Would you like to read something audio related for a change? Are there any other forum members who have SDA's? If so, do you like tweaks?
One good thing leads to another with SDA's. MSP's recommendation for replacing the stock foam speaker seals with Mortite caulking cord is given in the first post in this thread.
Ok, since the Mortite recommendation came from a credible source, I got some. I also got some speaker seal tape sold by Parts Express and some vinyl foam weather strip tape from Home Depot to do a mini shootout.
Left to right: Parts Express speaker gasketing tape, Mortite caulking cord, Frost King
3/8" wide x 3/16" thick vinyl foam weather strip.
The stock seals were replaced by Mortite on the right speaker and compared to the left. My preamp was switched to mono operation and the balance control was shifted left and right.
A 90 foot roll cost $4.98, inclusive of tax. The roll was 11.25 feet long and came preformed into eight 1/8 "cords" that were stuck together side by side. The cords are a little more than 1/8th inch in diameter. Most of the time, the individual cords were easy to peel apart. In cases where the separation didn't come easy, the putty was easily cut with scissors. Due to the elastic nature of the putty, cutting with a knife is not as efficient.
If you are of the "a little is good, but more is better" mindset, don't use more than one cord of caulk around a driver, tweeter or passive radiator perimeter. For the RD0198 tweeters, I placed the caulking cord just inside of the plastic rim around the underside. Using more than a single cord will make it difficult to screw down the driver and the added thickness will decouple the driver from the baffle.
I thought Mortite would be stiff and it would make it difficult to screw the divers back flush with the baffle, but it was very soft and flexible. It's consistency was similar to soft modeling clay and it was very easy to work with. It has moderate adhesion to wood, metal, plastic, and masonry, but does not stick to fingers. It is very easy to peel off of surfaces it is adhered to.
Mortite made a better air seal than the stock foam seals. The drivers took almost 3 seconds to float back down after the passive radiator was pushed in. It takes 2 seconds with the stock seals.
After application, the mids and highs were clearer. The bass seemed to be lower in sound level, but had increased in clarity and weight. In other words, my ears heard "less" bass, but the tactile sensations, vibrations and rumbles coming through the floor, furniture, and air were heavier. Growling sounds made by bass instruments were a bit lower pitched and more well defined. I was hearing cleaner, more articulate bass (less resonance) due to the Mortite having a firmer grip on the driver rim. This, coupled with the previous foam tape application to the baskets, drastically reduced the vibrational energy that was coloring the vibrations of the driver cones, tweeters, and passive radiator.
The bass instruments were apparently much faster. On songs where the activity of the drummer was previously blended into the background, the drum kit now called attention to itself because of the increased speed and clarity. It was somewhat annoying at first because there now seemed to be a spotlight on the drum kit. This spotlighting faded away as my ears got more accustomed to the more accurate tonal balance. The next day, the bass spotlighting effect was gone and everything was tonally cohesive.
Another thing I noticed was that is was much easier to follow the drummer's hands as he was playing various parts of the drum kit. The drum kit and other heavy electronic percussion sounds were also pushed further back in the sound stage on some recordings.
Parts Express Speaker Gasketing Tape
Mortite was clearly superior to the stock seals, so it was left in place on the right speaker and the left speaker's stock seals were replaced with the Parts Express gasketing tape.
A 50 foot roll of this tape cost $14.45 ($5.49 for the tape and $8.97 for shipping). This stuff was bad...awful...horrible. It has the consistency of cork and it acoustically decoupled the drivers from the cabinet. It would only compress a little, therefore the drivers would not screw down flush with the baffle. It sounded like I had inserted an equalizer and filtered out the bass. The highs took on an edgy, "electronic" sound. The monoliths hated it...but your speakers..and ears...might like it. Different strokes and all that.;)
This tape made a slightly better air seal than the stock seals. The drivers took a little over 2 seconds to float back down after the passive radiator was pushed in.
Frost King Vinyl Foam Weatherseal
The Parts Express tape was hastily removed from the left speaker and replaced with Frost King vinyl foam weather strip tape. The cost, inclusive of tax, was $1.95 for a 17 foot roll.
This foam was 3/16" thick and was very soft and would compress down to paper thinness. It was a softer foam than the stock seals. It sounded like the stock seals from the midrange and up, but it didn't couple the drivers to the baffle as well as the stock seals, therefore the bass sounded a little slower, less defined and had less tactile impact than the stock seals. Its bass performance was far, far below that of the Mortite.
This tape provided an air seal comparable to the stock seals. The drivers took 2 seconds to float back down after the passive radiator was pushed in.
I replaced the left speaker's stock seals with Mortite and proceeded to get acquainted with my 1.2TL's "new sound". I had to get used to the "new sound" the same way I had to get used to subwoofers that produced clean, ultra low distortion, minimum resonance bass. It took me about 45 minutes to get re-acclimated.:)
Now, don't get alarmed when it seems like some of your bass has gone away. Give it some time. Close your eyes and concentrate on the bass vibes flowing through the room...and through you...go back and forth between the Mortite treated speaker and the stock seals speaker. If you still prefer the sound of the stock seals by the next day, then by all means reinstall them. It's your world.:)
For those who find new, more thunderous bass and enhanced detail from top to bottom, who would have thought that window caulk would contribute to Such Good Sound?
Enjoy your retirement...you old bass stealing thieves!
The monoliths are glad to finally be rid of those parasitic seals.:)