Yeah well although I do consider myself more as a 'Ri-Fi' (as for Ri-ght Fi-elity) rather than 'Hi-Fi' guy in 'orthodoxy', I often take my gear to the limit as a tweaker. This to get the best out of my old 45 rpm 7" groove. That I do by ear rather than from specifications or measurements only. And these Empire tonearms are of high effective mass. Begging to match best low-er compliant cartridges I'd have believe... Could be wrong though. The Grado 'Black' cartridge is of medium compliance from what I got.
Hence why I am surprise with that match of yours. Here I've been tweaking my tonearm to seriously enhance gradually it's effective mass to meet the low of low but unknown given compliance of my cartridge. Hearing it gradually opening up from good to fantastic all along. That only with my ears. This to tell that the match (precise as approximative in the extremes) between these two interlinked components is rather crucial for both to be truly complementary and so performing to their optimum from good to great...
More ; I've even heard "cheap" phono gear for whom I have no attraction to but when well combined with well calibrated gear really sounded surprisingly good. That I had to revise my pre-conceptions on those... Right damn ! Having witnessed once again that all the calibrations between the phono components in the chain is always crucial. Either to accommodate a matching pair and bring the best of both or to compensate a weaker feature in a pair. This second compensation "calibration" thing is only true in the amplification chain though.
If a cartridge nominal compliance figure is only given after laboratory measurements, in real situations these specifications would be evidently else. People at Grado are rather "shy" in regard of their cartridges and styluses specifications FWIW. That for such non reliable reasons which we can understand as it's not relative to a real situation. But only to lab specs. Yet for the rest they still do not disclose much specifications, explanations or the work-out of their mysterious 'Prestige' carts IME. Anyway I've heard a Grado Prestige cart sounding great on one phono with some LP records.
But not yet on all systems nor with any records. I am still trying to get me head around what exactly in the amplification chain should suit them best. Although I am lead to believe that more crucially the HF section of the speakers should really be of very well controlled rendition in playback. The Grado Prestige 'clarity' is what seduced me when I first heard it at a friend's place. But on two other phono system trials they proved really fussy in the HF with a lot of "hairs" on the outlining of the highs out of the tweeters. Giving a really "bright" image of the music. That was truly nothing pleasant.
Not willing to give up two failures with the Grado Prestige carts I still intend to pursue in finding how to grace them 'exotic' cartridges best. Anyway what is that you find with your Grado 'Black' that could be improved through another cartridge ? Are you seeking a MI, MM or even MC cartridge specifically or not ? In what budget ? What is your preamp or phono section from your amp capable to take/handle for cart ? Now finally what sort of records and music you to listen to ? All that was a lot to take at one time on a simple cartridge recommendation but I hope it could maybe prove useful to some...
Post scriptum ; I've manage to dig some further on the Empire 598 turntable and the 990 tonearm and although it's a heavy effective mass tonearm, it boasted back then in 1969/70 to be able to handle such ultra light compliant and tracking cart (@1/4 Gram) like the Empire 1000ZEX cartridge... If so then other light compliant cartridge should be no problem as well. Could this be due to it's 'dynamic balance' design ? Although in physics I don't see where that would change the forces at work but hey... And indeed I read that there was no undesired tonearm to cartridge resonance there and then with light compliant cartridges so...