How To Install A Bass Blocker For Your Car Speaker

I had just turned up the volume on my car stereo when I heard a loud pop. The sound was so intense that it made me jump, and then the door speaker buzzed loudly and started irritatingly humming as I tried to tune out what sounded like an angry bee.

I blew my car speaker. If you drive long enough, you’re bound to do the same, especially if you’re running an amp or factory speaker.

The way to prevent this from happening is by installing a bass blocker. But how do I do that? We’ll show you how to install bass blockers for your car speaker.

Tools Needed to Install Bass Blockers

Installing a bass blocker isn’t difficult, but it will require working with your car’s electrical system. It doesn’t matter if you have a factory or aftermarket head unit, as you won’t need to remove the head unit anyways or modify the factory wiring harness it’s connected to.

List of Tools Needed

  • Crimping tool
  • Wire stripper and cutter
  • Screwdriver set
  • Male and Female spade connectors
  • Door Trim Removal kit (with spare clips because I always break one!)
  • Electrical tape
  • Your Cars manual
Wire Crimper
Channellock Wire Crimping Tool
Channellock Wire Crimping Tool
  • Cuts and crimps 10-22 AWG wire
  • Crimps both insulated and non-insulated solderless connections and terminals
  • Laser heat-treated edges last longer
  • High-carbon C1080 steel
  • Made in the USA
Check Price
Wire Stripper & Cutter
Channellock 958 Wire Stripper and Cutter
Channellock 958 Wire Stripper and Cutter
  • PRECISION cutting edges cleanly cut and strip AWG 10-20 wire
  • DURABLE coiled spring reduce hand fatigue
  • LEAN pliers nose pulls and loops wire
  • LASER-ETCHED gauge indicators
  • LOCK for safe storage
  • CHANNELLOCK BLUE grips for comfort
  • 100% MADE IN USA
Check Price
Screwdriver Set
CRAFTSMAN Screwdriver Set, Assorted, 12-Piece (CMHT65044)
CRAFTSMAN Screwdriver Set, Assorted, 12-Piece (CMHT65044)
  • Alloy-steel blades are heat-treated for strength and durability
  • Coated with a satin-nickel finish
  • Comfort Optimized handle for high & low torque applications
  • Full Lifetime Warranty, refer to “Warranty & Support” section below for full details
Check Price
Spade Connector Kit
Qibaok Spade Connector Kit
Qibaok Spade Connector Kit
  • Wire Range: AWG 22-16 (Red), AWG 16-14 (Blue), AWG 12-10 (Yellow)
  • 840PCS Wire Terminals
  • Strong Copper Barrel to hold the wire tight when crimped.
Check Price
Door Trim Removal Kit
GOOACC 240PCS Trim Kit
GOOACC 240PCS Trim Kit
  • UNIVERSAL FIT KIT – 12 popular size, fitting for door trim, radiator shield yoke, fender, bumper and splash shield retainers replacement for Ford, GM, Chrysler, Toyota, Honda and more
  • EASY STORAGE – Comes with a plastic box with 12 compartments for organized storage
Check Price
Electrical Tape
Wapodeai 3PCS Electrical Tape
Wapodeai 3PCS Electrical Tape
  • Premium performance
  • Each roll is 49 ft long and 0.62 in wide
  • Strong durability
Check Price

General Preparation

Remove Power

It’s safest to remove power from your vehicle before you work on it. I recommend disconnecting the car battery.

Look in the Owner’s manual and find the location for the car battery. Most of the time it will be under the hood of the car, but some car’s like BMW’s, will have the battery in the trunk.

Remove the black cable connected to the negative battery terminal. This will effectively remove power from your vehicle and you can safely work on it now.

Locate Speakers

Refer to the Owners manual or a repair manual and find the locations of the speakers in your car. Usually there are four, one in each door, and they’ll be 3″ or larger.

Some cars may have component speakers, usually a speaker in the door connected to a tweeter located higher up in the door or in the dash. If this is what you have, usually accessing the door speaker is the goal and the steps will be the same.

Gain Access To Speaker

You need access to the rear of the speaker where the wiring connects to the speaker terminals. They’re normally found at the rear of each speaker. This is necessary to be able to install the Bass Blockers.

In most situations you’ll need to remove the door card (also called door panel) using a nylon pry bar to pop the plastic rivets on the backside of the door card.

If it has a plastic membrane, it’s usually attached with a sticky putty like substance that can be re-used to seal the door. So don’t remove all of it, you’ll want to use it again. Carefully peel away the plastic membrane closest to the speaker. Goal here is to open it up just enough so you can remove the speaker.

Identify Speakers Positive Terminal

Most bass blockers attach inline with the speakers positive terminal. Refer to the owners manual of the bass blocker you buy to be certain.

Once you have the speaker free, look at the back, and you should find 2 connectors, one red and one black. The red one is the one you want so you can insert the bass blocker.

You may also see a + and – symbol’s next to the terminals. The + is the same as red, that’s the one you want.

If you don’t see any of these, refer to the Owners book or repair manual and they should be able to help you identify which one is the positive terminal.

Techguys also has a great article that can help you further with identifying + and – on a speaker.

How To Install Bass Blockers

Now that the speakers are accessible and the positive terminal has been identified, you’re now ready to install the bass blocker.

From the positive terminal, measure roughly 3″ to 6″ and cut the positive wire using your wire cutters.

Use your wire stripping tool to remove 3/8 inches of plastic wire insulation from both ends of the positive speaker wire.

Find a matching set of male and female spade connectors. Insert them onto each end of the wires you just stripped. Use your wire crimper and crimp both ends.

If your bass blocker already has spade connectors, attach them now to the new spade connectors. Check with the installation manual for your bass blockers to see if they care about polarity (directional), most of the time it doesn’t.

Now it’s time to securely mount the bass blocker to the speaker so it doesn’t move around and cause unwanted buzzing or bumping noises. You can use electrical tape or any sturdy tape and fasten the bass blocker to the back side of the speaker.

Screw back in your speaker to the door, replace the plastic membrane, and re-install the door card.

Lastly, remember to reconnect your car battery.

Recommended Bass Blockers

PAC BB-6PR Bass Blocker for Tweeters
PAC BB-6PR Bass Blocker for Tweeters

Reduce bass frequency below 5600 Hz

Check Price
3.5″ and 4″ Speakers

Reduces Bass Frequency below 2.8 kHz

Check Price
5.25″ Speakers
PAC Bass Blocker
PAC Bass Blocker

Reduces bass frequency below 800 Hz

Check Price
6″ and 6.5″ Speakers
PAC BB-2PR Pair of Bass Blocker
PAC BB-2PR Pair of Bass Blocker

Reduce bass frequency below 600 Hz

Check Price
6×9 Speakers
Audiopipe Bass Blockers
Audiopipe Bass Blockers

Reduces bass frequency below 300 Hz

Check Price

Frequently Asked Questions


Bass Blockers do a great job at protecting speakers, especially if you like to turn up that volume! They’re simple to install with basic hand tools and all 4 speakers in a car can be done in an afternoon.

While you can DIY by figuring out what size capacitor to buy and install, most of us will like the convenience of a Bass Blocker kit. They’re just simpler, easier, and brain dead simple.

Leave a Comment

Your email address will not be published. Required fields are marked *