ebay.com/itm/Mini-3-5mm-Flexible-Microphone-Mic-For-PC-Laptop-Skype-MSN-Internet-Telephony-/110939322300?pt=US_Computer_Microphones&hash=item19d47fb7bc#shId)

Chris Harding
August 27th, 2012, 07:26 AM
Hi Renton

Just make sure the mics are self powered!! I bought a neat el-cheapo from Jaycar here and it doesn't work as it's a dynamic mic ..I have always been under the impression that only condenser mics need either a battery or phantom power and dynamic mics work without powered inputs...the Hero didn't like it at all!!!

Let us know how those work?? I shot a wedding 2 weeks ago and used the Hero in the Church and the audio was quite good ..I guess it was because they had a speaker bank about 3 m from the floor and I had the GoPro on a stand just a tad lower and it was in the skeleton case.

Chris

Warren Kawamoto
August 27th, 2012, 10:34 AM
I've yet to hear a decent audio recording from a GoPro. The bitrate is so low that no matter what I did, the audio was pretty much useless.

Renton Maclachlan
August 27th, 2012, 02:42 PM
I'm not look for top notch audio from it. Just better audio...from a mic just outside the case, or a lot closer to the sound source...

Renton Maclachlan
August 27th, 2012, 02:47 PM
Hi Renton

Just make sure the mics are self powered!! I bought a neat el-cheapo from Jaycar here and it doesn't work as it's a dynamic mic ..I have always been under the impression that only condenser mics need either a battery or phantom power and dynamic mics work without powered inputs...the Hero didn't like it at all!! ChrisIf they don't work, there's little loss. I've seen some others suggested...but they cost more...

Lynne Whelden
August 27th, 2012, 03:04 PM
Yes, good luck in your experiment. I tried six different mics ranging from $30 to $80 to no avail. You'll discover that unless the audio is constantly LOUD, you're going to get hiss and static. The Hero's preamp, coupled with an AGC that's impossible to control, is always the insurmountable problem.

Allan Black
August 27th, 2012, 03:41 PM
I've yet to hear a decent audio recording from a GoPro. The bitrate is so low that no matter what I did, the audio was pretty much useless.

That's right, you need a separate audio recorder to get usable audio .. especially if you're going to match and mate it to 'good' audio from your real camera.

Cheers.

Lynne Whelden
August 27th, 2012, 05:08 PM
Who knows, maybe the ProTune upgrade will address this problem?

Ian Newland
August 27th, 2012, 06:54 PM
Who knows, maybe the ProTune upgrade will address this problem?

Nope, poor audio is hardware based.

Best audio I've had from a GOpro with mic socket is a powered lav, battery is inline.

Dean Sensui
August 28th, 2012, 03:37 AM
I modified a "skeletal" housing by making an adhesive gasket out of 3M's VHB, then covering the openings with transparent packing tape.

The result is a housing that's splash-proof yet allows sounds to get to the GoPro's built-in mics.

Had a problem when inserting GoPro's dessicant strips. I made the mistake of putting them on the sides. They got stuck to the adhesive packing tape, and blocked the sound. So if you do this mod, be sure to keep the dessicant strips on the top and bottom -- not on the sides.

The audio qualtiy overall isn't great. But all I need is a sync reference. The production audio comes from wireless mics feeding a 4-track recorder and the main camera.

Kevin Walsh
August 28th, 2012, 02:36 PM
I plugged a Rode NT3 into my GoPro for a quick test. It doesn't sound that bad to me.

GoPro with Rode NT3 (http://player.vimeo.com/video/48396246)

Lynne Whelden
August 28th, 2012, 04:08 PM
The test I'd really like to hear with that Rode NT3 is to simply record "room sound" or "room tone."
See what the AGC does then. Room tone is such a valuable sound to have on hand for editing but it's also very hard to capture. (Same goes for "natural sound," that pervasive outdoor sound of faint wind, or rustling grass, or distant birds and insects. Beautiful audio but oh so hard to get.)

Lynne Whelden
August 29th, 2012, 01:25 PM
Ian...can you mention the brand lapel mic w/ battery that worked for you?
What's your take on why it worked better than others? An inherent noise level that inadvertently served to tamp down the Hero's AGC? A better impedance match?

Renton Maclachlan
September 6th, 2012, 02:01 AM
Well...the first el cheapo mic has turned up and works...

Dean Sensui
September 6th, 2012, 03:09 AM
Well...the first el cheapo mic has turned up and works...

That looks great. You should market it!

How's the sound, and how weather resistant is it?

Renton Maclachlan
September 6th, 2012, 04:19 AM
That looks great. You should market it!

How's the sound, and how weather resistant is it?I've got the Go Pro case pretty waterproof but the mic won't be water proof at all. I'm expecting another el cheapo mic of a different sort any day so it will be interesting to see what that is like.

What's the sound like? Who knows? I tested the sound in the sealed case, and couldn't hear a thing. With the mic, it was fine...well...better than nothing. I haven't anyway of testing its quality, but I wasn't expecting great audio from it...only cost a couple of $US...

Chris Harding
September 6th, 2012, 10:08 PM
Shucks Renton

Sure you could afford such a mic??? I have bought one too...for AUS$4.70 (and free shipping) it's worth a shot as I really only use the Hero audio to sync footage ...at that price if it doesn't work I can toss it in my junk box

Amazing how cheap they can sell these for!!!

Chris

Renton Maclachlan
September 7th, 2012, 01:15 AM
My second elcheapo mic turned up today...and works...although it is quite a lot lower in volume...

Dean Sensui
September 7th, 2012, 04:01 PM
Well...the first el cheapo mic has turned up and works...

Could you post a few photos showing this modification?

Renton Maclachlan
September 7th, 2012, 04:54 PM
I presume you mean the modification of the Go Pro case?

I bought an extra case, marked the centre of the external mic plug on the outside of the case, drilled out with small to large drills until I got a hole size that would take the rubber gomit I got. (First I located a suitable 'L' mini jack > mini jack, and then got a gromit with a hole to suit the size of the plug. As it turned out I didn't have many options.)

I've found in drilling out using small to large drills - particularly in softer material such as plastic, that the larger drills can tend for some reason to wander off the centre, and this happened. This meant that the gromit is unfortunately not actually centred on the external mic output. It's near enough however and the rubber squashes up on one side as the jack is plugged in. The plug is a pretty snug fit in the gromit but I'm not sure if the case is totally waterproof with the plug in it...certainly not waterproof for immersion in water...I'm not going to try it. It's probably not bad for rain, though the mic would get wet...

Also the gromit on the inside needs to be compressed a bit by the camera as it is put in the case, because it encroaches a bit on the camera space. ( I may pare the gromit down a bit on the inside...or maybe not...)

The slot in the gromit for accomodating the case material was slightly narrower than the case so I countersunk the outside of the hole in the case very slightly to allow the gromit to fit better.

Peter Riding
September 9th, 2012, 04:07 AM
Renton, for future reference when drilling a smooth surface such as plastic or metal you do indeed need to start with the narrowest drill bit possible to avoid wander; but also try sticking a piece of tape such as gaffer tape to the surface as this should give the bit just enough purchase to keep in it the right place.

This works on bathroom and kitchen tiles as well :- )

Pete

Renton Maclachlan
September 9th, 2012, 04:47 AM
Renton, for future reference when drilling a smooth surface such as plastic or metal you do indeed need to start with the narrowest drill bit possible to avoid wander; but also try sticking a piece of tape such as gaffer tape to the surface as this should give the bit just enough purchase to keep in it the right place.

This works on bathroom and kitchen tiles as well :- )

PeteThanks Peter. I've never had an issue on harder materials....though sometimes the same thing happens when drilling aluminium...particularly thinner stuff. I normally put masking tape on ceramic tiles but more to allow me to have easily discernable marks to cut to...does help reduce chipping as well. I've done plenty of cutting of ceramics...use diamond blades...but not much drilling...have tried diamond drills...still takes ages. Difficult to centre punch ceramics but the surface needs to be broken.

I actually can't imagine any tape would stop drill wander. The only thing that will I think is that as the drills get bigger, you shouldn't use too big a step up in size....

Larry Stephens
March 10th, 2013, 12:34 PM
Renton,
Do yo remember where you found the 90deg "L" jack? I have looked everywhere and can't find one with long legs on both ends like that.
Thanks Larry S.

Renton Maclachlan
March 10th, 2013, 01:00 PM
As I recall, I just picked it up from the electronic store 'Jaycar' in Wellington...
Adaptor 3.5mm Stereo Socket - 3.5mm Stereo Plug Right Angle - Jaycar Electronics (http://www.jaycar.co.nz/productView.asp?ID=PA3503&form=CAT2&SUBCATID=990#1)

Larry Stephens
March 10th, 2013, 08:28 PM
Thanks for the info!
Larry