why does audioconvert create these caps?
audio/x-raw-float, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 8 ], endianness=(int)1234, width=(int)32;
audio/x-raw-int, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 8 ], endianness=(int){ 1234, 4321 }, width=(int)32, depth=(int)[ 1, 32 ], signed=(boolean){ true, false };
audio/x-raw-int, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 8 ], endianness=(int){ 1234, 4321 }, width=(int)24, depth=(int)[ 1, 24 ], signed=(boolean){ true, false };
audio/x-raw-int, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 8 ], endianness=(int){ 1234, 4321 }, width=(int)16, depth=(int)[ 1, 16 ], signed=(boolean){ true, false };
audio/x-raw-int, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 8 ], endianness=(int){ 1234, 4321 }, width=(int)8, depth=(int)[ 1, 8 ], signed=(boolean){ true, false }

and not just?
audio/x-raw-float, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 8 ], endianness=(int)1234, width=(int)32;
audio/x-raw-int, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 8 ], endianness=(int){ 1234, 4321 }, width=(int){8,16,24,32}, depth=(int)[ 1, 32 ], signed=(boolean){ true, false };