Rear Speaker Installation

The installation of the rear speakers should have been a simple project... but it was not.

I've historically been a big fan of Polk speakers.  When I found the front Polk component speakers and they were one of the only styles mounted with the stock three screws, I was sold.  To have similar sound coming from the front and back, it is best to have as close to the same speaker as possible.  That caused me to select the Polk MM572 5"x7" speaker (no DB version is made) for the rear.

The speakers arrived and looked great.  I quickly noticed they changed up the basket from how they were produced years ago.  Instead of a thin metal basket, the entire basket was made of plastic and the mounting tabs were all 1/4" thick.  It was quickly apparent the original speaker screws would not work as they were not long enough. 

I took the original speaker off the grill, put the Polk speaker in its place and found the shape and thickness of the basket caused other problems.  The speaker was spaced over 1/4" off the grill due to the thickness of the basket and design relative to the stock speaker grill.  After some research, I decided I would use some thick 1/4" closed cell foam tape to close the gap.  I wasn't convinced this would solve the problem but it ultimately worked far better than I expected.  I ultimately put foam on both the speaker and the grill so that when screwed in place there was a solid seal and good compression of the foam.

I was able to get the speakers mounted to the grills only to find they are not so spaced back from the face of the grill, they barely fit in the car.  This was really a surprise as they have such a small magnet.  Regardless, there is a support bracket that they make light contact with.  That said you can get them installed but can tell the bottom of the speaker grill is bowed out just a bit.

Strangely enough, they also decided to use unique sized speaker terminals on the back.  Instead of the normal large and small speaker spade, the negative is a medium size.  It wasn't a big deal as I just took their provided wiring, soldered it to the Metra speaker wiring adapter plug and everything connected fine.  It is just one more instance of Polk departing from normal with these and causing some problems with the installation process.

I installed stereo systems for years and installed many 5"x7" speakers.  It is surprising to me that 25 years later, Polk decides to start changing up a design that has worked forever.  With the old metal baskets, the speaker would protrude out from the basket more, seal better against this type grill, and provide more space behind the speaker.  Regardless, they are installed, sound good, and look fine.  It is just unfortunately that even small things like this take far more effort and are not as seamless of an installation as they should be with a speaker design that has existed for well over 30 years.

I weighed the stock and Polk speakers for comparison.  The stock speaker weights 1 pound and 7 oz while the new speaker weighs only 1 pound and 4 oz.  The total across the two of them is then only 6 oz lighter with the new speakers installed.