[LAU] [Sort of OT] Ringing in filters

[Patrick Shirkey]

On 05/17/2010 07:29 PM, Ken Restivo wrote:
>
>> In my untutored opinion, all conventional mastering tools
>> will use a somewhat similar network and similar effects.
>>
>>      
> They do indeed seem similar in layout. As for the quality of the filters in them, that varies. But if we're all using the same LADSPA effects, the results should be comparable.
>
>    
>> If you understand how to use the individual effects, I think
>> there will not be any unfathomable mystery in the aggregate.
>> The mystery and artistry will be in your own creative
>> choices.
>>
>> What I think Jamin does better than the others is that
>> it allows you to use different mastering parameters (scenes)
>> for different parts of the song.
>>
>> Ron Parker is a respected engineer who not only approves of
>> Jamin but also wrote the mastering with Jamin tutorial.
>>
>> http://jamin.sourceforge.net/en/tutorial.html
>>
>> You say you hear some artifacts. Did you ever approach
>> the author?
>>
>>      
> Well, Fons kind of sniffed at Jamin-- "you are mastering through a vocoder"-- and I've seen and heard the quality of his code so I tell he knows a LOT more than most folks about DSP. Meanwhile, the code of JAMIN looks like some cut-and-paste filters off of a web forum, and indeed their EQ is an FFT. The GUI is pretty and well-organized, but I'm not sure if what's going on underneath the hood is any good.
>
>    

The toolchain uses ladspa fx. The gui is just a nice and compact way of 
working with them. The overall sound quality is as good as 2 very 
experienced dsp devs, 1 mastering engineer and 2 user interface 
designers could come up with over approximately 500 hours worth of their 
time. It's not perfect but it does a pretty good job and some people 
have mastered some great music with it as a result.



> My ears are not good enough to hear DSP artifacts-- and to know that's what they are. I did have some problems in the 6K and 12K range, which I fixed in the mix (my mixer going straight to the mastering stage in one chain). And I guess I'm just worried that I may have used a tool that introduced artifacts I can't hear or see, but others will. It's not a big deal. It's not like millions of CD's are going to get printed up.
>
>    


As Fons said, if you are happy with the sound that is what counts. If 
you are looking for a specific thing such as the perfect radio dynamics 
or a more powerful way of processing the sound then you may need to try 
out some other tools. As far as I know Jamin is the only app for 
Linux/Jack native that attempts to provide a professional mastering 
toolchain. I haven't used postfix though but would expect it to be of 
similar quality or better depending on how much time Monty has been able 
to spend on it.

In terms of introducing artifacts. There have been some reports of very 
specific items which as far as I know have been fixed in svn or else no 
one has had any time or motivation to work on them. You owuld have to 
check the mailig list to find out if they are anything you need to be 
concerned about. I'm pretty sure that anything that is a major 
showstopper will be immediately squashed and committed.

Now on the other hand if Fons has an idea for a more advanced mastering 
tool and wants to share it I'm certainly interested in the possibilities 
that represents. Jamin was built becasue we didn't have anything for 
that step in the audio production process but it has been over 5 years 
since any seriously active development has gone into it so we may be in 
need of a refresh and broadening the options for getting the perfect 
sound is always a good thing (tm).




Cheers.

--
Patrick Shirkey
Boost Hardware Ltd.