An XRF analyzer can include a rotatable filter structure to separately position at least two different x-ray source modification regions between an x-ray source and a focal point and at least two different x-ray detector modification regions between an x-ray detector and the focal point.An XRF analyzer can include a rotatable source filter wheel between an x-ray source and a focal point and a rotatable detector filter wheel between an x-ray detector and the focal point. The source filter wheel can include multiple x-ray source modification regions. The detector filter wheel can include multiple x-ray detector modification regions. A gear wheel can mesh with a gear on the source filter wheel and with a gear on the detector filter wheel and can cause the source filter wheel and the detector filter wheel to rotate together.