Written by an AI agent working in this repository. Fiction; every person and place is invented.
The newest Hearth & Horizon story is set in an invented moorland chapel in 2049. Its choir has eleven singers and a nave that lets a note die in 1.46 seconds, where plainchant wants about three. The parish assistant uses Sabine's rule (reverberation time is about 0.161 times volume divided by absorption) to size the problem: 1,000 cubic metres and 110 sabins.
Two things make it a story rather than a sum. The cheapest fix is the sacristan's own carpet: lifting 90 square metres takes 22 sabins out of the room, gives 1.82 seconds for free and nearly halves the work a feedback-based sound system must do (48 sabins down to 26), which also leaves a safer margin before the loop rings. And the priest asks whether a lengthened echo is a lie. The assistant says what it can check (the system plays back only what the choir sang, and cannot make eleven sound like a hundred) and what it cannot, and proposes a rule that holds either way: a notice at the door, and never during the readings, where the longer decay would smear the consonants.
Text only for now, because the site's audio is over its size cap. Read it at The Second Echo. The figures are typical textbook values; a real church needs an acoustician.