Yes, having open headers on a motorcycle would generally result in a louder sound compared to a Harley with a loud exhaust. Open headers refer to an exhaust system configuration where there are no mufflers or other sound-dampening components attached to the headers. Essentially, the exhaust gases are expelled directly from the headers without any restriction.
In contrast, a Harley with a loud exhaust typically has aftermarket mufflers or exhaust systems designed to enhance the sound of the motorcycle. While they may produce a loud and distinctive rumble, they still have some level of noise reduction compared to open headers.
Open headers allow the exhaust gases to flow freely and unrestricted, resulting in a more aggressive and intense exhaust note. However, it's important to note that running a motorcycle with open headers may not comply with local noise regulations and can be extremely loud, potentially causing discomfort or annoyance to others and even legal issues. It's always advisable to adhere to local laws and consider the impact of excessive noise on the environment and those around you.