Frequency response (at 2 meters): 47 Hz to 20 kHz ±3.6 dB
Bass limits (lowest frequency and maximum SPL with limit of 10% distortion at 2 meters in a large room): 60 Hz at 82 dB
For our tests, the speaker was mounted in a bare, half-inch sheetrock wall. The curve in the frequency-response graph is weighted to reflect how sound arrives at a listeners ears with normal speaker and listener placement, averaged over a ±30-degree window with double weight at 30 degrees (the most typical listening angle). All measurements were taken at a full 2 meters, which emulates a typical listening distance, allows large speakers to fully integrate acoustically, and (unlike near-field measurements) fully includes front-panel and wall reflections, as well as floor-boundary effects that will always be present in normal use. Because the LC265i-IP has built-in amplifiers, impedance and sensitivity measurements are meaningless and therefore are not included here.
The LC265i-IP measures better than any other in-wall speaker I've had the opportunity to test. The overall spectral balance has a very mild upward slope. The curve also shows a mild floor interaction centered at 117 Hz and a tweeter resonance peak at 19.5 kHz. (The latter is at the very edge of the audible range and thus won't be a problem.) Directivity is well controlled, but highs above 10 kHz fall off quickly at listening angles of ±30 degrees and greater. The system has better bass extension than typical for wall-mounted systems, where the radiation from the surrounding drywall is often out of phase with the speaker output below 100 Hz.
In short, the Polk LC265i-IP's frequency response sets a new standard for in-wall speakers, and its bass performance rivals that of some floor standing loudspeakers.