Firstly, I find the external engine sounds especially at flypast are stunning (minus the random volume fluctuation ruining them)! But, the interior engine sounds.. are.. lacking something? Ive only flown (though, MANY times) on a Trent 900 powered a380 so I cannot speak for the Engine Alliance sounds, but for the Trents, based from experience are definitely missing a lot of growl.. During takeoff, looking past the late onset of the growl during spoolup like the OP mentioned, they also seem to be drowed out by some kind of.. whooshing or rumbling sound? Maybe some kind of low quality recording? Or.. sometimes i feel like the "buzz-saw" growl may be somehow cancelling itself out, a double layer maybe..? As if it may be possible that two different recordings are fighing over each other though i may be wrong.. Either way something sounds off. Again, its really hard to explain.. but its easy to hear what they SHOULD sound like on any youtube video (such as this one, my favourite, gives goosebumps https://www.youtube.com/watch?v=lRe-l6Zgk4w&t=2s ), or even by using the freeware a380 competitor, whom in contrast i feel got the interior engine sounds spot on. (Id expect a Payware aircraft to sound better than a freeware in this regard) Contrary to popular belief, whilst in general the a380 is a VERY quiet aircraft to fly on, the engines growling during takeoff should sound rather clean and clear (though not overly noisy) and really, rather beautiful when in front of the wing. They do not sound muffled in person, like they currently do in this model. In Addition, during spoolup ive been comaring the exterior sounds (beautiful) with the interior sounds (needs work), and found that the interior sounds do not match what is happening on the exterior. For example during the FADEC METOTS pause before TOGA, in the exterior there is already a gentle but noticable and clear growl. In the interior the engines sound like they are at a lower power setting, with no growl. The inside and outside sounds dont match.