Comparison: Home made Silencer vs Pre-constructed Silencer

I had previously purchased a Silencer (attenuator) to place between my ceiling joists. The specs show certain frequencies it attenuates and how many db it attenuates at those frequencies. What I'd like to do is to list a comparison of about 3 Silencers that could be bought along with the frequencies they attenuate, the amount of db they attenuate at those frequencies and the price compared to those we build on this site. I've seen them listed from $99.00 to $500.00 on up. The problem is I can't find any info on the Silencers listed on this web site (that are to be built). Depending on the needs of each studio, budgets and time factors, it may be better to buy one then make one. It at least gives a choice. I'll post the info back on here for the other Silencers along with info for the ones built on this site (if I get the info). Anyone got any info on the homemade Silencers??