Try fixing multiarch-problem by using depends_$CARCH

PKGBUILD

@@ -0,0 +1,21 @@
+# Maintainer: Oliver Rümpelein <oli_r nospamat fg4f nospamdot de>; Siegfried Krug <siegfried nospamat fg4f nospamdot de>
+pkgname=x32-edit
+pkgver=2.3
+pkgrel=1
+pkgdesc="Program for preprogramm or remote control your Behringer X32 console"
+arch=('i686' 'x86_64')
+url="http://www.behringer.com/EN/products/X32.aspx"
+license=('unknown')
+depends_i686=('libxext' 'alsa-lib')
+depends_x64_86=('lib32-libxext' 'lib32-alsa-lib')
+_archive="X32-Edit_V${pkgver}_LINUX.tar.gz"
+source=(http://www.behringerdownload.de/X32/${_archive})
+md5sums=('35d978adf7f432a291ebcf7da4ec00ad')
+
+package()
+{
+    cd "${srcdir}"
+    tar xf ${_archive}
+    mkdir -p ${pkgdir}/usr/bin/
+    install -m 755 X32-Edit ${pkgdir}/usr/bin/
+}