ompt stereo separation

[BooT-SectoR-ViruZ]

by the way... what does it do exactly?
i don't hear much differences...

[LPChip]

I believe its the following: (but not entirelly sure)

Old modules usually have extreme pannings (entirelly left, entirelly right) It corrects this to put them more in the middle.

[pelya]

Does OMPT have some option to pan sample not by just changing right/left channel volume ratio, but by adding small delay to one of channels? There's some option names "Pro-Logic Surround", but it seems to work only with quadrophonic output.
Does OPMT have the option to copy front channels to rear for quadro output mode (e.g. when song contains only 2 channels)? Or that is what "Pro-Logic Surround" does?

[LPChip]

I'm not sure (again... de-ja vu? )

But it could be indeed. Maybe you can see if that happens by looking at the sourcecode?

[SoundCrafter]

Maybe...(I could be entirely wrong on this)...it does one of two things:

1. Keeps levels between L, C, and R pannings equal. Old hardware, when panned hard left or right, lost signal amplitude. Maybe it corrects this?

OR

2. Acts like Reason's MClass Stereo Imager, which maintains panning, but makes the sound further or closer on the stereo spectrum (you kinda have to hear it to understand it.)

So those're my theories.

[Saga Musix]

don't try with desktop speakers to find out. use headphones or a stereo. you will find out that it has a great effect on both, especially on headphones. a very wide paddning will hurt your ears.

[Sam_Zen]

First let's keep seperate the issues here. Stereo separation is another function than the surround thing.
It's about the setting in the Soundcard tab. I have this setting default at 100 % so the output will be exactly as it is meant from the mix, according to my own way of working.
If the slider is set to less than 100, so to make the stereo more narrow, than a part of the right channel is added to the left, and vice versa. So more common sounds, so more situated in the virtual center.
If the slider is going >100, then I must assume things here, because I don't know the formula of the OMPT sourcecode.
But most of the times part of one channel is added in a negative format (so 180 degrees inverted) to the other channel, so any common
material of the two channels (in the center) will be dampened to a lower volume.

The slider goes from 25 % to 400 %, but it seems to behave within a very moderate area, with indeed not much of a change.
So I think BSV has a point here to focus on this function.

2 pelya
You come up with four extra issues within this topic, concerning the 'surround' thing. But ok.

Does OMPT have some option to pan sample not by just changing right/left channel volume ratio, but by adding small delay to one of channels?

Every format has its code to delay the start of the sample. If you want to use this technique for panning one sample, just copy the channel into a new channel, set with a different panning and apply the delay to the note-code.
(This means an equal sound in two channels, so both volumes has to be adjusted lower to get the same output level)
So the sample at one position will start a bit earlier than the same at another position. Setting of both volumes defines the rest.
An inverse option can be done by applying a code to skip the sample during some ticks at the beginning. Dunno about other formats,
but in XM it is 9xx. In fact, the sample starts somewhat earlier, than the regular one in the other channel, so also creating delay.

There's some option names "Pro-Logic Surround", but it seems to work only with quadrophonic output.

This is not a correct expression. "Pro-Logic Surround" can produce a quadrophonic output, but is not dependent of that to function.
I skip the surround options of single IT-channels here, but just about the setting in the Player tab of OMPT.
This is a general playback-setting (which is also valid if exporting to wav), one could see as an expansion of the Stereo Separation
setting. More sliders to play with.

Does OPMT have the option to copy front channels to rear for quadro output mode (e.g. when song contains only 2 channels)? Or that is what "Pro-Logic Surround" does?

This is definetely too far way off and needs another thread.

[BooT-SectoR-ViruZ]

There's some option names "Pro-Logic Surround", but it seems to work only with quadrophonic output.

This is not a correct expression. "Pro-Logic Surround" can produce a quadrophonic output, but is not dependent of that to function.
I skip the surround options of single IT-channels here, but just about the setting in the Player tab of OMPT.
This is a general playback-setting (which is also valid if exporting to wav), one could see as an expansion of the Stereo Separation
setting. More sliders to play with.

i would recommend to keep that option turned off.
imho it sort of destroys all mono stuff in your tracks.
e.g. bassdrums will sound flanged/reverbed and normally
that's nothing to wish for if you plan on having a crunchy sound
(for use on CHANNELS it might be ok... but not for the whole mix)

[Saga Musix]

well,i  simply love surround as it really adds to the stereo panorama. and my BDs do not sound flanged/reverbed at all, they sound very normal. and i also have to set stereo seperation to 25% - else, it would sound terrific on my stereo

[Sam_Zen]

..imho it sort of destroys all mono stuff in your tracks. e.g. bassdrums will sound flanged/reverbed

If you mean with 'mono stuff' sounds in the center of the stereo, they will be affected indeed. And BDs are in that center as a default.
But flanged/reverbed ? I can't think of any cause for that.
This option is, I guess, a combination of some stereo-separation, plus the fact that a portion of the sounds of extreme left and right gets a small delay and is mixed in the opposite site.
And imo it's not so much a matter of turning on or off. If one sets the sliders to Low and 5ms, there's almost no difference.

i also have to set stereo seperation to 25%

Quite peculiar First you narrow down to 25%, then a tool to widen it up again.

[BooT-SectoR-ViruZ]

If you mean with 'mono stuff' sounds in the center of the stereo, they will be affected indeed. And BDs are in that center as a default.
But flanged/reverbed ? I can't think of any cause for that.
This option is, I guess, a combination of some stereo-separation, plus the fact that a portion of the sounds of extreme left and right gets a small delay and is mixed in the opposite site.

yeah, that's what i'm talking about...
quit picking on my poor knowledge on technical terms

and my "warning" is more about a high rate on that surround option
(although i don't really know how it sounds now... quit using it a long time ago)

[Saga Musix]

i also have to set stereo seperation to 25%

Quite peculiar First you narrow down to 25%, then a tool to widen it up again.

do i? what tool do you mean? the speakers?

[Sam_Zen]

2 Jojo
Sorry. I meant enabling the 'Pro-Logic Surround' function in the player-tab to make it wider.

[Saga Musix]

well, the surround thing does not only make the sound wider. it also fills the space between the speakers, and that's what i want