One of the best bookshelf speakers I've ever heard was constructed of bamboo plywood but, because it was a while ago, I don't remember the manufacturer. It may have been Canalis but that's just a guess. I don't know if the sound quality of those speakers had much or anything to do with the bamboo construction but I'm preparing to build enclosures for single full range drivers to be used in a small listening area and, because I don't like working with MDF, I'm trying to decide whether to try plain hardwood, birch plywood or bamboo plywood. I've done a little shopping and have found that the several choices in 3/4 inch "carbonized" bamboo plywood are not sold in many of the local outlets and that it is very much more expensive than other wood.
This thread has been helpful in that regard but I would appreciate comments regarding the use of bamboo. I admit that I'm leaning toward bamboo partly because it's different and looks neat. |
Thank you all very much for your great comments.
I have decided to build the first pair cabinets to the Audio Note spec.
I have to say that I was very impressed with so many of your comments and knowledge. We have a very valuable team here in Audiogon in our diverse and passionate views with our hobby.
Thank you all.
Matt |
I found this article that makes extensive comparison between birch plywood and MDF:
http://www.tnt-audio.com/clinica/cabinet_walls_e.html
To my surprise they found birch to be better. 11-ply Baltic Birch plywood might be good. |
As I recall, Audio Note speakers evolved from MDF to Baltic Birch for a reason. The drivers and the minimally-braced Baltic Birch cabinet are designed to work as a unit. The interaction has been likened to the way a stringed instrument projects its sound. While it might be fun to experiment with different cabinet materials, it is not how (and why) the speaker was designed to produce its characteristic sound. That is correct. I have a pair of older Audio Note AN/J speakers with the MDF and particleboard construction that are at least 15 years old. I haven't heard the newer baltic birch versions but they are reputed to sound better with the change in cabinet material alone. Go with the recommended birch. |
A Jazz drummer friend has an old pair of Sonor drums I believe, solid rosewood! Were very expensive at the time. Anyway, back to speakers. |
"Do you really believe that kit speaker was designed to have sound of it's own especially when before same box was called to be made of MDF?"
That is my understanding, but I could be wrong, though this is a common theme I have heard regarding Audionotes.
Tonian is another brand that follows this admittedly minority design approach using baltic birch, I believe as well. That is where I heard of it first.
From wikipedia article on birch wood:
"Tonewood
Baltic Birch is among the most sought after wood in the manufacture of speaker cabinets. Birch has a natural resonance that peaks in the high and low frequencies, which are also the hardest for speakers to reproduce. This resonance compensates for the roll-off of low and high frequencies in the speakers, and evens the tone. Birch is known for having "natural EQ."
Drums are often made from Birch. Prior to the 1970s, Birch was one of the most popular drum woods. Because of the need for greater volume and midrange clarity, drums were made almost entirely from maple until recently, when advancements in live sound reinforcement and drum microphones have allowed the use of Birch in high volume situations. Birch drums have a natural boost in the high and low frequencies, which allow the drums to sound fuller.
Birch wood is sometimes used as a tonewood for semi-acoustic and acoustic guitar bodies and occasionally used for solid-body guitar bodies. Birch wood is also a common material used in mallets for keyboard percussion." |
There might be different reasons why manufacturers use birch. One of them is perception of quality - hardwood vs. MDF. People often choose kitchen cabinets with plywood shelves not knowing that MDF works much better (less sagging). The other reason might be ease of working with (cutting, sanding, drilling) and finally weight. I have small bass cabinet made by Carvin built of light hardwood advertized as very light. Weight is important for people who play out and have to carry it. As for light bracing - I'm not an expert on speaker construction but it is definitely not a violin. Resonating walls add coloration to sound and 99% percent of manufacturers do anything possible to reduce it. Revel uses laser reflectometr to design for minimum vibration, Dali uses layers etc. Do you really believe that kit speaker was designed to have sound of it's own especially when before same box was called to be made of MDF?
Mapman - not every guitar is designed for long sustain. Flamenco guitar for instance isn't. Guitar has presence, projection, sustain, separation and tone. Some guitars have great presence but poor projection. Flamenco guitar has huge projection but poor presence and sustain, but good separation. If you design speaker cabinet to interact with guitar then how much of presence, projection, sustain, separation and tone it should have? Would it be the same if you listen to Flamenco? |
"why not guitar wood? THe electric guitar world (some of it anyway) is obsessed with tone sustain. Strum a chord or a note and it just keeps ringing one forever."
My understanding that is in line with why AN uses Baltic Birch cut to their specs these days to help deliver the unique appeal of their speakers, but I could be wrong. |
why not guitar wood? THe electric guitar world (some of it anyway) is obsessed with tone sustain. Strum a chord or a note and it just keeps ringing one forever. Now very nearly everyone feel that several factors contribute to this but the body wood is one of them. That said there have been claims about "basswood" "mahogany" and "swamp ash". likely others. sort of a back to front speaker wood approach but what the heck. another possible item of interest is that many guitar builders swear that the finish can inhibit the "breathing" of wood and a thin nitrocellulose finish is frequently most prized. the cedar and spruce tops that kijanki mentions sound like acoustic guitars and +1 on his thought that they would vibrate. I'm thinking solid body electrics with wood that does not bleed off string energy. At least thats the thought. different anyway. |
I'm with GSM as well.
Always fun to experiment though I suppose. That's worth something....
I'd keep an eye on re-sale value though were I to tinker with an already well received and not inexpensive design, like the Audio Notes.
But I suppose, as long as you have the ability to take it apart and start over again as needed, or that you are open to living with the results whatever that may be, there is no harm with tinkering in the long term. |
As an aside, I believe that some of the older, original Sonus Faber speakers designs are made from solid wood. They used multiple small pieces, rather than large boards and just the sides are wood. The staves, as they call them, are carefully dried before assembly. It is a complicated process, more akin to furniture making than typically speaker making. I do not believe they have continued that tradition with some of the newer models - my guess is that they have moved away from that process for economic reasons. |
As I recall, Audio Note speakers evolved from MDF to Baltic Birch for a reason. The drivers and the minimally-braced Baltic Birch cabinet are designed to work as a unit. The interaction has been likened to the way a stringed instrument projects its sound. While it might be fun to experiment with different cabinet materials, it is not how (and why) the speaker was designed to produce its characteristic sound. |
MDF and cover with hardwood would be my choice! |
Matt - I don't quite understand analogy with guitar woods. Cedar and Spruce are two woods with the highest strength to weight ratio and often used for the guitar tops to make it vibrate well. You don't want vibration and the one of the best materials is high density MDF or stone (marble, granite etc). Some speakers (like Paradigm) have internal crate in form of crossing boards along and across that have holes (circles) cut outs resembling honeycomb. Some more expensive speakers have either irregular shapes or round sides getting narrower at the back, to prevent standing waves. |
@Photon46...good info man. Yeah, clamping the speaker stands with all the layers and glue was no easy task. :-) Luckily I have friends that helped out. It was completely worth it, as they look great!
I was thinking of using the same technique for compression/clamping that Magico uses. They have a steel bar that runs through the layers, and then I would screw that down for compression. We'll see how that turns out. :-D
@Ngjockey...that looks promising, but spendy.
Mot |
Mattzack2, I just took a look at the #3 kit. The birch ply is a no brainer, imo. They look fun enough to build, maybe you can play with a couple of proto builds and see which you like in your system. Careful. It can be addicting. :-)
Thank you, Isochronism. My amateur status shows itself in the finishes. ;-) |
What did Kondo recommend for speaker material? |
A fairly new and non-traditional alternative is bamboo plywood. Not expensive, fairly dense, and a bit "greener".
http://www.calibamboo.com/bambooplywood.html |
Im not a carpenter i give up!! |
Solid hardwoods will give you problems with dimensional stability, with wood expanding up to 1/8" per foot across the grain and negligibly with it. Raised panels on furniture are made with undersized floating panels for this reason.
People who successfully use solid hardwood for speakers tend to limit themselves to small speakers, floating baffles, and open baffles where pieces don't have joints with grains at 90 degrees to each other (if it all expands in the same direction it doesn't matter). |
Magico Audio Notes.
Take the best of both worlds and sounds like a winner,
doesn't it?
Or does it?
Is it Magico or Audio Note?
Or something totally different?
Only one way to know for sure.
Someone build it and listen and see!
My bet though is the cabinet is a big part of what makes
Audio Notes Audio Notes.
And Magico's Magicos.
Each in a totally different way.
Interesting dilemma! |
Its said they would be even more money now.Foolish its not. |
Ebm - That would be a good suggestion if he were building Magico MINI 2 speakers. He claims he isn't - so why push that foolish notion?
The way I interpreted the OP's query is this: He wants to build a pair of speakers because such a project enables him to merge his two hobbies. He has already done some research and is willing to gamble on the Audio Note design he mentioned without the advantage of hearing them first. Not his first choice method but he feels it to be a worthwhile gamble. He posted here in the hope that he could benefit from the knowledge and experience of others. It does not appear that he wants to be steered toward your favorite speaker or distracted by speculative misinformation. I could be wrong about all this though - I'm not him, after all. |
Layered Birch used in MAGICO MINI 2. |
"Right now, I am not convinced that baltic birch is my best choice although I realize it is my safest."
Given that it is seemingly the choice of the people who designed the speaker, ie the "experts", I would assert that it is also the best choice for now as well as the safest until someone proves an alternative to be better.
How they would do that short of having done it and allowing you to hear, I do not know.
Plus, Audio Note is not a company known to cut corners with its products as best I can tell. If they know of a way to do it better, they probably will, but you will also have to pay for it if it matters to you, of course.
I suppose the other way to look at it is that if you use any good materials for a good reason, the results should at least also be pretty good.
But to claim "the best", at least to me, there has to be some proof to go along with the claim.
Hearing is believing!
BTW, I am a big fan of companies like Audio Note that stick with a basic good design and attempt to tweak it to the max over time, but also offer lesser versions at different price points along the way. |
I guess my theory is that it is possible that baltic birch is used in part for its cost, weight and ease of manufacturing in the cabinet process.
I agree with starting this without being better informed is not the best strategy. I was hoping to hear that cost being no object, baltic birch was the best way to go. I have not heard that yet.
Another question asked was whether I have heard these speakers at all. No, I have not. I tried to find someone with a pair in the Chicago area, and have had no success.
I am willing to take a chance after gathering more info as I can always build the baltic birch cabinets if I need to. Right now, I am not convinced that baltic birch is my best choice although I realize it is my safest.
Again, if anyone in the Chicago area has any Audio Note speakers that I can listen to, I would be most grateful. |
I think Br3098 and I are on the same page with this.
My question again would be has the OP heard the end product as a reference?
Hearing them first would be the first pre-requisite I would think before making any valid decision about how to improve the standard design, or even if that is needed or desirable.
No way does using "the best wood", however one determines that, assure the best sound. There is a lot more to it than that.
One has to expect that the engineers that designed the kit model in a high end line like AN have done the research needed. To take a different approach without doing all the homework needed prior sounds like a risky endeavor if the desired end result is a particular sound. |
Mattzack2, you have received a lot of advice from guys who don't seem to understand Audio Note's speaker design technology. As you undoubtedly know, Audio Note speakers are upgraded versions of Peter Snell's original designs. Snell built his K, J and E speakers out of fibreboard (not MDF) for cost reasons and also because that the current vogue in speaker design.
After offering what were virtually copies of the Snell designs for years, Peter Qvortrup of Audio Note UK decided that the speakers sound better using resonant plywood cabinets. Audio Note eventually settled on a particular thickness and grade of Baltic birchwood that they believe sounds best.
I have helped a few friends build Audio Note kit speakers, some using factory cabinets and some using home made boxes. I can tell you from experience that the home made cabinets did not sound the same as the factory cabinets. Not worse, not better, just different. My unsolicited advise is if you want your speaker to sound like Audio Note speakers, either order the cabinets pre-made from Brian or get the plans and build them as closely as possible to the specs.
If it were me, I would not bother experimenting with MDF or any other wood product. It might sound better, but (again in my experience) probably not. |
Manoterror, our studio constructed a number of sculptures from baltic birch plywood using a two-axis cnc machine to cut the basic shapes before lamination and finishing. It is very time consuming to work with this construction technique from a finishing standpoint if you are seeking a high end look like Penn and Magico. The best baltic birch we could source locally here in Tampa was riddled with small voids in the plies. Be prepared for a lot of filling (and color matching the filler) and sanding to get them ready for a finish. I also would think very carefully about how you'll be able create enough compression force to properly laminate the many, many layers of plywood you'll use. All of the plywood I've ever used is ever so slightly non-plane across any cross section of the size you'll use to make a speaker. We were only working in twelve inch deep sections with about sixteen layers and that was a challenge to glue up and get clamped before the glue started to set. I'd imagine Penn and Magico have multi person teams working the laminate glue ups that then go into a hydraulic clamping system. |
Dan, you are NO amateur woodworker as your speakers and matching rack will tell. Exquisite!! Your choice of components, etc, agree in accordance.
Amateur comedian.....? :) |
I'm an amateur woodworker also but I build horns. Still the basic idea of eliminating resonances holds true. If the box is properly braced it should not matter much what it is made of. I would only be concerned about dimensional stability with the use of hardwoods alone. This is especially important for the baffle that the drivers mount to. Most chose to build the cabinet frame using void free plywood, or MDF, and then laminate the hardwood on top. Not only does it give a beautiful finish but if you go 1/4" or thicker it adds stiffness. I'm not saying it can't be done with all hardwood, but I know I sleep better knowing my seams and surfaces are going to stay tight.
Good luck with the build. |
I've been researching the same thing for the last year, as I'm looking to make some speakers myself. It boiled down to this...MDF is acoustically inert and doesn't warp easily....which is the main reason it is used commercially by most high-end builders. I'm not interested in using it for health reasons, and Baltic Birch Plywood (BBPW) is the second choice, as seen above.
Magico and Penn Audio both use a technique of layered horizontal layers of BBPW, and that is what I'm going to do. It looks beautiful, is rigid as all hell, and easy enough to work with. I built some speaker stands with this method last year, and love it. I'm leaning towards the PenAudio Charisma style for simplicity.
Let us know what you decide,
Mot |
Mat,
Sounds like a fun project!
Good luck!
Just wondering, have you heard what the speakers sound like following the standard AN recipe?
USually best to taste the soup before adding seasoning! |
Mapman
You make some very points. I am wrestling with my decision to use Baltic birch as recommended. My two passions are audio and woodworking. It seems that there are many schools of thought on cabinet design. I understand not mucking with the recommended recipe, but really want to gain enough quick knowledge to make a wise choice whether to experiment or not with this. I can always build the Baltic birch cabinets if I want to, but this is probably my only realistic time frame to make that choice.
Thanks for your opinion. |
I found an article on TNT Audio from Italy . I clipped this section out and specifically noted that they choose birch plywood anywhere that they are not using solid hardwoods.
Despite less high-tech resources the home constructor can conduct original research, which may be more relevant to him or her, to help guide design and construction decisions, rather than rely on published research more suited to production in the commercial domain.
To summarise, in these experiments, for low frequencies below perhaps 300Hz (I did not explore different frequencies, so a bass-to-mid crossover point anywhere between 200Hz and 400Hz would probably suffice) 25mm materials of any type were better than thinner materials of any type. Birch-plywood (void-free birch all the way through, sometimes known as BB grade) was slightly better then the much cheaper mdf; birch-ply also has no health hazard rumours, but is more difficult to work. You pay your money and you make your choice. I now choose birch-plywood anywhere that I am not using solid hardwood.
For midrange frequencies, 12mm birch ply loaded with foam+bitumen sheets sounded clearest in our little experiment. The human voice range sounded most natural with this cabinet configuration. Voices singing have much of the energy concentrated in the decade from about 500Hz to 5kHz, even though bass voices can reach fundamentals of around 100Hz, tenors 165Hz and even sopranos lower than 300Hz, the lowest fundamentals of each human sound are isolated 20-23dB peaks at the lower end the spectrum analysis (Driscoll p51) with the centre of a bell-curve cluster of harmonics typically a decade above fundamental (i.e. bass voice 1kHz, tenor 1500Hz, soprano 3kHz), many harmonics 12-15dB in amplitude. The 15mm chipboard official cabinet was obviously inferior in the midrange. All thicknesses tried of mdf squashed the life out of the music, but fear not if you have mdf cabinets; I will explain how to rescue them and give them a new lease of life in a future article.
For now, if you are planning a new project, or rehousing some familiar drivers, the message is simple, the home constructor has the time and resources to build far superior loudspeaker cabinets to any that can be bought ready-made at real-world prices. |
The one that looks best?
Seriously, you need to focus on what is best for that specific Audio Note kit.
Audio Note is a line that seems to focus a lot on optimizing the design and performance of their products.
Personally, I would not muck with the recommended design and materials unless I were really very well educated on this topic and only if I were very familiar with teh sound of the recommended design first and found a clear reason to change it.
Also, in general, there seems to be two key lines of thought that determine box speaker enclosure designs. One focuses around making the enclosure as sonically inert as possible at a price point. Most speakers follow this model.
The other focuses on using a purposefully less inert enclosure to help tune the sound, similar to many wooden musical instruments. This is a key aspect of teh unique sonic appeal of this design pattern.
I am under the impression that AN speakers fall into the latter camp. Changing teh cabinet has a major effect on the sound! The end result may sound nothing like the original if the recommended cabinet design is altered drastically. Denser, more inert wood or materials could actually work against you?
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Below is a thread on "real wood" speakers. I have heard the Daedalus speakers championed by Al, and they certainly sound good. Other companies, like PBN Montana, do the front baffle of some models in a 2" hardwood slab. I agree with Has2be that cost is likely a major factor in the use of MDF, and I doubt there is an exceptionless rule here. Why not contact Audionote and ask them what the would use, were cost no object? John http://forum.audiogon.com/cgi-bin/fr.pl?cspkr&1275949549 |
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I too have been thinking of building a set of speakers, possibly Audio Note, in the future. The following link to a forum thread on Audiocircle references an interesting material to be incorporated in constrained layer speaker cabinet construction. This looks like an interesting and potentially rewarding tactic for someone seeking to build inert as possible cabinets. http://www.audiocircle.com/index.php?topic=92198.0 |
The best product to use is one that does not resonate where you don't want it to and does resonate where it will be the least problem. You'll have to build and measure the cabinet resonant frequencies to determine that. It's basic engineering but it costs a lot of time, effort and money. |
For as long as I can remember I have always heard birch plywood is best for speaker cabinets. However, I have heard good sounding speakers made of MDF, chip board, synthetic marble and no cabinet at all. |
Musical Affairs speakers look very interesting. But you can only audition them in Chicago. |
MDF is used primarily to reduce cost and is easy to work with and cheap and easy to obtain. Moisture affected like real wood is and not very durable and easily crushes at corners.
HDF ordered a full inch thick is dead an inert and a great choice for better controlling the box from resonating or flexing and is very easy to machine and glue and provides better weight to the cabinet. This is used in better built cabinets and by some for the front baffle only. Consciderably less affected by moisture and change of temperature.
17 mm Grade A A Birch Ply offers great control over flexing and resonating ( think turntable plinth) and is the easiest to work with but as a traded commodity is more expensive but offers superior results when braced properly as any choice needs to be. Not affected by moisture and humidity changes. Cuts and machines wonderful with nice clean chip free edges. Tone seems to be better when used for speaker boxes( subjective ) but as you were rightfully cautioned braced well, but all good results require that in your design.
My suggestion and what I have done with best results. Build them from Baltic Birch cross brace them internaly as much as your design allows. Don,t brace them from side to side, brace them with a box frame (like a picture frame) dadoed into place. Then cover them in solid wood that serves to further stiffen the box and no longer having to worry about what wood to choose for sound characteristics (other then weight) only astetics you can have whatever you want and not worry about chipping or ding corners of paper thin veneers. At about a 100 bucks a sheet not knowing how big your speakers will be and how much you will need if cost is a factor and you would rather put more towards even better drivers the HDF is your best substitute but at 1 inch thick and very dense it is heavy to work with.
Cheers and happy building!
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Birch, oak and walnut are acoustically "stupid" woods and you want to have nothing to do with them. If you must use something other than MDF use cherry. And, yes, cherry can be very different. I think, Michael Green used cherry in his reference free resonance Chameleon speakers. If I remember right he imported it from a particular mill in Canada. And the way the cabinets of his speakers were constructed required serious skill and great hearing. Are you up to this?
Acoustic guitars's top is made of spruce, right, but "the body" can be made of different woods. Of what I heard a guitar made of some sort of rosewood sounded best. |
When I first got into the high-end business, many years ago and started to meet the designers, I was told by many that you should never build a speaker completely out of solid wood. That was over thirty years ago, but I think the principals/rules are still the same. |
BTW, I was opportuned to listen/enjoy MAGC's and was quite smitten! |
Al's example, whom does give serious thought/research in choices, makes me ponder further. His example in Daedalus chooses a different material as baffle for a reason, I'd assume. Violins and high end Archtop guitars also use spruce tops as a soundboard, with differing material, in this case maple backs and sides. Musical Affairs Grand Crescendo's are designed loosely as a resonating violin or guitar body. The plot thickens.... |
Having been a cabinet maker for 15 years before I changed careers I would say that If you're serious about building speakers and are relatively efficient why not try building a pair of them from one of the solid woods you mention AND a pair from baltic birch and see which you like better? Or build
the Baltic-birch first and if you feel they can be improved upon, then build one from a solid wood you find appealing.
There's a very informative book by R.Bruce Hoadley titled "Understanding Wood" that gets into scientific/mathematical
formulae for calculating engineering data for various wood species, including specific gravity,stress loading under tension/compression etc.
Another factor to consider is that the regional characteristics for hardwoods do vary somewhat; Claro walnut is quite different in density than the black walnut that I used to buy in Mi. Red Oak differs somewhat from white oak, and southern cherry (from say, Tenn.) will likely differ in weight per board ft. compared to cherry from New York or Penn. I'm thinking you probably want the stiffest varieties of these species to minimize cabinet resonance- but I don't really know.
Let us know how it works out! |
Most speaker cabinets are made from particle board. Usually a medium to high density particle board. You should not make speakers with a real hardwood cabinet. Real wood has a resonate frequency depending on type of breed of wood that can adversely color the sound. I have only heard one speakers made with real wood that sounded good to my ears. It was the Magico Mini II. It is made out of stacked marine grade Baltic Burch plywood. Plywood has lots of glue, resins and is very dense like medium to high density particle board. Even some of the most expensive speakers use particle board with extreme bracing and usually with very expensive veneer work. |
Lou Hinkley of Daedalus Audio undoubtedly possesses one of the best combinations of knowledge about woodworking and speaker building around. His speaker cabinets are made from renewable solid hardwoods, except (I believe) for the front and rear baffles, which I believe are birch ply covered with solid wood. The wood choices he offers are shown here. As a Daedalus owner, I have never encountered any indication that the selection among those choices is sonically significant. Lou emphasizes the importance of heavy internal bracing, btw. Good luck! -- Al |
