It does matter with speakers or not because you are dampening the road and wind noises. I have had good luck with Seel & Peel...something like that (sold by Lowes). I am in the midwest and experience humid summers and cold winters and I have never had a weird smell or any fall off or lose tackiness. Thats my personal preference because of price and the fact that I don't compete or anything special. No matter what you use, if you can afford to add layers it will make a difference as well.