Bill
You can get the foam mattress topper at Walmart the cheapest I have seen is $6.95 for a queen size and that is it.
Rememeber this is really for acoustic use not for damping that is done from peel and stick tiles from HD or Lows.
Then after the mattress pad is put in place we use just a small hand full of poly behind each driver.
Nothing fancy zip.
That is the way that we showed them at RMAF last year.
You can line them with any 1" foam just make sure the foam does not have a face on it like BH5
Hope your cabinet maker can get them going for you soon.
Ted is just hammering away and will have them finished I am sure this week, just then waiting for his HVLP gun but he has said that finish will be done in the summer till then he is running them full out
