Isolation door with no improvement — why?

[Tlepsh]

Hello,

I recently installed an isolation door for the main entrance of my studio:

So far, the isolation performance compared to the previous basic wooden door is pretty similar, which tells me there’s still more work to do.
At this point, I’ve filled parts of the frame with foam:

However, there are still some visible gaps where you can see through to the other side, like this:

There’s also a plastic seal at the bottom that should help reduce sound leakage:

Before I go ahead and fill the remaining gaps with more foam, I wanted to get some input from people with more experience. The results so far haven’t been what I was hoping for, and I’m wondering if the remaining gaps are the main issue or if I might be overlooking something else.

Any advice or suggestions would be greatly appreciated.

 

[ddude003]

So tell us more about your space and kit...

 

[Todd Anderson]

When you say the results haven't been what you were hoping for... how are you comparing before and after?

 

[Sonnie Parker]

I've never known foam to help much... nor a single door of any kind. I use two doors, and it absolutely works. I'm not sure how easy that would be in your situation. I don't have any issues with the way my doors open, and I have 8.5" thick walls.

 

[Todd Anderson]

I've never known foam to help much... nor a single door of any kind. I use two doors, and it absolutely works. I'm not sure how easy that would be in your situation. I don't have any issues with the way my doors open, and I have 8.5" thick walls.

You’re so lucky. Not many people have that kind of extra thickness to take advantage of!

 

[DonH57]

My media room's door is a heavy, thick, solid-core wooden exterior door with threshold and full weather (sound) sealing all around. The frame is fully sealed with acoustic caulk (not foam). The difference between it and a specialized studio (isolation) door was only a few dB despite a substantial cost difference. If you already had a well-sealed solid-core door it's possible the extra sound reduction was not a large change. As mentioned above, most recording studios I have been in or seen use a double-door system, though that is partly to stage people moving in and out as well as add isolation.

There is a lot more than the door, of course. My media room's walls and ceiling have 6" (wall) to 12" (ceiling) of dense rock wool inside. The inner walls and ceiling are doubled 5/8" drywall (with seams spaced to not coincide) floating on Kinetics Iso-Max clips and rails, fully sealed (acoustic caulk) at all corners/boundaries (wall, floor, and ceiling). There is no ducting to the rest of the house; HVAC is provided by a dedicated vent and a mini-split unit. Any holes for outlets, lights, switches, etc. are sealed with insulation and caulk to minimize those sources of transmission. It is in the basement so I did not float the floor; it is concrete with extra surfacing, thick carpet foam, and carpet. The room has numerous absorption panels but those are to control sound within the room, not for isolation.

The end result is a room that allows me to listen loudly without disturbing the rest of the house, including the bedroom on the other side of one wall.

You did not say what exactly you feel is lacking, e.g. STL/SPL readings and frequency(ies) of interest, or describe the rest of the construction. What other sound transmission sources are there? You can use a wideband sound meter and/or directional mic to try to locate the main leakage sources and decide how to address them if needed. REW or any of the pro acoustic analysis programs can help zero in on specific issues.

FWIWFM - Don

 

[Todd Anderson]

Ok @DonH57, your room reads SPECTACULAR! Looks like you left no stone unturned!

 

[DonH57]

Ok @DonH57, your room reads SPECTACULAR! Looks like you left no stone unturned!

Thanks! I did take two shortcuts:

1. I did not fully decouple the ceiling from the floor above so heavy footfalls from the kitchen are transmitted into the media room, albeit at a low level. I would have had to support the ceiling on the floating walls, which would have required more complex construction, and I decided was not worth the extra effort. With everything off, you can hear when people stomp hard; normal footfalls at normal (relatively modest for me) listening levels are not a problem.

2. The vents to the outside are not baffled, or only minimally, partly because that (new) requirement was unknown until final inspection, and I decided it was not worth the effort. We live on 2.5 acres in a quiet area, so sound through the vents is almost nonexistent (think loud thunder or a bird trying to nest in the vent opening, something I strongly discourage ), and sound to the outside is also minimal and only heard standing very near the vents. I did work with our contractor to use a very quiet exhaust fan (required by code) that is switched so I can have dead silence when desired.

I have previously posted here (somewhere) my basic construction notes and attached here for reference. There were a few changes, such as 6" mineral wool is in the walls and 12" in the ceiling, and the duct (from another area of the house that passed through the joists) was wrapped for additional sound proofing.

The construction crew appreciated the Kinetics clip system; it worked very much like normal drywall installation. The drywall company foreman/owner did the media room whilst the rest of the crew did the rest of the basement remodel, a bit of attention to detail I appreciated. He thought it was a cool design so I think he just wanted to do something different.