designdude
New member
I am a new Martin Logan owner with a nice pair of Sequel II's that I refurbished using a lot of knowledge contained on this board. I wanted to share a couple of tweaks that I used that might be helpful – and very easy to implement.
I read a number of threads that discussed the vibration in the steel housing that holds the crossovers and such. (I call this the electronics module). I also read about various solutions including adding weights, etc. I’ve always thought that unwanted vibrations were the bane of high fidelity, so as I did my refurbishing I paid special attention to this module.
The first thing I noticed was that the steel plate is coupled directly to the frame in several locations. Not only is it held in place with 4 screws (with a couple of scrawny pieces of foam tape to “cushion” it – HAH!), but the edges contact the side frame in several places. I believe these contact points transmit vibration from the cabinets to the module. I did several things to decouple these connections.
First, I added a little vinyl trim to the edges of the plate. This is standard door edge trim found at any auto body store. It won’t fit on the sides, but there is plenty of clearance front and back, and on the notches – as shown in the first photo. (This also adds a dampening factor to any resonance this plate may have.)
Second, I replaced the beat up foam on the underside of the coils with new neoprene sponge rubber (weather stripping from Home Depot) and put a layer on the wood braces underneath the module (right beneath where the 4 screws are inserted). This effectively decouples the module from the wood frame in the vertical direction.
Third, I took a pair of 1” diameter neoprene washers with adhesive, cut them in half, and then stuck them to the sides of the cabinets where the modules rest. These fill the small gap between the sides of the modules and the vertical support walls of the panels. This decouples the module from the wood frame in the side to side direction.
These three tweaks can all be implemented by removing the 4 screws that hold the module in place – although it is easier if you remove the moldule completely by disconnecting the panel and woofer wires.
The last tweak – which takes a little more doing – was to add some Dynamat damping material to select areas of the steel plate to deaden it. You have to dis-assemble the boards from the module to install this, and take special care where it goes so as not to interfere with re-assembly.
The final re-assembly is what I call dead solid, you can rap your knuckles on the plate and get a nice solid thunk – no ringing at all. And there is no vibration at all during music playback (although I have yet to put a stethoscope on it).
I hope you all find these tweaks useful. I look forward to your comments.
I read a number of threads that discussed the vibration in the steel housing that holds the crossovers and such. (I call this the electronics module). I also read about various solutions including adding weights, etc. I’ve always thought that unwanted vibrations were the bane of high fidelity, so as I did my refurbishing I paid special attention to this module.
The first thing I noticed was that the steel plate is coupled directly to the frame in several locations. Not only is it held in place with 4 screws (with a couple of scrawny pieces of foam tape to “cushion” it – HAH!), but the edges contact the side frame in several places. I believe these contact points transmit vibration from the cabinets to the module. I did several things to decouple these connections.
First, I added a little vinyl trim to the edges of the plate. This is standard door edge trim found at any auto body store. It won’t fit on the sides, but there is plenty of clearance front and back, and on the notches – as shown in the first photo. (This also adds a dampening factor to any resonance this plate may have.)
Second, I replaced the beat up foam on the underside of the coils with new neoprene sponge rubber (weather stripping from Home Depot) and put a layer on the wood braces underneath the module (right beneath where the 4 screws are inserted). This effectively decouples the module from the wood frame in the vertical direction.
Third, I took a pair of 1” diameter neoprene washers with adhesive, cut them in half, and then stuck them to the sides of the cabinets where the modules rest. These fill the small gap between the sides of the modules and the vertical support walls of the panels. This decouples the module from the wood frame in the side to side direction.
These three tweaks can all be implemented by removing the 4 screws that hold the module in place – although it is easier if you remove the moldule completely by disconnecting the panel and woofer wires.
The last tweak – which takes a little more doing – was to add some Dynamat damping material to select areas of the steel plate to deaden it. You have to dis-assemble the boards from the module to install this, and take special care where it goes so as not to interfere with re-assembly.
The final re-assembly is what I call dead solid, you can rap your knuckles on the plate and get a nice solid thunk – no ringing at all. And there is no vibration at all during music playback (although I have yet to put a stethoscope on it).
I hope you all find these tweaks useful. I look forward to your comments.
