Plate Reverb pre EQ Issue

[RoadrunnerOZ]

It churns in the stomach when I see that mechanical damper ...

Yeah - the aim being to have the damping material cover a range of proximity to apply a suitable amount of air damping to give a good range of reverb time control - it never actually comes into contact with the reverberation plate. The effectiveness of the damper will be governed by the sound absorption material used as a face. Asbestos used in the EMT obviously not a great plan these days and also unavailable.
Thereis compressed glass fibre board that has cloth facing which is extremely effective - it can be glued to a thin sheet of MDF for additional stability - this compressed glass fibre board is rigid and easily cut with a box cutter. This can be mounted in U section aluminium channel framing. It comes in various thicknesses and densities. I use the 96Kg/cuM compressed glass fibre boards as sound absorption material inside studio wall construction - this is available in 13mm and 25mm with cloth facing on one side - the 13mm then sandwiched to 6mm MDF backing with the cloth side facing out. You can glue this with spray contact adhesive and seal the cut edges of the glass board with spray contact adhesive as well. These combined would slot into 19mm aluminium channel framing or you could use L section angle aluminium screwed to the MDF. You need to seal the glass fibre edges so fibres don’t fly around and get into everything.
The mechanical traveller assembly brackets would need to be fastened to the plate framework to mount and control the position of the damper.

 

[Sounddesign84]

You need to seal the glass fibre edges so fibres don’t fly around and get into everything.

How to seal the glass fibre edges? I intended to have the plate in the bedroom =) So rather I dont breathe in glass fiber in my sleep ...

The mechanical traveller assembly brackets would need to be fastened to the plate framework to mount and control the position of the damper.

Where can I look more closely on the mechanical traveller?

Its really something that the damper does not touch the plate!

 

[c1184701]

Yeah - the aim being to have the damping material cover a range of proximity to apply a suitable amount of air damping to give a good range of reverb time control - it never actually comes into contact with the reverberation plate. The effectiveness of the damper will be governed by the sound absorption material used as a face. Asbestos used in the EMT obviously not a great plan these days and also unavailable.
Thereis compressed glass fibre board that has cloth facing which is extremely effective - it can be glued to a thin sheet of MDF for additional stability - this compressed glass fibre board is rigid and easily cut with a box cutter. This can be mounted in U section aluminium channel framing. It comes in various thicknesses and densities. I use the 96Kg/cuM compressed glass fibre boards as sound absorption material inside studio wall construction - this is available in 13mm and 25mm with cloth facing on one side - the 13mm then sandwiched to 6mm MDF backing with the cloth side facing out. You can glue this with spray contact adhesive and seal the cut edges of the glass board with spray contact adhesive as well. These combined would slot into 19mm aluminium channel framing or you could use L section angle aluminium screwed to the MDF. You need to seal the glass fibre edges so fibres don’t fly around and get into everything.
The mechanical traveller assembly brackets would need to be fastened to the plate framework to mount and control the position of the damper.

Great info thanks! Could you post a link or product name for these fabric-faced fibreglass boards please?

 

[Sounddesign84]

Regarding the quality of electricity I meant more the condition of the sockets actually.

I was thinking maybe there will be a groundloop if the sockets are old and so can have some deficiency/worn down components inside of them...

 

[RoadrunnerOZ]

The glue I use for adhering the compressed glass boards to backing is a spray contact adhesive by Sika.

How to seal the glass fibre edges?

I actually said how earlier in my post:

You can glue this with spray contact adhesive and seal the cut edges of the glass board with spray contact adhesive as well

So when you glue the back of the glass fibre board with it face down on a disposable dropsheet you can just spray the edges at the same time - then spray the MDF - once the glue has tacked off you carefully place the MDF onto the glass board.
But alternatively I would suggest using electronic circuit board spray lacquer for the edges (after glueing the sheets together) as this is not sticky to handle once dry.

Where can I Look more closely to the mechanical traveller?

Have a look at the construction diagram I posted in post #101 - it’s just four swiveling U channel brackets with a handle on one of the two axles. The brackets and pointer/handle are locked to threaded rods using nuts - these threaded rods are fitted to the reverb plate chassis at the four legs that stick out at right angles, the other ends of these brackets go to the smooth rods connected to the damper plate assembly. You need to have a good look at the construction diagram to get your head around how this all works. There’s quite a bit of construction and the whole thing needs to be strong

 

[RoadrunnerOZ]

Great info thanks! Could you post a link or product name for these fabric-faced fibreglass boards please?

You’d need to google to get the local products in your area - all I have is our local suppliers who make and sell it in Australia like Bradford Quietel 130Kg/cuM 13mm and 25mm and Fletcher Pink Partition HD 168Kg/cuM 13mm and 96Kg/cuM 25mm (may be superseded). Some sizes available with cloth facing - usually the 25mm and above.
If the thinner compressed board is not available cloth faced fabric can be stretched over the glass board and stapled to the back board - I have made panels like this in studios where the client wanted their own choice of fabric. Thin T shirt jersey fabric works really well.
For the application of a damper there are other semi-rigid acoustic panels made from other materials easier to handle than glass fibre - there are also lots of companies selling decorative acoustic absorption panels with a range of coloured fabric finishes.

If you just google high density glass wool acoustic panels you should get something local to you

 

[Sounddesign84]

The glue I use for adhering the compressed glass boards to backing is a spray contact adhesive by Sika.

I actually said how earlier in my post:

So when you glue the back of the glass fibre board with it face down on a disposable dropsheet you can just spray the edges at the same time - then spray the MDF - once the glue has tacked off you carefully place the MDF onto the glass board.
But alternatively I would suggest using electronic circuit board spray lacquer for the edges (after glueing the sheets together) as this is not sticky to handle once dry.

Have a look at the construction diagram I posted in post #101 - it’s just four swiveling U channel brackets with a handle on one of the two axles. The brackets and pointer/handle are locked to threaded rods using nuts - these threaded rods are fitted to the reverb plate chassis at the four legs that stick out at right angles, the other ends of these brackets go to the smooth rods connected to the damper plate assembly. You need to have a good look at the construction diagram to get your head around how this all works. There’s quite a bit of construction and the whole thing needs to be strong

"You can glue this with spray contact adhesive and seal the cut edges of the glass board with spray contact adhesive as well"

-Like when you learn to dance foxtrott and then there is a doublestep, so naturally you will step on a foot and after maybe fall over it to =)


I will look in to post #101