diff --git a/bpm-tag b/bpm-tag
index beec29a..8ee6b64 100755
--- a/bpm-tag
+++ b/bpm-tag
@@ -43,7 +43,7 @@ while getopts "fhn" OPT; do
 done
 shift $((OPTIND - 1))
 
-if [ -n "$1" ]; then
+if [ -z "$1" ]; then
 	usage >&2
 	exit 1
 fi
diff --git a/bpm.c b/bpm.c
index a763e04..4871455 100644
--- a/bpm.c
+++ b/bpm.c
@@ -276,7 +276,7 @@ int main(int argc, char *argv[])
 		nrg[len++] = v;
 	}
 
-	bpm = scan_for_bpm(nrg, len, 72.0, 168.0, 1200, 1200, fdiff);
+	bpm = scan_for_bpm(nrg, len, 72.0, 168.0, 1024, 1024, fdiff);
 
 	printf(format, bpm);
 	putc('\n', stdout);