Thank for the comments, Walt. Please see inserts
Rob D.
>Rob Danielson wrote:
>> Hi Rich--
>> It's possible that the low number of bits that get used in a low
>> level field recording may be the bigger culprit. I've gone this
>> route which, indeed, you may already be doing. I carefully equalize
>> as I normalize every field recording trying to minimize the "resonant
>> grunge" with 2-3 passes of Waves Q10 or Waves Ren 6 (which I find
>> smoother). The noise is not in perfectly discrete bandwidths but it
>> does have some more noticeable concentrations in the low to lower-mid
>> range. Important to eq at the speaker level I intend to play it at.
>> After the amplitude is high, I do the head/tail fades when burning
>> the file to audio CD using most of the 16 bits for most of the fade.
>> I also notice that after I have a saturated, fat file, the processing
>> outcome if I must do additional equalization or file mixing comes out
>> much closer to what I heard in preview mode. I believe all waves
>> plugs dither in 32 bit.
>> Rob D.
>
>I'm not inclined to buy in so big to the low end being somehow unique in
>number of bits actually used. A high intensity sound that has little
>dynamic range will be just the same. And in most cases we are really
>talking sounds that are only about half way down in the dynamic range,
>not stuff way down at the bottom.
I was thinking of lower levels, say around 2-4% saturation in the
orig field recording-- about the amount I'd quess Rich would be
working with if he's hearing dithering artifacts.
>
>For instance my Portadisc has over 120 dB dynamic range. If I record
>with 10 dB headroom that quiet sound that's down at -50 dB below the
>louder stuff is half way down. Still quite a lot of bits to work with. A
>reality check is to isolate some of those quiet calls and do a gain
>adjust to bring them up and then listen to them, often they are as rich
>and complete as the stuff originally recorded up at the top.
>
>In the dynamic filtering I've played with it's rare that cutting stuff
>below -70 dB has any effect at all. Typically when doing this my cut
>point is between -45 dB and -55 dB, though that varies.
>
>The dynamic filter I use most of the time works on all frequencies at
>once. It would be nice to have a filter that combined a multi-band eq
>with dynamics. As it is most eq just moves the gain moving the whole
>range at once. In my case being able to remove, say, loud insects at a
>certain frequency range while preserving the lower level ambiance at
>that range is what I'm talking about. Or maybe being able to set the
>upper and lower limits of the dynamic range for that band that will be
>passed would be a good way to have it.
Perhaps something like Waves C4? I'm trying to learn how to use C4
effectively for this but not with much success.
>
>I would certainly agree that much of the noise we deal with is in the
>lower frequencies, but this is a different issue. Bit depth is sound
>intensity. A frequency filter will change intensity, but is not
>specifically filtering along the intensity line.
My guess is a good part of the choppiness that stems from the low bit
rate becomes most audible in the low range,.. have no proof of this,
just that selective reduction works best in that range.
>
>I do a similar process, though I don't use Waves software. I work along
>several parameter lines to remove unwanted sound. Cutting along
>frequency bands is one and probably the most used. But it's also
>possible to remove parts of the dynamic range selectively. And then we
>get into active noise filters which you can "train". And I also will
>"filter" along the timeline to remove some unwanted calls, sometimes
>substituting a equal slice of time from where there is no call.
>
>I think probably a first step if moving into high end equipment is to
>look at your software and make sure its working a larger bit depth in
>it's processing. That will help a lot, and it's not a universal property
>of all software. Sometimes it's even settable.
>
>Walt
>
>
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