• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

building my own speakers

sawmill

sawmill

Member
Hi all, I'm getting closer to finally building my set of music mains. I've settled on the components suggested by Gary at PE after quite a bit of conversation. The box I am going to build is 18 cu. ft. ported for the woofers, mids and a tweeter. My question is; after looking at a lot of diy solutions on the internet, most people are using mdf for the main structure and bracing. In my mind, it would be much stronger to use baltic birch or even marine plywood for the structure as it is so much stronger than mdf. Can anyone comment on why so many people use mdf in lieu of other sheet goods? Rob
 
Register to hide this ad
18 cu. feet! Holy horseshoes what are you putting in cabinets that size and what is the woofer tuning. Ideally the mids should have their own sub enclosures. If the tweeters are not closed back they need their own enclosures also.
 
To answer your ? It would be best to use HD particle board. With cabinets this large you will need good internal bracing all the way around, otherwise you will hear cabinet breathing and a poor way to clearly hear your music. Bill Fitxmaurice sells very good plan ideas, a few I have bought plans for and built. The Tuba sub woofer will completely blow you away- it is a 15" horn loaded driver and box that you can build off from
DC
 
Last edited:
darkblue 94, you are correct on everything but the strength statement as regards to MDF, hence my original question as to why better sheet goods are not used in carcass construction, or even composite materials .
JoeESP9, Good point! Please expand...The components are two AuraSound NS 18 992's, two TangBand W82096's, and a Morel ST 1108 tweeter.
 
sawmill said:
darkblue 94, you are correct on everything but the strength statement as regards to MDF, hence my original question as to why better sheet goods are not used in carcass construction, or even composite materials .
JoeESP9, Good point! Please expand...The components are two AuraSound NS 18 992's, two TangBand W82096's, and a Morel ST 1108 tweeter.
Click to expand...

I'm no expert on woofer tuning and cabinet size. It just seems that 18cu feet is rather large. As for the separate enclosures. If you decide to do that the enclosures only need to be large enough to accommodate the drivers. In addition many midranges and tweeters are closed back.

MDF is inexpensive relatively inert and takes easily to being veneered.

BTW: Some of the more expensive speakers use composite materials for the cabinets. Wilson Audio being one of the major players in that arena.
 
I wonder if the density plays an effect on acoustics. Also never any voids are a few things that come to mind. It might not be strength so much but density for eliminating harmonic vibrations that a speaker would need maybe? ID like to build my own subs someday and would also want to know the real reason it is favored.
 
JoeESP9, The woofers and mids are long throw open back and I have no idea about the tweets . I will be veneering in old growth wood I generate here, not sure what species yet. When I say composite ,I'm thinking carbon fiber and foam /epoxy as it would be extremely rigid and save some weight. This is my first speaker build. Rob
 
sawmill said:
darkblue 94, you are correct on everything but the strength statement as regards to MDF
Click to expand...
He said it's "strong enough" and he is absolutely correct.

Don't ask if you're immune to the answers.

Plywood, especially hardwood plywood will require additional damping, and somewhat different bracing techniques as it acoustically "rings" quite a bit. Professional/commercial speaker builders tout it quite a bit because of it's inherent tensile strength which is of importance for cabinets that will endure a lot of handling and repeated load-outs and load-ins over the course of their lifetime.

Alobar said:
I wonder if the density plays an effect on acoustics. Also never any voids are a few things that come to mind. It might not be strength so much but density for eliminating harmonic vibrations that a speaker would need maybe?
Click to expand...
It's self-damping properties are a significant factor in manufacturer's choice/preference for MDF.
 
sawmill said:
In my mind, it would be much stronger to use baltic birch or even marine plywood for the structure as it is so much stronger than mdf. Can anyone comment on why so many people use mdf in lieu of other sheet goods? Rob
Click to expand...

Because it's cheap. BB or cabinetry grade plywood is much nicer to work with, but is a lot more expensive. 18cu is an enormous box, and will weigh a ton built from MDF.

jeff
 
Last edited:
Bowtie427ss, Thanks , not immune to answers, just my experience with wood , and compositions of wood.What you say about plywoods makes sense.
 
vinylkid58,Thanks Jeff, Weight may be a factor, not to mention more elegant solutions are out there.The cabinet grade ply is what I'm referring to as Baltic Birch earlier. I infrequently use it in my business and it has nice qualities. Budget wise I'm only building two speakers so the one shot price is not a factor. Not trying to diss one material over another, just looking for folks experiences on this site with speaker building.When bowtie427ss mentioned "ringing" it makes me rethink going in a composition direction for carcass fabrication. Not making idle chat , I actually learn a lot online. Rob
 
How did you arrive at 18 cubic ft for the enclosure? Parts Express has it as ~8 ft for vented application and 4 for sealed.

Nice driver, by the way!
 
I once tried building 12 cu ft cabinets for University drivers that worked pretty well in their <2 cu ft cabinets. I thought I'd have soooo much bass...

I only built one.
 
18 cubic feet!!!! That's actually bigger than what I have all my beer and Christmas dinner stored in right now:beerchug: My thinking is you'll need lots of bracing or double up on the sheets of mdf to keep the box from flexing or both. I'm also thinking something that gigantic needs to be built in place or have casters mounted on the bottom. Do you have an airplane hanger you need to fill with music:banana:?
 
You must log in or register to reply here.
Back
Top Bottom