A smaller tightly-enclosed listening room with a high amount of 'room gain' (a naturally rising low-end response) may cause an excessively strong bass response from the Ultra Tower model, regardless of its placement location in the room. If this occurs, insert the included foam port plugs into the port opening of each Ultra Tower. To obtain a good seal, insert the foam port plug slightly below flush of the port flare.

Inserting the foam port plug creates a low-Q sealed acoustic alignment, and results in an earlier roll-off of the bass response. This will often be a better complement to the acoustics of a smaller tightly-enclosed listening environment, resulting in a more balanced and natural-sounding bass response.