Hi all. I have used Sox for simple stuff in the past but am intrigued by the FM Radio processing example which (in different variations over time) appears in the man page. It may be just what I am looking for - but I can't get it to work. Referring to various posts on the Internet asking about this and also different versions of the man page scattered around, I have gleaned that the sinc effect is now the filter effect? However, there is still something wrong I get an error. Oddly, the sox manpage for Ubuntu 18 still uses the "sinc" version. I am using it in a script file that contains this: play t1.wav gain -3 filter 8000- 32 100 mcompand \ "0.005,0.1 -47,-40,-34,-34,-17,-33" 100 \ "0.003,0.05 -47,-40,-34,-34,-17,-33" 400 \ "0.000625,0.0125 -47,-40,-34,-34,-15,-33" 1600 \ "0.0001,0.025 -47,-40,-34,-34,-31,-31,-0,-30" 6400 \ "0,0.025 -38,-31,-28,-28,-0,-25" \ gain 15 highpass 22 highpass 22 filter -17500 256 \ gain 9 lowpass -1 17801 but I get the following error message "play FAIL gain: usage [-e] [-b] .." For reference this is copied from the manpage at https://linux.die.net/man/1/sox Very likely this is just some silly formatting issue I have missed, but if so, I have looked at this for so long now I will probably never find it! Can anyone assist me? Thanks in advance Alan T. Cornwall UK.