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Gear / Technical Help => Battery Boxes, Preamps, Mixers, ADCs, and Processors => Topic started by: mblindsey on June 09, 2011, 10:55:17 PM

Title: boosting gain w/pre after recording
Post by: mblindsey on June 09, 2011, 10:55:17 PM

I recorded a piano recital this evening.  My daughter's teacher held it at a small local college's music hall.  For speed and low-profile, I spaced a CA-11's cards inside the grand piano per some of the recording tutorials I read at the last minute (CA-11->9100->r-or9HR @ 48/24).  I asked the piano teacher to play up and down and the levels looked hot.  She had to greet parents and I didn't get a second chance, so I guessed on how much to turn the 9100 down - I guessed wrong.

The levels when the kids between the ages of 5 and 11 play are much quieter.  As a result the average dB is around -35.  Otherwise, it sounds pretty good for a shot in the dark mic placement on a grand piano based on a google images search. 

The noise (hiss) is obtrusive in the software programs I casually know how to use to increase volume (Reaper/Audacity). 

Would running this recording from my R-09HR -> V3 -> R44 result in an increase in gain with less noise than software?  Dumb idea, or would that work?  If reasonable, digital or analog to the R-44?  I guess I could do something similar with the 9100 if that is a better idea....

Other ideas welcome.

Thanks in advance for any suggestions!

--Michael
Title: Re: boosting gain w/pre after recording
Post by: page on June 09, 2011, 11:02:05 PM

I recorded a piano recital this evening.  My daughter's teacher held it at a small local college's music hall.  For speed and low-profile, I spaced a CA-11's cards inside the grand piano per some of the recording tutorials I read at the last minute (CA-11->9100->r-or9HR @ 48/24).  I asked the piano teacher to play up and down and the levels looked hot.  She had to greet parents and I didn't get a second chance, so I guessed on how much to turn the 9100 down - I guessed wrong.

The levels when the kids between the ages of 5 and 11 play are much quieter.  As a result the average dB is around -35.  Otherwise, it sounds pretty good for a shot in the dark mic placement on a grand piano based on a google images search. 

The noise (hiss) is obtrusive in the software programs I casually know how to use to increase volume (Reaper/Audacity). 

Would running this recording from my R-09HR -> V3 -> R44 result in an increase in gain with less noise than software?  Dumb idea, or would that work?  If reasonable, digital or analog to the R-44?  I guess I could do something similar with the 9100 if that is a better idea....

Other ideas welcome.

Thanks in advance for any suggestions!

--Michael

Nope.

Can you post a sample (say, 1min in 24/48, both with non-playing and playing)? I might be able to do something with noise reduction, especially since I suspect it's constant.
Title: Re: boosting gain w/pre after recording
Post by: Church-Audio on June 09, 2011, 11:14:26 PM
You always have to ride levels when you are dealing with this type of program material.
Title: Re: boosting gain w/pre after recording
Post by: mblindsey on June 09, 2011, 11:29:03 PM
You always have to ride levels when you are dealing with this type of program material.

I wish I could have watched levels and corrected Chris - believe you me.  First time and a monumental mistake, because I have a two shot HD cam that is great (horrible audio).  But, I just couldn't slide between the crowd of parents and the small but courageous  performers....this was beyond stage lip and completely blind.  ;)
Title: Re: boosting gain w/pre after recording
Post by: mblindsey on June 09, 2011, 11:44:54 PM
Here is about as low as it goes:

https://docs.google.com/leaf?id=0B9fSwo6XauOqNGNmNjVlNTItYTFlNi00NWFhLTgwN2YtMTkyOGZjMjRjMmQz&hl=en_US

If there is a software resolution, I'll link this over to the appropriate forum.  I was fishing for a "hardware I have response".

Thanks again!

--Michael
Title: Re: boosting gain w/pre after recording
Post by: page on June 10, 2011, 12:50:58 AM
yeah, this can be salvaged. Not perfect by any means, but it can be salvaged. I'll post a sample for critical listening tomorrow morning (letting it run overnight). When do you need it done by?

If you can find someone who has a copy of Izotope RX, I can copy down the settings I'm using and you can just do it. Otherwise I'll help you out of a jam as long as you don't need it ready in the next week or so.

edit: finished early. here's the same thing back: http://iput.it/5f7c08
Title: Re: boosting gain w/pre after recording
Post by: Church-Audio on June 11, 2011, 10:08:47 AM
You always have to ride levels when you are dealing with this type of program material.

I wish I could have watched levels and corrected Chris - believe you me.  First time and a monumental mistake, because I have a two shot HD cam that is great (horrible audio).  But, I just couldn't slide between the crowd of parents and the small but courageous  performers....this was beyond stage lip and completely blind.  ;)

You absolutely need to ride levels on program like this.
Title: Re: boosting gain w/pre after recording
Post by: it-goes-to-eleven on June 11, 2011, 11:07:58 AM
This is a situation where I really prefer microphones with balanced output... So I can run long cables to mics on stage, or on the ceiling, etc.  Just because my mics are on stage doesn't mean I need to be.

Another option would be a line driver that has balanced output, and you locate that near the mics.  Mshiliarious's PFA has that ability, but requires 48v which you don't have in your rig.

With some gear setups you can get away with long unbalanced cable runs.  So you might want to try that.

I've been wondering about using parallel compression in situations like this to flatten the noise floor and raise the dynamics, but haven't tried it seriously yet.

One gotcha I have found when reducing noise is that some software algorithms can add "computer sound" like patterns to the remaining noise.  I find that intensely annoying.  It is way worse than louder random white noise.
Title: Re: boosting gain w/pre after recording
Post by: page on June 11, 2011, 12:45:39 PM
^^ i agree w/ the software algo adding "water noise" of sorts.

Izotopes RX has a setting to reduce it (with compromise of course) but I find it works fairly well, if you run into w/ that, you end up backing off of the NR a bit.

Sent via android
Title: Re: boosting gain w/pre after recording
Post by: Napo on June 19, 2011, 12:55:06 AM

If you can find someone who has a copy of Izotope RX, I can copy down the settings I'm using and you can just do it. Otherwise I'll help you out of a jam as long as you don't need it ready in the next week or so.


Hey, page;

Can you please send me the RX settings you are using for my future tweaking of noise. Thank you in advance.
Title: Re: boosting gain w/pre after recording
Post by: page on June 20, 2011, 10:39:24 AM
Hey, page;

Can you please send me the RX settings you are using for my future tweaking of noise. Thank you in advance.

RX is finicky in that it's truely a case by case basis for how you do the settings (it's based off of a sound sample that it learns from). If you want to take his sample as posted for a starting point in learning how noise reduction works though, I'll take a screenshot or do notes or and post it tonight.
Title: Re: boosting gain w/pre after recording
Post by: Napo on June 20, 2011, 12:07:51 PM
Hey, page;

Can you please send me the RX settings you are using for my future tweaking of noise. Thank you in advance.

RX is finicky in that it's truely a case by case basis for how you do the settings (it's based off of a sound sample that it learns from). If you want to take his sample as posted for a starting point in learning how noise reduction works though, I'll take a screenshot or do notes or and post it tonight.

WOW, Page; that woud be fantastic! Thanks a million
Title: Re: boosting gain w/pre after recording
Post by: page on June 20, 2011, 07:07:58 PM
Ok, so how this works is I'm hearing a lot of constant broadband noise, not so much a tonal issue. So I find the spot in the sample thats 4 or 5 seconds long and has as little signal (or "non-noise" if you will) and use that in the learning section of RX. From there it's finding the optimal threshold, then reduction amount, then the finer settings such as the knee or smoothing or stuff like that. A lot of how well it works is dependent upon your initial selection for learning. The bright side is that RX allows you to tinker with it while it's computing a preview and compare a bunch of settings. So I can see what it's like with different knee values and stuff.
Title: Re: boosting gain w/pre after recording
Post by: Napo on June 20, 2011, 11:11:46 PM
Page,

this 'sounds' very interesting. I wished I could be close to your place of resedence and get some learning sessions.
Maybe there is a market for a manual with samples >:D
 
Title: Re: boosting gain w/pre after recording
Post by: page on June 21, 2011, 12:00:31 AM
Page,

this 'sounds' very interesting. I wished I could be close to your place of resedence and get some learning sessions.
Maybe there is a market for a manual with samples >:D

It just takes a while to learn and play with it. Just make sure you've got a very detailed playback setup, and always remember, less is better. Sometimes I leave what I can tell is an issue, just so I don't create a new issue by having a heavy hand in it.
Title: Re: boosting gain w/pre after recording
Post by: Napo on June 21, 2011, 12:02:50 AM
It just takes a while to learn and play with it. Just make sure you've got a very detailed playback setup, and always remember, less is better. Sometimes I leave what I can tell is an issue, just so I don't create a new issue by having a heavy hand in it.

Very true. I tried several times to eliminate coughing but most of the time I ended up worse off, eliminating sound as well.
Title: Re: boosting gain w/pre after recording
Post by: page on June 21, 2011, 12:26:00 AM
It just takes a while to learn and play with it. Just make sure you've got a very detailed playback setup, and always remember, less is better. Sometimes I leave what I can tell is an issue, just so I don't create a new issue by having a heavy hand in it.

Very true. I tried several times to eliminate coughing but most of the time I ended up worse off, eliminating sound as well.

For something like that, I use RX's spectral selector and then either use a straight gain adjustment (on just that selection) or something similar. I've reduced people who whistled after every song and stood next to me that way. Its a handy little tool if you've got the time to learn how to use it well.
Title: Re: boosting gain w/pre after recording
Post by: it-goes-to-eleven on June 21, 2011, 10:25:06 AM
Very true. I tried several times to eliminate coughing but most of the time I ended up worse off, eliminating sound as well.

Have you tried throwing cough drops at the problem?