Steel Plates!

[Solderburn]

Hi ,

I saw some advice on the internet about taking out the wadding to your speakers (well,Goodmans Magnum Ks to be exact) and replacing it with “steel plates”- that’s lining the cabinet with steel plates!

I am intrigued to know what the benefit of “steel plates” would bring to a speaker like the Goodmans because I own a pair, and would consider dabbling if it were to improve the sound.

Any ideas to what the science is behind this recommendation?

Thanks


Dean

 

[Silent Screamer]

You would only want it on the front baffle. The theory is that it stiffens up the baffle.

 

[richie00boy]

Did they not say to replace the wadding after fitting plates? They perform totally different functions.

 

[Solderburn]

You would only want it on the front baffle

.

There isn't much space on the front

The theory is that it stiffens up the baffle

the front is about 1 inch thick ply and the sides would be the thinnest,so I guess I would apply them to the sides to achieve more strength?

Did they not say to replace the wadding after fitting plates? They perform totally different functions

The wadding is "not" to be replaced.
what is the purpose of the wadding?
In the Goodmans it is very thick sponge type http://i50.tinypic.com/16a428i.jpg

Thanks for the replies

Dean

 

[Silent Screamer]

Check this thread out for the only use I know http://www.diyaudio.com/forums/mult...e-aligned-constrained-layer-construction.html

 

[richie00boy]

The foam absorbs the sound splashing around inside the box. Adding steel panels will make it splash around even more as it's more reflective than the wood. Properly attached steel panels (firmly glued all over) will strengthen the walls and reduce cabinet vibrations. Poorly attached steel panels (just screwed at corners) will just weigh the box down.

So you can see that you need both.

There is a lot of nonsense on the internet regarding modifications!

 

[Solderburn]

Check this thread out for the only use I know http://www.diyaudio.com/forums/mult...e-aligned-constrained-layer-construction.html

Thanks for the link-interesting stuff, and I can see what mean now "wow"! I don't think I'll be doing that with the Goodmans it's way out of my budget.

The foam absorbs the sound splashing around inside the box. Adding steel panels will make it splash around even more as it's more reflective than the wood. Properly attached steel panels (firmly glued all over) will strengthen the walls and reduce cabinet vibrations. Poorly attached steel panels (just screwed at corners) will just weigh the box down.

So you can see that you need both.

That "actually" makes sense to me! I would glue the plates to the both sides (internally) of the speaker cabinet,I guess there is no harm in strengthening the cabinet?.I can always add some sort of wadding later to experiment.Is there better stuff than the foam sponge that's already inside the Goodmans?

There is a lot of nonsense on the internet regarding modifications

I know! that's why I've decided to come here because I feel this is probably the most balanced forum on the web.

Thank you both for your contribution .

I will post my little project and findings in due coarse.

Cheers

Dean

 

[Charles Darwin]

Without the foam/wadding some of the sound that splashes around inside the box will find its way to the outside through the cones leading to comb filtering/smearing of the original signal.

 

[Silent Screamer]

Without the foam/wadding some of the sound that splashes around inside the box will find its way to the outside through the cones leading to comb filtering/smearing of the original signal.

Hmmm had never given the filler that much thought, but definitely is food for thought.

 

[Solderburn]

Without the foam/wadding some of the sound that splashes around inside the box will find its way to the outside through the cones leading to comb filtering/smearing of the original signal.

Thank you for your input.

I've been running the speakers today without the sponge/foam and in someways they are better, but there's something not quite right,I guess it must be what you're describing ,I've never heard of "comb filtering" but there's definitely a lack of cohesion (comb filtering?) ,I'm going to leave out the foam and source some steel plate to see if that will improve things.

I've done some research on the Goodmans Magnum Ks and apparently they were designed to be "air tight" so I'd better make sure that I seal-up the speakers when I finish.Does anyone know what I can use to make an airtight gasket,Silicone maybe?

thanks

Dean

 

[Bare]

As suggestion: rather than using steel which is a PITA to mate/use with wood.
Perhaps line your cabinets with Self adhesive SBS rubber membrane.
Found at (real) Construction Supply houses as Roofing Membrane, for affordable coin.
Use the 5/6 mm thick variety.
That will dampen the woodwork More than a steel lining that one can reasonably DIY.

 

[Cal Weldon]

You can use lead sheet in addition to wadding but you still want the damping of each. They work together, not in place of one another. Steel? Not sure what that would achieve other than what's been mentioned.

 

[Solderburn]

OK guys,thanks for that,it's given me food for thought

 

[Charles Darwin]

Instead of lead sheet you could use something like this stuff:
Acoustistop 1.2Mx1M Sound Blocking Sheet at Studiospares

It'll be easier to work with and less poisonous than lead.

 

[Cal Weldon]

I like to lick the lead before I install it in the cabinets. Nothing like the taste of lead in the morning.

 

[Solderburn]

Instead of lead sheet you could use something like this stuff:
Acoustistop 1.2Mx1M Sound Blocking Sheet at Studiospares

It'll be easier to work with and less poisonous than lead.

Thank you for the advice & link CD, that's something I will definitely consider.

Cal Weldon =I like to lick the lead before I install it in the cabinets. Nothing like the taste of lead in the morning.

Not sure where you're going with that Cal but I guess it takes all sorts


All the best

Dean