Need help/guidance to make cabinets for GR Research X-ls encore kit

[magma]

I agree.


I disagree.


Joshua, if that were true, plywood would be already be conforming to the CLD principle. But it does not. The damping layer should be some sort of a viscoelastic material.

If I really needed a Q&D CLD solution, I'd layer 18mm MDF with 5mm MDF [5mm on the inside of the cab] with the thinnest rubber sheet I can find as the damping layer between the 2 MDF layers. Any shop that sells baby products sells rubber sheets - it is actually fine fabric sprayed with rubber. Should work fine. Hell, lets go anal and layer three 5mm layers with the rubber sheet between the 3 layers. I bet it would be killer!!!.
Bibin, you want to try this for Amit's cabs?

sir

i disagree

plywood cannot be compared to a multilayer MDF joint with fevicol

plywood rings because it is not evenly packed as MDF is
Plywood may be heavier but the non uniform density isisnt exactly good for a speaker build

though there are builds with plywood
many have tuned the speaker to work with plywood

Many manufacturers infact design the box to "ring " along

advised rubber layer between woods panels is not at all adviced

we are building a speaker here
not absorbing vibrations from a machine

only damping is not the game here

remember speaker building is NOT equal to ABSORBING all vibrations

if that were true we wouldn't use wood in the first place

MDF is used because it finds a good balance tonally, structurally and is inert

otherwise one could very well build all aluminium enclosures with rubber lining
Many have tried in vain
Magico does this but in a very differnt way
using composites to get thing right - tonally though - many enthusiasts find them "off"

 

[keith_correa]

IMO, the best box is one which does not contribute ANYTHING sonically by way of artifacts caused by exitation of the material used to build the box. And yes, I believe we should do a lot to prevent this excitation. If it means equating this to absorbing vibrations from a machine, so be it. Everything (within reason) should be done to prevent this.

 

[captrajesh]

We have to use damping material over the tiles to overcome the reflections. The kind of glue (silicon based) used for stick the tile is also important here. This makes the enclosure walls really solid and reduces the vibrations.

Then what is the role of ceramic tiles. If rigidity is what you are seeking, multiple pieces of ceramic tiles would not be of any use here IMO.

 

[magma]

One should remember box design also goes hand in hand in how that box can be tuned

The truth is , an absolutely inert box can be made
simply by having a mould and pouring in concrete
under pressure with one of those GRACO machines



No bracing - no flex - no nothing
All you gotta take care of now are the standing waves
which can be easily dropped by having a curvature in the rear

though this box is highly inert
it sounds tonally crap - or just maybe i couldnt tune it
or maybe the softwares that exist to tune dont exactly work with this construction

so maybe a stone box would satisfy " no vibrations" but the problem is there are hardly any helpful devices that will allow you to tune this
Tuning with all the existing softwares doesnt exactly work out

 

[keith_correa]

You are not tuning just the box alone, you are tuning the box for a driver. And the material used to create the enclosure should not matter to the software used. No software assumes that you are using inert material or material that will resonate.

I have a friend who likes his speakers made of particleboard. He likes the "sound" of the board and thinks MDF is too dense and does not contribute enough to the sound. His ears like it. Who am I to try to convert him. In this case, likewise.

 

[quad]

This is an oft referred BBC paper by Harwood etc on cabinet materials -

http://diy-audio.narod.ru/litr/1977-03.pdf

 

[magma]

You are not tuning just the box alone, you are tuning the box for a driver. And the material used to create the enclosure should not matter to the software used. No software assumes that you are using inert material or material that will resonate.

this is correct theoretically

but doesnt work practically
i have tried with an aluminium enclosure and a concrete one - i dont find them sounding right

well its possible they do sound right - but i dont like the way they sound
the same enclosure made with MDF using the same dimns and software sounded better to me

BTW that particle board thing is not a ONE off
i know a coupe guys who like particle board over MDF
the problem is the durability and their wear in humid climates

 

[AmitKumar]

Update:

Over last few days i spoke to Esteemed FMs GeorgeO, OMishra and Manniraj. They gave good amount of motivation to start this build up of the cabinets. I moved around in our area checking with few carpentars for the cabinet work and checking the MDF shops to check the MDF prices and the possibbilty of buying half sheet of MDF and DEcorative Ply( 4 mm Veneer).

Finally i made a visit to one of the oldest and prestigious plywood shop yesterday. It is called Balaji Glass and Plywoods, the same is located on Infantry Road. Most of the people in Bangalore would have heard the name of this place i believe. The setup which looked medium sized turned onto a massive set up of glass/plywood/veneer. I was surprised to see such a huge setup in the middle of the city. People at Balaji Plywoods were generous enough to give me half sheet of 18mm mdf and a half sheet of mohagny colour 4mm veneer(Decorative Ply)

Two Carpentars near my home has agreed to make up a part of the job. one of them will make the holes and another guy has agreed to make the cabinets. I am yet to buy the dampening materials. Pls guide me about the dampening material to be used and from where i could buy the same.

 

[exljp]

Bitumen sheets available in hardware shops. I got mine from a shop (basement) at Madiwala, opposite to Iyappa temple on Hosur Road.
See my build here. This is the floor stander design which Danny mentioned in page 1 of this thread
http://www.hifivision.com/diy/34927-gr-reasearch-x-ls-encore-floor-stander.html

 

[AmitKumar]

Bitumen sheets available in hardware shops. I got mine from a shop (basement) at Madiwala, opposite to Iyappa temple on Hosur Road.
See my build here. This is the floor stander design which Danny mentioned in page 1 of this thread
http://www.hifivision.com/diy/34927-gr-reasearch-x-ls-encore-floor-stander.html

Thanks a lot for your response on this.

I saw your build up thread, your speakers have come up well.

Also wanted to know if the bitumen sheet you used is a self adhesive one or some other type. It will be a great help if you could share the name of the shop and the name/brand of actual product.

Thanks in advance, Amit

 

[exljp]

Bitumen sheets are heated and pasted. I used a hair dryer to heat the sheets . I dont recall the brand, let me check and get back to you.

Thanks a lot for your response on this.

I saw your build up thread, your speakers have come up well.

Also wanted to know if the bitumen sheet you used is a self adhesive one or some other type. It will be a great help if you could share the name of the shop and the name/brand of actual product.

Thanks in advance, Amit

 

[exljp]

The brand says STP Shalimar

Bitumen sheets are heated and pasted. I used a hair dryer to heat the sheets . I dont recall the brand, let me check and get back to you.