The front speakers in my 2012 Honda Civic Coupe sound good, but the rear speakers do not. This car has the standard sound system without the subwoofer. I replaced the stock rear speakers with 6.5 inch Polk 2-way speakers. I had recently replaced the speakers in my Trailblazer with the same type and they sound great. Unfortunately they didn't make much of an improvement in the audio quality of the Civic. I noticed that the rear deck in the Civic is full of holes that allow the pressure wave from the rear of the speaker to easily reach the front of the speaker, thereby canceling each other; especially at lower frequencies. I was thinking about buying some “Dynamat” to seal the openings, but found a thread on another forum that recommended using “Peel and Seal” roofing repair tape as a low cost alternate. I bought a roll of Peel and Seal at Lowes and this is what the rear deck of the Civic looked like when I was finished.
The Peel and Seal did help somewhat, but not much. Apparently the OEM Honda Head Unit doesn’t provide a very good signal to the rear speakers. I used the Peel and Seal to fill the openings in the rear deck of a 2009 Chevy Cobalt with Alpine 6x9 Speakers, and the OEM Delco Head Unit, and it worked great in this application. There was a dramatic increase in low frequency performance.
Here is a picture of the OEM Honda speakers that I removed, which are among the least impressive that I have ever seen.
The Peel and Seal did help somewhat, but not much. Apparently the OEM Honda Head Unit doesn’t provide a very good signal to the rear speakers. I used the Peel and Seal to fill the openings in the rear deck of a 2009 Chevy Cobalt with Alpine 6x9 Speakers, and the OEM Delco Head Unit, and it worked great in this application. There was a dramatic increase in low frequency performance.
Here is a picture of the OEM Honda speakers that I removed, which are among the least impressive that I have ever seen.