How to “Build a Home Theater System Room using Home Theater Sound Proofing Principles”

Learn home theater sound proofing to build home audio surround sound systems and your home theater room that won’t annoy the rest of your family or neighbors.

Keeping sound from exiting the home theater room may be very difficult and often expensive

So lets look at the simplest options then move onto more advanced methods.

We want to isolate your home theater audio system sound from the rest of your home. But first we need to understand the challenges…

The Problem is mostly due to the Home Theater Subwoofer:

High sound pressure levels create vibrations and vibrations like to carry from one rigid structure to the next. Homes are built using wood, drywall, plaster, and other hard surfaces. And, they are all connected in home construction.

In addition to vibrations, pressure will also cause sympathetic vibration.

If a room is not completely sealed from the other rooms of the house; that pressure will enter the other rooms too. (exiting through the walls, under the door, heating and cooling systems etc.)

home theater installation

In essence, your home surround sound system will be heard through the house. (At least the bass)

Then that pressure can vibrate the other walls and surfaces in addition to the home theater room. Home Audio Subwoofers or bass systems are usually pretty good at causing this pressure.

So to be really successful with home theater sound proofing you will need to isolate the listening room from the entire house.

You will need to isolate the room from being connected to any other part of the home including the floor, walls, and ceiling. HVAC systems present their own problems in addition to what is mentioned here.

How to build Cheap Home Theater Sound Proofing systems into your Home Audio Design:

You could achieve decent results by working toward sound absorption only instead of home theater sound proofing. This will yield pretty good results. Just don’t expect things to be dead silent within the home outside of the home theater room.

A floating floor or suspended floor can help to limit the vibration. This works by placing the supporting floor joist of the home theater room on rubber bumpers that absorb vibration.Home theater room walls built within the structure will take this one step further. These walls cannot contact any of the other walls in the home. The home theater walls are completely self-supporting to not pass on vibration into other rooms.Multiple doors with weather stripping on the entrance can help seal in the pressures. Notice the use of the word “help”. Unless you are building your home theater inside a bank vault, some pressure will still escape.

Having no outside windows will keep sound from going through the glass and entering through other outside walls of the home.Keep in mind even if you go to these lengths it would still be impossible to completely eliminate the pressure from escaping.

The heating and cooling ducts are a prime culprit of escaping pressure. One way to help with this is to make a dedicated duct run from and back to the HVAC system. This keeps the pressure from entering the rooms nearest your home theater from the common duct trunks.

So you may want to try and minimize the sound emanating from your home theater by using a sound limiting philosophy instead of going whole hog with home theater sound proofing.

A simple and effective way to limit sound distribution within the home (from your home theater)

  • • Use acoustic traps within the room to keep the interior room from being too lively.
  • • Use multiple sealing doors for the entrance. (if possible)
    • o If you can only use one door make sure it’s an exterior metal type door with magnetic seals.
  • • Use a double layer of drywall on all the interior walls of the home theater. This is an effective mass loading principle.
  • • Use bass traps or a Helmholtz resonator to limit bass peaks within the room. Bass peaks can be 20 to 30 decibels higher than the bass notes should be.
    • o Use room correction to limit the bass peaks as well.
  • • Place Owens Corning insulation in the walls. (do this before placing the drywall)
    • o Use insulated 2×6 walls if possible.
  • • Cut the power to your room’s outlets and take your electrical outlets out, then caulk the holes in the back of the electrical boxes (where the wires come in). Reinstall the outlets when you are done. Do the same for any light fixtures or any other openings as well.
  • • Caulk between your electrical boxes and the drywall.
  • • Place non resonant baffles in the HVAC vents to limit sound escaping. These would be boxes made of insulated fiberglass board with channels to deaden sound. I think some companies make these but I would personally try to fabricate them myself to save some dough. I’m sure buying them retail is not cheap.
  • • If you use home theater ceiling speakers or in wall speakers make sure to seal around the cabinet that sits within the walls/ceiling. Don’t allow the use of speakers that are open backed into the walls or ceiling.

Sound deadening Mats: There are sound absorbing mats available that can be placed on the drywall to help with sound. They are typically a pretty thin rubberized material.

These may help some but they are limited to upper mid and treble frequencies.

In my opinion the upper frequencies can be tamed in simpler and cheaper ways; such as controlling the echo in your room with the use of traps and sound panels.

These sound absorbing sheets can do a good job if used with the right expectations. Just don’t assume that these methods will make your room “sound proof”.

Go Crazy with Home Theater Sound Proofing:

I have heard of some installers using ¾ in drywall in two layers to damp noise.

This would yield 1.5 inches of drywall on the walls. (I would not try this on the ceiling as the weight could kill a person if the ceiling fell in –especially important if you live in an earthquake area)

This would certainly go a long way toward decreasing vibration because this method is using mass to control sound and pressure. Mass is always a good idea; unless the supporting construction cannot support the weight of the drywall. Then you would have another problem on your hands.

A Home Theater room within a room: Think of it like this; building a room within the house that uses its own supporting structure and having doors that seal the pressure inside the room. Any pressure and sound that escapes could possibly excite the other walls of the home which will introduce vibration outside the room.

Most consumers are unwilling to go to this extreme to ward off vibration and noise. You are only limited by your imagination and resourcefulness regarding Home Theater Acoustics. Use your head and have fun with your project.

Other Related Articles to – Home Theater Sound Proofing:


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