The MX-series features LPF24, LPF18, LPF12, LPF6. Within a Voice, each of the 8 possible Elements has its own Filter... you select from among the four Types.

As you move up the synthesizer line to the MOXF, from there and above you will get a full complement of 18 Filter Types. That is, the MOXF-series, the MODX-series and the MONTAGE-series. These engines feature: LPF24D, LPF24A, LPF18, LPF18s, LPF12+HPF12, LPF6+HPF12, HPF24D, HPF12, BPF12D, BPFw, BPF6, BEF12,
BEF6, DualLPF, DualHPF, DualBPF, DualBEF, LPF12+BPF6.

Thank you !

I'm surprised, because it seems that the "old" little XS Rack already have all filtertypes.

I guess .. if i want a cheap but powerful engine, then i need an MODX. Most important part will be that the Melas voice-editor really works.

The “‘old’ little rack”, (size means nothing), is a Motif-Rack XS. Completely different series. Again, the entry level Yamaha Synth is MX.. next up the line is MOXF-series, followed by the Motif-series (discontinued), followed by the MODX-series, and topped by the MONTAGE.