Bests & Worsts Reviews from Amazon

Let me clear up some misinformation here. This product is not a sound barrier at all. It's a CCF (Closed Cell Foam) decoupler and as a decoupler it does an excellent job, especially with the adhesive backing. Anyone who says this reduces noise has been a victim of the placebo effect -- it doesn't. 37 square feet of this foam weighs 2.5 pounds. 2.5 pounds of material does not weigh enough to block or damp any kind of sound. To be sure, before installing this in the doors of my Mazda3, I played music from my phone and covered the speaker with this foam. As expected, the sound was not reduced or filtered much at all. Covering my phone with 1/16" MLV on top of this foam instead reduced the music to a whisper. So what is the purpose of this foam? It's intended to be used along side a sheet of MLV, or Mass Loaded Vinyl. MLV is the actual sound barrier -- heavy, dense and limp -- that severely impedes any kind of sound waves that try to pass through it. Even a 1/16" sheet of MLV cuts any noise passing through it by 27-40dBa (!) depending on frequency. MLV isn't quite as effective when it's pressed right up against a hard surface like sheet metal though -- and that's where this CCF comes in. It decouples the MLV barrier from the noisy resonating sheet metal so it can remain limp and do its job better. This foam also compresses easily to seal any cracks and gaps, so not only is it a decoupler but can also be considered a "gasket" for the MLV. The correct procedure is like this: [Noico closed cell foam decoupler] >> [Mass Loaded Vinyl barrier] Or if you also want to kill sheet metal resonance for a proper and complete deadening job: [Car sheet metal] >> [Noico Butyl 50 or 80 mil deadener mat] Then inside the door cards, under the carpet or inside the trunk lining: [Noico 1/6" CCF or 1/8" generic neoprene foam] >> [1/16" MLV] I attached a picture of the correct procedure. Also, unlike butyl deadening mats (Dynamat, damplifier, fatmat, etc.) that only need 30-50% surface coverage to kill resonance, an MLV sound barrier needs complete, unbroken coverage to avoid noise slipping between the gaps. The only holes or gaps that should be cut are to run wires through. "So where can I find this magical material known as MLV?!" I can't post links, but a simple Google search for 1/16" MLV will take you to what you need. For reference, I picked up 112 sqft 1/16" MLV for $130 and free shipping with just a little searching for 20 minutes. To be honest, for the best bang-for-the-buck you can skip CCF completely, as the MLV barrier works without it, but the CCF does help keep it from flopping around in the door and the compression attributes of the CCF helps seal the gaps and areas sound can leak through. Hope this helps break any confusion and allows this whole "car sound deadening stuff" to make sense!