diff --git a/audio/mp3/decode_notjs.go b/audio/mp3/decode_notjs.go
index d629dc65f..c3b8efc2d 100644
--- a/audio/mp3/decode_notjs.go
+++ b/audio/mp3/decode_notjs.go
@@ -37,7 +37,6 @@ func (f *frame) numberOfChannels() int {
 }
 
 func (f *frame) decodeL3() error {
-	out := make([]uint32, 576)
 	nch := f.numberOfChannels()
 	for gr := 0; gr < 2; gr++ {
 		for ch := 0; ch < nch; ch++ {
@@ -46,6 +45,7 @@ func (f *frame) decodeL3() error {
 			f.l3Reorder(gr, ch)
 		}
 		f.l3Stereo(gr)
+		out := make([]uint8, 576*4)
 		for ch := 0; ch < nch; ch++ {
 			f.l3Antialias(gr, ch)
 			// (IMDCT,windowing,overlapp add)
@@ -54,33 +54,13 @@ func (f *frame) decodeL3() error {
 			// Polyphase subband synthesis
 			f.l3SubbandSynthesis(gr, ch, out)
 		}
-		if err := f.audioWriteRaw(out); err != nil {
+		if _, err := writer.Write(out); err != nil {
 			return err
 		}
 	}
 	return nil
 }
 
-func (f *frame) audioWriteRaw(samples []uint32) error {
-	nch := f.numberOfChannels()
-	s := make([]uint8, len(samples)*2*nch)
-	for i, v := range samples {
-		if nch == 1 {
-			s[2*i] = uint8(v)
-			s[2*i+1] = uint8(v >> 8)
-		} else {
-			s[4*i] = uint8(v)
-			s[4*i+1] = uint8(v >> 8)
-			s[4*i+2] = uint8(v >> 16)
-			s[4*i+3] = uint8(v >> 24)
-		}
-	}
-	if _, err := writer.Write(s); err != nil {
-		return err
-	}
-	return nil
-}
-
 func getByte() (uint8, error) {
 	for len(readerCache) == 0 && !readerEOF {
 		buf := make([]uint8, 4096)
diff --git a/audio/mp3/l3.go b/audio/mp3/l3.go
index 32c13211e..d627016f6 100644
--- a/audio/mp3/l3.go
+++ b/audio/mp3/l3.go
@@ -552,7 +552,7 @@ var g_synth_dtbl = [512]float32{
 
 var v_vec = [2][1024]float32{}
 
-func (f *frame) l3SubbandSynthesis(gr int, ch int, out []uint32) {
+func (f *frame) l3SubbandSynthesis(gr int, ch int, out []uint8) {
 	u_vec := make([]float32, 512)
 	s_vec := make([]float32, 32)
 
@@ -595,18 +595,20 @@ func (f *frame) l3SubbandSynthesis(gr int, ch int, out []uint32) {
 			}
 			samp &= 0xffff
 			s := uint32(samp)
-			// This function must be called for channel 0 first.
+			if nch == 1 {
+				// We always run in stereo mode and duplicate channels here for mono.
+				out[4*(32*ss+i)] = uint8(s)
+				out[4*(32*ss+i)+1] = uint8(s >> 8)
+				out[4*(32*ss+i)+2] = uint8(s)
+				out[4*(32*ss+i)+3] = uint8(s >> 8)
+				continue
+			}
 			if ch == 0 {
-				// We always run in stereo mode,& duplicate channels here for mono.
-				if nch == 1 {
-					out[32*ss+i] = (s << 16) | (s)
-				} else {
-					// Note that this is different from original PDMP3.
-					// Samples are set in little endian order here.
-					out[32*ss+i] = s
-				}
+				out[4*(32*ss+i)] = uint8(s)
+				out[4*(32*ss+i)+1] = uint8(s >> 8)
 			} else {
-				out[32*ss+i] |= (s << 16)
+				out[4*(32*ss+i)+2] = uint8(s)
+				out[4*(32*ss+i)+3] = uint8(s >> 8)
 			}
 		}
 	}