The Cap reference does not have boomy bass by itself.
Here is a very simple trick to find out if your player is suffering from standing wave "bass boom":
Play a track with heavy bass (not a single-note solo, you want the bass notes to go all the way from top to bottom) and walk around the room with your ears at the player's height.
Hear for bass boom where your player is located. If boominess is present, keep walking, find a spot with no boominess, place the player exactly in that spot.
Bingo!
P.S. Sometimes a higher or lower shelf will get rid of standing waves, because room modes propagate in three axis.
Here is a very simple trick to find out if your player is suffering from standing wave "bass boom":
Play a track with heavy bass (not a single-note solo, you want the bass notes to go all the way from top to bottom) and walk around the room with your ears at the player's height.
Hear for bass boom where your player is located. If boominess is present, keep walking, find a spot with no boominess, place the player exactly in that spot.
Bingo!
P.S. Sometimes a higher or lower shelf will get rid of standing waves, because room modes propagate in three axis.