# New speaker project questions



## fschris (Oct 31, 2009)

I think I see some people building speakers with baltic birch ? I thought wood was not as good as MDF because it would contract and expand etc ? or can that be alleviated if you seal it up properly ?

I was think about the sides and top using birch and the baffle would be MDF... is that a bad idea?


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## robbo266317 (Sep 22, 2008)

You are correct real timber expands and contracts with the seasons/humidity. Manufactured wood, either mdf or ply, is less affected. 
The larger the piece the more it is an issue, so you may get away with using it for the top however the sides could be a problem.
Most people find it easier to use mdf and simply laminate the outside.


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## fschris (Oct 31, 2009)

okay thanks.... i see many people use ply/birch to build subs... are they not concerned about this?


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## fusseli (May 1, 2007)

I also think that MDF is a bit more dense. I'm not sure how bad of an ambient air, humidity, etc. swing there would have to be to actually stress or break a glue joint. Based on how commonly it's used I would guess it's not a big issue...


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## fschris (Oct 31, 2009)

fusseli said:


> I also think that MDF is a bit more dense. I'm not sure how bad of an ambient air, humidity, etc. swing there would have to be to actually stress or break a glue joint. Based on how commonly it's used I would guess it's not a big issue...


Im really thinking about building a pair of 'statements' as tall as they are they are not that much bigger than my previous build. i wanted to stain them, that is why i was thinking of the Baltic birch. I think I may build some smaller desk top monitors to try out veneering.


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## fbov (Aug 28, 2008)

Do not confuse Baltic birch with hardwood. Hardwood is unsuitable for speakers, unless you really know what you're doing. 

Baltic birch is a trade name for a really good plywood. Apple-ply is similar. As such, the expansion and contraction issues are greatly reduced by virtue of crossed plys, and in this case, lots of crossed plys. Unlike conventional plywood, it's typically void free, so you get a tight box without internal resonances, the real problem with plywood. 

MDF is cheap, works easily even if it's tough on tools, and is quite inert. If you get MDF wet, it falls apart, and MDF seams are near impossible to hide. Veneer is a good option, but it's easier to build big boxes with pre-veneered plywood.

Have fun,
Frank


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## robbo266317 (Sep 22, 2008)

fbov said:


> Do not confuse Baltic birch with hardwood. Hardwood is unsuitable for speakers, unless you really know what you're doing.
> 
> Baltic birch is a trade name for a really good plywood. Apple-ply is similar. As such, the expansion and contraction issues are greatly reduced by virtue of crossed ply
> Have fun,
> Frank


Thanks for clearing that up Frank. It is good to have local knowledge of the product. :T

So being a plywood then it is fine to use. I look forward to some pics of the build. :bigsmile:


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## fusseli (May 1, 2007)

fschris said:


> Im really thinking about building a pair of 'statements' as tall as they are they are not that much bigger than my previous build. i wanted to stain them, that is why i was thinking of the Baltic birch. I think I may build some smaller desk top monitors to try out veneering.


Give it a shot and be sure and post your progress and results  The Statements seem to be really popular and proven.


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## fbov (Aug 28, 2008)

If building statemetns, just be sure to upgrade wattage and provide airflow around resistors in the midrange network. They've been known to become toast....

HAve fun,
Frank


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