hi, im a professional diesel engine mechanic and can easily explain what youre hearing.
Most italian/european sports cars (with the exception of Mercedes in the past 3 years because American customers) have machined their crankshafts as "flatplane" cranks. Flat-plane cranks, no matter what firing order they have, will always alternate from bank to bank. This yields optimum exhaust scavenging and thus doesn't require the more complex header primaries that have to cross over from one bank to the other. Due to their design they don't need huge counterweights, which is why they rev up so quickly. The downside is that they suffer from secondary vibrations and have lower torque.
Americans typically machine closer to if not dead-on a crossplane crank or cruciform crank. the four crank pins are positioned in two planes, offset by 90 degrees. Typically the two outer pins are perpendicular to the outer and the two end pins are in one 180-degree plane. exhaust gas scavenging isn't as efficient as with a flat-plane crank, but that sound is worth it. This design necessitates larger counterweights to achieve a proper engine balance. The result is that you don't have the secondary vibration problems associated with flat-plane cranks. But they also don't rev as fast or as high. pick crossplane when you want torque imo.
I personally understand that a euro flat-plane crank is superior in its efficiency and power for racing, but the crossplane sound just melts my cold American heart when i hear it.