I've found that there are plugins that overtly and covertly emit noise. Some plugins purposely emit noise to emulate vintage plugins like waves (anything that has a analog button on it), satson channel and buss) while others have no reason to be emitting noise. So far I've found two that covertly emit noise Fabfilter Simplon and Toneboosters Barricade and tape plugin. Barricade has no reason to be emitting noise unless its in dither mode but even with dither turned off barricade which is a limiter still emits noise. Granted the noise is so low the human ear can't even hear it but why is there noise there to begin with? Funny thing is with all these fancy analyzers out there i would have never detected it unless i used Nugens Visualizer which has the capability to meter down to -190db's!!! Other analyzers don't have this capability and the noise would just pass by undetected. I've also noticed reverb units that give off noise long after the said decay time has been reached. Notably Valhala Room and Vintage. I've set reverb decay to 9 secs and long after that time has been reached there is still noise being let out. It would eventually die after about a min but a MINUTE!!! thats way to long for noise to still be hanging around especially if the last sound in your track goes through this reverb which let me to another discovery. After trying to figure out how to kill the noise i said why not use a gate. And to my surprise many plug in gates do not even gate noise beneath a certain level. The only gate i've found to gate noise all the way down to pure silence is Melda's gate found in Mdynamics!!! My daws own gate didnt even work, Fabfilters "PRO"-G didnt work either!!! These gates except for meldas have a limit and you may think you don't hear noise after you gate something but surprise noise is still passing through you just cant see or hear it!!!

Wait for my write up on my discovery of compresseor plugins and their inability to achieve pure compression

 

wow. nice find

 

barricade emits noise when _noise shaping_ is on (not dither).
The same for tape I guess. There is noise, hiss, all kinds of things added with a good tape emu that will produce sound even if you feed it pure silence.

Having said all that, there are basic DSP audio techniques that require something of a noise floor. With 24bit (well, the bit precision 32bit floating point gives you) the theoretical noise floor is getting around -180db to -190db.... exactly where you see the noise :P.

So I think what you are seeing are techniques to battle DC-offset-pops and other things, by making a small noise signal at the bottom of the theoretical noise floor.

 

Are you sure you don't have any other opened plugin? I've checked my Valhalla verbs & fabfilter plugins, but none of them gives any noise (noise floor without audio playing and those plugins on is at -320 db with Ableton's Spectrum, even though at 24 bits anything below 144 dB is useless since it's gonna be truncated by the SNR).

 

I know, lot of pluguins create noise also at -144 db. I usually work with busses, I mix my track after the mixing stage I usually create mute automations on busses wherever they aren't supposed to play. Or mix the track bounced down steams and just cut audio clips in the silence parts.

Waves Mv2 and Maxxvolume create a lot of background noise at -170 db. I use a lot fabfilter simplon, I'll check out this too thanks.

Maybe can be some different between vst3 and vst2 version.

 

i've checked 2 plugins in a blank audio track with no clip or audio signal.

This is the Waves MV2



This is the Fabfilter Simplon vst3 (same results for vst2). But what i usually do is automate the dry/wet knob because bypass automation can create some little click. if you turn down the knob to 0% the background noise is gone

 

The valhala verbs i said will continue to emit noise after the decay time has been reached not by just sitting there, you must run a sound through it first. Toneboosters barricate will emit noise even with noise shaping at zero! Toneboosters Reelbus offer hiss and apserity controls but even when turned all the way down still emits noise. Fabfilters Simplon is picking registering noise at -140db just on default settings. Just tested again with no other plugs running.

 

now try using presonus studio one gate to stop it and you will find it won't work as presonus gate will only gate noise down to a certain db as does pro-g.

 

Voxengo SPAN+ (with custom settings) and iZotope insight (if you zoom out) can go to -180dB, and should be able to detect your noise floor of -174dB. While Flux Stereo tool ISN'T an FFT, it can still detect low noise floor if they're discorrelated, so if you don't see a straight line, it's making noise.

Most/all reverb should do this. the 'decay time' could be the RT60 time. The RT60 time is the time it takes for the reverb to reach -60dB below the original level. Another thing, since many reverbs are zero latency, they do reverb via feedback, which means that the signal may last a long time. Go read up on how reverbs work and are made.

Most of the gates I tested, do gate really quiet stuff. ReaGate, MR Gate, GGate. The only one that didn't was drumroll.... TB_Gate v2.

If you're going to complain that you set a threshold of n dB and the compressor allows peaks to go above, this is normal. a ratio of 30:1 is almost infinity, but isn't infinity. If you want no peaks to go above your threshold, use a brickwall limiter instead.

Read up on how compressors work.

 

I notice it in Logic Pro X since audio track have a green led wich means audio signal going on, while the track wasn't supposed to play. Never used Studio One's stock gate, I usually automate mute channel or if I need a quick adjustable range I use Waves Rvox and play with gate threshold until I'm happy with the settings.

 

-80?(P) UNDERWATER NUCLEAR SUBMARINE MICROPHONES LISTENING TO SHRIMP CHEWING ON FOOD AT 100 METERS DISTANCE
-30 (N) ONE HUMAN TALKING 20 MILES AWAY ( 60 DB / METER AT A DISTANCE OF 20 MILES )-REF.1.2003
-4 TO +4 (N) THE TICKING OF AN ORDINARY WRISTWATCH AT 1 METER -REF.1 2003
0 (N) BEGINNING OF HEARING, A MOSQUITO 10 FEET AWAY, THE EAR DRUM MOVES
LESS THAN 1 / 100 THE LENGTH OF AN AIR MOLECULE (N) -REF.1.1990

http://www.makeitlouder.com/Decibel%20Level%20Chart.txt

ps still trying to find - 190

sorry it right here and a frist i should add
- 190 plugins - REF.1.2015
we will have to up-date the list,

after a quick check it falls under (P) as well,

 

hmmm well i was gonna say that when you set many compressors to the smallest attack settings they dont attack at zero aka the beginning of the wave rather a few milliseconds after still letting a small peak through uncompressed. I found this out because i had a real attacky wave file that happened at the beginning and i tried to compresss it but not squash the whole thing as you suggest with a brickwall limiter. I cold even see the uncompressed audio in the form of a spike using smexoscope!!! The only plug i found to be able to get close to zero if not zero was meldas compressor! Many plugins will actually tell you this when you read the attack setting it will give you a display in milliseconds and when you turn it all the way down you will notice some will stop at 5ms and wont go lower. That enough time to let a really unwanted sharp transient to poke through.

 

If your gate is on master and your fx on a track ...
if your spectrum analyzer is on master and your gate and fx are an audio track ...
-- are you sure you dont have a send and/or return track on ( with fx or not )
(im in ableton live)

 

it is if 32 bit processing.
64 bit even less...as I know if you insert one more plugin, noise will not be inscreased as analysers show...also, turn off your analyser while rendering, they give you noise as well...SPAN doesn't
DMG EQs don't, PSP Neon doesn't...
don't remember them all...as I know FabFilter Pro-Q2 give you the same stuff)

 

Great topic, love a bit of deep audio exploration.

Momo killing it! "-80?(P) UNDERWATER NUCLEAR SUBMARINE MICROPHONES LISTENING TO SHRIMP CHEWING ON FOOD AT 100 METERS DISTANCE"
Who doesn`t wanna hear that!?

 

Did you even read when I said somewhere at the top that this is _intended_ and _normal_, and is there to combat DC offset and pops and other common audio-DSP issue? Also the reason why a gate won't remove it: IT WILL ADD IT BACK IN AFTERWARD because basically every plugin does this. You _want_ it, it prevents issues.


And it's not like something around the -140 dBFS mark (or even quieter) is going to matter, even if you try to compress the shit fuck out of it.

Every (good, well written? don't know) plugin consists of a few startup routines in it's algorithm, then it does its thing, then it does exit routines.
In the startup routines are basic gates to filter out the noise at < 140 dBFS, and at the exit routines some noise around the noise-floor is added back in. This is to prevent DC pops.

Just another reason why people shouldn't dive into super precise analyzers without knowing all the details about digital audio first (and trust me, there is a lot of shit about digital audio I'm pretty sure you all don't know (and yeah, there is a shitload I don't know either :P). Once you start writing plugins the world opens up so to speak).

 

I'm going to have to agree with what dipje said. It is probably there to either to combat DC Offset or alternatively denormals

 

If you don't hear it there is no problem.
Stick to the pragmatic approach

 

Fuggedaboutit