DIY ISOLATION PAD
Today’s guest post is written by my better half, Matt! On Monday I shared what the movie room looks like, but he’s popping in today to share how we got it to sound awesome as well. Take it away Matt……
Seeing as Stephanie normally gets to do all of the writing (it is her blog after all) I thought that I should get a chance to contribute as well.
To make a long story short, we were in the process of revamping our basement with a shiny new paint job and a new surround sound configuration. On average, we probably watch about 5-7 movies a week so sound is key. We have a 7.1 (7 speakers and 1 subwoofer) surround sound system set up in our basement. You will have to forgive me but I need to geek out here and describe the system in brief detail before moving on—be patient.
Everything is powered by a Denon AVR-791 receiver that I am in absolute love with. My center channel speaker (where most of the dialogue comes from) is a Klipsch KC-25 and my front left and right speakers are Klipsch KF-28 floor standing speakers. This is where most of the power comes from in the system so it was important for me to have nice clear sounding speakers. The KF-28s, in particular, are excellent sounding speakers. For my surround left and rights, I eventually went with Klipsch KS-14 2-way speakers. Your surrounds give off most of your “moving sound.” For example, if a car whizzes by in a movie you will hear it as it moves from left to right across your whole room. The term 2-way just means that there are 2 individual speakers in each main speaker. This gives the speakers more movement and reach in your room. My surround back left and rights are Polk Audio TSi 100 bookshelf speakers. I bought these many moons ago and while they don’t match the remainder of my setup they do sound excellent—and have a nice cherry wood finish to boot. Last but not least I have a Klipsch SW-450 for my subwoofer (the subwoofer puts out the entirety of the bass or low end in your surround sound; in other words, it is an extremely important part of your system). I had replaced a Polk Audio subwoofer with this new monster and I immediately had a problem: my room was vibrating. This leads us to my featured project, a DIY Subwoofer Isolation Pad.
I did a great deal of research online about ways to fix vibration in a room from a subwoofer. What I kept coming to was something called an isolation pad. Essentially, this setup raises your subwoofer off the ground by about 2 to 3 inches. This coupled with heavy carpeting and soundproofing underneath was supposed to drastically cut down the vibration in a room. Basically, having a subwoofer on the ground can create many problems due to unwanted vibration and an overall “boominess.” We have the luxury of living in a house and not having to worry about neighbors so volume isn’t a problem. Apartment dwellers should especially take care here, as nothing is worse than having an awe inspiring setup but not being to use it thanks to sharing a space.
I found that you could purchase several different types ranging from $50-$100 online (mainly from Auralex), but this didn’t work for me. I had just spent a good deal of my hard earned money on upgrading my system, so I decided to build my own isolation pad.
The purpose of an isolation pad is in the name: it is meant to isolate the bass frequencies from the surfaces around the subwoofer. Raising it off the ground allows the bass to travel to the viewer and not to the walls, heating vents, and doors in your room.
Total cost: under $40
1. I started by laying the MDF down on the ground and placed my 2X3s 6” in on both sides. I made pencil lines to mark where the 2X3s would sit on the MDF. I then applied the Liquid Nails to the 2X3s making a zigzag pattern as I went.
2. Next, I lined up the 2X3s (with Stephanie’s help) and pressed them firmly against the MDF. I wiped away the excess adhesive and gave them about 15 minutes to dry. I then made pencil marks on the 2X3 bases every 2” or so. These would be my rough positions for my drywall screws. I then drilled in the screws to firmly hold and seal the 2X3s to the MDF. This part was loud and long but it’s important to secure these boards.
3. Once the screws were in we flipped the pad over to its top. I sprayed the bottom of the carpet and the top of the MDF with the 3M adhesive (awesome stuff by the way!) and let them sit for 2 minutes before lining up the carpet and pressing it down firmly on the MDF. It will adhere quickly but be forewarned: the 3M spray has a strong smell. If it’s a nice day I would recommend spraying it outside—we didn’t! We let the carpet sit again for about 15 minutes.
4. Once the carpet adhered on we busted out our trusty staple gun. I flipped over the pad and folded the excess carpet onto the bottom. Once it was pulled tight, I put in a liberal amount of staples to ensure it was secure and snug. I repeated the step on the opposite side. Next we had some excess on the front side of the pad so we folded that under and stapled it to the front (Stephanie used a black Sharpie to color in the staples—what a woman!).
5. Once the carpet was secure I decided to use some of the Auralex soundproofing I bought to fill in the middle of the pad’s underside (in between the 2X3s). I had already bought some for the room so I cannot say how it would sound without it but you could always try it to start. This stuff can be expensive but I believe you can buy it in small quantities from Amazon. I cut a piece to size using a bread knife (you needed to use something with teeth, like this or an electric carving knife). We broke out the foul smelling 3M adhesive once more and sprayed both the bottom of the pad and the soundproofing foam. After 2 minutes I pressed the foam tightly and snuggly into the section. I flipped it back over and it was finished.
I can vouch for the quality of an isolation pad. From the second I put my subwoofer back on it and went through a few of my favorite sounding blu-rays I heard the difference in the room. The bass was louder but clearer. It was no longer muddy sounding and I had done away with vibration in the room. Obviously, every room is different and you might need to do some extra work to make the room “tighter.” For about $35, however, you cannot go wrong with making your own isolation pad. For the home theater enthusiast or for the noise-restricted apartment dweller, an isolation pad is a must have!