SL3 / Legacy model mods and other useless information for all ML speakers

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Gordon Gray

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Hi folks,

This mod I am about to describe is applicable to most if not all legacy models assuming you can access (get inside of) the woofer module. This will require removing and reinstalling the rails, woofer grills and bass driver and should take a couple of hours. Cost is about $100 for the material.

The basic premise is to dampen the inside of the module as well as the driver and requires the installation of "RoadKill Sound Dampening Material" manufactured by Stinger Electronics, which is used to dampen vibrations and attenuate road noise in car stereo installations. It comes in sheets with an adhesive backing that you cut to size and "press" into place. The other product that is generally used is Dynamat. However, Road Kill appears to be a more robust (read thicker) product.

MOD NO. 1 / DAMPEN THE INTERIOR OF THE BASS MODULE

Step 1. Disconnect the speaker wires and the AC plug from the back of the speaker. Lay the speaker on its side. Use a rug or whatever so you don't scratch the speaker. Pop off the rails with a rubber mallet. Cushion the rail you will be hitting with the mallet to avoid any marks on the rails. A wash cloth or small towel will work just dandy. Depending on your model, you may have to gently pound "to the left" on the bottom of the rail (assuming the top of the panel is on the left side when on the floor) or "to the right" on the top of the rail. If you try a couple of times in one direction and the rail doesn't move, try the other direction. Once the rails are removed, gently pry the metal mesh covering the woofer module loose. It is being held in place by a double sided sticky foam strip. I would suggest that you order some of this material from ML prior to doing this mod (or find out what they use and get it from your local hardware store) since the foam strip will adhere to the screen or speaker cabinet and will likely need to be replaced once you reinstall the grill.

Step 2. Remove the screws that attach the driver to the speaker. Pull the driver out of the module so you can see the two wires connected to the driver. Detach the wires from the posts. Make sure you mark positive and negative leads on the wire and the posts. Remove the driver from the cabinet as well as the batting material from the module.

Step 3. Install the RK product to all inside surfaces of the module as well as the metal exterior and spoke ribbing of the driver basket. Cut to fit. The only surface I didn't install the RK on was the surface upon which the crossover is mounted. You may want to install RK on this side also without interfering with the crossover.

Step 4. Reconnect the wires (remember polarity) and reinstall the batting. You may want to gently "pinch" the metal connection down once your install the clip to the post to ensure a tight connection. Reattach the driver to the front of the module. Be careful to not over tighten. The module material used by ML is not wood but a composite material of some sort. It is somewhat soft and you may "strip" the existing hole if you tighten the screws down to much.

Step 5. Reinstall the grill using the double sided tape. Make sure to remove any of the old tape so that the grill is uniformly attached to the module.

Step 6. Reinstall the rails. Your done. Repeat on the other speaker.

WHAT TO EXPECT.

A tighter, quicker, better defined low end with less bloat. Most notable in the mid bass area. Better sonic integration between the panel and the woofer. More musical.

As an aside, do the "knuckle" pounding test on the module before and after the install. That will give you some idea of the effectiveness of the new dampening material.

MOD NO. 2 / STABILIZE THE COUPLING BETWEEN THE FLOOR AND YOUR SPEAKER. ADJUST THE PANEL RAKE (VERTICAL) ANGLE

The way your speaker couples with the floor is a critical element to optimizing performance and eliminate speaker / floor vibrations. If you are using those thread plastic feet, ditch them ASAP. My advice also applies to the factory supplied spikes.

Purchase the most robust spike / cone assembly you can buy. Remember to verify the thread size before purchasing. Also, remember to order the correct depth of the penetrating spike so you can get to your subfloor for those who have carpeting. If you are placing on a wood floor, I highly advise the use of a decoupler, between the spike and the floor. I have used the BDR pucks on my Summits with great success. If done correctly, you should hear / feel minimal deep bass coming through the floor from the speaker.

On the SL3, I used the Mapleshade brass cones but there are many other products available. I also bought a "taller" cone for the rear versus the front. This enabled me to adjust the panel rake angle closer to vertical. The benefits of this can be quite astounding. With Jason's wonderful replacement spikes, I was able to adjust my rake angle to within 2 degrees of perpendicular.

One note of caution. If you decide to adjust the rake angle, measure and make sure the angle is exactly the same for both panels.

The bottom line is to make spike / floor interface as rigid as possible (carpeted floors) and in the case of wood floors, use the BDR product or equivalent for the last bit of total isolation / vibration attenuation.

Final price will vary depending on the product(s) purchased.

WHAT TO EXPECT

An overall improvement in presentation. Reduction in blurring. Better imaging / dimensionality.

MOD NO. 3 / TRY WEIGHTING THE TOP OF THE BASS MODULE WITH VARYING WEIGHTS

Think of this as the final tuning of the bass output assuming your speakers are otherwise correctly positioned in the room.

You may or may not like the results but give it a try. For the aesthetically minded. I ended up buying some black granite leftovers and had them cut to size. Of course, you can go to Hope Depot to see what they have available.

Remember to attach some padding on the underside of the weight (use stick on rubber tips, etc) so you don't scratch the top of the bass module.

Final price should be minimal. In my part of the world, I go to one of the many creeks / streams in the valley and pick out some nice looking, relatively flat rocks.

WHAT TO EXPECT

Unknown. Try different weights and let you ears tell you what is better.

For those who are not tool users and / or mechanically inclined, don't worry. I'm a total Klutz and was able to do this.

That's it folks. Good luck and Happy Listening.

PM me if you have any questions.

Gordon
 
Gordon, all great mods. Thanks for sharing the detailed steps.

Dampening the interior of the woofer box is indeed a good one, and worth the effort.
 
Gordon, I use archive cardboard boxes full of lead shot on top of my SL3s woofers (your mod #3). Works fine for me.

Guido.
 
Gordon, thanks nice mod, does it matter how thick the sound dampaning material is? I have some at work from a specialist in foam manufacturing company that makes sound proofing foam. Its 25mm thick and heavy. Is this too thick. Thanks
 
Hi Bomber,

The basic idea is to "deaden" any module resonances.

Road Kill is specifically designed to do that with automobile sheet metal and does quite well in this application.

My sense, assuming your product does the same and firmly "adheres" to the inside cabinet, is that more is better.

As you know, many speaker manufacturers go to great lengths to eliminate any cabinet vibrations.

My only question is how it will work with the metal bass driver basket and ribs.

Good luck and tell us what you think after installation.

Gordon
 
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