While they are under the legal noise limit, the low frequency of harleys travels significantly easier through obstacles, making them seem louder inside a house

While they are under the legal noise limit, the low frequency of harleys travels significantly easier through obstacles, making them seem louder inside a house or around a wall / fence / bush than a higher frequency noise at the same dB. I'm definitely not arguing that 2-stroke is quieter though. Just that it's not quite an apples to apples comparison due to both variables having an impact.