Dynamic Rumble Filter

[davidcw]

About 35 years I came across an audio amplifier that had a dynamic rumble filter that reduced turntable rumble on quiet passages, but was turned off when there were load passages. It was actually quite effective.
Could such a filter be implemented with Audacity or with a VST plug-in?

[Trebor]

If by "quiet" you mean "should be silent" then a gate will do this: when the amplitude of the audio drops below threshold it is zeroed by the gate.
(I've got the "GGate" VST plugin working successfully on Audacity)
You'll need the VST enabler to use VST plugins on Audacity, (even then not all VST plugins work, but "GGate" does).

[kozikowski]

I don't think the poster is looking for Cut To Silence during the quiet passages, I think they want a high pass filter switching in and out depending on the show volume.

Koz

[davidcw]

I don't think the poster is looking for Cut To Silence during the quiet passages, I think they want a high pass filter switching in and out depending on the show volume.

That's right, it was a variable or switching high pass filter.

[steve]

About 35 years I came across an audio amplifier that had a dynamic rumble filter that reduced turntable rumble on quiet passages, but was turned off when there were load passages. It was actually quite effective.
Could such a filter be implemented with Audacity or with a VST plug-in?

You can do it with my Noise Gate plug-in.
To install the plug-in, unzip it into your Audacity plug-ins folder and restart Audacity.

To use it as a rumble filter, set the "Gate frequencies below" to a fairly low frequency, say around 100Hz (this sets the "corner frequency" of the filter, so although it is a fairly steep filter, it still needs to be set a bit above the rumble frequencies that you want to remove).

There is currently no documentation for this plug-in, but I think it is not too hard to figure out.

It can also be used as a hiss filter.

I'll be away for a couple of weeks, so if you need any help with the plug-in perhaps Koz or one of the other guys will be able to figure it out.

[steve]

I see some downloads - any comments? Did it work?

[davidcw]

I see some downloads - any comments? Did it work?

Hi Steve,
It seems quite promising, these are the settings I used ( see attachment ).

P.S. It might be an advantage to change " gate frequencies above 20 " to say
5HZ to remove subsonic turntable frequencies.

[steve]

P.S. It might be an advantage to change " gate frequencies above 20 " to say
5HZ to remove subsonic turntable frequencies.

I "think" that setting "Gate Frequencies Above: 20Hz" actually disables that filter, so it is the same as "Gate Frequencies Above: 0Hz".

Originally this plug-in was set up just for gating, and "hiss gating", not "rumble gating" (which I added later in response to your original post).
I'm away this weekend but will check it out when I get back. Feel free to post a reminder here if you do not hear back from me soon after the weekend.

If required, the Attack and Decay settings could be independent rather than automatically the same (if that would be useful to anyone). What do you think - an extra slider, or as it is now?

[jtp_60]

About 35 years I came across an audio amplifier that had a dynamic rumble filter that reduced turntable rumble on quiet passages, but was turned off when there were load passages. It was actually quite effective.
Could such a filter be implemented with Audacity or with a VST plug-in?

http://sound.westhost.com/project99.htm

Effective in which way ... more 'bassy' /softier sound (additional loundness switch)?

Anyway, yes, I think this could be done (least) as VST implementation. Easiest way to go would maybe be to change the filter order (steepness, roll-off curve) or(/and) corner frequency "on-the-fly" by the "load" level measured from certain frequency area(s).

Juha

[jelly6759]

Effective in which way ... more 'bassy' /softier sound (additional loundness switch)?

Anyway, yes, I think this could be done (least) as VST implementation. Easiest way to go would maybe be to change the filter order (steepness, roll-off curve) or(/and) corner frequency "on-the-fly" by the "load" level measured from certain frequency area(s).

Juha

Hi jtp_60,

Thanks. It looks good. How do we get it in VST plug-in?

Once I had nyquist "Noise Gate" plug-in made by someone else, but it was identical to above. It easily messed music up.
Especially in the sounds of the piano and reverbration, they were often turned into metarllic sound in some part.
I don't want to review the whole track after effecting to see any part was ruined or not.



Does someone know where we can get that in VST plug-in?