diff --git a/birdnet-pi/rootfs/helpers/spectral_analysis.sh b/birdnet-pi/rootfs/helpers/spectral_analysis.sh
index 74217ef38..0c3352f27 100644
--- a/birdnet-pi/rootfs/helpers/spectral_analysis.sh
+++ b/birdnet-pi/rootfs/helpers/spectral_analysis.sh
@@ -5,19 +5,19 @@ source /etc/birdnet/birdnet.conf
 # Read the logging level from the configuration option
 LOGGING_LEVEL="${LogLevel_BirdnetRecordingService}"
 # If empty for some reason default to log level of error
-[ -z $LOGGING_LEVEL ] && LOGGING_LEVEL='error'
+[ -z "$LOGGING_LEVEL" ] && LOGGING_LEVEL='error'
 # Additionally if we're at debug or info level then allow printing of script commands and variables
 if [ "$LOGGING_LEVEL" == "info" ] || [ "$LOGGING_LEVEL" == "debug" ];then
   # Enable printing of commands/variables etc to terminal for debugging
   set -x
 fi
 
-[ -z $RECORDING_LENGTH ] && RECORDING_LENGTH=15
-[ -d $RECS_DIR/StreamData ] || mkdir -p $RECS_DIR/StreamData
+[ -z "$RECORDING_LENGTH" ] && RECORDING_LENGTH=15
+[ -d "$RECS_DIR"/StreamData ] || mkdir -p "$RECS_DIR"/StreamData
 
-if [ ! -z $RTSP_STREAM ];then
+if [ ! -z "$RTSP_STREAM" ];then
   # Explode the RSPT steam setting into an array so we can count the number we have
-  RTSP_STREAMS_EXPLODED_ARRAY=(${RTSP_STREAM//,/ })
+  RTSP_STREAMS_EXPLODED_ARRAY=("${RTSP_STREAM//,/ }")
 
   while true;do
 
@@ -29,7 +29,7 @@ if [ ! -z $RTSP_STREAM ];then
     for i in "${RTSP_STREAMS_EXPLODED_ARRAY[@]}"
     do
       # Map id used to map input to output (first stream being 0), this is 0 based in ffmpeg so decrement our counter (which is more human readable) by 1
-      MAP_ID=$((RTSP_STREAMS_STARTED_COUNT-1))
+      MAP_ID="$((RTSP_STREAMS_STARTED_COUNT-1))"
       # Build up the parameters to process the RSTP stream, including mapping for the output
       FFMPEG_PARAMS+="-vn -thread_queue_size 512 -i ${i} -map ${MAP_ID}:a:0 -t ${RECORDING_LENGTH} -acodec pcm_s16le -ac 2 -ar 48000 file:${RECS_DIR}/StreamData/spectrum.wav "
       # Increment counter
@@ -38,7 +38,7 @@ if [ ! -z $RTSP_STREAM ];then
 
   # Make sure were passing something valid to ffmpeg, ffmpeg will run interactive and control our loop by waiting ${RECORDING_LENGTH} between loops because it will stop once that much has been recorded
   if [ -n "$FFMPEG_PARAMS" ];then
-    ffmpeg -hide_banner -loglevel $LOGGING_LEVEL -nostdin $FFMPEG_PARAMS
+    ffmpeg -hide_banner -loglevel "$LOGGING_LEVEL" -nostdin "$FFMPEG_PARAMS"
   fi
 
   done
@@ -46,12 +46,12 @@ else
   if pgrep arecord &> /dev/null ;then
     echo "Recording"
   else
-    if [ -z ${REC_CARD} ];then
-      arecord -f S16_LE -c${CHANNELS} -r48000 -t wav --max-file-time ${RECORDING_LENGTH}\
-	      	      	       --use-strftime ${RECS_DIR}/StreamData/spectrum.wav
+    if [ -z "${REC_CARD}" ];then
+      arecord -f S16_LE -c"${CHANNELS}" -r48000 -t wav --max-file-time "${RECORDING_LENGTH}"\
+	      	      	       --use-strftime "${RECS_DIR}"/StreamData/spectrum.wav
     else
-      arecord -f S16_LE -c${CHANNELS} -r48000 -t wav --max-file-time ${RECORDING_LENGTH}\
-        -D "${REC_CARD}" --use-strftime ${RECS_DIR}/StreamData/spectrum.wav
+      arecord -f S16_LE -c"${CHANNELS}" -r48000 -t wav --max-file-time "${RECORDING_LENGTH}"\
+        -D "${REC_CARD}" --use-strftime "${RECS_DIR}"/StreamData/spectrum.wav
     fi
   fi
 fi