diff --git a/README.md b/README.md
index 55240ee..4c51d6e 100644
--- a/README.md
+++ b/README.md
@@ -13,13 +13,11 @@
 </p>
 
 ## it supports audio backends
-- PortAudio (linux/macOS/*windblows**)
-- PulseAudio (parec/FFmpeg)
-- AVFoundation (macOS FFmpeg)
 - ALSA (linux FFmpeg)
+- AVFoundation (macOS FFmpeg)
 - DirectShow (windblows FFmpeg)
-
-*portaudio is difficult on windows. by default it is disabled on windows.
+- PortAudio (linux/macOS/windblows)
+- PulseAudio (parec/FFmpeg)
 
 ## it depends on
 
@@ -30,14 +28,14 @@
 	- github.com/lawl/pulseaudio
 	- gonum.org/v1/gonum
 
-- c libraries (optional, disable all with `CGO_ENABLED=0`)
-	- fftw (fftw3) (disable with `-tags nofftw`)
-	- portaudio (portaudio-2.0) (disable with `-tags noportaudio`)
-
 - binaries
 	- ffmpeg (required for FFmpeg backends)
 	- parec (required for PulseAudio backend with parec)
 
+- c libraries (optional, requires CGO - `CGO_ENABLED=1`)
+	- fftw (fftw3) (enable with `-tags withfftw`)
+	- portaudio (portaudio-2.0) (enable with `-tags withportaudio`)
+
 ## get it
 
 ```sh
@@ -50,17 +48,11 @@ cd catnip
 # build and install catnip
 go install
 
-# without cgo
-CGO_ENABLED=0 go install
-
-# without portaudio on linux/unix/macOS
-go install -tags noportaudio
-
-# with portaudio on windows
-go install -tags portonwin
+# with portaudio
+go install -tags withportaudio
 
-# with fftw3 on windows
-go install -tags fftwonwin
+# with fftw3
+go install -tags withfftw
 ```
 
 ## run it
diff --git a/catnip.go b/catnip.go
index 57a452d..67ce9c7 100644
--- a/catnip.go
+++ b/catnip.go
@@ -181,7 +181,6 @@ func catnip(cfg *config) error {
 //  - super smooth detail view
 func newZeroConfig() config {
 	return config{
-		backend:      "portaudio",
 		sampleRate:   44100,
 		sampleSize:   1024,
 		smoothFactor: 80.15,
diff --git a/fft/fftw.go b/fft/fftw.go
index 49e6898..f064d70 100644
--- a/fft/fftw.go
+++ b/fft/fftw.go
@@ -1,4 +1,4 @@
-//go:build cgo && ((!windows && !nofftw) || (windows && fftwonwin))
+//go:build cgo && withfftw
 
 package fft
 
diff --git a/fft/gonum.go b/fft/gonum.go
index 02fc5c5..5a4a83b 100644
--- a/fft/gonum.go
+++ b/fft/gonum.go
@@ -1,4 +1,4 @@
-//go:build !cgo || nofftw || (windows && !fftwonwin)
+//go:build !cgo || !withfftw
 
 package fft
 
diff --git a/portaudio.go b/portaudio.go
index 9542f92..ce5ebac 100644
--- a/portaudio.go
+++ b/portaudio.go
@@ -1,4 +1,4 @@
-//go:build cgo && ((!windows && !noportaudio) || (windows && portonwin))
+//go:build cgo && withportaudio
 
 package main