I don't know why Amazon asks about adhesion. I don't think this product was intended to include adhesion. I used carpenters glue. If there was an adhesion system, I didn't find it.

I bought this, at the suggestion of another Amazon customer, who wrote a review about a box with acoustic panels, to put a microphone in. The customer thought you could save money by buying your own panels and putting them in a cardboard box. So I decided to try this.

There was just barely enough for the cardboard box I chose. There was just barely enough space to put my microphone in once I finished. I probably did save about $35 that way.

I'm not sure that this process really is helping my acoustic issues, in my basement recording studio. I probably really need a recording booth.

It's kind of amazing how little 6 ft.² is.

These panels weren't as thick as I expected, but I do think that they work. I can't be sure though, because I don't really have a sophisticated system to test them.

I have always been frustrated with the seal/sound bleed around my window air conditioning units. I bought these to try and block it out. It worked okay. I used 2 on either side of the units in most windows that had AC units. I put the bumpy sides facing each other so they "locked" together and used clear, weather stripping tape to seal the edges. I placed them in front of the accordion style flaps on either side of the AC units (on the inside/home portion, NOT the exterior of the house). I think it worked okay. It was ultimately better than in past years where I had little to nothing additional around the AC units. I also used the foam strips that came with the units as well as additional ones I purchased to place in the gap between the opened bottom window pane (under which the AC unit was) and top pane and taped over that as well (in past years I only used the foam strip between the window panes - no tape).

Quick Notes:
- Make a Noticeable but not a dramatic reduction in noise from the room they are in and from noise outside the room they are in
- No More echo in a 10'x12' room with TV placed right against TV.
- They are not perfectly square and don't match each other exactly.
- High quality foam. They come wrapped in plastic and I know they were beaten up because USPS damages almost all my packages, but they were not deformed at all.
- Getting rid of echo in room dramatically improves sound quality.
- I would 100% recommend these to any consumer who wants a little less noise and better sound quality in a room.
- I would not recommend these to someone looking to set up a professional recording studio since they aren't perfect squares.
- Shipped next Business day after placing order and arrived in 2 days from CA to NY with the free shipping.

Full Review:
I ordered these after doing a lot of research online about acoustic foam I wanted something that reduced noise and could eliminate the echo from my tv(my room is about 10'x12' and the TV has rear facing speakers and is against a wall). I put 3 tiles behind the TV and then 9 on the wall between my room and my roommates to try and reduce some of the noise transfer since the walls are made of cardboard(not really but sound does travel right threw them without so much as being dampened). To my enjoyment about 90% of the echo is gone with just placing them behind the TV the sound quality is much better and it is actually easier to watch at a lower volume and still here what's being said. As expected these didn't eliminate the sound transfer between the two rooms but placing the 9 tiles above my dresser and other furniture that's against that wall did help reduce the noise by a noticeable amount. I will defiantly be purchasing more to do the other walls in my room. The foam is really high quality as mentioned above it didn't come deformed even though it was only wrapped in plastic and to further test it I left 2 pieces together and used them as a seat cushion for a few days and the always bounced right back with no permanent deformities. I used T-pins and a hammer to hang these on drywall as I didn't want them in a permanent place.

--*If you have any questions please leave a comment and I will try and respond as soon as I can, but I have a job and things to do so please don't expect a response immediately.*

First - you need to understand what the purpose of these panels is. Many of the negative reviews state that it didn't make things quiet enough etc, and of course not because it isn't designed to. These foam panels are designed to reduce higher-frequency reflected sound (like echos) which makes listening to speakers or recording on a mic much clearer.

To that end, they work great. I installed these yesterday in my home theater room and they did exactly what I wanted - eliminated first reflections off my walls and ceiling from the forward 5 speakers. Dialogue and sound effects in movies are much more crisp and clear now, in addition to surround effects being clearer, sharper, and easier to localize since I'm not hearing a reflected sound on the wrong side slightly after the original speaker sound hits me.

As others mention, the foam quality is great, but whoever cuts these is on crack. They are definitely not uniform 12" x 12" so you need to accept that you can't make perfect square or rectangle patterns with them. Also, they are not a uniform color. I bought 2 packs of 12 each and have a variety of blacks ranging from almost dark grey to deep black color, but this doesn't bother me considering how dirt cheap they are and that while watching a movie the lights are dim or off and you shouldn't be looking at the walls or ceiling anyway.

Highly recommend these for an inexpensive home theater room to eliminate unwanted echoes, or a recording studio to give a cleaner, flatter sound. I might end up buying more to cover more of my walls for an even flatter, tighter sound experience.

Note: many reviews for foam mounting state that spray adhesive doesn't work but I think they were using either a wrong kind or had a poor application technique. I bought some 3M number 45 stuff at a hardware store and sprayed the wall and foam separately, waiting about 30-60 seconds for the adhesive to tack slightly before pressing the foam into place. This has created quite a strong bond and I'm positive the foam is not going to fall off my ceiling or walls any time soon.

I buy these for every speaker builds. Works perfect