Turning my walk-in closet into a vocal room. Need feedback.

[CarlosM]

Hello everybody,

I am a Miami-based journalist who runs a news site called PINAC News where I have been reporting on police abuse and corruption for the past 14 years. I am planning on launching a weekly podcast show where I will discuss the stories of the week as well as interview people relevant to the issue of criminal justice reform.

Since I work from home, I’ve decided to turn the walk-in closet in my bedroom into a vocal booth. The space is about 25 square feet so it’s not very big but it will only be used by me. The guests I will interview will be at their own location and I will ask them to record the interview on Zoom and have them send it to me to ensure the best possible audio.

As you can see in the Sketchup design, the closet space has five sides and I plan to stand in the middle of the room and speak towards the short, slanted wall. I also plan to add a floating table to the right side of the closet as you can see in the sketch.

The dimensions of the room are 68” x 51” x 25” x 37” x 55” and they are listed in the screenshots of the Sketchup design.

I did not add any diffusers, acoustic panels or bass traps to the sketch because I still have not figured out how to place them precisely on the software.

My condo is on the 11th floor and although I live in a noisy area, the noise factor within my condo is not bad as long as I have my balcony door closed. When I stand in my empty closet while using a decibel-measuring app and not making any sound, I register 35 decibels inside the closet with the flimsy door shut. When I stand outside the closet on the other side of that flimsy door, I register about 45 decibels.

I’ve done several other tests placing a speaker inside the closet and standing in various parts of my condo measuring decibels and there is usually about a 20 decibel transmission loss. When I stand outside my condo in the hallway, there is about an additional 20 decibel transmission loss.

My main concern about soundproofing is I do not want to disturb my neighbors because I tend to talk loud and my voice tends to carry and I plan on doing my recordings late at night. I also want to add the right acoustics to ensure the best sound which is why I am here. The closet is in a very central area of my condo so it does not share a wall with neighbors.

My plan is to install 5/8 soundproof drywall panel, either QuietRock or SilentFX, using Green Glue as an adhesive. I also plan to add 5/8 rubber mats on the floor and I’m considering placing MLV underneath it.

The ceiling is a little complicated because there is a fire sprinkler and an air-conditioner vent. The ceiling in the closet, at 7’1’, is also one foot shorter than the rest of the condo so perhaps that helps as it creates more distance from my upstairs neighbors but I’m a little concerned about the vent, wondering if my voice would carry into other people’s units through the ducts.

It appears as if the ducts are only connected to my unit but I plan to place a sound-deadening pad over the vent to reduce sound vibrations. I also plan to use a 4x4 ceiling diffuser which would cover most of the ceiling.

What I really need help in is acoustic placement throughout the room. My initial plan is to place a diffuser on the short, slanted wall which is what I’ll be facing when speaking from the center of the room as well as a diffuser on the long wall that will be behind me.

I was also thinking about placing corner bass traps in the two rear corners and maybe on the third corner as well.

I was also planning on adding acoustic panels to the two walls connecting to the slanted, short wall.

The door space is 36 inches and I was planning on buying a solid-core door but now I’m thinking of narrowing the door frame in order to use a 24-inch solid-core door.

This is all very new to me and I’ve spent the past several weeks researching the science of sound waves, soundproofing and acoustics but now I need expert advice and would appreciate any help or suggestions.

[gullfo]

overall sounds like a plan. i'd use rebonded carpet foam on the floor and add 2x 3/4" plywood. on the ceiling, add the additional drywall leaving the openings for the duct and water line. on the ceiling - create a large insulated plenum for the vent - this will help attenuate the sounds in and out of the vent. you might need to extend the water line for the fire head.

for treatment - build some 2'x4'x4" absorbers using OC 703 or equiv. distribute around the room and ceiling. the other option is mount frames on the wall and ceiling and fill with insulation and cover with cloth. add slats or panels if it is too "dry".

if you do the solid core door, add a silenced ventilation box on the door to draw air out into the the rest of the living space.