per hifigo (this generally apply to most eartips): > Narrow bore Ear tips tend to increase the lower end presence, producing a powerful bass response. They bring a slight cut down on treble extensions too. When you use Wide Bore Ear Tips, they bring out the treble energy of the IEMs, the soundstage is also wider and spacious. The wide bore Ear Tips also add a bit of brightness to the IEMs.