Thanks, the reason I ask is because I understand that a sweep tone test is too easy and gives an unrealistically good FR. Music is more wideband.
A wideband tone FR will give an FR measurement more representative of complex music with numerous instruments playing together.
Unfortunately they are not all that similar, eg
The top is the spot frequency FR, which would be much like a sweep tone FR, and the bottom is a wideband tone FR of the same cartridge (Rega Exact).
It would be easy to get cocky about the flat response of cartridges using the sweep tone, when in fact they are not doing so well at all with music.
The really ugly reality, that the discrepancy between the above two graphs tells us, is that the FR of a cartridge is chaotically jumping up and down as the music varies from simpler to more complex. Ugh!
cheers