Ease
of Use
DC6's EZ Clean filter offers new users an easy way
to get started, yet extremely in-depth options are also
available without much digging. The manual has tutorials
to walk you through some of the more advanced filters, but
the it uses a lot of terminology that video-oriented people
may not be familiar with, so be patient and use your ears
to hear the difference a filter makes. As an additional
help, the manual includes a table of common NR senarios
with suggested filters to use. One really nice feature is
that the program allows you to select a different portion
of audio while the filter windows are still open, unlike
most apps that would force you to close the filter/plugin
window in orfer to change your selection. DC6 can
function as a host for DirectX plugins which means that
you can actually use Sound Soap 2 and other third party
NR tools in conjuction with the many DC filters. This would
make for a powerful combination I'm sure! I was a little
disappointed that it wouldn't host my VST plugins though.
DC6
allows you to process left and right channels of a stereo
file independently. This is very useful if you are recording
separate subjects on their own channel (as in the "Outdoor+Cell"
test file we'll be working on a bit later). Another nice
feature is that you can open video files directly into DC6,
set the start and end points to the section you want to
clean up, then extract the audio for NR processing. Unfortunately,
DC6 won't allow you to save the cleaned up audio
back into the video file, but most of your video editing
apps should allow you to manually replace that section of
audio with your new and improved file.
In terms
of usability I do need to mention two beefs I have with
DC6. First, compatibility: It is available for PC only--and
only for sound cards using legacy MME or DirectX (WDM) drivers
at that. This excludes many users with professional grade
audio interfaces that use the popular ASIO specification.
In my case it wasn't a problem because my MOTU 828mkII lets
me turn legacy drivers on and off at will. I'd like to see
this program (or perhaps just its filters) be ported over
to various plugin formats so we can use them within the
context of a video editor or at least our primary audio
editor. If for some reason this isn't feasible, at least
build in support for multiple plugin formats that can be
used on Mac or PC.
The
other issue I have with DC6 is the GUI. While it
does not technically inhibit the functionality of the algorithms,
I found it mildly disruptive to my workflow.
One thing I love about my primary audio production app is
that I can use keys to control playback regardless of what
window is active. In the main window, DC6 will start and
stop playback using the spacebar like many other apps. However,
while tweaking the settings for a filter, accidentally hitting
the spacebar to stop the preview sometime applied the filter
and or closed the window. Is it my fault that I didn't remember
to use the preview button -- of course. But I think the
program would be more friendly if you could just always
use the spacebar to start/stop. Also, unlike most editors
that by default allow you to simply click anywhere you want
and begin playback at that point, DC6 wants you to make
a selection first. There is an option to right-click and
select "Play from here", but I find this implemtation
cumbersome when trying to audition different points in a
file quickly.
Depth
of Options
Options, options, and more options! I have to say that I
found DC6 to be one of the most flexible, tweakable
NR programs I've used. Two editing modes are provided. One
that uses source/destination files for each process you
perform, thus giving you multiple files representing the
history of your edits after each stage. The second is called
Fast Edit Mode and functions more like typcial audio editors
that remember your edits in the undo history until you save
the file -- but by default it performs a save as function
making it less likely for the user to overwrite their source
material.
Perhaps
the most flexible "filter" in the progam is called
the "Multifilter". It functions much like a plugin
chainer found in many editors, allowing you to chain together
multiple filters and change their order at will. Interestingly,
you can preview the affects of each filter individually
or of the entire chain. This allows you to listen to the
affect that one filter would have if the others weren't
present in the chain, then tweak the settings in the context
of the other filters.
Value
DC SIX is the most tweakable NR software for the price that
I've seen. Bang for the buck ranks right up there with SS2
as far as I'm concerned. If you have some audio that requires
some of the more advanced NR tricks but don't want to spend
more than a few hundred bucks, this is the package for you.
Test
Results
I chose four different types of sound issues to really test
Diamond Cut 6. The first was an old record with lots
of scratches. The next was a living room interview that
had lots of quiet background noises like hums from computers
and air conditioners. The third example we looked at was
a conversation held in a large, echoey foyer. And the final
one was an outside two channel cell phone interview for
an experimental documentary called The Virtual Kevin
Project.
Old
Record: I cleaned this file up a couple of different
ways just to compare the EZ Clean filter to doing it the
old fashioned way. EZ Clean was of course easy and fast
and offered pretty solid results. Then I used Mulifilter
to chain Impulse Noise (click/crackle remover), High Pass
EQ (for rumble), and the Continuous Noise filter (for
the hiss). I did acheive better results with this setup,
mainly due to the ability of the Continuous Noise filter
to tailor the aggressiveness of the NR according to frequency
bands that I define -- quite nice.
Living
Room: Good results with relative ease. I discovered
one of my favorite filters in DC6 while cleaning this
file: DeClipper. Many times low budget video projects
are plagued by audio that is at least somewhat distorted.
DeClipper helped rebuild some of the audio data that gets
cut off when this happens, making for a more natural sound.
The PC fan running in the background of this interview
was no trouble for the Continuous Noise filter!
Large
Foyer: Good results, though in this partiular casse
I had to be careful not to make the subject's voine sound
weird. I used the same combination of filters as I did
with the Living Room test file: DeClipper, Continuous
Noise, and Paragraphic EQ. With the default settings,
the A/C running in the background gave the Con. Nosie
filter a little of bit of trouble descerning betwee the
noise and the desired voice. However, I simply reduced
the aggressiveness of the filter in the lower end of the
subject's vocal range and it sounded much better.
Outside+Cell:
A nearly impossible task for any NR solution, yet
DC6 performed suprisingly well! I decided to see just
how much noise I could remove, even if it did make the
desired dialogue sound a little "flangy". DC6's
ability to process each channel separately came in very
handy because we had one person on the left and one on
the right -- with DC6 I could process them separately
and then even combine them into a center-panned signal
when finished. The subject on the left was on a cell phone.
Not too much you can do with a cell signal since it is
already so processed, but I was able to get rid of the
noise between phrases as well as enhance the intellegibility
of what he was saying. I used the following filter chain
within multifilter: Brick Wall (to get ride of any undeeded
frequencies outside of the range of a cell phone) + Continuous
Noise (for hiss & white noise) + DeClipper + Paragraphic
EQ (to brighten up the signal a bit in the higher freqencies)
+ Dynamics (as a noise gate that basically turns down
the volume between phrases).
In the
Outside+Cell test, the right channel gave me the most trouble.
A combination of terrible wind noise, rumble, buzz induced
into the line from the cell phone, and a soft-spoken subject
made it very difficult to pull out anything usable. Again,
I just wanted to see how much of the noise I could take
out. Here is the filter chain I came up with after tweaking
around for a while: Brick Wall + Continuous Noise + Median
(adds intelligibility to soft speech) + Paragraphic EQ (to
accent the speech frequencies) + Punch and Cruch (set up
with an Expander setting to automatically increase the volume
of her only here words) + another Punch and Crunch (set
up with a Compressor setting to keep her words from getting
so loud they distort) If you listen to the results, you
will notice that there is still some cell phone buzz and
that her voice sounds a little thin and flangy. In my opinion,
it's not broadcast quality yet. In a situation where I was
forced to use this clip, I'd probably let more of the wind
noise come through in an effort to keep her voice from sounding
that flangy. If you have audio this bad, you may want to
consider simply reshooting the scene! But it made for a
good experiment!
This
is one of those clips that would benefit from a couple of
the very advanced filters found in DC LIVE/Forensics. Specifically,
the Spectral Filter would allow me to remove each specifi
frequency that makes up that annoying cell phone buzz. I
know what the freq's are because DC SIX/LIVE provides a
Spectrograph window that revealed them to me instantly when
I isolated a section of the noise and played it with that
window open. Also, the DSS filter allows me to use the left
channel as a reference and then look for that signal bleeding
into the right channel (the was in fact the case) and automatically
take it out! Pretty snazzy!
