My experience with htese has been only favorable. I have 4 placed under my turntable and 4 under my CDp. I use them with the flat side up and use the teflon pucks that come with them between the rounded end and the surface beneath.
I have never tried 3 since 4 has yeilded such good results.
I attest that the turntable does not skip at all and with out I cannot walk with a natural gape in the vicinity of the table. I would recommend using all 4 first and then experiment with 3. As far as the surface on the underside of the component I had some 1/2 glass cut at my local glass shop. I had the match the measurments of the component. Then I place the component on the glass then the glass on the AQ feet. This has worked for years, good luck.
I have never tried 3 since 4 has yeilded such good results.
I attest that the turntable does not skip at all and with out I cannot walk with a natural gape in the vicinity of the table. I would recommend using all 4 first and then experiment with 3. As far as the surface on the underside of the component I had some 1/2 glass cut at my local glass shop. I had the match the measurments of the component. Then I place the component on the glass then the glass on the AQ feet. This has worked for years, good luck.