I've only performed one direct cabinet material comparison when I made like-for-like cabinets out of both MDF and birch ply, and I couldn't reliably detect a difference that could be attributed to the cabinet material. However, I should qualify this by saying:
1. I used the higher grade, higher density, moisture/water proof variety of MDF. (It machines up much better than the standard stuff.)
2. The cabinet was only about 40 litres.
3. The cabinets were well braced.
My early cabinet designs used 3/4", but I have since found that 1" is noticeably better. I never really considered why there was such an apparent improvement for what was only a 1/3 increase in thickness, until I realised that doubling the thickness increases the stiffness by a factor of 4 (it might even be 8, I really can't remember). One could obviously go thicker, but I find 1" works very well in most situations and provides a noticeable improvement over 3/4".
My preferred choice is still birch ply; it takes a screw or threaded insert much better (especially near an edge) and glues up much stronger than MDF. The fibrous nature of MDF does not provide the strongest of joints. More recently I have used 3/4" birch ply to construct the cabinet and then laminated it with 1/4" MDF. Originally this was done because I found filling all the screw holes prior to veneering was a bit tedious, but subsequently found it better than using a single 1" layer. I guess this could be something to do with the damping provided by the glue layer. It also means one can be less fussy about the finish of the cabinet during construction and the outer layer of MDF then provides a nice smooth, flat surface ready for either veneering or painting. Another advantage is the option to use pre-veneered MDF without having to worry about any screws or fixings.
Steve
“Better to say nothing and be thought a fool, than open your mouth and remove all doubt”
1. I used the higher grade, higher density, moisture/water proof variety of MDF. (It machines up much better than the standard stuff.)
2. The cabinet was only about 40 litres.
3. The cabinets were well braced.
My early cabinet designs used 3/4", but I have since found that 1" is noticeably better. I never really considered why there was such an apparent improvement for what was only a 1/3 increase in thickness, until I realised that doubling the thickness increases the stiffness by a factor of 4 (it might even be 8, I really can't remember). One could obviously go thicker, but I find 1" works very well in most situations and provides a noticeable improvement over 3/4".
My preferred choice is still birch ply; it takes a screw or threaded insert much better (especially near an edge) and glues up much stronger than MDF. The fibrous nature of MDF does not provide the strongest of joints. More recently I have used 3/4" birch ply to construct the cabinet and then laminated it with 1/4" MDF. Originally this was done because I found filling all the screw holes prior to veneering was a bit tedious, but subsequently found it better than using a single 1" layer. I guess this could be something to do with the damping provided by the glue layer. It also means one can be less fussy about the finish of the cabinet during construction and the outer layer of MDF then provides a nice smooth, flat surface ready for either veneering or painting. Another advantage is the option to use pre-veneered MDF without having to worry about any screws or fixings.
Steve
“Better to say nothing and be thought a fool, than open your mouth and remove all doubt”
The best i have ever used is "Panzerholz". It is a beech plywood made using epoxy resin and sometimes also with kevlar layers.
http://www.ltlewis.co.uk/b15.htm
Another good alternative to wood is cotton reiforced phenolics (bakelite).
/Anders
http://www.ltlewis.co.uk/b15.htm
Another good alternative to wood is cotton reiforced phenolics (bakelite).
/Anders
Hi bappe
Tank armour ... Ye-ha, now we're talking
Looks like real good stuf.
Zero One
Seems you are applying all the medicine.
Do you have any pictures of these speakers?
The main reasom for starting this thread was because I'm thinking of re-building my mid-high cabinets. These are made of soft-wood (pine) glued together to form a 6 cm front baffle that is highly rounded to minimize diffraction, 5 cm sides and 2,5 cm back .... very solid, but maybe a bit too wide. ...... the speaker sounds a bit too up front, and the sound stage a bit too narrow.
At the moment I dont think the cabinet is actually the main problem (if at all) but rather the fact that they are placed very close to the wall. .... have a new project to fix that by reducing the first refledtion by DIY diffusors
At the moment I'm building a sub cab for a Peerless 12" XLS, and decided to go for a 40 x 40 x40 cm cube of two layer 19 mm MDF ..... it feels pretty solid, and will probably end up good
Tank armour ... Ye-ha, now we're talking
Looks like real good stuf.
Zero One
Seems you are applying all the medicine.
Do you have any pictures of these speakers?
The main reasom for starting this thread was because I'm thinking of re-building my mid-high cabinets. These are made of soft-wood (pine) glued together to form a 6 cm front baffle that is highly rounded to minimize diffraction, 5 cm sides and 2,5 cm back .... very solid, but maybe a bit too wide. ...... the speaker sounds a bit too up front, and the sound stage a bit too narrow.
At the moment I dont think the cabinet is actually the main problem (if at all) but rather the fact that they are placed very close to the wall. .... have a new project to fix that by reducing the first refledtion by DIY diffusors
At the moment I'm building a sub cab for a Peerless 12" XLS, and decided to go for a 40 x 40 x40 cm cube of two layer 19 mm MDF ..... it feels pretty solid, and will probably end up good
Attachments
The best speakers I ever heard are those made of composite material with portland cement mixed with particles of very different shapes and densities.
http://wavebourn.com/forum/viewtopic.php?p=21995#p21995
http://wavebourn.com/forum/viewtopic.php?p=21995#p21995
Hi everybody:
I apologize of reading too fast the comments. Probably some one talked about the same I think, and I wasn´t unaware of it.
What I think is that not only the material is important, but also the construction.
Time ago I worked for a company that marketed in Mexico B&W loudspeakers. As a service man I looked into them and I couldn´t see something special in the used material, but ... wow!...
The building of the internal panels of the Matrix enclosures!!!...
What a dedication!
Panels crossed each other to form a matrix of many cells. And the panels were having round openings in each formed cell.
And all the cells were filled with a not too much extrange material. It could be polyestirene foam, or something similar.
I beleive they use untreated MDF for the panels and the external cabinet. I don't beleive they have special treatments for wood, as many says the Stradivarius violins have.
Well, is just a concept about it.
Regards.
Hugo
I apologize of reading too fast the comments. Probably some one talked about the same I think, and I wasn´t unaware of it.
What I think is that not only the material is important, but also the construction.
Time ago I worked for a company that marketed in Mexico B&W loudspeakers. As a service man I looked into them and I couldn´t see something special in the used material, but ... wow!...
The building of the internal panels of the Matrix enclosures!!!...
What a dedication!
Panels crossed each other to form a matrix of many cells. And the panels were having round openings in each formed cell.
And all the cells were filled with a not too much extrange material. It could be polyestirene foam, or something similar.
I beleive they use untreated MDF for the panels and the external cabinet. I don't beleive they have special treatments for wood, as many says the Stradivarius violins have.
Well, is just a concept about it.
Regards.
Hugo
Well, I just got home from Pilates and had a couple of beer, so am at risk of breaking this rule:
But I kind of liked the gold idea. Where's auplater when we need him.
To be (a bit) more serious: I also want the answer to Planet10's question "Do you know where that ply comes from?", since I have often lamented the fact that here we are (those of us in the Pacific Northwest), surrounded by magnificent trees (what's been left to us, at least, by those two joint pests: the forest companies and the pine beetle), and what do we do with it? Well, we ship the good stuff to Japan in its raw state; and we make - ok, all the adjectives I want to use here are going to run afoul of the censor, let's just say, um, poor quality - plywood out of it. If I want to build a boat, I buy stuff that's shipped from Europe; if I want to build speakers, I buy stuff that's shipped from Europe - um, what's wrong with this picture?!?!
Anyway, duke, you are probably right; but thanks for the opportunity to vent on one of my pet peeves.
Regards.
Aengus
[edit] Edited to make it appear that I know how to spell "northwest".[/edit]
simon5: & simon dart
I suspect that the issues of fabricating, made his ( Hajo Prodan ) mixes cost prohibitive.
At the end of the article he mentioned that he obtained German & US patents for the OM technology and OMACPRO ( Opposite Moduli Acoustic Compound for Professionals ).
I questions I have is:
The operating circumstances for Pro Sound guys mandate durable enclosures - Ideally as light as possible.
Should materials with different acoustic properties be used based upon the design:
In other words: Should the same material be used in a open baffle, vs a closed box vs a B/R vs a T/L vs a Horn ( LF vs Full range ).
Recently ( March 2009 ) Stereophile had a review of the YG Acoustics Anat Reference II Professional loudspeaker:
It is one of the least resonate enclosures measured, and it is made entirely from 6061 T651 Aluminum w the baffle an alloy of Aluminum and Titanium.
There is no mention of how it is implemented ( internal baffling/mounting and interior damping etc ).
So do that mean virtually any material - depending on HOW it is used?
I suspect that the issues of fabricating, made his ( Hajo Prodan ) mixes cost prohibitive.
At the end of the article he mentioned that he obtained German & US patents for the OM technology and OMACPRO ( Opposite Moduli Acoustic Compound for Professionals ).
I questions I have is:
The operating circumstances for Pro Sound guys mandate durable enclosures - Ideally as light as possible.
Should materials with different acoustic properties be used based upon the design:
In other words: Should the same material be used in a open baffle, vs a closed box vs a B/R vs a T/L vs a Horn ( LF vs Full range ).
Recently ( March 2009 ) Stereophile had a review of the YG Acoustics Anat Reference II Professional loudspeaker:
It is one of the least resonate enclosures measured, and it is made entirely from 6061 T651 Aluminum w the baffle an alloy of Aluminum and Titanium.
There is no mention of how it is implemented ( internal baffling/mounting and interior damping etc ).
So do that mean virtually any material - depending on HOW it is used?
Does anyone have experience with soundproofing plywood (two multiplex boards with dampening middle layer?
http://www.sperrag.ch/?mid=TWpnNA==
http://www.delignit.de/contenido/cms/front_content.php?client=1&lang=1&idcat=17&idart=48
http://www.rudolf-rost.de/de/w_baryvam.htm
Seems to be available from many supplyers.
http://www.sperrag.ch/?mid=TWpnNA==
http://www.delignit.de/contenido/cms/front_content.php?client=1&lang=1&idcat=17&idart=48
http://www.rudolf-rost.de/de/w_baryvam.htm
Seems to be available from many supplyers.
Anders,
You mentioned bakelite. I have also been interested in that material but have never tried it. It might be difficult to machine with woodworking tools. It is stiff but brittle and hard.
I have recently made baffles with 1/8" and 1/4" thick sheets of PVC with a layer of Dynamat laminated between, and that proved to be very effective at damping vibration on the baffle. It is more dense than equal thickness plywood, and equally stiff. It is very easy to work with regular tools.
Peace,
Tom E
You mentioned bakelite. I have also been interested in that material but have never tried it. It might be difficult to machine with woodworking tools. It is stiff but brittle and hard.
I have recently made baffles with 1/8" and 1/4" thick sheets of PVC with a layer of Dynamat laminated between, and that proved to be very effective at damping vibration on the baffle. It is more dense than equal thickness plywood, and equally stiff. It is very easy to work with regular tools.
Peace,
Tom E
So my local exotic woods supplier suggested marine Plywood if I was looking for a dense uniform ply. He claimed a mininum of 13 or 15 ply for a 25mm thick 4x8 sheet. The cost is a killer $245 CAD for the sheet.
I saw some disparaging posts regarding the glue used in marine ply as it had to be waterproof and affected the resonance. okey dokey....
My main concern would be how would it glue up and take to routing.
Any experience out there?
Anthony
I saw some disparaging posts regarding the glue used in marine ply as it had to be waterproof and affected the resonance. okey dokey....
My main concern would be how would it glue up and take to routing.
Any experience out there?
Anthony
Coulomb, you are wasting your money!
Good quality Finnish or Russian birch ply of furniture grade will be fine. Any internal voids will be tiny, they just cut the knots out and replace the area with a new piece. They will be almost certainly be confined to one ply in any location. Marine ply is not guaranteed to be void free anyhow unless specifically certified. Its just water resistant.
Paying attention to the quality of your design and jointing technique will swamp the effects of any tiny voids in the ply by orders of magnitude.
Good quality Finnish or Russian birch ply of furniture grade will be fine. Any internal voids will be tiny, they just cut the knots out and replace the area with a new piece. They will be almost certainly be confined to one ply in any location. Marine ply is not guaranteed to be void free anyhow unless specifically certified. Its just water resistant.
Paying attention to the quality of your design and jointing technique will swamp the effects of any tiny voids in the ply by orders of magnitude.
Got a question. Assuming that one could make a
box that's dead no sound signature of it's own.
Will that equate to good sound ? Theres so many
variety of speaker cones available & each has a
different sound. Would it not be more appropriate to
to find cabinet materials that's more suitable for a
particular driver instead ?
box that's dead no sound signature of it's own.
Will that equate to good sound ? Theres so many
variety of speaker cones available & each has a
different sound. Would it not be more appropriate to
to find cabinet materials that's more suitable for a
particular driver instead ?
Glenn,
I bought my PVC sheet through a local plastics distributor. I think total cost for four sq ft of both sheets was $50, so it's not cheap. It would be very expensive to build an entire enclosure, but I used mine for only the baffle in an OB design. It works very well, as it is dense, somewhat stiff, and very dead, especially with a soft layer laminated between. It is also available from McMaster-Carr in a multitude of sheet sizes and thicknesses, as well as other structural shapes such as bars and angles.
Peace,
Tom E
I bought my PVC sheet through a local plastics distributor. I think total cost for four sq ft of both sheets was $50, so it's not cheap. It would be very expensive to build an entire enclosure, but I used mine for only the baffle in an OB design. It works very well, as it is dense, somewhat stiff, and very dead, especially with a soft layer laminated between. It is also available from McMaster-Carr in a multitude of sheet sizes and thicknesses, as well as other structural shapes such as bars and angles.
Peace,
Tom E
JC951t wrote:Got a question. Assuming that one could make a
box that's dead no sound signature of it's own.
Will that equate to good sound ?
This is a good question, my take, I feel most people are so used to listening to boxes that they really have very little idea of how the music should really sound, so when they hear a system devoid of box influences it probably sounds a bit dead/odd. But after a little while you realise that what you are hearing is more detailed, real and satisfying.
OBs well done really do get one closer to the music, but they are not practical for everyone, thing is though, once you have listened to them for a little while you find you can pretty much hear the sound of almost any box, especially with vocal and acoustic instruments, the bloom of the box seems to add something that degrades the sound.
Matching speaker to cone etc probably has merit, for example many full range drivers have very thin, light cones that easily transmit reflected energy from inside the box.
In the end though I think construction method/details are more important than the material itself, but if I were to try to built the ultimate box. I would probably go for 2 cast concrete boxes, one inside the other with an air space, with lead lining on the inner one and lots of internal damping and a baffle covered in thick felt and the box covered in carpet. Of course not very practical and super heavy, but I imagine that once one got over the lack of box sound it would likely sound very nice. I would also probably use sealed cabinet rather than ported layout.
box that's dead no sound signature of it's own.
Will that equate to good sound ?
This is a good question, my take, I feel most people are so used to listening to boxes that they really have very little idea of how the music should really sound, so when they hear a system devoid of box influences it probably sounds a bit dead/odd. But after a little while you realise that what you are hearing is more detailed, real and satisfying.
OBs well done really do get one closer to the music, but they are not practical for everyone, thing is though, once you have listened to them for a little while you find you can pretty much hear the sound of almost any box, especially with vocal and acoustic instruments, the bloom of the box seems to add something that degrades the sound.
Matching speaker to cone etc probably has merit, for example many full range drivers have very thin, light cones that easily transmit reflected energy from inside the box.
In the end though I think construction method/details are more important than the material itself, but if I were to try to built the ultimate box. I would probably go for 2 cast concrete boxes, one inside the other with an air space, with lead lining on the inner one and lots of internal damping and a baffle covered in thick felt and the box covered in carpet. Of course not very practical and super heavy, but I imagine that once one got over the lack of box sound it would likely sound very nice. I would also probably use sealed cabinet rather than ported layout.
I have some trophies that are essentially blocks of clear acrylic, mounted and engraved. It seemed to be a good material for speaker enclosures until I found out how much it costs.
Around AU$700-$1,000 for enough acrylic material for two cabinets put that idea to rest very quickly.
Maybe one day...
Cheers,
Alex
Around AU$700-$1,000 for enough acrylic material for two cabinets put that idea to rest very quickly.
Maybe one day...
Cheers,
Alex
Steel plate for speaker cab's ,why shouldn't it work .
This is what I was thinking of doing ,use 3mm plate make cabinet with a matrix style brace out of steel or ply and glue using a Loctite or Sika adhesive spray with body deadener .Then tack weld 10mm standoffs on the outside skin and make another shell and fill the void with 2 part foam .
The other way would be to make the front & rear baffles out of ply the the centre section folded on the long with a 25mm 90degree edge so you could screw & glue the baffles on from the inside .
Cheers
This is what I was thinking of doing ,use 3mm plate make cabinet with a matrix style brace out of steel or ply and glue using a Loctite or Sika adhesive spray with body deadener .Then tack weld 10mm standoffs on the outside skin and make another shell and fill the void with 2 part foam .
The other way would be to make the front & rear baffles out of ply the the centre section folded on the long with a 25mm 90degree edge so you could screw & glue the baffles on from the inside .
Cheers
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.