06-06-2019 06:50 PM - edited 06-06-2019 09:10 PM
In one of our courses, we play the drum, and I am looking for fix for the poor quality of the drumming - you can hear clicks and scraps while I play the drum. We have had a negative comment on it in a review this morning, so looking for an urgent solution. The audio was recorded with a Rode Lavalier microphone. I also have the audio of the camera (canon rebel T6, but it is even worse). I edit edit with adobe premiere...what settings should I be using?
I am adding a part of the video to help my explanation of the problem.
06-06-2019 07:53 PM
Maybe if you post a portion of the audio file, people will have a better idea of the kind of issues you mention and can make better suggestions.
06-06-2019 08:14 PM
thanks Carlos, I have updated my original question with a video, any ideas on how to fix the audio problem?
06-07-2019 07:02 AM
That sounds like distortion due to the level being too high at some points.
I don't know the audio editing capabilities of Premiere, but I would try normalizing it to -2.5 dB (or even below). If premiere doesn't have that feature, you could export the audio en edit it with Audacity.
If normalization makes some parts too quiet, you might need to try lowering the gain only on the peaks, but I don't really know if there is a way to automate that.
06-08-2019 10:39 PM - edited 06-08-2019 10:43 PM
What you are hearing is digital distortion created by overdriving the microphone's element, better known as clipping. In short, the drumming is too loud and the mic cannot handle it, or it's simply being recorded too hot (too much gain) and the software is clipping the audio. There is no way to "fix' this because once it is recorded that way, it's there permanently. Now, if by some chance the original audio was recorded lower and it was by normalizing the audio when you edited the video that made it distort, it can be fixed. If not, you will have to re-record the videos.
Digital audio cannot record anything above 0db (decibels) - unlike the days of old and using tape, you cannot push the signal above 0db to give it a hotter, more in-your-face sound. Digital audio is all math and anything above 0db does not exist, so the program literally chops it off, creating digital distortion (not the cool distortion guitar players use, the ugly kind) and once it has been recorded that way, any audio that clips (goes above 0db) get's clipped off leaving the ugly distortion. Some programs, have a "de-clip" option that can "fix" minor issues, but it'll never be crystal clear because it's still distorted, it's just hiding (masking) it so it doesn't sound as distorted. It still is, just not quite as noticeable. Again, this is for minor fixes... major issues cannot be "fixed" and have to be re-recorded.
As mentioned, if it was recorded and didn't clip but your video processing raised the volume (normalized it) too much and created the clipped audio, then you can go back to the original recordings and manually adjust it. That is, wherever the audio spikes (compared to the rest of the audio) you can lower that spike by a few dB (2-3 dB) and then raise the entire track by 2-3 dB to increase the overall volume without re-introducing clipping.
In most cases, the human ear cannot detect a sudden shift in volume that is less than 3 dB, meaning the "feel" of the drumming will not be lost by reducing those spikes. If for example there is a 6dB difference, some of the finer nuances of the drumming will be lost because you're adjusting the spikes too much. In other words, the parts you want to emphasize in the passages will no longer have as much emphasis and it'll lose the overall feel. The goal is to record the drumming so you don't have to manually adjust those emphasized hits afterwards.
Part of the problem you are having is the microphone itself. Lav mics are great for the human voice because our vocal range is fairly limited. The element that captures the sound in a lav mic is very small compared to a larger microphone - it's important to remember that microphone elements are like a speaker only in reverse...
Where a speaker receives an electrical signal and then vibrates the speaker to move air, a mic element captures the moving air and turns it into an electrical signal. The bigger the speaker, the deeper the bass you can play through it. It stands to reason then that the bigger the mic element, the more bass you can capture with it. Lav mics, as mentioned, are very, very small. It cannot capture those deeper lows without distorting. If you have a different mic with a larger element, that it what you should be using to capture drum sounds.
If you do not have a larger mic, then your only option is to move it farther away from the sound source. If the mic is meant to pick up the sound of a person explaining the drum pattern and then recording the drum sounds, you're asking for trouble. You will need a second mic. The lav mic for the voice, the 2nd mic for the drums, and during editing you will mute the lav mic so only the 2nd mic is heard. If you're recording the lav directly to your camera, this will be a headache because you need a mixer and someone to "mix on the fly" as it's being recorded. Not as easy as it sounds. The best option then is to simply move the lav mic farther away from the sound sources (the instructor and the drums) and record the hottest (loudest) signal you can without it distorting. It also means manually increasing the parts of the audio track when they are talking so that their volume is fairly matched to the volume of the drumming (unless the instructor can really project his or her voice, in which case you won't need to make as many adjustments later during editing.
When all is said and done, if the original recordings are clipping, you're better off just biting the proverbial bullet and re-recording those videos with the microphone further away and, if possible, use a microphone with a bigger element so the finer nuances of the drumming can be properly recorded.
If you have any questions please do not hesitate to ask.
Best of luck,
06-09-2019 12:26 AM
To resolve your problem is pretty simple, you have to low the gain of your mic while recording...
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