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I used the iron on method, wood glue evenly spread on, diligently ironed to a flat finish. Months later I have some blistering which is darn annoying. Some commercial edge strip veneer I bought was pre-glued and it ironed on really nicely and is fixed solid. Seems to me the secret is all in the glue.
What I've noticed about MDF is that it's heavy, produces nasty dust and it's kind of wobbly compared with ply. Plywood is so much stiffer and we know how important this is don't we 😀
What I've noticed about MDF is that it's heavy, produces nasty dust and it's kind of wobbly compared with ply. Plywood is so much stiffer and we know how important this is don't we 😀
suit yourself on the gluing method ( as Bigun alludes, the "secret" with the iron on method is in painting an even layer of glue on both surfaces, and thorough application of the iron )
not all wood glues have the same chemistry
as for plywood vs MDF - excuse me if I suggest that your parsing of the question feels a bit like a troll 🙄
this matter has been debated ad naseum over the past several years, with of course no consensus based on theory - but if you care to experiment for yourself - pick a small enclosure design and build a pair of each.
just looking for some friendly debate on the topic, trying to uderstand the value of doing what i am not,,,..thats all.
a quick rough sketch.. I will not be routering the edges but leaving them square,, will this pose any issues in the design? are the 45's cosmetic in Dave's design?
Thanks.
Thanks.
haha,, ill be honest, im not quite sure what he said.
thanks.
Johnny - sorry I sometimes get more than a bit testy, and assume too much. You may not be aware that this particular subject (ie. choice of construction materials) is one of many frequently baited by forum pos(t)ers for the specific purpose of devolving into pointless vituperative exercise of semantics and self-aggrandizement.
Troll:
Troll (Internet) - Wikipedia, the free encyclopedia
As Dave noted above, the chamfers are not just cosmetic: the larger a facet or radius a specific design / construction technique allows, the greater the mitigation of edge diffraction artifacts.
The chamfers can be cut on a table saw rather than by router.
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Short version: Good multiply is recommended (and MDF discouraged) on these loudspeakers.
dave
well my apologies for my ignorance, I did a search on the word and thought you were trying to either tell me i was luring you in or i was a short creature.
My question was genuine, simply wanting to know if there was an audible difference in the two materials...there are many things i dont know allot about,,wood is not one of them. i enjoy the art of manipulating wood into a treasure, the sound or speaker is secondary, but not by much. Just the latest vehicle.
My maple face is only three eighths thick, to highlight this material i can not chamfer. I pose the question to have a feel of what i will notice audibly if anything...
i have a plan and i will stick to it. I am just curious on how my speakers will sound different than others without the deviations..
my intent is not to posts inflammatory, extraneous, or off-topic messages in an online community,nor am i interested in provoking other users into a desired emotional response.
I apologize if this is how i came across..........
Cabinet Materials 101 -- a discussion on the rationale of matrial selection and techniques for the boxes i design
dave
dave
my favourite topic of discussion....materials.
As far as materials go for making enclosures out of...nothing beats compressed cardboard (in a circular form no less....sonotube). Self dampening, non resonant... excellent sounding.
Of typical sheet goods I feel that BB ply is the only way to go. It's pluses outweigh its minuses in my opinion. It is not that MDF cannot be made to sound good, but by the time (and effort) that's done, the difference in cost between adequately strong MDF and BB ply are minimized.
The densities between MDF and BB ply are 48#/ft^3 for MDF, and 44.93#/ft^3 for BB ply. Based on that alone, and the excellent strength of BB ply, it is easy to see that the sonic characteristics will be different. Less energy will be stored in the BB ply. Some feel that he BB will flex more, but it actually has better dimensional stability, and can be braced to better effect than MDF. It is quite stiff (stiffer than MDF) and is glued between layers. MDF must be sealed on both sides of a sheet if one is to actually use it for enclosures. In OB speakers, the use of MDF kills the sound.
For the increase in cost over MDF it must be superior, and to my way of thinking it is. It also produces less dust and fine formaldehyde particles while being machined. It machines like solid wood.
The use of BB ply vs. MDF always stirs a hornet's nest. But simply based on the time you take to make a loudspeaker project, the relative cost difference is a non-issue. And BB ply is easier to finish (it can be sealed and stained or glazed), or veneer over. The long term results are worth the extra cost.
Everything else being equal, a lighter material will store less energy and release it in a more controlled manner. It is generally accepted in instrument making that a thinner sound board (on a piano or guitar top) is capable of also generating deeper frequencies. So the fact that it is stiffer, but less dense suggests that the sonic characteristics of the material will be capable of producing fundamentally lower frequencies when excited by strong changes in pressure (such as amplified sounds), and dissipating small signal, spurious ones more quickly.
Sometime I think I'll build me a set of "ultralights" to prove a point.
JohnnyFamous. If I had some 1/8" Maple available, I'd finish both sides of it. Then create a sandwich with some styrofoam SM or similar rigid sheet insulation. You'd have a beautiful looking and sounding (although somewhat tedious to make) pair of loudspeakers.
As far as materials go for making enclosures out of...nothing beats compressed cardboard (in a circular form no less....sonotube). Self dampening, non resonant... excellent sounding.
Of typical sheet goods I feel that BB ply is the only way to go. It's pluses outweigh its minuses in my opinion. It is not that MDF cannot be made to sound good, but by the time (and effort) that's done, the difference in cost between adequately strong MDF and BB ply are minimized.
The densities between MDF and BB ply are 48#/ft^3 for MDF, and 44.93#/ft^3 for BB ply. Based on that alone, and the excellent strength of BB ply, it is easy to see that the sonic characteristics will be different. Less energy will be stored in the BB ply. Some feel that he BB will flex more, but it actually has better dimensional stability, and can be braced to better effect than MDF. It is quite stiff (stiffer than MDF) and is glued between layers. MDF must be sealed on both sides of a sheet if one is to actually use it for enclosures. In OB speakers, the use of MDF kills the sound.
For the increase in cost over MDF it must be superior, and to my way of thinking it is. It also produces less dust and fine formaldehyde particles while being machined. It machines like solid wood.
The use of BB ply vs. MDF always stirs a hornet's nest. But simply based on the time you take to make a loudspeaker project, the relative cost difference is a non-issue. And BB ply is easier to finish (it can be sealed and stained or glazed), or veneer over. The long term results are worth the extra cost.
Everything else being equal, a lighter material will store less energy and release it in a more controlled manner. It is generally accepted in instrument making that a thinner sound board (on a piano or guitar top) is capable of also generating deeper frequencies. So the fact that it is stiffer, but less dense suggests that the sonic characteristics of the material will be capable of producing fundamentally lower frequencies when excited by strong changes in pressure (such as amplified sounds), and dissipating small signal, spurious ones more quickly.
Sometime I think I'll build me a set of "ultralights" to prove a point.
JohnnyFamous. If I had some 1/8" Maple available, I'd finish both sides of it. Then create a sandwich with some styrofoam SM or similar rigid sheet insulation. You'd have a beautiful looking and sounding (although somewhat tedious to make) pair of loudspeakers.
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thanks Dave, there seems to be quite a bit of debate on this topic that i was unaware of....
thank you sir,,😀
Well i have built the boxes already,, to be honest i cant see re building them at this point, everything i have read up until now has condoned the use of mdf as the preffered material...it seems the fullrange forum is a little different🙂 perhaps Chris was right when he suggested i build a set of each and decide for myself..
my original decision to use MDF was fueled by the use of veneer and solid wood,, BB has voids and trying to veneer on a cut plywood edge would not be as sound as a cut edge of MDF..
what do you mean the mdf must be sealed on both sides ?
I planned on glueing my maple onto a piece of three eighths mdf. given that it is a heavly spalted piece, i must treat it first with a epoxy fill on both sides and then attatch it to the mdf..
Well, some might disagree with Stew's assertion that BB is (sic) "easier to finish or veneer than MDF", but all the materials under discussion have multiple compromises in the grand scheme of things ( oh, is there only one ? 😉)
Since switching exclusively to BB for speaker cabinets at least 6yrs ago, I've found several methods to deal with finishing and veneering this material. Quality HDP ( High Density Plywood), regardless of brand or generic name should have very few and small voids in the internal cross ply layers. Any that might be exposed on edges should not affect the structural integrity of the enclosure, and are easily filled with bondo or even glue-sizing before veneering.
Painting or staining of exposed edge grain of either MDF or plywoods requires a "certain" degree of careful preparation (including veneer or solid wood edge banding before assembly). Indeed, just for fun ask any professional finisher about work time/materials involved in a high gloss piano finish on MDF speaker boxes. 😉
Johnny - no further apologies on the subject required
Since switching exclusively to BB for speaker cabinets at least 6yrs ago, I've found several methods to deal with finishing and veneering this material. Quality HDP ( High Density Plywood), regardless of brand or generic name should have very few and small voids in the internal cross ply layers. Any that might be exposed on edges should not affect the structural integrity of the enclosure, and are easily filled with bondo or even glue-sizing before veneering.
Painting or staining of exposed edge grain of either MDF or plywoods requires a "certain" degree of careful preparation (including veneer or solid wood edge banding before assembly). Indeed, just for fun ask any professional finisher about work time/materials involved in a high gloss piano finish on MDF speaker boxes. 😉
Johnny - no further apologies on the subject required
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Indeed! i played around a little with the piano black on a subwoofer build some months back,, I strategically did not do the edges🙂 it aint fun!
no time to work on the boxes,, i will post a pic or two once there close..
Attachments
folks, leave it to me start things, AGAIN... 😉
JOHNNYFAMOUS, take what I say with a grain of salt. Strongly consider chris' advice...he has had more "exposure" to cabinet building than perhaps 20 or so "normal" people.
Certainly the BB is not solid wood, and there are some very small voids, but part of the "standard" of this material is to be essentially void-free.
One of the "secrets" using MDF is to finish both the interior and exterior faces of it. This has been well known in "car audio" for a very long time. MDF can "chuff. Glueing the maple to the exterior faces of the enclosure should create an air boundary. The same needs to be done on the inside, although paint can be used and is easy to apply with a spray can once the driver cutouts are made.
It has been reported that air can be blown through a panel of MDF, causing the "chuffing" sound. Painting the interior of any MDF enclosure (whether commercially made or DIY will bring a clarity to the sound and extend the bass... well actually make it more articulate).
have a great night all...
JOHNNYFAMOUS, take what I say with a grain of salt. Strongly consider chris' advice...he has had more "exposure" to cabinet building than perhaps 20 or so "normal" people.
Certainly the BB is not solid wood, and there are some very small voids, but part of the "standard" of this material is to be essentially void-free.
One of the "secrets" using MDF is to finish both the interior and exterior faces of it. This has been well known in "car audio" for a very long time. MDF can "chuff. Glueing the maple to the exterior faces of the enclosure should create an air boundary. The same needs to be done on the inside, although paint can be used and is easy to apply with a spray can once the driver cutouts are made.
It has been reported that air can be blown through a panel of MDF, causing the "chuffing" sound. Painting the interior of any MDF enclosure (whether commercially made or DIY will bring a clarity to the sound and extend the bass... well actually make it more articulate).
have a great night all...
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the basic box has taken shape, i will post a pic once its presentable, I have painted with flat black and sanded in between coats on all interior surfaces as Nanook suggest, Smooth as o babys bum....
hit a design issue though, in Dave's design there is a small brace atop the port, I will need to remove this piece and alter the box volume to account for it or put it somewhere else.. As mentioned earlier the mMar Ken will be inverted and i visually need to put the driver close to the port, the brace is in the way..
Any thoughts on the best way to deal with this? I could cut the piece in half and mount it on either side of the port top and allow for the driver? I am not sure if you want to maintain a certain distance from the walls of the cabinet to allow for the driver?
hit a design issue though, in Dave's design there is a small brace atop the port, I will need to remove this piece and alter the box volume to account for it or put it somewhere else.. As mentioned earlier the mMar Ken will be inverted and i visually need to put the driver close to the port, the brace is in the way..
Any thoughts on the best way to deal with this? I could cut the piece in half and mount it on either side of the port top and allow for the driver? I am not sure if you want to maintain a certain distance from the walls of the cabinet to allow for the driver?
the brace atop the port panel is less important than the driver/magnet brace - I've built more than a few pair without the former, and I doubt its absence would be audible
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