I do have a schematic for the Empire 8000P speaker system that I drew up while replacing the wax and paper capacitors in the crossover and to run LTspice simulations on the network. Unfortunately, I don't think this will help you as the crossovers used in the Grenadier 6000's are different than the ones used in the 8000P. Even though I have never owned a pair of the 6000s, if you look at eBay right now, there are a pair of these crossovers listed for sale. Looking at them, I can see there are components intentionally missing in this crossover design that are utilized in the 8000P. I have heard from other Empire owners who have the model 8000, 8000P and 9000 that a lot of problems with the midrange and tweeters in these units (which all use the same gold face plate array) that these components suffer from electrolytic corrosion problems which stem from the use of aluminum wire in the voice coils where they interface with the copper wire used for further interconnect. This causes intermittent problems with these drivers in the early stages of corrosion and permanent loss of functionality as the corrosion progresses to open circuit. They can be repaired, but it is a tricky and delicate repair. I can not say this same problem exists with the 6000 as I do not know what tweeter and midrange is used in this model and how they are constructed. This may not be the answer you wanted to hear, but hope it helps in tracking down your issue. If you take your speaker apart, you can use your DVM/VOM/VTVM to check for open circuit or high impedance through the midrange and tweeter components. That should give you a good idea where the problem is. Be sure to check all the solder connections of the wiring on the crossover board terminal strips and of course those pesky old capacitors. Best Regards.