Reduced Tire Noise 25% by accident

[Who Knows]

Everyone here knows how noisey these cars are---I changed all of the following at the same time: 15mm spacers front, 20mm spacers rear, Eibach
springs, Adjustible upper front control arms, rear adjustable camber arms. I really, really like how the car looks and handles/ much better than stock but the neatest thing about all of this is my car is at least 25% or really closer to 35% more quiet---guys it's as different as day and night!!! I noticed the new Eibach springs have much larger coils and the weight of them is at least twice of the stock springs---maybe there is some metal harmonics going on
with the stock stuff, could be the upper control arm is acting like a tuning fork I really don't know. My car is completely different and in a very good
way--just thought I would pass this information on