# Placement & SPL — 300-person church ## Goals - Speech clarity (STI-oriented): prioritize 500 Hz–4 kHz - Comfortable sermon level ≈ **65–75 dBA** at pews - Headroom ≥ 10 dB for peaks / music beds ## CAMS-1 capability (order-of-magnitude) | Condition | Level | |-----------|--------| | Sensitivity mid (typ.) | ~90–93 dB / 2.83 V / 1 m | | Amp mid continuous | ~40–50 W into 8 Ω | | Peak @ 1 m | ~108–112 dB | | Continuous @ 1 m | ~104–107 dB | Distance loss ≈ 6 dB per doubling in free field (less in reverberant churches). | Distance | Approx continuous (one speaker) | |----------|----------------------------------| | 2 m | ~100 dB | | 4 m | ~94 dB | | 8 m | ~88 dB | | 12 m | ~84 dB | For **300 people**, typical sanctuary depth 12–20 m: - **Recommended:** **two** CAMS-1 (L/R) or one CAMS-1 as **center vocal fill** under existing mains. - **Single unit:** place on stand **ahead of first pews**, HF aimed at last third of seating; keep volume so farthest seats ≥ 65 dBA without forcing clip. ## Aiming 1. HF axis toward ear height of rear congregation (~1.1–1.2 m seated). 2. Avoid aiming into bare parallel walls (slap-back). 3. Use HF trim pot to tame harshness if sanctuary is reflective. ## Mixer gain structure 1. Desk output +4 dBu nominal → CAMS input. 2. CAMS master at 12–2 o’clock; structure gain so clip never lights on speech peaks. 3. Optional external compressor/limiter before CAMS for pastors who vary level. ## VERIFY on site - Walk the room with speech program; note dead spots. - Check for stand tip hazard in aisles. - Confirm residual hum (ground lift only on DI — not by lifting IEC earth).