Help. This cartrdige sounds great except for the fact there is no low bass. I've tried changing the VTA, tracking etc. Any ideas on where to start?

I have an ARC VT100 MKIII, LS15 preamp and Anthem Phono Pre. The HG10SX Velodyne hardly detects anything except some low level rumble.

I am using an Acoustinc Signature TT with 250 tonearm.