Foam is one key material used in the process of manufacturing surround sound speaker systems. Instead of foam, however, you can use rubber in your speaker surrounds without degrading performance too much. The material you choose depends on different factors. In this article, we discuss foam and rubber speaker surrounds.
So, can you replace foam speaker surrounds with rubber?
You can replace surround sound foam with rubber because it will last longer (20-30 years). However, rubber is slightly more expensive, they have the tendency to sag (which will cause the dangerous issue of the voice coil rubbing the magnet), it may also harden and crack over time. Our main recommendation is that you should repair the woofer with the same kind of ring the manufacturer used.
Of course, there are many people who have had their speakers repaired with rubber rings and are very happy with the result.
Foam vs Rubber For Surrounds
- Control: The way foam and rubber control the speaker cone is different. These mechanisms may or may not be important to you.
- Weight: The weight and the weight are different. Rubber rings can weigh up to 10 times that of foam rings.
- Longevity: Rubber will last much longer than foam. Rubber can last up to 30 years, while foam will break down after about 5 years. Of course, this depends on certain conditions such as temperature and sunlight.
- Efficiency: Foam will deliver greater efficiency because it is more flexible.
Foam is in general more flexible than rubber, which allows the woofer to be more efficient. Foam is also lighter and doesn’t last as long (up to 5 years). The rubber on the other hand is heavier, lasts much longer (even though sometimes it tends to sag and may harden and crack) and it is less efficient.
Replacing Foam Surrounds On Speakers
The foam surround on your speakers will usually wear out after ten to twenty years of use. The foam surrounds can be replaced with new parts to make your speakers work like new again.
You can do this regardless of the speaker brands that you use. Besides, foam replacement can be done with foam, rubber, or cloth surround replacements. Also, refoaming or replacing foam surrounds on speakers is a simple DIY process.
DIY Speaker Refoam
Refoaming your old speakers is a good step towards improving performance and longevity. Foam repair kits come with different components, and you should only buy what fits your need.
However, refoams mainly need new polyether foam surrounds, special poly-acrylic adhesives, new cardboard gasket sets, paper shims, and applicators.
Follow the DIY steps below to refoam your speakers.
Step 1: Separate The Gasket From The Steel Frame
Old speaker surrounds look dilapidated and good for nothing. Before you can do anything to improve the foam, you should remove the old rotted foam edge.
Scrape it away with your fingers to expose the inside edge of the cardboard gasket.
Now separate the gasket from the steel frame gently using a razor knife. Be patient, as this will take several rounds to remove completely.
Step 2: Clean The Steel Frame
Once the gasket is removed, use a wood chisel or a small putty knife to clean the steel frame. Do not be worried if you see some glue residue on the surface. The surface should, however, be smooth and even.
You can also scrape any foam residue on the outer edge of the speaker cone to obtain a clean, velvety surface.
Step 3: Remove The Dust Cap And Shim The Voice Coil
Using your knife, gently cut the dust cap around the circumference while keeping the knife parallel to the cone. Leave a small portion uncut to help you flip the cap out and then back.
You can also secure the cap out of the way with a small piece of tape. The voice coil should now be well exposed. Take care not to get debris into the coil.
Step 4: Install Paper Shims
Now cut 3 or 4 paper shims from magazine covers or business cards and fix them right between the voice coil bobbin and the steel pole of the speaker. Make sure the shims are evenly spaced, and the fit is snug.
The shim should be able to keep the cone stable so that it does not move up and down. Also, use the shims to set the cone in the right position so that the orange disc or spider stays flat and does not sag toward the magnet.
Step 5: Place The Replacement Foam
Apply the white speaker glue around the circumference of the cone. Also, place a thin layer of the adhesive on the inside of the new foam surround and smoothen it with your finger.
Join the foam by carefully placing it on the glue area and pressing it down gently. Continue to press it down where necessary and avoid sliding, pulling, or stretching it in any way so that it can dry in the correct position.
Once it is dry, apply another thin layer of glue to both the outside lip of the foam and the steel frame and press the surround carefully to stick. You can also use the gasket to help press it down.
Step 6: Reattach The Gasket
Once the glue dries up, reattach the gasket by covering the backside with an even layer of glue and holding it down with a board or just flip it over the table and allow it to dry.
Step 7: Remove The Shims And Check For the Center
It is now time to remove the paper shims and check for the center. Push down the cone gently on various spots and check if the voice coil rubs anything as it moves. If not, then the repair is successful.
Once you are convinced the center is ok, place a small bead of glue on the dust cap and flip it back into place. Allow it to dry.
Step 8: Dress The Repaired Parts
Now apply an even layer of glue to the areas around the cap and surround. Spin the speaker while you smooth the glue out with your finger. Paint with black paint to finish.
Speaker Foam Repair Kit
There are many different types of speaker foam repair kits to use. Here are just a few you can get from Amazon.
- Cerwin Vega 12 Inch Foam Speaker Repair Kit FSK-12AR (Pair)
- Large Advent 10 Inch Foam Speaker Repair Kit Masonite Frame FSK-10AD (PAirP
- Standard 10″ Angle-Attach Speaker Foam Surround Repair Kit-Universal 10 Inch
- Cerwin Vega 10 Inch Foam Speaker Repair Kit FSK-10AR (Pair)
- Boston Acoustics 8 Inch Foam Speaker Repair Kit FSK-8 (Pair)
- Simply Speakers 8 Inch Foam Speaker Repair Kit Compatible With JBL 116A, 116H, FSK-8 (Pair)
- Bluecell 10″ Rubber Speaker Edge Surround Rings
- Audiopipe 10″ RING-10BZ MDF Speaker Ring Recess with Bezel MOUNTING Spacer
- Universal EVA Self Adhesive Sponge High Rebound Waterproof Car Door Speaker Foam Fast Baffle Kit
- Paradigm single edge 10-inch Foam Speaker repair Kit FSK-10A-1
Best Speaker Refoam Kit
This is one of the best speaker foam repair kits you can get for your next DIY job.
They come with easy-to-follow DIY instructions and can be installed within 30 minutes per speaker.
- Free technical support
- Easy to install
- YouTube video with instructions available
- A little expensive
Best Speaker Surround Material
Speaker manufacturers use different surround materials, including foam, rubber, and treated cloth. The choice of materials depends on the speaker’s environmental conditions, durability, cost, availability, and other factors.
Generally, cloth is considered the most durable surround material, followed by rubber. Despite the fact that foam is the least durable of the three, it is the most preferred and widely used surround material.
So, Why Is Foam Preferred Over Other Materials?
- It is more flexible than rubber – enhances speaker efficiency
- It is cheaper than rubber – helps lower the production cost of speakers
When Should You Replace Foam Surround With Rubber Surround?
- When the speaker is being used near the sea or ocean. This is because the salty sea air may easily and quickly affect the foam edges.
- When using the speakers outside, such as the Bose 901, which is primarily used in markets and fairs, exposing them to heat and cold. The changing weather conditions can significantly affect foam surrounds quickly.
- When using the speakers in tropical and humid conditions.
Repair Speaker Surround With Silicon
Like we already said, repairing the speaker surround is an easy process that you can complete within a short time.
If your speaker surround wears out or tears and you do not have the white speaker glue, you can still use silicon to repair it. Here’s what to do.
Step 1: Wear some latex or nitrile gloves
Step 2: Clean the torn area with a cloth
Step 3: Place some RTV silicon on a disposable plate
Step 4: Cut the cotton swab’s end to transform it into the RTC applicator
Step 5: Dip the swab into the RTV silicone and apply it to the underside of the tear of the speaker
Step 6: Put a dab of RTV silicone across the front part of the torn area and spread
Step 7: Allow it to dry and stick the torn piece together
Why Do Speaker Surround Manufacturers Use Foam?
There are certain advantages to using foam for speaker surrounds. Here are the main ones:
- Foam is generally more flexible than rubber. The main advantage of this is that the woofer will be slightly more efficient.
- In general, foam is slightly cheaper than rubber which means that the cost of producing it is lower.
While you can replace surround sound foam with rubber foam and it’s a good idea because the rubber will last much longer, however, always keep the disadvantages of using rubber. Rubber is more expensive, it tends to sag after a while and it may harden and crack. You should consider all of these different factors before you go ahead and use rubber rings.