DSP vs PAN

[Veloce_Dada]

Hi There!

 

I noticed that we cannot change de Pan in the Hex-Layer Zone independently when a DSP effect is On. It would be Nice to expand the sound in the Hex Zone like this, Layer 1 Full Left, Layer 2 Full Right, etc With a DSP Effect ON. I've been using the Wah Effect to Simulate the Filter Cut-off with the Last two Faders (Manual and Resonance) because we can't adjust the filter cut-off and/or the resonance in real time in Hex-layer Mode/PCM Sounds/SYNTH with the Knobs, But I was surprised when I Found that this was a sort of Cut-Off/Resonance simulation with the wah Effect... Not Bad at All!!! 

The Only way that I found out to expand the Sound as I Was expecting to, is to add a Pan Change in Other Two Zones with PCM/Synth Sounds without the DSP WAH on... is This a Confusing explanation? 

 

The XW-P1 is a Powerfull Synth in Solo Mode when we tweak a Knob to Affect the Filter Cut-Off and Resonance, but very, Very Weak in a Poly Situation... I Never Liked Monosynths.

 

 Can Someone explain Me why can't we tweak a Knob in Real Time for the Filter Cut-Off and why isn't possible for us to change the Pan, Layer by Layer in Hex Mode with a DSP Effect On?

[AlenK]

After doing some tests I can confirm what the OP reports. Any stereo imaging of the layers in hex layer mode disappears when you pass the sound through the Wah DSP effect. In fact, it disappears if you enable _any_ DSP effect. As it turns out none of them are true stereo effects. This is something the manual doesn't seem to mention (at least, I can't find any mention), which is hardly surprising given that the manual doesn't even give us an accurate diagram of how the various effect blocks are configured. 

 

Any stereo imaging on a PCM tone also disappears if you enable a DSP effect. However, that's not as serious a limitation since there are only a handful of stereo PCM tones. It's also not possible for the same reason to enable a DSP effect on different PCM tones in a mix and have them retain independent stereo positions. They will all share the stereo position of one of the tones (which one I'm not sure - it may depend on several factors).

 

A true stereo effect processes both sides of a stereo input separately, although it can mix left and right outputs from the effect if need be. None of the XW's effects can do this although a few of them do produce a stereo output from a mono signal (collapsed from stereo if that is what you started with), specifically Auto Pan, Delay, Chorus (the latter only when the "stereo" type is selected) and possibly Rotary speaker (I didn't check that one). I must say that I'm surprised that Casio couldn't do better than this even given the XW's low price. After all, Korg's M1 managed to give us true stereo DSP effects back in 1988. Today, processor power is orders of magnitude less expensive per MIPS. 

 

But hey, at the end of the day the XW architecture is a cleverly designed extension of a basic ROMpler. To a custom LSI for the PCM engine, shared by several Casio keyboards, they added some additional processing power to do synthesis algorithms. I am guessing that the extra processing power is just a portion of the total computing bandwidth of a single, general purpose processor that also handles the effects, the user interface, MIDI, USB and all remaining functions of the synth. That's the way I would have done it in such a low cost product, at any rate. I doubt Casio is using an actual DSP chip for any of that unless it is their own custom design (like the PCM LSI).  

 

But exactly how they did it doesn't really matter. The various limitations of the XW synths, more of which are coming to light every day as we actually try to USE them for projects, suggests that Casio tried to bite off more than they could really chew with this particular design, which just isn't powerful enough to do a truly great implementation of everything they threw in there (except for the step sequencer, which IMO is brilliant). I'm not trying to denigrate it. It gives huge value for money, does some things very well, some things acceptably well and other things not so well. 
 

[Veloce_Dada]

Hello AlenK, Thank you very much for your reply and for your (Always) Wonderfull and Technical opinions!

I Agree with you, the Step Sequencer is Brilliant, (well, it could have 128 steps like Korg's EMX) And I enjoy working with it along with the phrase Player... I Thought it would be harder to program it in Performance Mode, but when we start to understand the XW's language, it's ok... Sometimes it feels a bit stressed up and slows a lot and loses Sync when we're trying to change some parameters with the step sequencer and a phrase or an Arpeggiator running at the same time, but that's understandable, I guess... Not as Understandable when We think that if the XW is a Performance Synth, it would be very Bad the loss of Sync during a Performance... All we need to do is think that we can't be Ad libbing with an XW-P1. That's a Fact.

The DSP limitation is actually strange when we compare the XW with older or less interesting synths... and I always feel disappointed when everyone in my band are tweaking their synths and browsing for sounds because we feel that lots of the sounds in the XW are "tottally centered", we don't feel a Sound Expansion in our ears... but I Guess that all of this is just like some Kind of challenges that I Need to face in order to get a Sound just as I Imagined...

I'm Always Trying to Create a Sound From Scratch, using a Preset...This is Another Thing that I Regret ... The wave section browsing is only possible in Hex Layer Mode... I Was hoping to find them all in the "Synth" or "Various" Sections, in order to use let's say a Particular CZ or MG wave in a Performance separately from the Hex Layer... But that's not possible.

I Love the Hex-Layer Mode And Today I'm thinking that I won't probably sell my XW-P1 if I can still Create sounds that pleases me or my Band... I Want Warmth envolving Pads, Powerfull Synth Basses, Arpeggios Made from Scratch, And until Know, I'm Still Able to create sounds more and Less like I Want to... And I am Always Hoping that someday a Firmware Update may fix the impossibility to tweak Cut Off and Frequency "in a Normal Way" in Polyphonic Sounds...

Let's See what the Future will bring to the XW Series...