What I did was screw 1 1/4 in. # 6 oval head phillips head
screws through the carpet, into the underlayment until they were flush with the top of the rug, then set the spikes into the screw heads. To find the proper position for the screws, i set my speakers on a pc. of cardboard, then used that as a template for the location of the holes. Just be careful when going through the carpet, punch a hole first between the loops, (don't drill). A berber is even more prone to pulls than a regular pile. then use a level to even up the screws,and get rid of any wobble.
good luck
screws through the carpet, into the underlayment until they were flush with the top of the rug, then set the spikes into the screw heads. To find the proper position for the screws, i set my speakers on a pc. of cardboard, then used that as a template for the location of the holes. Just be careful when going through the carpet, punch a hole first between the loops, (don't drill). A berber is even more prone to pulls than a regular pile. then use a level to even up the screws,and get rid of any wobble.
good luck