John Sayers' Recording Studio Design Forum Archive

I own one automatic door bottom and I think it is useless. It's made by Draft Seal. Every other door bottom I've found online seems to have the same flaw.

Once the seal/bottom drops, there is a void around the sides and top of the unit for sound to easily make it's way around. Some models have neoprene inserts to try and fill the void some, but they are far from tight and just really don't seem to do their job. Yes, we all know that making a hole smaller will ultimately attenuate the sound a little bit, but I think incorporating a second regular style door seal along the bottom of the door instead of an automatic door bottom would be a better option.

Here is a picture of the Zero International 365AA model that does have the side/top neoprene installed. You can see how off center the bottom module is, really exposing how much gap is left from the metal to the neoprene. It makes sense that the sides cannot physically be super tight otherwise the mechanism would not slide in and out. Please correct me if I'm wrong on this.

Greg

Of course you are correct. Many of the systems and products people use are really poor compromises between cost and engineering. Gobos with a a Gap underneath, seriously?
DD

Thanks for sharing Greg, I always wondered if these drop seals were effective or a waste of money. I think I'm just going to extend my door jambs to the bottom and live with a step. Not ideal, especially for wheeling gear in and out, as well as a tripping hazard, but it seems like the only way to get a good seal all the way round a door.

Paul