Reinforcing Side Panels to Reduce Resonances

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Early B.

Reinforcing Side Panels to Reduce Resonances
« on: 1 May 2019, 11:30 pm »
To reduce cabinet resonances for those of us who already built our GR Research servo subs, it may be helpful to add MDF, wood, tile, or stone panels to the sides of our cabinets. I'm willing to try it, but I have two questions:

1. How would you recommend appending the material to the sides of the cabinets? For instance, if MDF, is glue sufficient? If so, which kind of glue? Will glue or epoxy (or whatever) work for stone or tile???

2. What ideas come to mind about making the side panels decorative? Any particular colors, shapes, etc.? Any sample images? For instance, my friend has his servo subs housed in this elegant cabinet:


Of course, my subs are much more DIYish with black Duratex paint, but the side pattern on these are pretty cool.

Elizabeth

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Re: Reinforcing Side Panels to Reduce Resonances
« Reply #1 on: 2 May 2019, 12:24 am »
My suggestion would be to glue and use carriage bolts and using a tensioning device to tension the two sides into each other. This would not be a good idea if it is hard to get back inside the cabinet. Or if you do not want any added holes.. Plus you would need to be certain the tensioning method would work before doing any work to the cabinet.
Another way glue and countersunk screws (then cover/cap the screw heads) to lock the added siding to the base side. I would not try to use stone unless you are really really good working with it.

emailtim

Re: Reinforcing Side Panels to Reduce Resonances
« Reply #2 on: 2 May 2019, 07:19 am »
You may have to remove the Duratex paint to get a good adhesive/glue seal.

This member clad the outside of his H-Frames in bamboo flooring.

https://www.audiocircle.com/index.php?topic=78791.msg752907#msg752907


ThePriest

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Re: Reinforcing Side Panels to Reduce Resonances
« Reply #3 on: 2 May 2019, 07:28 am »
I have glued 3 mm steel sheets (not stainless) to the sides of my subs.
Before glueing, the sheets were lying in a mix of sand and acetic acid, in order to make them look rusty.
I used a non-hardening marine glue, and 2 mm plastic spacers, to achieve a uniform (or near) glue layer thickness.
Top plate was cut with the extra 2x2 mm glue layers on the sides in mind.


Afterwards, I used beeswax to 'seal' the rust. This makes the nice orange rusty colours more brown, but it still looks nice.

I just finished glueing last week, and have not had time to listen properly. A/B tests wil be difficult...

/ThePriest

Peter J

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Re: Reinforcing Side Panels to Reduce Resonances
« Reply #4 on: 2 May 2019, 03:12 pm »
Early, I  was recently made aware of this stuff:

https://www.zoro.com/search?q=GE%20Iron%20Grip&kw11&gclid=CjwKCAjwqqrmBRAAEiwAdpDXtMZqgdR1nT5Aee2KbPZOJkGKpP0F4HewEKbZKJydFrVPXB2e8VD6whoCHQEQAvD_BwE&gclsrc=aw.ds

While I'm not a big fan of silicone caulk as an adhesive, it seems like it would be ideally suited to the task at hand. Intuitively it would seem better than something like PL Premium which I use and like a lot. The bond would accommodate some differential movement and if near 100% coverage, might also provide some minor damping of its own.


No experience to back up what amounts to intuitive conjecture on my part, so take it with whatever salt you deem necessary.

Tyson

Re: Reinforcing Side Panels to Reduce Resonances
« Reply #5 on: 2 May 2019, 04:03 pm »
I have glued 3 mm steel sheets (not stainless) to the sides of my subs.
Before glueing, the sheets were lying in a mix of sand and acetic acid, in order to make them look rusty.
I used a non-hardening marine glue, and 2 mm plastic spacers, to achieve a uniform (or near) glue layer thickness.
Top plate was cut with the extra 2x2 mm glue layers on the sides in mind.


Afterwards, I used beeswax to 'seal' the rust. This makes the nice orange rusty colours more brown, but it still looks nice.

I just finished glueing last week, and have not had time to listen properly. A/B tests wil be difficult...

/ThePriest


Those look amazing!!

Early B.

Re: Reinforcing Side Panels to Reduce Resonances
« Reply #6 on: 2 May 2019, 04:18 pm »


This is ridiculously cool!!! Love the look.

One thing I like about your subs is no overhang on the top plate. My subs look like pedestals. 

emailtim

Re: Reinforcing Side Panels to Reduce Resonances
« Reply #7 on: 2 May 2019, 04:35 pm »
I have glued 3 mm steel sheets (not stainless) to the sides of my subs.
Before glueing, the sheets were lying in a mix of sand and acetic acid, in order to make them look rusty.
I used a non-hardening marine glue, and 2 mm plastic spacers, to achieve a uniform (or near) glue layer thickness.
Top plate was cut with the extra 2x2 mm glue layers on the sides in mind.


Afterwards, I used beeswax to 'seal' the rust. This makes the nice orange rusty colours more brown, but it still looks nice.

I just finished glueing last week, and have not had time to listen properly. A/B tests wil be difficult...

/ThePriest

Outstanding.  You just invented the MadMax Dynamat Heavy Metal Extreme edition.  What non-drying marine glue did you use ?

ThePriest

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Re: Reinforcing Side Panels to Reduce Resonances
« Reply #8 on: 3 May 2019, 07:47 am »
Outstanding.  You just invented the MadMax Dynamat Heavy Metal Extreme edition.  What non-drying marine glue did you use ?

Thanks for the kind words, and for correcting the picture. I am very satisfied with the 'industrial' look on them. The main speakers match, of course. And everything is open baffle.

I used a glue called SikaFlex 291, but I would think any non-hardening glue would do. Look for glues for use in boats, for example.
I wanted one that stays flexible, in order to soak up vibrations.

/ThePriest

Captainhemo

Re: Reinforcing Side Panels to Reduce Resonances
« Reply #9 on: 3 May 2019, 04:20 pm »
Pretty dam cool  man , nicely done  8)

jay

grimace

Re: Reinforcing Side Panels to Reduce Resonances
« Reply #10 on: 6 May 2019, 08:32 pm »
I have glued 3 mm steel sheets (not stainless) to the sides of my subs.
Before glueing, the sheets were lying in a mix of sand and acetic acid, in order to make them look rusty.
I used a non-hardening marine glue, and 2 mm plastic spacers, to achieve a uniform (or near) glue layer thickness.
Top plate was cut with the extra 2x2 mm glue layers on the sides in mind.


Afterwards, I used beeswax to 'seal' the rust. This makes the nice orange rusty colours more brown, but it still looks nice.


I just finished glueing last week, and have not had time to listen properly. A/B tests wil be difficult...

/ThePriest

Amazing look.  Would you be wiling to share some more details on how you did this?

ThePriest

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Re: Reinforcing Side Panels to Reduce Resonances
« Reply #11 on: 8 May 2019, 01:18 pm »
Amazing look.  Would you be wiling to share some more details on how you did this?

Sure. Is there anything in particular you are interested in?

The top plate is cut 10 mm wider than I built the plywood cabinet, to allow for 2 mm glue and 3 mm steel on each side.
As the subs are quite heavy even without the steel, and I had no extra help the days I had time to attach the steel plates, I used double sided tape to affix 32 little plastic spacers to the standing subs.
They are a fixed thickness (2 mm) and I cut them into smaller parts, as they have no other role than to keep the steel plate away from the wood when I glue.
They I distributed a thick layer of glue, and clamped the steel plate on, evening the clamping force with plywood boards.
I did one steel plate at a time, allowing at least a day for settling.

The picture  below is taken before I used the plywood boards.




(how do I rotate pictures???  :duh:)

emailtim

Re: Reinforcing Side Panels to Reduce Resonances
« Reply #12 on: 9 May 2019, 01:28 am »
...



(how do I rotate pictures???  :duh:)

grimace

Re: Reinforcing Side Panels to Reduce Resonances
« Reply #13 on: 9 May 2019, 11:27 am »
Sure. Is there anything in particular you are interested in?

The top plate is cut 10 mm wider than I built the plywood cabinet, to allow for 2 mm glue and 3 mm steel on each side.
As the subs are quite heavy even without the steel, and I had no extra help the days I had time to attach the steel plates, I used double sided tape to affix 32 little plastic spacers to the standing subs.
They are a fixed thickness (2 mm) and I cut them into smaller parts, as they have no other role than to keep the steel plate away from the wood when I glue.
They I distributed a thick layer of glue, and clamped the steel plate on, evening the clamping force with plywood boards.
I did one steel plate at a time, allowing at least a day for settling.

The picture  below is taken before I used the plywood boards.




(how do I rotate pictures???  :duh:)

Thank you - cool process & I appreciate you sharing your technique.  How did you age it in the sand/acid?  And I like the saw marks/aged look of your cabinet too.  What are they made out of?  Basically, I'm wanting to clone what you did if you don't mind?  This look would go perfect in my home office. 

ThePriest

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Re: Reinforcing Side Panels to Reduce Resonances
« Reply #14 on: 10 May 2019, 07:43 am »
Thank you - cool process & I appreciate you sharing your technique.  How did you age it in the sand/acid?  And I like the saw marks/aged look of your cabinet too.  What are they made out of?  Basically, I'm wanting to clone what you did if you don't mind?  This look would go perfect in my home office.
You are welcome to clone.

I'm afraid the saw marks on the wooden frame is a result of camera resolution/dithering. No saw marks are visible.
The frame is made of 21mm Birch ply, stained in a 'black' nuance. I used a water/powder based stain.
This was in order to minimise the contrast to the rusty look, and still see the layered plywood. I still need to apply bees wax to the frames.

Regarding the rust, I had the steel sheets laying outside, and you just some sand on them, then acetic acid, and stir... Let them lie for a week and check if the degree of rust is how you like it. If not, you just let them lie longer  :)

You need to dispose of the acid filled sand in a proper way, of course.

/ThePriest

eichlerera1

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Re: Reinforcing Side Panels to Reduce Resonances
« Reply #15 on: 10 May 2019, 11:18 am »
I have glued 3 mm steel sheets (not stainless) to the sides of my subs.
Before glueing, the sheets were lying in a mix of sand and acetic acid, in order to make them look rusty.
I used a non-hardening marine glue, and 2 mm plastic spacers, to achieve a uniform (or near) glue layer thickness.
Top plate was cut with the extra 2x2 mm glue layers on the sides in mind.


Afterwards, I used beeswax to 'seal' the rust. This makes the nice orange rusty colours more brown, but it still looks nice.

I just finished glueing last week, and have not had time to listen properly. A/B tests wil be difficult...

/ThePriest

Aren't you concerned that these metal clad speakers will ring?

Paul Galli

ThePriest

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Re: Reinforcing Side Panels to Reduce Resonances
« Reply #16 on: 11 May 2019, 08:09 am »
In a word: No.
That is why I used a non-hardening glue in a 2 mm thickness. Remember, there is a lot of glue underneath.
There are no free-hanging, undampened metal hanging around to vibrate.
The weight of each sub has increased from around 50 kilos to 70 kilos.
Before adding the metal sheet, I could easily feel the frame vibrating when playing at louder volumes.
Now, not so much.

The main speaker is inspired by Dannys Line Force speaker, and it _does_ have an unbraced area, the wing:



It is constructed much the same way. Drivers are mounted in a 30 mm birch ply sheet, which is glued (again 2 mm layer) to a 4 mm steel frame.
The drivers only play from ~250 Hz, so there is not a lot of kinetic energy, compared to the subs.
I do not experience any ringing, but future tweaking could be damping of the wing.

Have a nice weekend.

The Priest

grimace

Re: Reinforcing Side Panels to Reduce Resonances
« Reply #17 on: 11 May 2019, 03:41 pm »
You are welcome to clone.

I'm afraid the saw marks on the wooden frame is a result of camera resolution/dithering. No saw marks are visible.
The frame is made of 21mm Birch ply, stained in a 'black' nuance. I used a water/powder based stain.
This was in order to minimise the contrast to the rusty look, and still see the layered plywood. I still need to apply bees wax to the frames.

Regarding the rust, I had the steel sheets laying outside, and you just some sand on them, then acetic acid, and stir... Let them lie for a week and check if the degree of rust is how you like it. If not, you just let them lie longer  :)

You need to dispose of the acid filled sand in a proper way, of course.

/ThePriest

Thank you, this is very helpful.