Big seemingly random glitches on lav mic recording

[nothgeid]

Hi all,

I'm a vfx artist but lately have been doing quite a few small jobs shooting and then editing - go to whoa. Being from the visual side audio is definitely not my strong suit so hoping someone has some advice on a problem I recently encountered. I recorded a speaker (a sort of Ted-talk style presentation) on a Rode SmartLav mic recording to an iPhone. While most of the recording was great and just needed a bit of noise reduction and balancing there are maybe up to a couple of dozen of these massive glitches or dropouts (sorry I don't know the correct term for them) that appear scattered through the timeline - seemingly at random. they are very short duration but massive. They don't appear to be pops or plosives or where he's bumped the mic or anything or where there's loud laughter from the crowd or anything like that. Speaking as a visual guy, I've found Audition a great tool - being able to paint on the patch you want to manipulate?!! AWESOME!! It has done an impressive job of cleaning them up with autoheal and some judicious painting & gain reduction - definitely not perfect and but when you see the source it's pretty amazing to get anything out of it at all!

But just wondering if anyone has encountered this before and could direct me as to how to avoid this in the future. Like I say, audio is still somewhat of a Dark Art to me so I won't be offended if I've done something really dumb and obvious like record levels must have been too high or I should be using a different/better lav or recorder on a long recording (it's an hour & a half) or whatever I would appreciate any advice! Thanks in advance,

Simon

[ryclark]

Unfortunately it is well nigh impossible to guess from just looking at the image what could have caused your glitches without also hearing them. Is it possible for you to post a clip from the original recording somewhere like Dropbox for us to take a listen to. The Rode lav mics are pretty good, so there should be no problems there. However they do rely on power from the iPhone. This means that the connection via the mini jack is the weak spot and can be susceptible to intermittency or interference.

[nothgeid]

Thanks for your quick response! here's a 10 second section from the start of the recording (before the actual speech so lots of extraneous noise) that I pulled out of the original .flac I downloaded from the iphone:
Dropbox - Glitch_test.wav

There are 2 examples in that section. When I opened up the original again I realised the record levels were actually too high but I'm pretty sure that this is not from that.
That's an interesting idea about the power from the phone though - I was just using an old iphone 4 . . .

thanks again for taking a look,

Simon

[SteveG_AudioMasters_]

That doesn't sound like a power fail as such. But since the phone is perfectly capable of sending power out by that route, and there's nothing much wrong with the recording itself, I'd still have to blame the iPhone, simply because there's nothing else in the chain. The problem with using any communication device to do something that it's not primarily cut out to do is that it doesn't exactly specialise in it, if you see what I mean - and that means that anything else going on in the phone is perfectly capable of taking priority with entirely unpredictable results.

If you are going to use these sorts of job for any type of revenue generation, then you need something reliable to record on, and that means a small recorder dedicated to the job. There are any number of these around now, and they really don't cost that much. Have a look at some of the Zoom offerings, or if you want to go slightly upmarket, the Tascam ranges.

[nothgeid]

Thanks for taking a look - I have an H4N but a little bulky to just shove in someone's pocket! - the appeal of the phone of course was the small format - & I didn't realise the potential pitfalls. Live and learn. Thanks for the tip - I'll explore other dedicated options as you suggest.

All the best

[SteveG_AudioMasters_]

There are some smaller dedicated recorders about, but they tend to attract a bit of a premium, and the really small ones, even from reputable manufacturers have some limitations. That said, you might like to look at devices like the Nagra Pico...