Digital Designs, or DD Audio is an American manufacturer of high-end consumer audio products. They produce home and mobile audio products, serving the sound quality and sound pressure categories of the mobile audio market.

Most people find that 70 or 75 dB on your SPL meter at your listening seat is a comfortable playback level. While 85 dB SPL is often used for THX movie theaters, that level is simply too loud for most listeners with test signals in the confines of an average-sized home theater or living room.

The size of a woofer can affect sound quality in certain ways. Generally, larger woofers are able to produce lower frequencies with more power and depth, while smaller woofers tend to be more precise and articulate in higher frequencies.