[linux-audio-user] Fwd: [Jamin] Re: soft clip: Achieving Gain, inconsequential overloads

Mark Knecht markknecht at comcast.net
Sun Apr 11 17:30:49 EDT 2004


On Sun, 2004-04-11 at 13:16, R Parker wrote:
> Hi,
> 
> Maybe some folks on this list have insites into the
> following conversation between Steve and myself. I
> need all the help I can get. The last three paragraphs
> are a topic for which I am woefully ignorant.

Ron,
   I'm not totally sure I'm in tune with the exact problem yet, but on
my end today I'm doing some first mixes of a Big Band group I recorded
Thursday and last evening. 8 horns, drums, bass, guitar and piano.
Probably not the same sort of music you're working on. (Strange music
for me too....jeez...I'm dancing close with a sexy brunette in 1940's
New York...) ;-)

   For the tracking we used only 2 R0de mics on the whole group. The raw
audio sounds pretty good, but since the 002 Rack has no compressor
between the mic pre and the A/D my recorded levels are low. I knew this
going in, so I kept the preamp gain low to minimize peak clipping in the
A/D, but I come up with less volume. (Obviously.)

   My first step, which doesn't effect sound if it's done right, was to
simply normalize the tracks up a bit. (I told the normalizer to make the
highest peak -1db) At that point things were better with volume, but a
bit dry, so I added some IR1 reverb, which was my plan before recording
since they couldn't get a room with a lot of ambiance. Now it sounds
better, but it's still low volume.

   At this point I'm working with a Waves C4 on the Master fader. I've
got about 3db gain on each band. I've got my breakpoints set at 100Hz,
500Hz and about 3K. You would adjust based on the music you're doing.
I've got the low-band compressor threshold set sort of low, like -25db,
and the high band set a bit low at -18. The two mid-band thresholds are
set around -12. All the ranges are set identically at -12. At this point
I get pretty close to 3db gain except during peaks in each band 3 when
the compressor kicks in. I can then raise overall gain to get a bit more
volume and tune the compressor thresholds of I'm having trouble in any
specific band.

   I'm no expert on compressors, but I think a 4-band compressor is a
really place to start for what you want to do, so Jamin should be
helpful. My biggest recommendation would be to compress as little as
possible. If I do too much it all sounds unnatural. In my case it's
really only the band below 100Hz that's consistently ranging down. The
other 3 are moving much less.

> 
> > --- Steve Harris <S.W.Harris at ecs.soton.ac.uk> wrote:
> > > On Sun, Apr 11, 2004 at 10:04:43 -0700, R Parker
> > > wrote:
> > > > Not sure but I probably mentioned something
> > about
> > > this
> > > > several months ago. Steve, do you have a soft
> > clip
> > > > LADSPA plug? If yes, I think it should be a
> > > candidate
> > > > for adding to the output stage of JAMin.
> > > 
> > > There are some soft clip LADSPA plugins, but I
> > dont
> > > think any of them are
> > > better than JAMin's "boost".
>  
> > The thing is my client has requested a %20 increase
> > in
> > volume across the entire album. The first question
> > is
> > does he know what he's asking for. Well, he probably
> > has a fair enough idea. He has compared the old
> > master
> > with stylistically similar million dollar masters
> > and
> > concluded the percentage to increase.
> > 
> > If anyone here has tricks for achieving gain, I need
> > to hear about them. My bag ain't got alot in it. I
> > basically cut dominant frequency either with
> > compression or equalization and with the leveled off
> > floor, achieve gain possible; input, compressor
> > makeup, limiter input, boost and output. Of course
> > then it's just a matter of tweaking ratios,
> > thresholds, etc.
> > 
> > The trade off in general is less dynamics and more
> > distortion with several deciables of increased
> > volume.
> > I love the work but this job is like a No Rules Cage
> > Match. I might eventually win the title but it's a
> > good thing I brought lunch and a first aid kit.
> > 
> > > I've heard that you can ignore peaks that only go
> > > over 0dB for less than a
> > > millisecond, but I've not experimented with it.

I think this is very specific to to where in the chain it happens as
well as the exact system you're using. 

> > 
> > If that's the case, then I might have this job in
> > the
> > bag. I'm watching overloads at the input channels of
> > my mixer flicker on and off. I've been trying very
> > hard to have absolutely zero overload indications.
> > 
> > Any idea how to test this potential point of
> > flexibility or how to push this limit? What am I
> > watching for and how do I watch for it? This seems
> > like a very interesting area of study. I've gotta do
> > a
> > dirt knap and then maybe google about or something.
> > 
> > ron
> >  
> > > - Steve 
> > 
> > 
> > __________________________________
> > Do you Yahoo!?
> > Yahoo! Tax Center - File online by April 15th
> > http://taxes.yahoo.com/filing.html
> > 
> > 
> >
> -------------------------------------------------------
> > This SF.Net email is sponsored by: IBM Linux
> > Tutorials
> > Free Linux tutorial presented by Daniel Robbins,
> > President and CEO of
> > GenToo technologies. Learn everything from
> > fundamentals to system
> >
> administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click
> > _______________________________________________
> > Jamin-devel mailing list
> > Jamin-devel at lists.sourceforge.net
> >
> https://lists.sourceforge.net/lists/listinfo/jamin-devel
> 
> 
> __________________________________
> Do you Yahoo!?
> Yahoo! Tax Center - File online by April 15th
> http://taxes.yahoo.com/filing.html




More information about the Linux-audio-user mailing list