Room boundaries alter loudspeaker output through reflected image sources

Evidence

One more important acoustic property of a loudspeaker is its directivity pattern. In an anechoic room, we are only interested in the direct radiation to the listener, but in normal spaces with wall reflections and reverberation the listener receives all these delayed signal counterparts as well. In a relatively reverberant room, it is desirable to use a loudspeaker that has some directivity; that is, it radiates more sound along the main axis than in other directions, especially at middle to high frequencies. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 474 (#expands, via linked claim)

Categorization

• XREF: connects to: Shared room acoustics let 1920 phonograph demos fool live audiences; A reflecting wall doubles total sound power output from any source; Reflecting walls are equivalent to mirror-image virtual sound sources — Eric J. Heller, Why You Hear What You Hear- An…, 515 (+22 more)

Related

• Non-environment rooms suppress all but direct sound for clearer audio detail and imaging (similarity 0.91)
• Room acoustics requires modeling direct sound then early reflections (similarity 0.91)
• Reverberant rooms make loudspeaker directivity important for sound quality (similarity 0.90)
• Room boundary reflections are the second loudest sounds a listener hears (similarity 0.90)
• Reverberant fields supply most perceived loudness in normal rooms (similarity 0.90)
• Room boundaries alter a sound source’s radiated power, not just its perceived sound (similarity 0.89)
• Room reflections can be modelled as sources in mirrored rooms (similarity 0.89)
• Small playback rooms impose their own early reflections on recorded sound (similarity 0.88)
• Early side-wall reflections range neutral to beneficial with well-designed loudspeakers (similarity 0.88)
• Room acoustics act as another system modifying the instrument’s output (similarity 0.88)
• Wide-dispersion speakers plus room reflections create listener envelopment. (similarity 0.88)
• Early lateral reflections are attenuated by loudspeaker directivity, not harmful. (similarity 0.88)
• Reverberant rooms favor directional loudspeakers to control sound colouration (similarity 0.87)
• Treating room walls as mirrors locates where early reflections need absorbing. (similarity 0.87)
• Reflected sounds physically dominate what reaches listeners’ ears (similarity 0.87)

Broader Connections

• Reverberant rooms make loudspeaker directivity important for sound quality #expands (0.82) — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 474