Update INSTALL.md

diff --git a/INSTALL.md b/INSTALL.md
index 3c3770dc34f861ce33ff869713d9111bc1052f7b..33058c8cd88288deb0a0c6d7d2b20582bdc66bda 100644 (file)
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -68,6 +68,8 @@ alsa =
 };
 
 ```
+The `volume_range_db = 60;` setting makes Shairport Sync use only the usable part of the built-in audio card mixer's attenuation range.
+
 The next step is to enable Shairport Sync to start automatically on boot up:
 ```
 # systemctl enable shairport-sync