XTC Sound Quality

[goaFromLivingRoom]

Hi,

in some threads people mentioned that XTC sound is worst than in normal Scope mode via routing. Is that right? What's about delays and phasing? Is that working correct in XTC mode?

I use SFP 4.0 with Scopecard, PulsarII and Elektra all cascaded.

[the19thbear]

I cannot tell the difference. Try it out. If you like it, use it! XTC mode is the ONLY way to go for me

[voidar]

Old threads are so much fun .

In XTC mode, as in native mode, gain-staging is important. With the usual floating point DAW this is not so, but it becomes important when integrating Scope FX as they will truncate the output to 32-bit integer.
While multiple VST Scope plug-in instances are possible, it makes economical sense to load MultiFX plug-ins when you know you'll use two Scope FX in a row. Not so fun as two VST instances though with VST-parameter mapping.

For phase-accuracy I find the Voxengo Latency Delay a must. Scope FX only report ASIO latency to the host and often thus miss by 2-4 samples or more due to DSP management and/or internal plug-in latency (look-ahead, RMS etc.). This might work better with XITE though.
For parallel processing I find sample-accuracy to be a must. If anyone doubts this I urge you to do a simple test. Phasing with compression is pretty obvious, but you will also hear how much more beautifull a reverb will sound when in phase with the dry signal component. Especially the ER part.

In this way I find XTC mode superior to native mode as you are able to fix these issues in a simple fashion, and they stay consistent on project recalls after setting up. You only need to worry after DSP optimization when everything is re-aligned.

[nightscope]

Old threads are so much fun .

In XTC mode, as in native mode, gain-staging is important. With the usual floating point DAW this is not so, but it becomes important when integrating Scope FX as they will truncate the output to 32-bit integer.
While multiple VST Scope plug-in instances are possible, it makes economical sense to load MultiFX plug-ins when you know you'll use two Scope FX in a row. Not so fun as two VST instances though with VST-parameter mapping.

For phase-accuracy I find the Voxengo Latency Delay a must. Scope FX only report ASIO latency to the host and often thus miss by 2-4 samples or more due to DSP management and/or internal plug-in latency (look-ahead, RMS etc.). This might work better with XITE though.
For parallel processing I find sample-accuracy to be a must. If anyone doubts this I urge you to do a simple test. Phasing with compression is pretty obvious, but you will also hear how much more beautifull a reverb will sound when in phase with the dry signal component. Especially the ER part.

In this way I find XTC mode superior to native mode as you are able to fix these issues in a simple fashion, and they stay consistent on project recalls after setting up. You only need to worry after DSP optimization when everything is re-aligned.

Valis,

I'm definitely not clued up on phase issues within Scopeland. If you can spare the time - why should I care, what are they, why do they occur and how can they be diagnosed and fixed. Think "phase issues" for the clueless.

I enjoy your informative posts. What I can understand of them, anyway.

ns

[maky325]

Old threads are so much fun .

In XTC mode, as in native mode, gain-staging is important. With the usual floating point DAW this is not so, but it becomes important when integrating Scope FX as they will truncate the output to 32-bit integer.
While multiple VST Scope plug-in instances are possible, it makes economical sense to load MultiFX plug-ins when you know you'll use two Scope FX in a row. Not so fun as two VST instances though with VST-parameter mapping.

For phase-accuracy I find the Voxengo Latency Delay a must. Scope FX only report ASIO latency to the host and often thus miss by 2-4 samples or more due to DSP management and/or internal plug-in latency (look-ahead, RMS etc.). This might work better with XITE though.
For parallel processing I find sample-accuracy to be a must. If anyone doubts this I urge you to do a simple test. Phasing with compression is pretty obvious, but you will also hear how much more beautifull a reverb will sound when in phase with the dry signal component. Especially the ER part.

In this way I find XTC mode superior to native mode as you are able to fix these issues in a simple fashion, and they stay consistent on project recalls after setting up. You only need to worry after DSP optimization when everything is re-aligned.

Yep! Everything you've said is absolutely true. Mixer per se will add 2ms. I've figured it with Voxengo (also using this free tool) when i was trying to calculate exact delay. This is not problem or anything as long as you know how things works inside scope - but great to read this here. THX

[voidar]

Valis,

I'm definitely not clued up on phase issues within Scopeland. If you can spare the time - why should I care, what are they, why do they occur and how can they be diagnosed and fixed. Think "phase issues" for the clueless.

I enjoy your informative posts. What I can understand of them, anyway.

ns

Well it can result in very audiable comb filtering when using Scope FX for sends. Just one sample offset is very audiable. This is actually how FIR/IIR works in principle.

Just test it. Load up a Scope reverb as a send effect. Use the plug-ins internal bypass (bypassing on the DSP). Phase-invert the channel. Insert Voxengo Latency Delay (free) before the Scope reverb. Send a test signal to the reverb send. You should hear some phased out signal. Now just turn the sample offset on the Voxengo plugin until there is no sound. You are now in phase.
Enable the plug-in again and disable phase-inversion.

[JoPo]

Yes! Valis ! Where are you ?

How do we detect & fix phase problems ?
And also DC problems such as in modular..?

[pollux]

Yes! Valis ! Where are you ?

How do we detect & fix phase problems ?
And also DC problems such as in modular..?

Just test it. Load up a Scope reverb as a send effect. Use the plug-ins internal bypass (bypassing on the DSP). Phase-invert the channel. Insert Voxengo Latency Delay (free) before the Scope reverb. Send a test signal to the reverb send. You should hear some phased out signal. Now just turn the sample offset on the Voxengo plugin until there is no sound. You are now in phase.
Enable the plug-in again and disable phase-inversion.

edit: voidar, not valis

[voidar]

Who? What? Valis?

[JoPo]

Sorry... I didn't read all...
So it's for XTC mode... I never use it.
So in normal mode, is there phase problems occuring ?

[nightscope]

Well it can result in very audiable comb filtering when using Scope FX for sends. Just one sample offset is very audiable. This is actually how FIR/IIR works in principle.

Just test it. Load up a Scope reverb as a send effect. Use the plug-ins internal bypass (bypassing on the DSP). Phase-invert the channel. Insert Voxengo Latency Delay (free) before the Scope reverb. Send a test signal to the reverb send. You should hear some phased out signal. Now just turn the sample offset on the Voxengo plugin until there is no sound. You are now in phase.
Enable the plug-in again and disable phase-inversion.

Thanks for chiming in void. This is getting confusing very fast. First off, I'm not in XTC mode. I know I'm in a XTC thread but what I'm after is a clear concise description of phase issues that can occur in Scopeland. I know jack schidt about this kinda thing in Scope.

I will attempt to answer my own questions to illustrate what I have gleaned thus far which is not a lot.

why should I care,
Because there are serious phase issues in Scope that I haven't taken any notice of so far and need to get up to speed on.

what are they,
Using certain Scope FX as auxs or track inserts can cause the other tracks in the project to be out of phase with the FX track/send.

why do they occur
Because there is a latency introduced somewhere when certain FX are loaded onto different DSP's for some reason.

and how can they be diagnosed and fixed.
Don't know, except when you've figured out which track/FX is hosed you can adjust the latency delay of the phase inducing FX somehow.

So, if some kindly person could direct me to the defintive "Idiot's Guide To Phase Issues In Scope" I would be much obliged.

ns

[voidar]

Sorry... I didn't read all...
So it's for XTC mode... I never use it.

Well, you're in the XTC forum after all .

[/quote]
So in normal mode, is there phase problems occuring ?[/quote]

Yes. Though it is much harder to cure.

[voidar]

So, if some kindly person could direct me to the defintive "Idiot's Guide To Phase Issues In Scope" I would be much obliged.

ns

Well, I think you are pretty much on the money. If you are bothered by it that is. Though some people might thing it contributes to "the sound". I wouldn't understand why though.

Of course, in the hardware processing world you can never obtain phase accuracy, but I am not talking about phase smearing/distortion which might indeed sound cool, but rather micro-delays/semi-inverted polarity, which certainly degrade SQ.

There is no easy way to battle this in native mode. With the STM mixers I can only think of routing buss and FX returns back to their own stereo pair so you can adjust sample delays for each stem.

Anyway, I enjoy XTC-mode more and more these days as I've started using more native VST stuff and I want to mix and match.
Hardware integrating DAW's (i.e. REAPER - ReaInsert plug) work nicely with native Scope mode, but requires too much planing ahead setting up ASIO send/returns, and the project window quickly becomes cluttered.
Like if I wanted to insert a native VST plug between two Scope FX, this quickly becomes old and tiresome.

Sure, if you religiously want to use Scope FX exclusively, then you could do it all in the project window, but for me; I can't ignores the great plugins available from Stillwell and Cytomic i.e.

[nightscope]

So, if some kindly person could direct me to the defintive "Idiot's Guide To Phase Issues In Scope" I would be much obliged.

ns

Well, I think you are pretty much on the money. If you are bothered by it that is. Though some people might thing it contributes to "the sound". I wouldn't understand why though.

Of course, in the hardware processing world you can never obtain phase accuracy, but I am not talking about phase smearing/distortion which might indeed sound cool, but rather micro-delays/semi-inverted polarity, which certainly degrade SQ.

There is no easy way to battle this in native mode. With the STM mixers I can only think of routing buss and FX returns back to their own stereo pair so you can adjust sample delays for each stem.

Anyway, I enjoy XTC-mode more and more these days as I've started using more native VST stuff and I want to mix and match.
Hardware integrating DAW's (i.e. REAPER - ReaInsert plug) work nicely with native Scope mode, but requires too much planing ahead setting up ASIO send/returns, and the project window quickly becomes cluttered.
Like if I wanted to insert a native VST plug between two Scope FX, this quickly becomes old and tiresome.

Sure, if you religiously want to use Scope FX exclusively, then you could do it all in the project window, but for me; I can't ignores the great plugins available from Stillwell and Cytomic i.e.

Thanks for your thoughts, void. I've tried out XTC mode I didn't get on with it too well. Many strange things happening with GUI's and certain synths not working properly. I will revist it at a later date. Main reason I wanted to get into doing it all in the host is to get my controllers into battle driving the Scope stuff with Automap and MCU protocols.

ns

[the19thbear]

@voidar: +1 !!
im more and more starting to use stillwell, bootsy, ssl duende and antress plugins instead of scope plugins in xtc mode - the only things that comes close in scope world would be DAS plugins i believe. the scope synths is another story though.

i stopped using xtc mode because i had to disable any extra cpu cores to get it to work
and the normal sfp mode is just a very non inspiring way to work for me so i just go native these days.

soundquality over workflow. i guess thats what im trying to say
-hope sc will do a xtc fix soon