If were talking about straight through pipes with no mufflers/baffles then a smaller diameter pipe will give you a snappier sound (high frequency) and a larger diameter pipe will give you a deeper sound (low frequency). Longer pipe lengths lessen the volume of sound and shorter pipes increase the volume of sound. Something to keep in mind is that the human ear is more sensitive to higher frequencies; this means that we perceive these sounds as louder. If a muffler or baffle is added to the equation then the pipe size has only a minor affect on the overall sound. Also, a muffler can alter sound significantly depending on the design. Many technologies are employed in the design of mufflers or baffles. At this point we need to understand the difference between a muffler and a baffle. A muffler is a mechanical assembly that employs multiple components and technologies to reduce sound in an exhaust system. A baffle is a mechanical device used to disrupt sound waves. In most cases baffles ar