Login

Nebula & THD plots

Officially Licensed 3rd Party Developer Libraries
Free 3rd Party Programs

Re: Nebula & THD plots

Postby audioanal » Sat Sep 10, 2011 4:00 pm

:)
Attachments
neve 1081 low peak2.jpg
neve 1081 low peak2.jpg (121.42 KiB) Viewed 684 times
neve 1081 low peak.jpg
neve 1081 low peak.jpg (120.28 KiB) Viewed 684 times
audioanal
User Level II
User Level II
 
Posts: 22
Joined: Thu Dec 16, 2010 12:21 am

Re: Nebula & THD plots

Postby yr » Sat Sep 10, 2011 4:02 pm

Thanks for the pics. If you want to check for difference (VPA/SPAN), you could compare presets that are dynamic (many eq are static) and have big frequency variation between the layers. If you want me to, I can make you a test preset later today with the "loud" layer eq'd differently then the soft one.
Reuven | post-production & sound-design | scenography |
website | nebula presets
User avatar
yr
Beta Tester
Beta Tester
 
Posts: 438
Joined: Mon Mar 29, 2010 9:04 am
Location: Amsterdam

Re: Nebula & THD plots

Postby audioanal » Sat Sep 10, 2011 4:05 pm

N**e 1081 master bus Thd. The difference is obvious with higher resolution (Span). Not so dirty as it seems with the VPA
Attachments
neve console thd 2.jpg
neve console thd 2.jpg (137.25 KiB) Viewed 682 times
neve console thd.jpg
neve console thd.jpg (139.26 KiB) Viewed 682 times
audioanal
User Level II
User Level II
 
Posts: 22
Joined: Thu Dec 16, 2010 12:21 am

Re: Nebula & THD plots

Postby audioanal » Sat Sep 10, 2011 4:06 pm

yr wrote:If you want me to, I can make you a test preset later today with the "loud" layer eq'd differently then the soft one.

yes please
audioanal
User Level II
User Level II
 
Posts: 22
Joined: Thu Dec 16, 2010 12:21 am

Re: Nebula & THD plots

Postby TranscendingMusic » Sat Sep 10, 2011 4:46 pm

Two things: the VST analyzer, in the harmonic distortion measurement, drives the given preset very hot. The input is receiving a 0 dbFS or close to (going by memory right at the moment) tone which will give you a "dirtier signal. Also, make sure you set your noise floors to something more realistic. You definitely don't need to show a 24-bit range let alone anything deeper than that such as -200 dbFS. I'd say what would be sufficient with a bit of cushion is like -120.
mixing | mastering
Win 10 x64 | Sonar Platinum x64 | 3930K(OC)
User avatar
TranscendingMusic
Expert
Expert
 
Posts: 1132
Joined: Sat Mar 27, 2010 7:01 am
Location: USA

Re: Nebula & THD plots

Postby yr » Sat Sep 10, 2011 5:38 pm

audioanal wrote:
yr wrote:If you want me to, I can make you a test preset later today with the "loud" layer eq'd differently then the soft one.

yes please


ok, I've uploaded a test preset (link below). After copying the files to the right folders you should look under preamp (PRE)/ test.

The 2 loudest repetitions are processed with HS boost and distortion. The weakest two repetitions are processed with HS cut and no distortion. If everything is as it should be, you will see a very different freq plot in VPA and SPAN. VPA will show the weakest repetitions (HS cut) regardless of the input volume. It will also show you the max THD which is actually coming from the loud repetitions.

https://www.wetransfer.com/dl/QEjCIRL2/ ... f0c1296323
Reuven | post-production & sound-design | scenography |
website | nebula presets
User avatar
yr
Beta Tester
Beta Tester
 
Posts: 438
Joined: Mon Mar 29, 2010 9:04 am
Location: Amsterdam

Re: Nebula & THD plots

Postby Cupwise » Sat Sep 10, 2011 8:08 pm

The 2 loudest repetitions are processed with HS boost and distortion. The weakest two repetitions are processed with HS cut and no distortion. If everything is as it should be, you will see a very different freq plot in VPA and SPAN. VPA will show the weakest repetitions (HS cut) regardless of the input volume. It will also show you the max THD which is actually coming from the loud repetitions.


ok but, for example, i've made tape programs that only have 10 dynamic steps, which only go down to -10db. if you are just using a NAT session straight out of the set, without changing anything such as how many dynamic steps you want to sample, then i think the preamp sessions usually go down to -30db, or around there.

i'm assuming that vst analyser just sends the tone through at a particular level, and at that same level every time. if that's the case, then it (the tone or noise it uses) would have to be below at or -30dbfs to show me the lowest sampled step in both my example going down to -10db and the default preamp session. but what if i made a program going down to -50db? unless vst analyser was specifically designed to know what nebula was doing, it couldn't always show the lowest step.
Cupwise
Expert
Expert
 
Posts: 773
Joined: Tue Nov 23, 2010 2:03 am

Re: Nebula & THD plots

Postby yr » Sat Sep 10, 2011 8:18 pm

It's very possible that VPA uses very low-level noise for the freq-plot. The standard template I used goes down to -40dBFS. Don't forget that Michael (CDSM) reported the same, and I don't think he always uses pre-made templates.

Whats important to realize, is that VPA is not showing you a frequency-plot which directly corresponds to the input level. So if, for instance, you are trying to show a VPA frequency response at nominal level (in manuals etc) you need to make sure you are using the proper layer.
Reuven | post-production & sound-design | scenography |
website | nebula presets
User avatar
yr
Beta Tester
Beta Tester
 
Posts: 438
Joined: Mon Mar 29, 2010 9:04 am
Location: Amsterdam

Re: Nebula & THD plots

Postby Cupwise » Sat Sep 10, 2011 10:04 pm

ok, i guess it could use a low enough level noise signal that for any typical nebula program it would show the lowest dynamic level. most sampled hardware isn't going to go down very low, because of the noise floor of hardware, so i suppose if the noise used by vstanalyser is below -50 or so then it probably would would be below the lowest sample of most/all programs that exist currently.

still that doesn't mean it always would be, because most importantly we don't know *exactly* how low the noise used by vst analyser actually is, and you would need to know that to know exactly how much to bring it up by to get a 'nominal' level graph. christian might answer that, if anyone cared to email him.

interesting stuff, i guess, although if you look at any high end preamp/console stuff they usually still have perfectly flat responses. tape's freq response would probably be effected more, but in my personal experience tape programs can't have as much dynamic range as preamps, so even the lowest sample's freq response is probably still pretty close to what you get in using the program.
Cupwise
Expert
Expert
 
Posts: 773
Joined: Tue Nov 23, 2010 2:03 am

Re: Nebula & THD plots

Postby yr » Sat Sep 10, 2011 10:11 pm

Yes its really not a big deal. Probably just better to use other "real-time" analyzers for a more relevant freq response (like SPAN). I only started testing because I couldn't understand the relation between the THD and the freq-plot in VPA/Nebula.
Reuven | post-production & sound-design | scenography |
website | nebula presets
User avatar
yr
Beta Tester
Beta Tester
 
Posts: 438
Joined: Mon Mar 29, 2010 9:04 am
Location: Amsterdam

PreviousNext

Return to 3rd party libraries

Who is online

Users browsing this forum: No registered users and 9 guests