If you are looking for my post about "massive changes", look below for the one poster earlier in May, 2010.
http://therobbcollections.blogspot.com/2010/05/massive-changes.html
For some time now, I have been modifying my various woofers to give them rubber surrounds, rather than foam that most come with.
I think the DCM KX-12s were the first that I did because their mid-range drivers come with rubber surrounds and the woofers foam.
HOW did I "rubberize" them, you may be thinking? By careful application of Room Temperature Vulcanizing Silicone glue. That's how. First look at some pictures of standard foam surround speakers:
Above is the OPTIMUS PRO 4000 15" woofer. Below is one of the Eosone 10" woofers. Note the small black patch, that is black RTV that I used to repair the hole I made accidentally with a screwdriver:
The silver material is plastic made to look like aluminum. Lyric speakers were very cheap, so they attempted to make them look more expensive by dressing them up. I have since stopped using the trim rings as you shall see below.Now for some photos of rubberized woofers:
The above is obviously one of the DCM woofers. Below is one of the Eosone woofers:
Next is two shots of the same woofer, closer detail of the front and detail of the back:
Now, below is one of the BOSE 301 Mark V woofers:
Hey, you may be thinking, you still haven't told us HOW you did it.
OK, RTV Silicone rubber glue comes in a tube similar to toothpaste. It is nasty smelling stuff and frankly electronics don't react well to the fumes either.
The tubes are sealed, but the top of the cap has a point in it to pierce the tube opening.
IF you attempt to do this wear latex or nitrile gloves and MOST importantly in a well ventilated place! Also, keep whatever you are using the RTV on away from electronics as much as possible while it cures so the fumes will not mess up your electronic bits and pieces.
Carefully remove the screws that hold your woofer in place and remove the woofer. You may have to carefully pry it out, or if you make the mistake of taking the screws out while the speaker is standing up, it will fall out when you when you least expect it! They are HEAVY!
Now, if the woofer has removable wire leads, they are shaped kind of like a shovel blade, then carefully slide the wire terminal off. Make NOTE of which wire went where! If they are soldered on, a little silver blob on the wire and speaker terminals, AND you don't solder, I hope you have enough slack in the wires to work on the woofer outside the box.
With gloves on, squeeze a little RTV onto the rounded surface of the foam and carefully spread it along the foam surface. Make it a THIN layer and even too.
Work quickly but neatly. In the thickness you are hoping to achieve it will dry(vulcanize) quickly. Set that woofer aside and do the other one.
Once the front RTV is cured, carefully turn the woofer over. Depending on the size of the woofer, 10" or bigger, you can apply RTV to the inside of the foam with a finger. 8" and smaller use a cheap paint brush about 1/4" wide to apply the RTV. Again, a thin, even and smooth layer is what you want.
Do the other one and wait until the next day to re-install them in the cabinets.
Once you have put the speakers back together, you can enjoy them for MANY, MANY years, hopefully without any surround-related failure.
I can't imagine that rubber surrounds can cost THAT much more that foam to make. Even very expensive speakers often have foam surrounds.
What I think happens over time is the foam deteriorates from exposure to air. Eventually cracking then falling to pieces. Many people never take their speaker grilles off, so never realize the foam has died.
When the foam fails not only does the front of the woofer cone no longer have ANY support, but the front of the cone is now exposed to the bass music waves from the rear of the cone. Below a certain frequency, these rear bass waves sonically cancel out the front waves. Thus a total loss of Bass music.
By the way, the RTV is shiny, but not nearly as is shown in the flash photographs.
Lest you be worried about causing harm to the woofers by applying this RTV to them, or changing the characteristics of your music, fear not.
All the RTV does is form an inert silicone rubber surface that seals the foam surround on both sides preventing the foam from deteriorating. It is very light and VERY flexible so it will not affect your music in any way.
I made some other changes as well. I wanted to add Banana jacks, sometimes called "3-way binding posts" to the BOSE speakers as they only came with spring-loaded terminals which don't work that well. I bought two pairs of Atlona ones via eBay for $4.95 a pair. Quite a bargain, look:
Note the size difference overall as well as the hole for bare wires. Also note the construction. $4.95 a pair! A steal! Here they are from another angle:
Banana plugs are shaped like straight bananas and provide a LOT more surface area for the music to travel through. Plus, they are easy to connect as they just slide in or out. Here they are installed:
I bought them as I said for the BOSE 301s, but they wouldn't fit where I needed to put them, so I put them in the Lyric/Eosone speakers.
While I pooh-poohed the smaller terminals above, they do work a whole lot better than the spring terminals, so I installed them in the BOSE:
It was cool looking inside the BOSE 301s, QUITE different from any other speaker I ever looked in!
How, as promised, here is comparison pictures of the Lyric speakers before and after rubberization:
The one on the right is what they looked like after replacing the rotted foam original woofers with the Eosone ones. The left is all Eosone drivers. Now, RTV'd:
On a side note, here is the numbers of the made-by-Polk EOSONE drivers (above) and what they were used in:
Tweeters are part number 1RD0013-1. It is a 19mm (3/4") titanium dome tweeter. Were used in: RSF-200 three-speaker two-way bookshelf speaker. Second rear-firing tweeter of a different construction. Retailed for $600 a pair.
Woofers are part number 1RD0002-2 and are 10" driver used in: RSP-910 sub-woofer, as well as RSF-1000 Seven-speaker, four-way, dual-woofer top-of-the-line speakers that retailed for $2,500 a pair. Frequency response down to 30Hz. Sub-woofer retailed for $549.
Mid-ranges are part number 1RD0008-2 and are 4" sealed back drivers used in: RSF-1000 Seven-speaker, four-way, dual-woofer top-of-the-line speakers that retailed for $2,500 a pair.
Please keep stopping by from time to time to see what I've been up to. Keep listening to that music! I do!
Scott
Hey, you may be thinking, you still haven't told us HOW you did it.OK, RTV Silicone rubber glue comes in a tube similar to toothpaste. It is nasty smelling stuff and frankly electronics don't react well to the fumes either.
The tubes are sealed, but the top of the cap has a point in it to pierce the tube opening.
IF you attempt to do this wear latex or nitrile gloves and MOST importantly in a well ventilated place! Also, keep whatever you are using the RTV on away from electronics as much as possible while it cures so the fumes will not mess up your electronic bits and pieces.
Carefully remove the screws that hold your woofer in place and remove the woofer. You may have to carefully pry it out, or if you make the mistake of taking the screws out while the speaker is standing up, it will fall out when you when you least expect it! They are HEAVY!
Now, if the woofer has removable wire leads, they are shaped kind of like a shovel blade, then carefully slide the wire terminal off. Make NOTE of which wire went where! If they are soldered on, a little silver blob on the wire and speaker terminals, AND you don't solder, I hope you have enough slack in the wires to work on the woofer outside the box.
With gloves on, squeeze a little RTV onto the rounded surface of the foam and carefully spread it along the foam surface. Make it a THIN layer and even too.
Work quickly but neatly. In the thickness you are hoping to achieve it will dry(vulcanize) quickly. Set that woofer aside and do the other one.
Once the front RTV is cured, carefully turn the woofer over. Depending on the size of the woofer, 10" or bigger, you can apply RTV to the inside of the foam with a finger. 8" and smaller use a cheap paint brush about 1/4" wide to apply the RTV. Again, a thin, even and smooth layer is what you want.
Do the other one and wait until the next day to re-install them in the cabinets.
Once you have put the speakers back together, you can enjoy them for MANY, MANY years, hopefully without any surround-related failure.
I can't imagine that rubber surrounds can cost THAT much more that foam to make. Even very expensive speakers often have foam surrounds.
What I think happens over time is the foam deteriorates from exposure to air. Eventually cracking then falling to pieces. Many people never take their speaker grilles off, so never realize the foam has died.
When the foam fails not only does the front of the woofer cone no longer have ANY support, but the front of the cone is now exposed to the bass music waves from the rear of the cone. Below a certain frequency, these rear bass waves sonically cancel out the front waves. Thus a total loss of Bass music.
By the way, the RTV is shiny, but not nearly as is shown in the flash photographs.
Lest you be worried about causing harm to the woofers by applying this RTV to them, or changing the characteristics of your music, fear not.
All the RTV does is form an inert silicone rubber surface that seals the foam surround on both sides preventing the foam from deteriorating. It is very light and VERY flexible so it will not affect your music in any way.
I made some other changes as well. I wanted to add Banana jacks, sometimes called "3-way binding posts" to the BOSE speakers as they only came with spring-loaded terminals which don't work that well. I bought two pairs of Atlona ones via eBay for $4.95 a pair. Quite a bargain, look:
Note the size difference overall as well as the hole for bare wires. Also note the construction. $4.95 a pair! A steal! Here they are from another angle:
Banana plugs are shaped like straight bananas and provide a LOT more surface area for the music to travel through. Plus, they are easy to connect as they just slide in or out. Here they are installed:
I bought them as I said for the BOSE 301s, but they wouldn't fit where I needed to put them, so I put them in the Lyric/Eosone speakers.While I pooh-poohed the smaller terminals above, they do work a whole lot better than the spring terminals, so I installed them in the BOSE:
It was cool looking inside the BOSE 301s, QUITE different from any other speaker I ever looked in!How, as promised, here is comparison pictures of the Lyric speakers before and after rubberization:
The one on the right is what they looked like after replacing the rotted foam original woofers with the Eosone ones. The left is all Eosone drivers. Now, RTV'd:
On a side note, here is the numbers of the made-by-Polk EOSONE drivers (above) and what they were used in:Tweeters are part number 1RD0013-1. It is a 19mm (3/4") titanium dome tweeter. Were used in: RSF-200 three-speaker two-way bookshelf speaker. Second rear-firing tweeter of a different construction. Retailed for $600 a pair.
Woofers are part number 1RD0002-2 and are 10" driver used in: RSP-910 sub-woofer, as well as RSF-1000 Seven-speaker, four-way, dual-woofer top-of-the-line speakers that retailed for $2,500 a pair. Frequency response down to 30Hz. Sub-woofer retailed for $549.
Mid-ranges are part number 1RD0008-2 and are 4" sealed back drivers used in: RSF-1000 Seven-speaker, four-way, dual-woofer top-of-the-line speakers that retailed for $2,500 a pair.
Please keep stopping by from time to time to see what I've been up to. Keep listening to that music! I do!
Scott
