I'm pretty new to speaker building, and had a question about materials.
What type of wood is really used in commercial speakers that cost $2-3000 usd?
I'm guessing MDF or particleboard with a veneer. I can see baltic birch used in very expensive speakers, but what is common in the better mid-price range?
-David
What type of wood is really used in commercial speakers that cost $2-3000 usd?
I'm guessing MDF or particleboard with a veneer. I can see baltic birch used in very expensive speakers, but what is common in the better mid-price range?
-David
dw8083 said:
When I had my company...I never considered plywood, because veneering to it reliably was difficult for us, especially at the end grain of the cuts.
At the very high end, people tend to go with composite materials similar to corian.
Particleboard is typically used in only the cheapest boxes....
Well braced, structurally sound boxes can be made of very many materials.
Scott
Baltic birch is typically found on professional boxes because it is very durable and can withstand the rigors and stresses of touring. It is also less likely to fall apart when "flown" by rigging than MDF.
MDF is thought to be superior for speaker cabinets because it has reduced resonance compared to plywood and solid wood. Although fine musical instruments are made from expensive hardwoods due to their resonant properties, speaker cabinets should be as non-resonant as possible. The speaker cabinet should not color the sound that the drivers produce.
As for speaker prices, I don't really think the type of wood used in cabinet construction is necessarily a factor. Of course, those expensive hand crafted solid wood models from Italy are an exception. I think you will find most mid- to high-end cabinets will be made of MDF. Of course, the veneers used themselves can be very expensive and that can contribute to the hefty price tag of some.
MDF is thought to be superior for speaker cabinets because it has reduced resonance compared to plywood and solid wood. Although fine musical instruments are made from expensive hardwoods due to their resonant properties, speaker cabinets should be as non-resonant as possible. The speaker cabinet should not color the sound that the drivers produce.
As for speaker prices, I don't really think the type of wood used in cabinet construction is necessarily a factor. Of course, those expensive hand crafted solid wood models from Italy are an exception. I think you will find most mid- to high-end cabinets will be made of MDF. Of course, the veneers used themselves can be very expensive and that can contribute to the hefty price tag of some.
no.dw8083 said:
good quality plywood will be stronger. Particle board is probably the weakest of the boards and probably also the most variable.
Before MDF most speakers were made from particle board or plywood.
All the boards will sound different. This can be used to voice a speaker, but will take a large development budget.
Agreed.
Without wishing to stir up a 'this is better than that' storm, a few general thoughts.
1) MDF is generally used in commercial hifi speakers (even some very expensive ones) because it's cheap & easily worked by moderate - large companies with CNC machines. Commerical hifi, like many other walks of life, is largely smoke & mirrors. They are businesses, ergo their goal is to maximise profits, not sonics.
2) Beware thinking that MDF is less resonant than other materials. It isn't, it's just different.
3) MDF is not an especially stiff material, typically 1 1/4 - 1 1/2in is needed to ~match the stiffness of 3/4in thick birch ply. Assuming equal thicknesses, being nominally a denser material, then on paper, and often in practice, MDF's natural resonance BW is at a lower frequency, and thus wider & of a higher amplitude than the ply equivalents & has a slower decay time. ROT therefore is that you will need to damp the stuff much more than particleboard (or chipboard as it's known here in the UK) or birch ply, or many solid hardwoods. This is generalised BTW -a host of other factors such as panel size naturally come into play in practice.
4) Erradication of panel resonance is a hiding to nothing. Best you can hope to do is push the resonant BW of the panels out of the cabinet's operating BW, to a place where it / they are less likely to be excited. Which you go for is down to preference, but raising it is often easier & will require less damping.
5) Despite being looked down upon these days, a good quality particleboard / chipboard (assuming you can find one) is a reasonable material for cabinets if it is used properly.
6) Solid woods (hard or soft) do not automatically resonate audibly in a cabinet's operating BW, and as many of them have an excellent stiffness-weight ratio, may be used very effectively if your carpentry is up to it, and if they are not going to be subject to sudden changes in temperature & humidity.
7) Combinations of materials can also be usefully employed; for e.g. a laminate of 1/2in particleboard with 1/4in MDF. And so on.
Without wishing to stir up a 'this is better than that' storm, a few general thoughts.
1) MDF is generally used in commercial hifi speakers (even some very expensive ones) because it's cheap & easily worked by moderate - large companies with CNC machines. Commerical hifi, like many other walks of life, is largely smoke & mirrors. They are businesses, ergo their goal is to maximise profits, not sonics.
2) Beware thinking that MDF is less resonant than other materials. It isn't, it's just different.
3) MDF is not an especially stiff material, typically 1 1/4 - 1 1/2in is needed to ~match the stiffness of 3/4in thick birch ply. Assuming equal thicknesses, being nominally a denser material, then on paper, and often in practice, MDF's natural resonance BW is at a lower frequency, and thus wider & of a higher amplitude than the ply equivalents & has a slower decay time. ROT therefore is that you will need to damp the stuff much more than particleboard (or chipboard as it's known here in the UK) or birch ply, or many solid hardwoods. This is generalised BTW -a host of other factors such as panel size naturally come into play in practice.
4) Erradication of panel resonance is a hiding to nothing. Best you can hope to do is push the resonant BW of the panels out of the cabinet's operating BW, to a place where it / they are less likely to be excited. Which you go for is down to preference, but raising it is often easier & will require less damping.
5) Despite being looked down upon these days, a good quality particleboard / chipboard (assuming you can find one) is a reasonable material for cabinets if it is used properly.
6) Solid woods (hard or soft) do not automatically resonate audibly in a cabinet's operating BW, and as many of them have an excellent stiffness-weight ratio, may be used very effectively if your carpentry is up to it, and if they are not going to be subject to sudden changes in temperature & humidity.
7) Combinations of materials can also be usefully employed; for e.g. a laminate of 1/2in particleboard with 1/4in MDF. And so on.
Good summary. To this point:
I would add that all speakers, with the possible exception of those kept in museums, are subject to humidity changes, and whether these are sudden or not, will cause the wood to expand and contract. If you don't know what you are doing when you build boxes from it - be they speakers or highboys - the wood will split.
Exceptions: wood allowed to move by the construction techniques chosen (not too easy for speakers which need to be airtight); wood saturated with epoxy (WEST technique), which will also change the resonant character of the wood; small boxes made from highly stable (typically very oily) woods like teak.
Regards.
Aengus
I would add that all speakers, with the possible exception of those kept in museums, are subject to humidity changes, and whether these are sudden or not, will cause the wood to expand and contract. If you don't know what you are doing when you build boxes from it - be they speakers or highboys - the wood will split.
Exceptions: wood allowed to move by the construction techniques chosen (not too easy for speakers which need to be airtight); wood saturated with epoxy (WEST technique), which will also change the resonant character of the wood; small boxes made from highly stable (typically very oily) woods like teak.
Regards.
Aengus
Thank you, John.
This has got me wondering - could one use the leakiness of a dado which allowed panel movement as an aperiodic vent? Could be tricky figuring out the exact amount of leakiness as the panel expanded and contracted, but perhaps using raised panel space balls would allow a consistent gap?
This is pretty academic as far as I'm concerned, since I don't plan on building any aperiodic speakers, but it is an interesting problem. Hmmm...
Regards.
Aengus
This has got me wondering - could one use the leakiness of a dado which allowed panel movement as an aperiodic vent? Could be tricky figuring out the exact amount of leakiness as the panel expanded and contracted, but perhaps using raised panel space balls would allow a consistent gap?
This is pretty academic as far as I'm concerned, since I don't plan on building any aperiodic speakers, but it is an interesting problem. Hmmm...
Regards.
Aengus
There are ways to accommodate the seasonal movement of solid wood and still maintain an airtight seal, but the effort is probably not worth the results. There is no better box, regardless of what it is made, than the one that is solidly and rigidly glued together.
A combination of solid and composite (plywood or MDF) can be the best of both worlds, if constructed properly.
A combination of solid and composite (plywood or MDF) can be the best of both worlds, if constructed properly.
PeteMcK said:
Looks like constrained layer damping. I'm trying it with my first speaker project (in progress) with Green Glue branded viscoelastic material.
In AES paper "Effect of Panel Damping on Loudspeaker Enclosure Vibration" by Juha Backman, the constrained layer method with thin viscoelastic layer proved to be effective while other options showed significantly higher level of panel resonances both in accelerometer measurements and far field acoustic output measurements. Amont the other enclosures were plain plywood, MDF, particleboard and plywood with material ("damping material" or lead) constrained between panels.
http://www.aes.org/e-lib/browse.cfm?elib=7384
Hello All, I found this thread while surfing around diyaudio. After reading the various arguments made for various material types, I did a google search for MDF to do a little more reading. Wikipedia mentioned the product in the weblink below. I thought it sounds interesting.
http://www.norbord.com/Hardwood_Splash.htm
Peace,
Dave
http://www.norbord.com/Hardwood_Splash.htm
Peace,
Dave
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