Video Guides
> Restoring Audio Quality > SoundForge Filters
Updated
November 2009
This is a visual guide to using audio correction
filters in Sound Forge. The guide does not describe every
filter in the program, or every filter in our downloadable
filter pack, but rather it teaches some fundamentals on how
the filters work, and how to use them in various scenarios.
You'll need either Sound
Forge Audio Studio (consumer version) or the full Sound
Forge professional version. Both versions will work
fine, for the filter work discussed here. A fully-functional
30-day trial of the consumer version is available from the
Sony site. For the best prices, buy
from Amazon, not Sony.
Using a Mac? No problem. Use Parallels
Desktop or VMWare
Fusion, install a copy of Windows XP inside it, and then
run Sound Forge inside of that. Native Mac audio tools are
very limited. Don't let anti-Microsoftism keep you from
using this excellent audio program.
Most of these filters use the Paragraphic Equalizer tool. This is a
helpful EQ method because it gives both numeric and
visual data values. Many of the filters were created in Sonic Foundry
SoundForge 6, but should work well in both most earlier and
all later versions of Sonic Foundry Sound Forge, now known as
Sony Creative Sound Forge.
Download
& Install the Free Filters
Download and install the official digitalFAQ SoundForge
Filter Pack, which adds more than
100 new filter preset settings to Sound Forge.
Understanding
the SoundForge
Interface
Sound Forge is often called "the Photoshop of
sound" and it deserves this distinction. Why? Well,
much like Photoshop, the program can be used as basic or as
advanced as the user wants. It appeals to users of all skill
levels, and has few limitations. The software is normally
limited only by a user's own skills and creativity, and not
the fault of the program itself.
Where are the tools?
- In the professional version of Sound Forge, most controls are located in the
Process menu.
- In the consumer Sound Forge Audio Studio, the filters are
under the FX Favorites > Sony menu.
This
image below shows how to find the EQ (Paragraphic) and below
that is the Normalize function:
General
Audio Notes
Try to not over-filter audio!
Editing audio with the
Paragraphic EQ is essentially a form of frequency carving.
You remove the bad parts of the signal, and then enhance the
good parts of the signal. Try to use no more than five filters
on an audio clip, and know that most audio work is
accomplished with only two or three filters.
Be careful of clipping! Altering the EQ of a file can
raise and lower the depth and scope of the audio, so be
cautious of "red-lining" the file (clipping), as
it can corrupt the quality with cracks and other noise. This
is very important to monitor as corrections are being made, as well as why audio files
should NOT be captured at peak volume levels.
Paragraphic
Equalizer Overview
An equalizer is an option to augment the sound of an
audio file. Anyone familiar with a high-quality stereo has
probably seen a very basic paragraphic EQ. It's normally the
3-10 little notches that can be moved up and down to raise
and lower the tone at various frequencies. But the
paragraphic EQ in SoundForge is much more complex. Using
these controls, you can remove hiss, raise or lower pitch,
remove noise ... basically just correct the audio quality of
the file.
Unlike some software, Sound Forge also has realtime
previewing of the audio changes. Tick and untick the
"BYPASS" box to compare original audio (bypass
checked) to the filtered audio (bypass unchecked). Use this
feature to your advantage.
Since this site is aimed at transferring video to
DVD, these audio filters are set to reach the same goal.
These are meant to remove the most common problems
videographers face: removing hiss, restoring high tonal
values to mono/lossy recordings, and to remove errant noise
(often from shoddy microphones). There are four categories
of paragraphic filters
Hiss Removal Filters
The Paragraphic EQ presetss offer different levels of hiss removal. Just
be careful when using them, as it can also muffle the sound
if done improperly or you use the wrong filter for your
given situation.
Try the small ones first. Try to use the standard hiss
cut as much as possible (the one included with Sound Forge).
If that is not strong enough, move on to the digitalFAQ Hiss
Cut presets. Try to find the one that
removes hiss while leaving the high tonal values as intact
as possible.
Stronger hiss filtering. Our "Alternate"
filters are for more severe hiss
problems, and may muffle some, depending on the source. Use
sparingly on audio.
Noise Removal/Correction Filters
These EQ presets have been especially good on downloaded
files, aging VHS footage, home videos, audio cassettes and
records. These sources often have corrupt or noisy audio due
to the storage media or the recording equipment used to make
the source.
Remove low rumble and harsh bass. These filters are
for files that have too much bass, too low of a tone, rumble
noise, or a rumbly sound. The "Remove Low Rumble"
setting is a default Sound Forge filter. The presets has
some added variations of this filter.
Remove AC/Fan noise and audio whine. These filters
remove high pitched sounds like artificial whining, wind
movements, and motor noises caused from air conditioners and
fans. These are often useful on home movies shot outside or
with cheap microphones.
Examples: Restore High Tones
A big problem with early VHS tapes is that they were all
monaural sound (mono). Even through the early 1990s many
VCRs used mono sound as the de facto recording standard,
especially the low budget models. Mono sound, at least on
VCR recordings, tends to have lower tonal depth that is a
far cry from the Dolby Digital Surround sound we insist on today. These problems
are also found on old homemade vinyl and cassette
recordings.
Normal usage. The most commonly used filters in the
digitalFAQ Filter Pack are High Restores H, I, J, G and E. The
rest of them are for more specialty use.
Example:
Combo Filters
Combo filters aim to achieve more than one goal. In the
sample image below, the high restore filter has a goal of
restoring the high tones, but without adding more hiss.
There are several combo filters found in the presets file.
Some remove whine and hiss, buzz/hum and hiss, high restore
and remove hiss, etc.
Hiss removal, maintaining high tone from high
restore. These presets are for removing hiss that appeared
after a high restore was performed. High restoring
essentially broadens the higher frequencies, but that is
also where most hiss is stored. This EQ preset will remove the
new hiss, but without undoing the high restore. This is
especially useful on mono VHS tapes. The "high"
and "low" variations are for controlling the bass
levels.
Normalizing audio
One of the largest problems with homemade DVDs is a lack
of proper audio richness. In addition to be properly attuned
(like having a proper tonal range free of hiss), it must
have a full body for proper presentation. Most people
confuse full body with volume. While a full sound is indeed
louder, it is not due to volume control.
1. Never raise or lower the
"volume" of the audio file - NORMALIZE it !!
2. Avoid normalizing BEFORE adjusting the tonal values or
removing noise !! Only in a very few cases must the
audio be tweaked quieter prior to filtering.
Not too high, only 80 percent at most. One of the biggest
mistakes made by those capturing audio is to overdo it or
underdo it, resulting in corrupt peak values and other
decay. I see other guides that say "use Besweet and tick
the normalize function" or "raise capturing volume
all the way up" which results in arbitrary values
usually nearing the 100% peak value range, and it can
crack or otherwise distort on some audio playback equipment
(as it does on one of my TV sets). Most "Hollywood
released" movies
appear to use a range of 60-80% for their audio, and with a
greater dynamic range than can be had from home sources.
Not too low. Inversely, many never pay attention to the
computer audio controls during capture, and leave it at MS
Windows default volume levels. They fall in the 25-50%
range. Only is special situations would you keep volume at
such a low level. Turning up this volume on the TV will
actually result in raising the hiss level. Capturing audio
at low volumes results in a captured file with a minimal
level of normalization and severe tonal flaws. You cannot
fix it by trying to adjust the "volume" in
software after-the-fact.
SoundForge filter. This is the 80% value curve based
on peaks that I suggest for all DVD-Video applications. Go
to Process > Normalize to initiate the filter:
You are now ready to use this audio in your video or audio
project.
Did this Guide Help?
If this page has been as helpful as a book or magazine you
might have needed, then please consider
donating a few dollars to our cause. This site is funded
through donations from readers like you.
|
