Cleanest, least colored freeware compressor? POLL ADDED!!!!

VST, AU, etc. plug-in Virtual Effects discussion

Most uncolored freeware compressor

BuzComp
20
19%
Compressive
6
6%
Kjaerhus Classic Compressor
33
32%
ReaComp
33
32%
Vanilla Compressor
12
12%
 
Total votes: 104

KVRist
204 posts since 12 Aug, 2006

Post Sun Mar 09, 2008 12:32 am

MrM wrote:OK, a small test.
[...]
Nice test, though may I suggest some things.
Test with a 1kHz sine wave too, because right now you test only the lowend and most audio effects are aimed to work on the whole frequency content and not just the lowend.

Well, anyway this will tell you that e.g. #4 has still reasonable distortion at 1kHz. Another thing would be sine sweeps to see how they act on the whole spectrum, e.g. here the Cockos ReaComp (default settings, with RMS size set to 0 and threshold so it yields a 6dB GR, but shouldn't matter since it is constant signal level anyway and thus constant GR etc..):

Image

Here you can see the distortion reaches way up to the 20k range, while the Kjaerhus Classic Compressor has distortion/artifacts only in the low end.

Image


So you need to consider what you define as transparent least colored, because as far as I can tell does you're test only ensure least coloration in the lowend, though if an effect is clean in the lowend it should be clean all over the spectrum anyway.

P.S. Before anyone asks the sinesweep picture stuff is explained here: http://www.cockos.com/forum/showthread.php?t=18471
(If anyone wants to add to the sine sweep collection, you're welcome, so when it is done I might trim all the pics and publish them on one site with other test data or if someone else wants to make a site like that take them or whatever.)

MrM
KVRian
1440 posts since 16 Jul, 2003 from Zwollywood, The Netherlands (Europe)

Post Sun Mar 09, 2008 12:32 am

dickiefunk wrote:Thanks for the test Mr M. Could you test the Jeroen Breebart PC-2 compressor and Barricade?

Thanks

http://www.jeroenbreebaart.com/audio_vst.htm
Just added, see the posting above.
-- Regards MrM --

MrM
KVRian
1440 posts since 16 Jul, 2003 from Zwollywood, The Netherlands (Europe)

Post Sun Mar 09, 2008 12:43 am

LOSER wrote:
MrM wrote:OK, a small test.
[...]
Nice test, though may I suggest some things.
Test with a 1kHz sine wave too, because right now you test only the lowend and most audio effects are aimed to work on the whole frequency content and not just the lowend.

...

So you need to consider what you define as transparent least colored, because as far as I can tell does you're test only ensure least coloration in the lowend, though if an effect is clean in the lowend it should be clean all over the spectrum anyway.
You are right, and I just tried to test with 1 kHz, but my internet PC lacks enough meters to test it. My DAW has plenty of meters, but I don't like to test on DAW - switch to internet PC - test on DAW - switch to internet PC to report, cause every switch requires a reboot: I run a dual boot system.

Maybe someone else will duplicate my test, and add the 1 kHz.
-- Regards MrM --

KVRAF

Topic Starter

2696 posts since 22 Mar, 2006 from cornwall

Post Sun Mar 09, 2008 2:06 am

MrM wrote:
LOSER wrote:
MrM wrote:OK, a small test.
[...]
Nice test, though may I suggest some things.
Test with a 1kHz sine wave too, because right now you test only the lowend and most audio effects are aimed to work on the whole frequency content and not just the lowend.

...

So you need to consider what you define as transparent least colored, because as far as I can tell does you're test only ensure least coloration in the lowend, though if an effect is clean in the lowend it should be clean all over the spectrum anyway.
You are right, and I just tried to test with 1 kHz, but my internet PC lacks enough meters to test it. My DAW has plenty of meters, but I don't like to test on DAW - switch to internet PC - test on DAW - switch to internet PC to report, cause every switch requires a reboot: I run a dual boot system.

Maybe someone else will duplicate my test, and add the 1 kHz.
Yeah that would be great!

User avatar
KVRAF
12422 posts since 7 Dec, 2004

Post Sun Mar 09, 2008 2:17 am

a standard distortion test is 1khz, this quantifies THD, then the average of an a-weighted spectrum. pass white noise through an a-weighting filter and compress that, test the difference between the spectra, not the difference between the transient data. in other words, take the average absolute difference between the source and processed spectra. this gives you spectral distortion.

in order to be "transparent", both should be very low. phase distortion need not be taken into account here as we're dealing with compressors. the ideal compressor should adjust phases to maximize rms amplitude to to peak amplitude ratio while providing zero harmonic / spectral distortion.

User avatar
KVRAF
19089 posts since 13 Feb, 2003 from Vancouver, Canada

Post Sun Mar 09, 2008 2:39 am

Freeware, pal; freeware. ;) That is clean as hell, though. :lol:

mjcompressor: forgot about that. Very clean. I put Vanilla Compressor; I don't think you can detect any "color" from that.

EDIT: Ah, I see Vanilla has lived up to its name. Good stuff. :hihi:

Jeez. You look at those BlueCat pics in the cokos thread, and it's clearly one of the cleanest! :shock:

KVRAF
20617 posts since 12 Jul, 2003 from West Caprazumia

Post Sun Mar 09, 2008 3:51 am

LOSER wrote: Nice test
is it? I'm not sure - but if you say so - I mean: you really know your stuff, so... :?


I'm just wondering what release mode Mr.M used on Vanilla? Or doesn't it matter at all for his test? And if it doesn't matter, of what use is the test?

Switching the release modes totally alters the character of Vanilla compressor, so it's not possible that they are all 'least coloured'.

Distortion surely also plays a role, but the character of a compressor is mainly in its release behaviour for me - breathing and pumping, or the lack thereof, etc.


So how valid is the test when it comes to measuring the 'colour' of compressors?

KVRAF
20617 posts since 12 Jul, 2003 from West Caprazumia

Post Sun Mar 09, 2008 4:01 am

bduffy wrote: mjcompressor: forget about that.

Will do!








:hihi:

MrM
KVRian
1440 posts since 16 Jul, 2003 from Zwollywood, The Netherlands (Europe)

Post Sun Mar 09, 2008 4:52 am

jens wrote:I'm just wondering what release mode Mr.M used on Vanilla? Or doesn't it matter at all for his test?
Mode used in test: ARC-1

Does it matter to choose another mode?
With 'pump' the distortion is @ -50 dB for test 1, other modes are no problem.
-- Regards MrM --

KVRist
281 posts since 14 Sep, 2006

Post Sun Mar 09, 2008 7:59 am

MrM wrote:OK, a small test.

Test 1,
20 Hz going into the comp, settings:
Treshold @ -20 db, ratio @ 1:6.7 no knee, attack @ 20 ms, release @ 200 ms, auto make up gain.
Interesting experiment, but...

This can be quite risky. Thresholds may be defined differently
in various compressors. It would be safer to adjust the threshold
such that a fixed amount of compression is obtained.

Also attack and release times are not always
specified in the same way; sometimes they refer to a -20dB release point,
or sometimes to RT constants. The amount of distortion of a compressor is directly linked to the attack and release time constants; faster response will give higher distortion.

Then last but not least; one would have to take undesirable pumping
or distorted temporal envelopes into account to see the tradeoff between
temporal behavior and distortion...

Just my 2 cents...

KVRAF
20617 posts since 12 Jul, 2003 from West Caprazumia

Post Sun Mar 09, 2008 9:06 am

djeroen wrote:
Then last but not least; one would have to take undesirable pumping
or distorted temporal envelopes into account to see the tradeoff between
temporal behavior and distortion...
that was sort of what I was trying to say...

User avatar
KVRAF
12422 posts since 7 Dec, 2004

Post Sun Mar 09, 2008 10:07 am

i'm not certain what the point of looking for a general-purpose "cleanest" compressor is anyway. different compressors are going to be better suited to different tasks. you cant really apply one compressor and expect it to sound good everywhere. certain times distortion is the main thing you're looking for when compressing, other times you want insane pumping.

for medical type gain control it might be better to manipulate things manually. the most accurate tool for compression might be one which takes a recorded clip and finds points where the dynamics are of interest. curved envelopes could then be drawn between these points to normalize the amplitude of the clip. no real-time processor is going to ever be able to do such a thing. i'm not sure if such a tool exists. you could always find an audio editor which allows spline amplitude envelopes and do this by hand.

User avatar
KVRAF
8998 posts since 3 Feb, 2003 from Finland, Espoo

Post Mon Mar 10, 2008 9:23 am

.. and that test is pretty much flawed. Clean doesn't have to mean that it has less distortion than others. Clean in my humble opinion means transparent, which is directly related to how it reacts to the audio material it is processing. Not only some steady state sine tone. This has been discussed before, in the case of limiters, where Mr Kjaerhus made a pretty controversial (and completely flawed) demonstration where his limiter had the least distortion when limiting a sine tone. However, he failed to mention that he didn't tweak each plugin for their optimum performance and the test also completely failed to demonstrate how the limiter reacted to transients which is much more important than some distortion that can not be completely avoided and becomes irrelevant unless abusing the limiter/compressor.

Just my thoughts on the subject..

Cheers!
bManic
"Wisdom is wisdom, regardless of the idiot who said it." -an idiot

MrM
KVRian
1440 posts since 16 Jul, 2003 from Zwollywood, The Netherlands (Europe)

Post Mon Mar 10, 2008 10:04 am

I can't disagree with all the comments.

Notice, I did write 'a small' test. I didn't say that it was an broad, extensive test.

And, I also wrote that for me, it counts far more how easy it is to operate a compressor.

Testing with transients is a good idea.

But: I also read somewhere (in this thread) that each compressor has its own sound, and sometimes you want that sound. Limiting yourself to only one - very clean - compressor is a bad idea in my book, expecially with all the free ones out there.
-- Regards MrM --

KVRAF
1669 posts since 4 Nov, 2007

Post Mon Mar 10, 2008 1:39 pm

can sy gimme a link to the vanilla comp? as ia said in an other thread i cant find it :(

Return to “Effects”