What kind of mufflers sound the best?

My 2007 civic si is making a kind of wump wump wump sound around the front right of the vehicle?

• about 3 weeks ago I was driving and I could hear a faint wump wump wump wump kind of sound coming from the front right side of the vehicle. I thought I was hearing things because no one else could hear it. This sound only really occurred when I was going about 40 mph or faster but as I would go even faster the sound would still keep the same rhythm. Then today I just drove from my home in Missouri back to Kansas, its about a 300 mile drive. Well about 15 minutes from where I needed to get to I noticed my exhaust didn't sound right. From like mid 3rd gear on it didn't have the usual throaty sound it made. Instead it would make like a sucking sound almost. The rpms at different speeds are the same as they have always been and the handling of the car has not been affected at all from what I can tell. The car doesn't shake or anything like that but it just makes that wump wump wump wump sound. Any ideas what it could be??

• Answer:

  Hmm... Check your intake, although its unlikely that's what it is. Play with the throttle body (always make sure you're in neutral with the handbrake pulled) and see if it makes the sound so you'll be able to track it down. Try checking your belts. I don't think it'd be your tires since you said the rhythm doesn't change.