Which wood to use for DIY subwoofer

[ketansethi1987]

I know the answer would be 18mm MDF but I wanna know WHY???

Why do we use MDF for building speaker boxes??

I have used commercial boards in two of my projects and it seems just fine.

I want my subs to be as sturdy as possible and my carpenter says he never uses MDF and its not good. There must be some audio quality it posses for which everyone uses MDF for speaker building or is it that we are just following without trying new things??

Eager for your response

 

[vivek.saikia]

When you say (solid) wood, it can be of many varieties (hardwood/softwood) which may exhibit different acoustic characteristics. Even within the same category, there may be variance in the properties.
On the other hand, MDF has more or less the same physical characteristics (density/acoustic absorption-reflection properties) making it ideal choice to get consistent/expected results.
You can very well use solid wood as a material for making speakers but that can turn out to be a hit and miss affair.

Expert DIYers may chip in and provide some more insight.

 

[sbg]

Lets put it my terms ( read LAYMAN ) for the sake of layman's understanding.
- going to the extremes!, does your plastic bucket sound the same as steel bucket that we use in the bathroom every time you hit or toss around ? ( lets say ,the underlying assumption - both are the same size, weight, dimensions etc )
i.e when you hit the side walls of the bucket , does it sound the same ?
( i guess, it does make sound in the first place - if not you are most welcome to use this bucket - no kidding !!!) .The analogy, is that the internal sound waves do exert a kind of kinetic energy to make the the side panels of the box flex/excite/vibrate ( resonate ) and at different frequency depending on material - density/consistency etc. ...and you do have a "Bonus" in addition to what is getting being done in actuality by the speakers diaphragm.

The rest, in Audiophile extremes is Cutting Edge Technology, for some, anything beyond 1+4=5 is not the answer, it should be (3000-2999+(1-5)+(5*1) - (4+1)) , in essence getting things done in a manner so desired by available resources, technology, ability to devote time , money, patience to ultimately have the Pleasure you seek - It is not always the same transparency(flat response) everyone seeks so we at times overindulge. ( 18mm MDF ?) ... we do seek double bonded on the front panel.... Brich Ply, Marine ply...additionally reinforced at time .
... but consistently to have matching timbre when you have multiple units and seek to have a well balanced signature / sound-stage etc. etc. ( would you drive your car with front lf wheel taken from a lorry front rt wheel taken from an auto, back wheel....
...Please be easy on me - but, does this make sense?

 

[GeorgeO]

WHY? Do a simple search on the web and you will get a lot of answers to your questions.

 

[ketansethi1987]

Thanks for the replies, I used 18mm commercial board which was left over from my last project and the results are amazing but would go for MDF next time.

Lets see if the difference is noticeable.

 

[koushik]

@sbg
I read your post number of times to see if I am missing something but it is just not making any sense to me.
I was gettin your point at the begining but started losing ground at later sentences specially after "The rest, Audiophile extremes . . . ".
I am not saying that you are out of context because I can't understand what you are saying.
Nothing personal, I am sayin this because I think you have some valid points but think you were in hurry while writing the post.

 

[bijinmb]

My understanding is the we can use literally any material for building LS Cabinets, but it should have good acoustic property which we need to do RND on before starting.

Can use plastic, metal, natural wood, granite, cement, MDF etc provided one should do research on those materials acoustic property before trying and also need to do additional modding to make it acoustically good if very keen on particularly using that material only.

Eg. some materials have ringing effect, some may resonate more...etc..and there are ways to tackle those things..

From my experience couple of things which can really make a material acoustically good is as:

1. Increasing the wall thickness. (reduces the ringing effect, resonance to a great extend)
2. Material having even surface so all areas perform uniquely. (good for lowering distortions, diffraction's etc)

and lots of other parameters are there as well.

As per my understand one of the reason why MDF is that much popular in LS cabinets are:

1. Easily available.
2. Comparatively lower cost than wood.
3. Even surface and also coming in a known dimension ( this helps in pre-planning the cuts before actually buying/doing it)
4. Easy to work with. (though side effects are there like heavy dust etc.. but that is the part of wood work)

Once I have done a project using thick pipe called HDPE Pipe which is having 19mm wall thickness and i am quiet satisfied with the results.

here is the link to that project for your reference:

http://www.hifivision.com/diy/25319-my-new-diy-project-3-way-floorstander-8.html

 

[keith_correa]

<snip>The rest, in Audiophile extremes is Cutting Edge Technology, for some, anything beyond 1+4=5 is not the answer, it should be (3000-2999+(1-5)+(5*1) - (4+1)) , in essence getting things done in a manner so desired by available resources, technology, ability to devote time , money, patience to ultimately have the Pleasure you seek - It is not always the same transparency(flat response) everyone seeks so we at times overindulge. ( 18mm MDF ?) ... we do seek double bonded on the front panel.... Brich Ply, Marine ply...additionally reinforced at time .
... but consistently to have matching timbre when you have multiple units and seek to have a well balanced signature / sound-stage etc. etc. ( would you drive your car with front lf wheel taken from a lorry front rt wheel taken from an auto, back wheel....
...Please be easy on me - but, does this make sense?

Does this make sense? Not to me!!!

 

[keith_correa]

IMO, you may use any wood. The key is to brace it well.

 

[sbg]

oops, sorry, here we go.

Why do we use MDF for building speaker boxes??

I have used commercial boards in two of my projects and it seems just fine.
...

I agree with this statement too. - as at times ( in my earlier "projects" - essentially on experimentation with all local available drivers - Beltron, Balton ,clarion (all local made with brandsnames stuck on the back/front , boxes in freestyle) etc ) - and had no access to MDF etc, only ply and boards in my local town - some 20+ years back ) - had to do a dual Equalizers passess some times to have some extra gain, then to an amp( source-> equalizer->equalizer-> amp - sbg's "Projects"hyeah: ). oh, even matka speakers was one of them.

please do mind , that I never knew we did have all these high end speakers in the market (my exposure was limited to Sony, philips, awia, pioneer,kenwood etc)

I want my subs to be as sturdy as possible and my carpenter says he never uses MDF and its not good. There must be some audio quality it posses for which everyone uses MDF for speaker building or is it that we are just following without trying new things??

its more of what we are looking for is how inert the final enclosure is.

@sbg
...I was gettin your point at the begining but started losing ground at later sentences specially after "The rest, Audiophile extremes . . . ".
...

oops again, I was trying to address as a layman,but I do realize I'm still a layman here.
my point is, what we see in the commercial space is just not simple 18mm mdf

say, for example, this one they use " bronze, silver and 18ct gold " and not 18mm mdf.
hart-audio

shapeaudio

and here they say they use ...the world's best materials... , - third para on this page ( ummm, I do not know what is being used here ). the 4th para also seems interesting, anyone in DIY attempted this?

use of glass and gold

at times Carbon fiber

synthetic material called Marlan for B&W

they use some thing called Cloaking Device

Enclosures made out of Specific "Hokkaido maple" harvested in Novermber only
for Sony SS-AR1

aluminum, copper and stainless steel for reinforcements magico

aircraft-grade aluminum construction here
.

Does this make sense? Not to me!!!

looks like I've gone a bit extreme/out of context to get the picture. hyeah:Ok, lets settle for something in between, like " would you like to drive your car with the Front Left wheel at 30psi pressure, Front Right wheel at 10psi ... all are same type of tyre and from the same manufacturer...

 

[captrajesh]

The primary purpose of an enclosure is to contain the sound emanating during the backward movement of the driver cone.

This is required to be constructed using commonly available materials though you would find manufacturers using several other materials each having its own pluses and minuses which would be used to their advantage by the designer.

Ideally, the enclosure should be rigid and should not resonate and thus colour the music when the speakers are playing. MDF is extensively used for making speakers because of it's characteristic of less resonance compared to wood or Plywood. Plywood usually have a lot of voids inside which would result in coloration of sound.

Most types of wood tend to expand / contract and even bend in response to prevalent climatic conditions and is inherently not ideally suitable for making boxes unless this aspect is taken into account. Moreover, good quality wood like Teak wood / Rose wood etc are more expensive compared to other options available. That is why speakers are usually made with MDF and lined with veneer, giving the real wood look which we audio nuts cherish.

 

[captrajesh]

Another thing; I think one of the posters is confusing 'Timbre' with 'Timber'

This is what timbre means

 

[gobble]

How about BWR grade block board like kitply or other brands - wouldn't that be better than regular ply? I've seen a few boards and they seem to be more densely and tightly packed than a regular block board.

--G

 

[captrajesh]

Such ply woods would have fewer voids. Marine plywood have even lesser voids. I've read somewhere that birch ply does not have voids but would be very expensive.

 

[ketansethi1987]

I chose commercial board as I wanted the box to be sturdy and the carpenter didnt recomend MDF.

As for finish I used sunmica which looks like veneer. It is easy to apply and less expensive plus no polish is required and there are more variety available than veneer.

My project is almost finished just a little paint job left to do, will post the pics soon.

 

[ketansethi1987]

My understanding is the we can use literally any material for building LS Cabinets, but it should have good acoustic property which we need to do RND on before starting.

Can use plastic, metal, natural wood, granite, cement, MDF etc provided one should do research on those materials acoustic property before trying and also need to do additional modding to make it acoustically good if very keen on particularly using that material only.

Eg. some materials have ringing effect, some may resonate more...etc..and there are ways to tackle those things..

From my experience couple of things which can really make a material acoustically good is as:

1. Increasing the wall thickness. (reduces the ringing effect, resonance to a great extend)
2. Material having even surface so all areas perform uniquely. (good for lowering distortions, diffraction's etc)

and lots of other parameters are there as well.

As per my understand one of the reason why MDF is that much popular in LS cabinets are:

1. Easily available.
2. Comparatively lower cost than wood.
3. Even surface and also coming in a known dimension ( this helps in pre-planning the cuts before actually buying/doing it)
4. Easy to work with. (though side effects are there like heavy dust etc.. but that is the part of wood work)

Once I have done a project using thick pipe called HDPE Pipe which is having 19mm wall thickness and i am quiet satisfied with the results.

here is the link to that project for your reference:

http://www.hifivision.com/diy/25319-my-new-diy-project-3-way-floorstander-8.html

Your project is amazing!!!!

Now the question is WHY????

Where did you get the idea from? Did you experiment putting some speaker in pipes and later decided to build one?

Is there any added advantage? Does the speakers sound better compared to other building materials?

Any disadvantage of building speakers like this?

These must have a lot of cost.

 

[ketansethi1987]

Link to the project:

http://www.hifivision.com/diy/35565-diy-subwoofer-you-can-sit.html

 

[bijinmb]

Your project is amazing!!!!

Now the question is WHY????

Where did you get the idea from? Did you experiment putting some speaker in pipes and later decided to build one?

Is there any added advantage? Does the speakers sound better compared to other building materials?

Any disadvantage of building speakers like this?

These must have a lot of cost.

I got the idea from Anthony Gallo's Ref. 3.5 http://www.anthonygallo.co.uk/pages/products-reference-reference3-5.php

though this design is a mix of that plus mine.

Yeah i have experimented with those pipe before actually going for building this. Did research for few months actually.

I couldn't find any noticeable advantage of this DESIGN other than its Visual Appeal.

But the material is good for building enclosure application and of course its costly material.

And when you try making cylinder out of wood this the best substitute in sake of money, effort and accuracy.

The disadvantage i have noticed is dealing with the standing waves, though manageable after few trial and error damping approaches. But those sealed enclosure are giving amazing tight bass response.

 

[GeorgeO]

Hsu Research used to make highly regarded subs using cylindrical cardboard tubes(sonotube). I am sure the options are endless, and not confined only to wood.