Replaced the rear speakers

Our 2015 Prius V doesn't have a bad audio system but the bass is pretty muddy and the rear speakers appear to be nearly silent. The recommended update is new rear speakers and an amplifier. I don't like cutting into wiring so I am trying to avoid adding the amplifier. I looked for the most efficient speakers to raise the rear sound level without an amplifier. I purchased some Infinity Reference 6 1/2" speakers from Crutchfield. The sensitivity (sound output for power input) of these speakers is 93 db which is the highest of the speakers that they sell. They came with adapter harness for Toyota and adapter rings to replace the Toyota adapter rings. I also ordered the Hushmat.

Installation was pretty easy, there is a youtube video on how to remove the rear door panels. Just two screws and pop out about 8 plastic clips holding the door panel on. Disconnect the two cables for door opening and locks plus the plug for the speaker wiring and the panel is free.

I unplugged the speaker connector. I drilled out the three rivets holding the standard speaker adapter rings and removed them. Once I had access to the speaker opening, I could install the Hushmat.

If you are not familiar with Hushmat it is about a 1 foot square piece of 1/2" thick peel and stick sound absorbing material. The Hushmat is supposed to be stuck to the outer door skin behind the speaker. The problem is there is a round door beam right in the center of that area. I positioned the Hushmat where it should be located and marked where the beam crossed that area. I cut the Hushmat into three pieces. One for the area above the beam, one for the area below the beam and an 1 1/2" strip to attach to the beam. I peeled off the adhesive back and stuck the pieces in place.

I plugged the adapter cable provided in the kit to the speaker terminals. There is one narrow and one wide lug on the speaker and the same for the adapter cable so you can't get the wire polarity reversed. The other end of that adapter cable has a connector that plugs into the original speaker harness so you don't have to modify any vehicle wiring. The old speakers wires connected on the outside of the inner door panel and the new speaker wires attach to the back of the speaker which is inside the inner door panel. I cut a slit in the clear plastic sheet covering the inner door panel at an existing one inch diameter hole near the speaker opening and slipped the harness through it.

The old speakers extended out from the inner door frame about an inch because of the original adapter ring. The new adapter ring does the same thing but has mounting holes for the new speakers. Three pop rivets secured the new adapter ring to the inner door frame. I had to elongate two of the holes on the new adapter rings so that all three holes lined up with the existing holes in the door.

I replaced the door panels and was ready to check out the sound.

The fader still needs to be shifted from neutral toward the rear speakers but not as much as with the original speakers. I selected some music with a lot of bass and put my hand on the outside of the door skin opposite the rear speakers and the vibration appears to be somewhat reduced on the rear doors compared to the front. The bass is cleaner and I am not sure how much is Hushmat and how much is the new speakers.

I would have to say that time will tell whether the improvement was worth the cost, $100 and the effort.

 

I didn't get much benefit from just upgrading the rear speakers. While the bass is cleaner with the new speakers, I am not sure that the improvement was worth the time and $100. I was trying to avoid cutting into the wiring and adding an amplifier but it seems that is what is really needed.

After driving the Prius for a while now I noticed that the road noise at freeway speed is considerably higher than our Odyssey EXL. The Odyssey is a large empty box with a lot of glass but it does a better job of keeping out road noise at freeway speeds. Honda must have realized that Odyssey's spend a lot of time on the freeway and they put an effort into containing road noise. There are different boxes to check when you are building a touring vehicle as opposed to building an economy car.

Aware of the Prius road noise, I wasn't too surprised that there is no soundproofing on the inside of the door skins just bare painted metal. Any bass from the speakers causes the door skins to vibrate. You can feel it when you put your hand on the outside of the door while playing music with a lot of bass. Ideal speaker enclosures are rigid.

An undeadened sheet metal car body is not ideal for sound reproduction but then it is not a concert hall, it is an economy car which is what it does best.

 

After installing the Infinity speakers, I have to agree with rjparker that you don't get the full spectrum of sound at the rear speakers. I was able to adjust the front/rear balance control more toward the neutral position with the new speakers. You may experience a little more bass and it may be a little cleaner. Was it worth the effort? Only you can decide.

It is, after all, an economy car. It has virtually no soundproofing. It transmits a lot of road noise into the cabin so it is never going to be a concert hall. I like my Prius V and have learned to appreciate the Prius for what it is and I am willing to live with what it is not.