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-   -   Need urgent solution to fix sound (https://www.dvinfo.net/forum/all-things-audio/111045-need-urgent-solution-fix-sound.html)

Jose Milan December 27th, 2007 12:24 PM

Need urgent solution to fix sound
1 Attachment(s)
Hello everyone,

The last post was incomplete and incorrect (when I wrote "this is not really what happend" I meant: "cant give all the details of all that happend", please forgive me for the error...this is all true I give my word...:-)

I'm in the need of DESPERATE HELP from knowledge people in sound to fix this sound (I've attached 2 sound clips one in this message the other in the next). I cant give all the details of all that happend, but I tried to recap:

1. Recorded using XL1S + MA200, 2 mics one directional (boom-Senheisser for public) and one wireless (AKG PR40 for spokeperson).

2. Recorded St1, 12bits (one channel for each mic).

3. We did our test and everything worked fine, but theres something with the spokeperson that brings some kind of strange noise that leave the sound kind of worthless.

I would like to know the reasons for this in the future, since the mic (wireless) works fine with other people except this person, but know I'm not interested in this, I'm interested in knowing a way to fix this problem in post. I doubt there is, but the last thing you loose is hope.

I'm no expert in sound in any way yet, and the software I use in sound for post is COOL EDIT PRO 2.0. If theres a solution to fix (and a detail step by step procedure please) this you will save me. I spent many hours to recorded this and if we can't fix sound we wont be able to get paid. We have to give an answer tomorrow!!! (need to really know if is possible to fix)

PLEASE I don't need (at least now) why this happend or reasons why we didn't use other material, no help with this right now...what I need is possible solutions in post please (later on if anyone is interested I'll give more explanations why we had no other choice).


Giroud Francois December 27th, 2007 12:28 PM

izotope RX is a nice program able to fix strange problems, i will try on this sample.
but i need a longer sample (or the full length original sound) and only the faulty channel.
look at the car beep sample at http://www.izotope.com/products/audio/rx/
the feature you need is SPECTRAL REPAIRE

Paul R Johnson December 27th, 2007 12:44 PM

Well, at first the left channel is missing, but it's just at a really low level. Normalising that channel only brings up perfectly usable audio, although it's a little distant. The other channel just has typical rf noise from the radio mics, a little annoying, but the two blended together aren't anywhere near unusable.

Just a bit of RF fizzing.

You sound really worried - what exactly is it that you are hearing that I'm not?

As for the cause - well, distance is the usual culprit - but you could find that the aerial was bent over making it less effective - the subject could also be sweating - salty bodies mask RF very well - maybe the clothes were rather tight, pulling the aerial closer to the damp skin - maybe it was exactly on the other side of the subject, meaning the body absorbs lots of the RF leaving less for the receiver. With a receiver on the back of the camera, reliable range can be amazing, or really short. I'm assuming it's a UHF system? Many run 50mw or so, but some don't, and are designed to be lower powered - it's often not a problem - but RF mics are never totally reliable.

Jose Milan December 27th, 2007 12:51 PM

Second Longer Sound Clip
1 Attachment(s)
Hello this is the second clip a little longer, I have erase one of the channels (the boom mic and left only the spokeperson).

Thanks for al the help I really needed!!!

Giroud Francois December 27th, 2007 01:06 PM

it sounds like a stange clipping (somebody shaking a box full of sand).
again , i am pretty sure that Izotope RX can clean this.
i need to go back to work and i will try... if you can wait 1 hour.
post the full length file so i can see if the cure is ok on all the file.

Jose Milan December 27th, 2007 01:16 PM

More Info
Hello again,

I really need info on how to fix this problem, and I don't sound worry, I am really worry tomorrow we have to give the answer if we are going to bill these recordings (6 days, making 10 hours of videos) and right now I trully don't think we can. You people say is not really that big, but we dont know how to clean this sound and make it professional.

Giroud, thanks for the info, please try to fix it yourself (if you dont mind) too and post the results (I have attached a second sound clip for testing), what I really need to know if is possible to fix.

Paul, the mics used were: PT40 pro + C417 L from AKG, the receiver has printed: Ultra hig frequency UHF pr 40 - 802.525 MHz for Europe). He spokeperson had his unit on his side, cliped on his belt. He was using a suit most of the time and some with only the shirt (the problem happened in both situations), he wasnt sweating at all, at least buy eye. In later test, with our people, we move around, touch the antenna, bend it, the cables of the mic and everything was okay.

Check this...we even did a test on the same spokeperson to check and everything was okay!!! as soon as we start recording the problem starts again!!!

We couldn't not stop the recording and we had to keep going.

Later on we did another test (with our people) and recorded on the camera and no problem, this is really strange!!!

But as I told I first need to know if we can fix it and later worry about the real problem, but of course all the info you are giving me is priceless and I'm thankful you are telling me.

Trully desperate...keep the help and insight coming please!!!

Jose Milan December 27th, 2007 01:20 PM

Is It Long Enough??
Hello I've posted a longer clip...about 14 second long. I wanted to posted a longer one but seems like it was a problem with the upload and had to lightend the file. I can post a .mp3 but think the resolution is much worse to test.


p.d. Of course I can wait, I'm going to be checking all night for help on this forum.

p.p.d. Thanks in advance

Jose Milan December 27th, 2007 01:23 PM

I have to leave for an hour too, please keep posting, as soon as I get back I'll check everything so please dont think I'm gone.

Giroud Francois December 27th, 2007 01:36 PM

you can send me a long sample of the original sound to my mail
francois(at)giroud(dot)com , my mail is not limited in size so even 200Meg are ok.
it must be the original sound, not a mp3 conversion or anything that has been modified. I will be at work in 30 min and will check this.

Jim Boda December 27th, 2007 01:43 PM


Originally Posted by Jose Milan (Post 798817)
... 2. Recorded St1, 12bits (one channel for each mic).

In the future, you really need to do a 16 bit recording.

Gerry Gallegos December 27th, 2007 01:46 PM

Well I can tell you for sure the problem (even though you dont want to know just yet ) is your wireless. After the fact all you can do is to see if you can extract the sound from the boom mic of your presenter. solo the sound from the shotgun mic and see if you can use that track. if you can then you could possibly add in the wireless track to re-enforce the sound and reduce the effect of the wireless spikes. sound is like baking bread, once the ingredients are mixed and baked they are extremely hard if not impossible to separate.

As far as what caused it, it is definitely your wireless. It is not likely caused by that particular person but it could be caused perhaps by his cell phone or other metallic objects upon his person. but frequency spikes like that are usually the cause of other RF problems in your area. whether you want to hear this or not.

So your best bet is to see how salvageable your shotgun track is. (it shouldn't have the noise in it).
then use this for your main track, and bring the wireless track up a little at a time to re-enforce the shotgun track find a happy medium and if you can automate the volume on the wireless track automate a lowering of say 3 db or so to minimize further over the short spikes.

If the izotope plug in some one else suggested works then its all good. if it only minimized it a bit then you can use both methods together to achieve a usable result.

Giroud Francois December 27th, 2007 02:36 PM

2 Attachment(s)
ok , it seems really hard to get rid of it, but setting a filter a 8500Hz (-70Db) is lowering a lot the problem.
it seems a simple set of filter should the trick

another correction with different filter

Jose Milan December 27th, 2007 02:52 PM

Hello again,

Gerry, is not that I dont want to hear about what caused the problem, quite the contrary, the thing is that I have a deadline (tomorrow. Here is already 20.30 and tomorrow morning we have know if this is "fixable" or not) to answer weather we are going to be able to get paid for this proyect or not and thats way I keep saying I would like to get ways to fix the sound...it doesn't mean I dont want to hear about the problem, of course not, so I'm greatful to get the insight you people are giving me.

The sound from the boom mic is not usable, because it was pointed to the people sitting in the hall and it only pick sound from the spokeperson sometimes not throughout the recording so this is not an option, the only solution is being able to fix the sound from the wireless mic.

Francois (I already emailed you), I have a 40 meg sound file, do you perhaps have a ftp server so I can send you the file???


Giroud Francois December 27th, 2007 03:02 PM

replied to your mail

Gerry Gallegos December 27th, 2007 03:18 PM

Excellent , sounds like Giroud got rid of most of it and it still retained a good amount of presence . one other solution you might want to try is utilizing a de-esser set at those frequencies, so the cut only happens when the noise crosses the threshold and leaving the rest of the recording alone.

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