For the most part, I use MDF for all my loudspeaker projects. I've heard many say Baltic Birch is better, but I've yet to find any genuine proof to back up this notion. Baltic Birch is stronger, no question. But is the added strength required for speaker building? MDF is more dense which I feel is more important than strength for speaker building. This is assuming there are no large unsupported spans. I also understand that having a speaker weigh less can be an advantage if its being moved a lot.
Acoustically, what advantages does Baltic Birch really provide.
Acoustically, what advantages does Baltic Birch really provide.
Well I'm neither of those 2, but I'll be happy to pipe in - short story - just build a pair from Baltic Birch (or equivalent)- identical to something you already have in MDF and decide for yourself
I've been using nothing but the BB for the best part of 10yrs - must be well over 100 pairs by now.
I won't attempt to comment in the differences in resonances, however, the dust from MDF is horrific.
However, if the cabinets are properly braced, can the difference be heard ?
As Troels points out, routering the back of the front baffle - behind a mid or bass driver - is critical.
This is to minimize turbulence at the back of a driver.
With a baffle made from Baltic Birch - I think the routering can be pushed farther than with MDF.
However, if the cabinets are properly braced, can the difference be heard ?
As Troels points out, routering the back of the front baffle - behind a mid or bass driver - is critical.
This is to minimize turbulence at the back of a driver.
With a baffle made from Baltic Birch - I think the routering can be pushed farther than with MDF.
High mass/density by itself is not a good thing.
http://www.diyaudio.com/forums/cons...ussion-what-materials-build-speakers-out.html
This has been discussed over & over again, go do your homework. When i 1st arrived here it was "common knowedge" that MDF was "the" material to build boxes out. Since then many people have essentially done what Chris suggests and are now building with superior materials (detect some bias there? There definitly is). Now days if you do a survey -- especially on the FR Forum -- a whole lot more people are building with quality plywood.
IMO MDFs only positive attributes are that it is cheap and relatively easy to finish (making it even cheaper) -- the attributes that marketing departments of commercial speaker manufacturers have pounded on so long & so hard that the myth is pervasive, otherwise competent speaker designers using it by default.
dave
There's a HUGE thread on this (in Multi- Way part of forum), one camp for MDF and 'tother for Ply and a third camp cant make their minds up.
Me, I'm for plywood. It has grain structure, has a higher resonant freq per panel size and its dust, though not considered a health and well being product, is way better than wood dust infused with formaldehyde based glue.
Me, I'm for plywood. It has grain structure, has a higher resonant freq per panel size and its dust, though not considered a health and well being product, is way better than wood dust infused with formaldehyde based glue.
I think you have to go to/for measurments to fully understand the different properties of different materials. There seems to be no material to be the unquestioned winner.
Rather than using just one material, combining some can make things better. Even if I rely on measurments some intuition is needed in my opinion. Which materials are worth to consider in the combined approch. Even a simple thing like "painting" MDF with epoxy changes the MDF to a rather different nature in this respect.
But I also think this is an area where people´s beliefs are more dominant than real knowledge.
I studied e.g. the measurments made by the renown Peter Comeau (working for
IAG) published in the July 2008 issue of Hi-Fi World. It was revealing!
There is a comparision between some High end loudspeakers in the German magazine Stereoplay issue 5/2012 where loudspeakers of quite differnet concepts are compaired by measurments to the resonances of their enclosures,
aluminium, slate, epoxy based materials and glass fiber sandwich between"end grain oriented " balsa wood leads to rather different results.
Inner damping, e-modulus, the weight of the material in question; all is important.
So between Baltic Birch plywood and MDF it should be a simple answer But I don´t get it, makeng a good speaker has to be more complicated. I can quote some results from Peter´s measurments but it´s better to read the whole story. The same for measurments in the Stereoplay 11/2006 supplement. Even more interesting to me is the interview with Andy Payor of Rockport Technology in The Absolute Sound issue 214.
By no means I intend to be rude by ignoring a simple question. But I believe you have to recognize the compromises involved in loudspeaker design and building. And going beyond the simple answers may make sense, the answer is dependent on what you want to achieve.
Rather than using just one material, combining some can make things better. Even if I rely on measurments some intuition is needed in my opinion. Which materials are worth to consider in the combined approch. Even a simple thing like "painting" MDF with epoxy changes the MDF to a rather different nature in this respect.
But I also think this is an area where people´s beliefs are more dominant than real knowledge.
I studied e.g. the measurments made by the renown Peter Comeau (working for
IAG) published in the July 2008 issue of Hi-Fi World. It was revealing!
There is a comparision between some High end loudspeakers in the German magazine Stereoplay issue 5/2012 where loudspeakers of quite differnet concepts are compaired by measurments to the resonances of their enclosures,
aluminium, slate, epoxy based materials and glass fiber sandwich between"end grain oriented " balsa wood leads to rather different results.
Inner damping, e-modulus, the weight of the material in question; all is important.
So between Baltic Birch plywood and MDF it should be a simple answer But I don´t get it, makeng a good speaker has to be more complicated. I can quote some results from Peter´s measurments but it´s better to read the whole story. The same for measurments in the Stereoplay 11/2006 supplement. Even more interesting to me is the interview with Andy Payor of Rockport Technology in The Absolute Sound issue 214.
By no means I intend to be rude by ignoring a simple question. But I believe you have to recognize the compromises involved in loudspeaker design and building. And going beyond the simple answers may make sense, the answer is dependent on what you want to achieve.
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His techniques are very good, very expensive too, Two lightweight and very stiff shells separated by a highly damped dissimilar material.
We are finally getting to implementaion of a technique that would have much of the rationale of the Paylor boxes -- a technique i've been thinking about for well over a decade, the pieces are just starting to fall into place.
Using sheets made from multiple materials (contrained or not) can take things to another level (performance, cost, and effort . The question i consider is given a single sheet material what works best? Most diyers, especially begineers, are not prepared to tackle anything beyond single sheet material.
As a frugal-phile(tm) it is important to me to get best bang for the buck. And it ain'td MDF, it does not meet the requirements we demand wrt DDR. Chris and i have both had our 10,000 hrs of critical listening training and we are very picky.
dave
totally agree ... the dust from MDF is very fine and lord knows what is in the glue.
Actually, I consider MDF glorified cardboard.
Here is the article from Troels about chamfering the backs of a baffle.
I think with Baltic Birch, the chamfering can be pushed more than MDF.
chamfering driver holes
.
It was mentioned in another thread that MDF can make a FR speaker sound "dead". If this is the main reason for using BB, than I understand where you're coming from.
As far as health risks, both materials use the same glue. Fiber board can produce fine dust, but a proper dust collection system will help this. Proper PPE (personal protective equipment) like dust masks should be warn when cutting any wood product. But that is another topic.
I know now this is a redundant topic, so forgive me for that.
As far as health risks, both materials use the same glue. Fiber board can produce fine dust, but a proper dust collection system will help this. Proper PPE (personal protective equipment) like dust masks should be warn when cutting any wood product. But that is another topic.
I know now this is a redundant topic, so forgive me for that.
I had seen somewhere that the material it self has a resonate point, BB was ~220hz, MDF ~280 or 300hz, and Particle-Board was~ 14hz. this intrigued me, so I build the Klaushorn with the three kinds of Material's. The PB was less resonance than either of the others, the MDF sounded more muffled. BB is better to work with and stronger.
regards Klaus
regards Klaus
This is true, I suspect you missed my point...... average amature shop vac isnt all that hot with real fine particals and mdf is VERY fine, ply woods slightly larger as it does not start as homogenised dust.
As for the same glue - most likely, though mdf (I suspect) uses a fair dose more to make a board. Think about that one!
PVA or Copydex
Aka a composite.
Is there a reason why you are going with polystyrene bead board ?
I think you are far better off with 400 weight styrofoam.
It can be purchased as small as 1/2" inch thick.
I've never worked with masonite (sorry if I am a wood snob).
Polyvinyl wood glue (aka carpenter's glue) will bond styrofoam to real wood just fine.
But I've never tried to bond the gloss side of masonite.
As always, regardless of which adhesive you select - try it on a sample first.
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