Ferrofluid

@tattooedtrackman  I will defer to those with more experience.  But if it was me and I did not notice anything that sounds wrong, as in your case, I wouldn't even think one thought of messing with my crossovers.

I would just sit back and enjoy your beautiful system.

Ferrofluids main purpose is to dissipate heat. When the coil heats up, it naturally cools within the fluid. I do not drive my speakers crazy hard an have compared sound with and without fluid several times. I always heard a tad more information without fluid, so I normally remove it. I have also measured many tweeters with and without ferrofluid, resonance also goes down a bit when it is removed and don't take this as a recommendation to remove it. I've been building, repairing and modifying speakers for more than 40 years, I would do this to my own, but to someone without personal skills, I would recommend to leave alone until it needs to be done. Ferrofluid  will thicken as it ages, so overtime, it will hinder driver movement and heat transfer 

if the tweeters sound good it's probably OK.  The risks to not replacing the ferrofluid on time is audible but also the risk to the voice coil.  The gunk may add physical friction and therefore heat the voice coil.

@timlub Thats exactly what Bill said at Millersound about it thickening as it ages and will harden overtime. Do u also build crossovers. ? If u do and or know about crossovers I would love your professional opinion on the crossovers from a maker on eBay as I mentioned a few posts up. You can look them up on EBay if u have it. Just search for B&W 800 Matrix crossovers. Thank you and I appreciate it. 

@tattooedtrackman     Yes,  I do design, build, mod and repair crossovers.  I know what I'm doing and want you to please take to heart what I tell you  here. Your speakers crossovers are well thought, complicated expensive. When I build,  Each woofer, tweeter mid, midbass and each crossover part is hand measured and matched for accuracy. If you want someone to replace caps and resistors, fine, upgraded parts will be audible, but understand, 1 person may say Wow, what a shocking improvement and another may say, well, I can tell its done, but it wasn't much different.  You can spend a ton and not hear alot of difference. With that said, when you replace inductor coils,  you are changing the line impedance sometimes over an ohm on a single part.  If you take off a 3mh ferite core, it may have a resistance of .8 ohms, when you change to a 3mh air core, it could be more than double that.  So you think you have a crossover frequency of say 3000hz, but because you changed the line impedance to that part, you may now be at 2800 or 3200.  On top of that, when I build, I build to have phase and time alignment, when you change parts without a proper plan, you throw that right out the window.  If you want to replace resistors and a few caps, I'm happy to pull schematics and tell you which to change and good idea of what to buy, but unless you are very highly qualified at speaker design, do not change the inductors.  It is alot of work to get this right and it is easy to blow by someone that can solder, but really doesn't know what they are doing,  So EBAY, for me, especially on such a nice speaker, That is a big NO WAY.