Harmonic distortion after OS 1.2.1 upgrade

RC-IA · Post by **RC-IA** » Wed Oct 11, 2006 9:33 pm

stephen: i really hear a difference. i programed some sounds that i know well, there is a difference. tomorrow i'll post samples of the problem i have with the filters too, it's really obvious. when i noticed the difference i told myself, oh no just being influenced by what i've read from elvis, but i decide to listen to bass and drum sounds, which are well programed i think, and now they sound different. just listen to a sound called weightless, end of bank A if i'm not mistaken, it is not sounding like in 1.1.1 too.

i'll see tomorrow, after sleeping, if i still think the same!

StephenKay · Post by **StephenKay** » Wed Oct 11, 2006 9:38 pm

master logic wrote:i personally can hear a difference using 2 different pairs of headphone. Not so apparent with AKG k171 but quite obvious with my Sennheiser HD 25-1. Reverb detail, level & generally the overall ambiance sounds better / clearer with V 1.1.1

It's mainly within the 1st bar i can hear it. I'm quite obsessive when it comes to detailed listening, so i definately feel that somethings going on.

And it's in the first bar where the velocity differences are. I would feel better about this sort of statement if the two examples were playing the same exact sequence of notes.

MarkF786 · Post by **MarkF786** » Wed Oct 11, 2006 9:38 pm

Oddly enough, I just loaded the 1.2.1 update and came to the forum to ask about a very similar problem. As I went through the new LAC-1 sounds, I noticed that some of them sounded distorted (unintentionaly), similar to the clipping when you overload an input on a mixer. I then switched to an AL-1 (F116) program to try the stereo spread feature, and as I tweaked the sound it began to clip (unison on, 16 voices, 100 stereo spread, and some detune).

I haven't registered the LAC-1 one yet, so it's hard to tell what's going on there, but with the new Unison features, is it normal for a sound to clip as you up the number of voices, spread, and detune?

Mark

StephenKay · Post by **StephenKay** » Wed Oct 11, 2006 9:41 pm

RC-IA wrote:stephen: i really hear a difference. i programed some sounds that i know well, there is a difference. tomorrow i'll post samples of the problem i have with the filters too, it's really obvious. when i noticed the difference i told myself, oh no just being influenced by what i've read from elvis, but i decide to listen to bass and drum sounds, which are well programed i think, and now they sound different. just listen to a sound called weightless, end of bank A if i'm not mistaken, it is not sounding like in 1.1.1 too.

i'll see tomorrow, after sleeping, if i still think the same!

OK - no problem.

I'm sort of playing devil's advocate here, because I want to see more scientific comparisons, and less subjective impressions. So if there is a difference, we can get to the bottom of it.

Brandon Daniel · Post by **Brandon Daniel** » Wed Oct 11, 2006 9:56 pm

MFenkner wrote: I haven't registered the LAC-1 one yet, so it's hard to tell what's going on there, but with the new Unison features, is it normal for a sound to clip as you up the number of voices, spread, and detune?

In short, yes, it's certainly possible to overcome the system's internal overhead when stacking large numbers of voices with Unison/Poly Unison, though this shouldn't be the case unintentionally with any factory sounds. Try turning down the level via the Master volume slider in any sound you hear this, and see if it helps.

Also, it's worth noting that as faithful models of analog synthesizers, the new LAC models have some clipping built into the signal path, depending on the gain structure of the sound being created.

Mag66 · Post by **Mag66** » Wed Oct 11, 2006 10:10 pm

Okay.. well, at Stephen's suggestion.. I decided to do an A/B comparison using a sequence I recorded directly to digitial several weeks ago.. using v1.1.1 and the exact same sequence using v1.2.1 that I recorded a few mins ago.. to the same digital recorder using the exact same mixer setup (A DPS24.. which allows one to copy across all mixer settings to a new recording..) and same speaker / headphones.. Same connections.. same everthing I could think of..

Listening to a straight A/B comparison.. and flipping back and forth... honestly.. I can hear no difference at all.. In fact I could hardly tell if at all.. when I had flipped from A/.B.. and Brenda heard no difference either due to the way both A/B were in perfect sync with each other.. The sequence contains several different programs and they all sound exactly the same to my ears. The thing is.. before I did this little test.. I have been swearing that my new Oasys sounded richer in tone than my old Oasys.. but that simply isn't the case it seems. Just some kind of acoustic trick of the ears... Certainly no difference between different OS versions to my ears at least... and my ears are pretty sensitive I think..

However, there is always the chance that something else is going on that is causing this apparent discrepancy.. to some people's O & Ears.. so I am not saying anyone is wrong or mistaken at this point in time.. Just that for me.. there is no difference I can perceive.

Nigel

lbartram · Post by **lbartram** » Wed Oct 11, 2006 11:23 pm

elvisjohndowson wrote:Feedback anyone?

It's as if I had a sonic imprint of how my OASYS used to sound earlier and I could immediately get a gut feeling/reaction that something was not right and from my perspective, this little experiment confirms it, alteast to my ears.

Elvis:
Here's another stab at the problem you are having. Could you have had a previously saved Global setting (that would kick in each time you powered up your OASYS) on the Global P0: Basic Setup page? Perhaps that had the MFX and TFX switched off in the little Effect Global SW box at the top, so that when you loaded it up by default, you weren't getting these global effects (e.g., reverbs, etc) applied? You'd mentioned that it seemed like there was a global "wash" over everything. I haven't had time to listen critically to a lot since updating, but I'll keep my ears open.

Mike Conway · Post by **Mike Conway** » Thu Oct 12, 2006 12:47 am

Why would the effects or HD-1 quality change? (Mega Mute Guitar uses samples.) The HD-1 didn't get a polyphony bump and there are still the same number of FX. The AL-1 and STR-1 modelling engines got bumped up, not the sample section. I would think any optimization of those 2 would have to do with their particular engines. I could be wrong, though.

It is possible that some defaults changed with the new OS. They might not be apparent, by looking at onscreen values.

I won't be reinstalling 1.1, but are you going to Global mode and turning off the effects, so you can hear the dry samples? If those sound the same, then it could be the effects. You could also open up the filters and suspect or rule them out.

Right now, I'm working on some sequences, in Song mode. I could slightly hear some sort of channel hiss, so I clicked on the AUDIO IN/SAMPLING tab and checked off the Global setting box. The hiss went away. It was just Input 1, with the L/R setting on. Normal signal noise. But, in my headphones, it's nice to cut that signal out. I'm not saying this directly applies, but it is an example of hearing something, besides the synth engine.

I also agree that you should test with a MIDI sequence, that plays the same, regardless of what OS you have going.

elvisjohndowson · Post by **elvisjohndowson** » Thu Oct 12, 2006 2:09 am

sebbytriton wrote:
elvisjohndowson wrote:.......You know that some law of conservation applies to the obtaining increased polyphony, right? Finite compute resources, increasing polyphony, reduction in accuracy/resolution of the processing or something like that.......
You gain something, you will definitely lose something...
I'm not agree with that. Optimization of code can be often a reason be have better performance without degrad something else.
Improvement in effect/oscillator computation can "free" ressources that are available to provide more polyphony.

I am aware of this

please read what I wrote completely

elvisjohndowson wrote:You gain something, you will definitely lose something, unless that %bandwith was pre-allocated or reserved for the target processor from the begining like one does for most real-time systems and they chose to either optimize the code or take the extra available bandwidth. I don't know.

Elvis Dowson

elvisjohndowson · Post by **elvisjohndowson** » Thu Oct 12, 2006 2:28 am

master logic wrote:i personally can hear a difference using 2 different pairs of headphone. Not so apparent with AKG k171 but quite obvious with my Sennheiser HD 25-1. Reverb detail, level & generally the overall ambiance sounds better / clearer with V 1.1.1

Yes, this is my observation too. Now regarding the suggestion about attempting this using MIDI and then re-sampling the performance, these are my observations:
a. The difference is readily apparent when you play the keyboard live
b. The difference does not seem to be apparent when you re-sample to hard disk and play back the wave file for Mega Mute Guitar. Please discard my initially uploaded wave file because they are not identical and generated from MIDI, but manually played. There are differences in velocity, etc.

If I had to do this test properly. I will have to record a performance for all the combis and programs that I mentioned earlier and then try re-sampling it, upgrade it to OS 1.2.1 again. My sounds and settings are already re-initialized to factory settings.

So its going to be a fresh install. I'm not going to touch or change any settings, maybe apart from enable loading EXs2. Its 6AM my time and I need to head to work and I'm going to be busy the whole day till late evening so I dont think I'll have 4 hours to dedicate to conduct this test. Will see about this tomorrow.

Elvis Dowson

MIDIguru · Post by **MIDIguru** » Thu Oct 12, 2006 3:16 am

I couldn't help but notice that the velocity response curve in the general system settings defaulted to curve number 4 after upgrading. That curve requires a much harder strike (than curve 6 or 7 that I prefer) to get higher velocities. Generally patches are programmed with the filters opening up at higher velocities. This could be the cause of your perceived muddiness.

Anyone else notice this?

StephenKay · Post by **StephenKay** » Thu Oct 12, 2006 3:58 am

MIDIguru wrote:I couldn't help but notice that the velocity response curve in the general system settings defaulted to curve number 4 after upgrading. That curve requires a much harder strike (than curve 6 or 7 that I prefer) to get higher velocities. Generally patches are programmed with the filters opening up at higher velocities. This could be the cause of your perceived muddiness.

Hmm... good point, however, I'm not sure how many people change that setting. But definitely worth checking. In general, I think it would be really nice if updates didn't reset your various global settings, since this can casue people to doubt what they are hearing...

elvisjohndowson · Post by **elvisjohndowson** » Thu Oct 12, 2006 4:08 am

Hi Stephen,
Would you be willing to reset your OASYS to 1.1.0 play the following patches and see if you can hear a difference after upgrading it to 1.2.1?

Programs
A114 Mega Mute Guitar

Combis
A032 Monster Power Synth
B057 Feel the Rush
B068 Dust Storm on Mars

I don't have high quality outboard gear at the moment and cannot perform a recording using the analog outs. The first test would be to see if you can hear the difference in those factory patches between OS versions. You could do record your performance and do the comparision, although in my case the difference was so readily apparent that I chose not to do that test. I won't be able to conduct this test myself for the next 7 hours or so.

Do keep in mind that to downgrade from OS 1.2.1 to OS 1.1.0 you will have to reformat your internal hard disk.

Elvis Dowson

elvisjohndowson · Post by **elvisjohndowson** » Thu Oct 12, 2006 4:17 am

lbartram wrote: Elvis:
Here's another stab at the problem you are having. Could you have had a previously saved Global setting (that would kick in each time you powered up your OASYS) on the Global P0: Basic Setup page? Perhaps that had the MFX and TFX switched off in the little Effect Global SW box at the top, so that when you loaded it up by default, you weren't getting these global effects (e.g., reverbs, etc) applied? You'd mentioned that it seemed like there was a global "wash" over everything. I haven't had time to listen critically to a lot since updating, but I'll keep my ears open.

This is a very good possibility. I didn't check it at the time. There is a global wash over everything including programs and combis. I'll be relieved if it was just this and if it's true then thanks to Korg, I would have ended up wasting a lot of my time over nothing.

Elvis Dowson

elvisjohndowson · Post by **elvisjohndowson** » Thu Oct 12, 2006 4:22 am

Another thing to keep in mind is the age of the listener. It would be nice if there is someone who's less than 20 years of age and who's capable of critical audio analysis to see if the differences can be percieved. As you get older you lose your hearning sensitivity and this may vary from person to person and duration of exposure levels to decibels. I'm 32, so although I can percieve the difference, someone considerably older say between 50 to 60 would probably not. I know this is probably something that someone who fits in that age group would want to hear, but it is a factor to be considered when testing this scenario. I apologize in advance for hurting anyone's sentiments, but it must be stated upfront.

Elvis Dowson

Korg Forums

Harmonic distortion after OS 1.2.1 upgrade

Do you think you have lost the sound quality of the original OS 1.1.1 factory program/combis after the OS 1.2.1 upgrade?