too loud vocals from the sample

I'm trying to maake a remix and I've got a fine beat. The only thing going wrong is the fact that in the sample there are some vocals so that when the rapper is spitting they overlap the rapper and you don't know what to listen to, the vocals from the sample are too loud. I was trying to do it that way: I divided the sample into 2 parts, one with the low frequencies and the other with high frequencies and turned the volume of the high frequencies down when there were vocals in the sample. Thesample is too loud however, so it disturbes the rapping and when I turn the volume of the sampe down even more the beat sounds whack. I was also trying to filter the sample but it seems that there is a huge loss of the quality, you know you can't hear all the sounds from the sample so it doesn't sound good. Any ideas? PEACE

eq the sample or instrumental so the frequencies of the vocal track dont clash with those of the voice on the sample

you might be able to do a vocal cut by removing the center channel.

Sounds like you need to use more precise eq to find the differences in frequencies between the rapper and the vocalist on the sample. I'd split the sample into a couple/few channels (avoiding phasing, cancellation, etc, unless that works) on a mixing desk and have the rapping on another channel and play with the eq till it all started to fit. Then maybe resample the eq'd beat and vocal separates back into the mpc.
You could also try sidechain ducking on the separated, eq'd vocal channel, with the sidechain fed from a split from the rapper... just tweak the compressor/limiter and the eq till something gels. Maybe also lower the volume of the affected vocal channel and make it a bit more wishy-washy with FX whilst layering your thump, kick, snare and hats (depending on how well your separation on the mixing desk went) over it. Trial and error really.

Failing all that, cut your sample up into leedle pieces and try making a beat with that. Each hit can then have it's own amp envelope so the rhythm of it will cut out the effect of the overlying vocal on it.
My 10 denk.