Assertion: speaker | /r/CapableOf | use large 15or 18
Facets:
value: often
type: TEMPORAL
Source sentences:
text: High-quality headphones can have an extremely flat low-frequency response down to 20 Hz within 3 dB. While a loudspeaker must use a relatively large (often 15" or 18") speaker driver to reproduce low frequencies, headphones can accurately reproduce bass and sub-bass frequencies with speaker drivers only 40-50 millimeters wide (or much smaller, as is the case with in-ear monitor headphones).