Korvpressor - AU vs IAA observations (solved - user error)

marliess

Hey dudes / dudettes,
I do all my recording in multitrackdaw and bounce to cubasis for mixing, messing around with arrangement, etc. I dig using AU in cubasis as it tends to be more stable than IAA, and cos i can use a bucketload of instances of preferred fx (the 6144 eq in particular), & the AU instances recall my per track settings. But i digress....

if i use korvpressor AU, i get unacceptable levels of hiss in my tracks. I didnt really notice at first...till i ran some more completed mixes thru final touch or audiomastering (which typically add compression) and, bam!...I hear hiss in my mixes.

Working backwards i eventually worked out korvpressor is the suspect....AU gives noise, whereas similar settings for korvpressor via iaa have negligible noise (interestingly, korvpressor presets I've developed in iaa dont carry over to AU instances for korvpressor - the presets simply dont show up in the AU version {same for squashit & esspresso too} - could be a cubasis bug). And while i cant compare AU to IAA in a single preset of korvpressor, ive set em up with very similar settings and one sounds f'n great, one sounds hissy.

Espresso is the same deal - I've got some de-esser presets that work f'n great with my voice over IAA....similar settings in AU strangle all the top end out of the vocal and i lisssssp like you wouldnt believe

Net result....Love these apps via IAA but dont bother with the AU versions. Seems like a waste...i would looove to use korvpressor on every tack needing compression. Instead I've got to do it by bouncing via a single instance of IAA....just feels so 2014!

RUST( i )K

I must admit, I love the products from this company perhaps more than I should.

I guess you can say they are not 100% effective for the desired outcome based on the app's defined purpose and description.

crony

Interesting points...I would love to ear some sample to illustrate.
I'll also compare as I'm a big user of AUX and Korvpressor...I know they're selling an other compressor, might be better.
But I would love to have an enlightment from @brambos about differences in audio's signals between the 2 technologies, as his Ruismaker has a remarkable sound quality to my ears. (and it's only AUX...)
It might be just a "coding problem" based on IAA plugins "poorly" ported on AUX and not related to AUX technology at all ?

sundhage

Hi, Johan from Klevgränd Produktion here.. There should be no sounding difference between the IAA and AUv3 version in any of our apps. The only thing I can think of is that the parameters might range a tiny bit different between IAA and AUv3 (since the AUv3-part is built with another framework (JUCE), the same as we're using to build our desktop versions).

I'll try to get some time asap and check those hissing noises mentioned asap, those shouldn't be there.. @marliess, if you have a sound example, I'd really appreciate if you can send a wav or aif to support(at)klevgrand(dot)se (preferably a version with korvpressor and one without).

Regarding preset sharing between standalone/IAA and AUv3; I'm sorry to say that that's more or less impossible for those apps just because we're using two different frameworks in the same app. In the future we might rebuild the standalone versions using JUCE tough.

brambos

@crony said:
But I would love to have an enlightment from @brambos about differences in audio's signals between the 2 technologies, as his Ruismaker has a remarkable sound quality to my ears. (and it's only AUX...)

The AU protocol itself does not modify or affect the signal quality in any way. In other words: an audio processing engine should sound identical through IAA and AU, all other things being equal.

What may be happening...? Perhaps the AU host is running at a lower bitdepth/sample rate than Korvpressor standalone. But then we'd have heard complaints about other AU effect plugins as well.

Most likely there is an actual difference in the DSP code between the AU version and the IAA version. Like an extra input-gain adjustment stage which is raising the noise floor?

It would be interesting to know where the noise came from in the first place. Was the source material a digital recording or something that was 'synthesized in the box' and did the hiss enter the chain inside the compressor?

AndyPlankton

Quantisation noise ? Is there a difference in how audio gets into/out of an AUx compared to IAA, could bit conversion be happening ?

marliess

I'll dig in later after work and see if i can record a couple of examples....my bass guitar tracks have been the main offender (recorded dry via line6 mobile in), tho i think its also happened with vocals recorded via a yamaha ag06 interface. Incidentally, I've been able to salvage hissy (rendered) tracks by going back to the dry/unrendered (frozen in cubasis) track and then using the exact same fx chain but with korvpressor IAA. This has solved the problem and ive never had to re-record, hence my theory about the AU version.

In the interim, thanks to everyone for the comments so far, really appreciate it. I really love the klevgrand apps, so will e interesting to see if this exists only in my head or in the tech of the AU version!

brambos

@marliess said:
I really love the klevgrand apps, so will e interesting to see if this exists only in my head or in the tech of the AU version!

I don't think anyone doubts your ears. It's just that in theory there should not be an audible difference between AU and IAA if the underlying DSP code is the same. So it could be a bug. Perhaps it's worth contacting the developer.

marliess

Hey brambos, all good...Johan from the dev team chipped in just prior to your previous post. I'll find a bass track (dry / +Au / +iaa) and send to Klevgrand later tonite and we'll see what turns up

marliess

Hey all, I've just done some testing using bass tracks from 3 or 4 songs in cubasis....(drum roll)... and have to call 'bullshit' on my earlier comments and offer a big apology to Johan and the Klevgrand team. Turns out the hissing issue was not the AU, but was actually between my ears, just not in the way I thought it might be. The korvpressor UI in IAA is fullscreen and works a treat with my, stubby sausage-like the fingers. When using AU, the UI is half the size, and without presets (for reasons outlined earlier) it turns out I'm really shit at dialling in desired settings in the app (which is configured by eye rather than by explicit numbering).

In testing this time round, I found both IAA and AU to sound basically indistinguishable...re my earlier "findings" - this was done in the context of trying to get a song mix right, and I'm guessing I found it much easier to dial out the hiss if I'd overcompressed in the larger IAA UI, and blamed the AU version of the app rather than my own lack of dexterity (ask my wife about that one!).

So, once again, big apologies to the Klevgrand folks and anyone else who's time I've wasted. I'll see if I can edit the thread title to 'Incorrect Observations'.

crony

Good point of that post is that we've killed in the egg for good the urban legend : IAA sounds better than AUX !