i discoverd that voices that had been transferred to performance mode often loose their richness and full sound.
I know it´s because of the effects but when I choose the "parameter with voice" field to be activated it is still not the same sound.
What else can I do to get the same sound quality in performance mode?

What you have discovered is true but once you know the reason, you can make adjustments to rectify the results. You do it all the time in the real world, without a second thought... Now let's see why this occurs and how you already "know" how to deal with it.

When you are in VOICE mode the single sound has exclusive use of all of the available processing.
When you move to Performance mode, the single sound must share some of the processing with the other sounds.

Our analogy in the real world would be that VOICE mode is a musician, say an electric guitarist, with a Wah pedal and Overdrive, sitting in his bedroom at home. The Wah and Overdrive are his Insert Effects connected "inline" with the guitar. The bedroom's acoustics are external to the player and his inserted effects. Part of the overall sound is the room you are in at the time. The sound in his bedroom would be the responsibility of the System Effects (Reverb and Chorus, the word "chorus" is a shorthand generalization for "time delay" effects).

Now that's VOICE MODE, the musician and his surroundings. Take the guitarist to band rehearsal at the local club... The guitarist brings along his personal guitar, Wah, and Overdrive (the Insert Effects remain with the Voice, they are inserted "inline" and are considered apart of the Voice. The player cannot bring along his bedroom acoustics!! He must now deal with a different room, with 3 other musicians in it!

The acoustics in this real world scenario would be determined by the size and shape of the local club you rehearse at. In fact, the other band mates will each share the same room acoustics now. So how do you get the same sound the guitarist had back in his bedroom (where the ceiling was low and there were rugs on the floor?)

A Performance is like the club, each of the four band mates can bring along their own personal inserted effects (2 of them each), automatically. But all Performance Parts must "share" the room acoustics. The so-called System Effects work just like a band's mixer at the club. Each member has a channel (or channels) on the mixer with an AUX SEND that sends a certain amount of that signal to a Reverb, say, the Reverb recreates the room acoustics and a stereo return is combined with the dry signal, just prior to the main output. Now, each band member's channel on the mixer has its own SEND amount to the reverberation chamber and to the time delay effect. But each member cannot have his own bedroom recreated... After all they are now all in one room, the same room. Make sense? Insertion Effects are inline. System Effects use a SEND/RETURN scenario.

Okay, that's why. If you want a Voice to sound exactly like it does in Voice mode, you would need to setup the same Reverb and Chorus TYPES in the Performance, thus recreating the external (bedroom acoustics of one of the players) for all band members to share. Remember all band members share the same room acoustics when they play as an ensemble via an individual Send and communal Return system.

Even when you copy the System Effects from a Voice to the Performance (and you can), you still have to manually set the SEND LEVELs for each, just as would on any mixer - your perception of amount of Reverb or delay is greatly affected by what else is sounding at the same time. The reverb when a sound is alone sounds different as you start to add other instruments... Masking of certain frequencies causes us to hear the reverberation less in a crowded mix.

While in PERFORM
Press [JOB]
Press [F3] COPY
Press [SF2] VOICE
Here you can copy information from the Voice in Voice mode. Mark the attributes you wish to Copy (Reverb, Chorus, etc) and press Enter to execute.

As mentioned this will setup the same System Effects, SEND AMOUNT must be done manually and as always, to taste, based on the other sounds using the same System Effects (room).

In the real world you learn to adjust to your new surroundings (you don't expect to bring the bedroom acoustics with you), at home (voice) will sound different from the club (performance) or the studio (song/pattern) where some effects are inserts (personal) and others are system (shared).

Hope that helps. If you are talking about a specific VOICE, let us know, we can show you how to analyze it and then how to recreate it, exactly, in a PERFORMANCE. Let us know. It can definitely be done.

I haven´t had the chance to do it yet because my motif is still with the touring eqipment. I´ll get it back this weekend.
I understand your explanations of the effect system in analogy of the real life circumstances of musicians.
What I don´t understand is why YAMAHA tries to rebuilt these real life limitations in a music synthesizer! Is it really necessary?
At the first look this just causes more work for the user.
I will try it anyway and let you know if I have been sucessfull or not 😉

thanks

That's funny,, real world situations are the model on which it is built because that is the model on which things work in audio systems. The natural system or "limitations" are the way one can choose to work when working normally, if you would like to record each individual PART with its own room acoustics, you would do the same thing you would do in the real world when you have just one studio, record each musician as audio one at a time. And that is, in fact, a legitimate way to work, it's done all of the time!

In a real recording studio, reverb is routed via Aux Sends (Send/Return scenario) and reverb is NOT recorded on the multiTrack. Because it is a communal effect... "Shared" by all. Effects like reverb are added at Mixdown, the vocal is initially recirded dry. Not a limitation, a preference actually as you opt toward isolation during record... So sweetening effects like reverb are added at final Mixdown (ask around) one could call it a limitation (the fact that studios don't construct multiple reverberation chambers), but only those who never worked in a studio would think so)!

I don't look at this as any type of limitation, I can't fly either, but it is not a limitation of me as human being. Neither is basing a synth work environment on real world situations. I'm happy you could understand my explanation, based on the real world (which is something we share in common) simply look at it as a limitation of our ability to communicate. I used the "real world" example because it helps others understand how and why things work as they do.

Understand these first, then look for workarounds (and plenty exist). Communal effects (reverb, time delays) are how recording and live mixers work. And there are really good reasons - to call them "limitations" is simply your point of view... Hopefully that will hopefully change (grow) as you get to know and understand the system. We built the black and white keys with the same 12 tone "limitation" as most keyboard instruments on this planet. You can change that tuning if you wish, but don't question why we built-in this "limitation"... Hope that helps.

It´s understood! Thank you!