hardwood for stereo speakers

[mandoman]

I'm getting rather tired of this pointless argument. Yes I have tried different soundhole sizes, and yes it does make a significant difference to the sound, and there is a wealth of violin research you can read, and no I have have not made a mandolin with no soundhole, and no I don't intend to because someone else already has done it and they won't do it again because the sound was not good. Done, and no more BS please.

We are drifting well away from the original topic. Bottom line is, yes you can make speakers from solid wood but with some restrictions because wood is not as stable as MDF or chipboard. The basic prinicples are - (1) keep cross grain dimensions as short as possible (2) make the joins so they can move. Since hardwood is usually stiffer and heavier than MDF or chipboard of the same thickness, and some woods have a lower Q, hardwood can sound better, but it will depend on the implementation. MDF and chipboard are much easier to work with, but hardwood can look handsome.

[soundman]

but building a speaker of any significant size out of solid timber is totaly impractical, due to the instability of the timber

Apart from the fact that the "Q" of the timber has such a minute effect on the matter it isnt even worth bothering about.

cheers

[mandoman]

Soundman, do you have anything positive to say? After so much carping and pedantic criticism and lectures on how to do research on musical instruments I wonder why I ever susbscribed to this forum. From now on I think I will stay with the boatbuilding forum where there is much helpful and useful information offered. My time is far better spent on building the next speaker which will be a mass loaded quarter wave tube (otherwise known as a transmission line with a port), made from solid hardwood. The cross grain dimensions will be a maximum of 21.5cm, which is close to about as far as I would go. Practical, yes. More difficult to design and build, yes, but so what!! It will be more of a challenge to design, will look far better than veneered MDF and get approval from SWMBO, and that is important to me. I have worked with MDF a lot in the past and got sick of it and the fine dust it produces. I would far prefer to work with wood, but that is my choice, and my experience is my solid wood speakers sound better than the indentical ones I made from MDF. If others want to build bigger speakers from MDF because of the advantages of MDF then go for it. Jeepers creepers, I am just trying to poiint out that it is not impossible to build speakers from solid wood. After all Sonus Faber do it.

Now that I am armed with such gems as mass is the most important thing, steel is too heavy, electrostatics are an entirely different matter, wood is totally impractical, musical instruments have an entirely different physics, etc etc, I think I should be OK now.

[soundman]

I like solid timber as well as the next man, but I have not a positive thing to say about making speakers out of solid timber, because for a variety of reasons it is an impractical and uneconomic prospect.

I have also heard more than my fair share of hokus pokus and mumbo jumbo about speaker construction and HIFI in general and have a very low tolerance to this sort of ........ stuff.

There are plenty of pelple who will argue about the " significant effects" of minute, insignificant and largely irrelivant techincalities of anything to do with sound and music.

The vast majority of speakers cabinets encounterd will be structrualy inadequate.
There will in the vast majority of cases be much more obvious causes of inadequacy than choice of box material.

I put discussing the "Q" of a piece of timber used in a cabinet up there with the best of the pointless arguments I have come across.

As far as My gems you quote out of context.
Understanding the role of MASS is one of the most important concepts in physics. Mass is one of the most important concepts in sound but too few ever realise that.

as far as steel being too heavy, this is an over simplification sorry.
Steel has does not have a good enough strength to weight ratio to build a practical speaker, to gain sufficient cabinet rigidity the steel will be too heavy.......If you want a realy good discussion on strenght to weight ratio and the benifits of timber over steel I sugest you have a read of the "gudgeon borthers on boat building."

If you are going to discuss realtive merits of a material for an application, using a completely unrelated technology as an example is unhelpfull and irrelivent.
Sugesting that someone "gets" some form of expensive, obscure and esoteric technology as a means of setting them straight is nothing more than insulting.
So you own a pair of electrostatic speakers.... so.

Anybody who has any exposure to good information on the behaviour of timber will understand that is has a variety of stability issues that make it impratical for use in building speakers of any significant size.

and
If you can not grasp the dramatic difference between the physics of speaker cabinets that have a very well described behaviour and musical instruments that even at the highest level people still argue about, I wonder.

I think your main problem is that you come to this thread with your " guitar wisdom" expecting to "set us all right on the matter".

If you come to this forum, confident in your own superiority, i think you wont be arround long.

as far as "Sonus Faber ", never heard of them.
There are all sorts of people doing all sorts of weird things in the HIFI market.
Lots of those things are not reasonable, nor practical.
you can build a speaker out of a length of sewer pipe, that doen't make it good technology or practical.

I supose there is one way you could make a servicable speaker out of solid timber.
That would be to make it using marine epoxy and coat all faces inside & out, as per west system, is it reasonable & practical....... dont think so.

See you in the boat forum

cheers

[mandoman]

Once again nothing positive to say, and it is starting to get unnecessarily nasty. If you want to be the only person contrributing to this forum then you are going the right way about it.

What materials one uses depends on one's individual preferences, biases and priorities. The different materials will mostly work with some advantages and disadvantages. My priorities are obviously different from your's, and insults ae not going to change that. Lets end it there and not get into a pointless slanging match. There are many other places on the net where one can discuss speaker buiulding and design in a more constructive manner.

[soundman]

Ahh a case of pots and kettles, lets leave it at that.

[Isaac Hunt]

Interesting discussion.

What material you use is not so important.All materials wil resonate-just differently.
What is important is that the sound of the box,drivers and crossovers come together to produce a nice sound.
You could call this their overall acoustic.This is the art of speaker design and what makes it so challenging.

Some speakers with lightly built cabinets sound great.The BBC designed Spendors and Rogers speakers like the LS3/5a from the 70s spring to mind.These used 12mm ply.Harbeth continues to make speakers like this and they are regarded as amongst the very best you can buy.

I used to own some Klipsch KG4 speakers.These are great sounding old speakers that work beautifully with low powered valve amps.I lead lined them because I thought this might improve them-but it completely ruined the sound.

Audio Synergy used to make solid jarrah speakers.They sounded superb.

[stan_nesta]

mandoman,
don't pay attention, there are people in every internet forum who will engage in endless discussions for the sake of it, it's a part of life.

on a different note, i have built speaker cabinet from solid Australian hardwood, actually two pairs, one from Blackwood, one from Jarrah. they both sound fantastic (using Vifa drivers in a WTW, or D'Appolito configuration, but that is not important). I still have the Blackwood pair and don't think selling it.

As for the stability of solid hardwood it all depends how dry the timber was and how are the boards assembled. What I mean is if you produce a board from several pieces laminated together (like the kitchen benchtops), sealed and then finished with polyurethane you will have no problems whatsoever, my speakers (which are DIY) are nearly 10yo and there are no signs of cracks, twists, etc. It's all in the preparation and the careful exsecution of the project.

About MDF, avoid it at all cost, it's dull medium for sound reproduction, the reason speaker manufacturers use it is it's cheap and uniform, easy to work with.
For top notch sound use solid wood, plywood, or combination of the two, like laminating a plywood carcass with solid wood, can even be pine.The end result will be way superior to the densest and thickest MDF box ever built. You can even line your box with lead sheets for improved performance.

At the end, when someone who pretends to be an expert says he/she has not heard of "Sonus Faber" and discards them as a valid point, I simply laugh.
One of the most innovative and creative speaker companies for the last 20 years, on a par with Duntech in regard to design, philosophy, prices, awards, and someone ignores these facts completely...I find it unbelievable and a bit arrogant. When their flagship model Stradivari Homage sells for $40000US, I think that deserves some attention.

I simple Google search will provide tons of information, here are a few links:

http://www.sonusfaber.com/eng/home.html
http://www.audioconnection.com.au/br...nt-Electronics
http://www.internationaldynamics.com.au/brand.asp?id=17
http://www.sumikoaudio.net/sonus/index.htm
http://www.tivolihifi.com.au/index.p...roducts_id=238
http://blog.stereophile.com/ces2007/011407elipsa/

Regards

Stan

[mandoman]

Thanks stan_nesta, I am over it and have since built 2 more pairs of speakers from solid wood. That now makes 6 pairs from solid Jarrah, solid Tassie Oak, and solid Tassie Myrtle, and not a single failure. Sure, the wood has moved, it has shrunk and swelled with the weather, but the cabinet design has taken care of that. The fact that I can make identical speakers from MDF and solid hardwood and the hardwood sounds noticably better is enough to convince me that the extra cost and effort is worth it, no matter what. They also satify the other half (which is very important). Arguing over the reasons why they sound better is somewhat pointless, and can get into a lot of speculative BS and denial of basic physics. The point is they SOUND better, no question about it, and isn't that what we all want? The argument that MDF is "better" for DIY becasue it is cheaper, more stable and easier to work with, but sounds worse is a little odd.

Ha yes, re Sonus Faber, I also laughed at that.

[Petebass]

Mandoman you clearly feel pretty strongly about this, and that's perfectly OK by me. But it seems pointless argueing the point without setting out to prove it. We can end this argument quite easily! All you have to do is build a cab which is identical in every way to one of your Jarrah cabs, but build if out of ply or MDF. Then scientifically measure the frequency response. We could even get some people who are independent and free from bias involved in some double blind testing to see if they can identify which speaker is which by ear alone.

I'm not being a smart alec, I'm dead serious. I'm no stranger to building 2 cabs which are identical except for one important difference to establish whether or not said difference alters the cabs sound of performance. I've done it before, I'll do it again. And until you go to the effort of doing this, your opinions, as strong as they are, will remain opinions and will always be open to challenge.

[mandoman]

Dammit, I have done it, but my ears and the ears of my other half did the measurements, not scientific instruments which I don't have. We both agreed that there was a significant difference, and we both prefered the sound of the Jarrah cabinets. I have done this twice with the same results (different speaker designs), and once where I could not hear much difference at all (much smaller cabinet). Maybe the differences are not significant as the dimensions get smaller, dunno.

Frankly I don't have the time, the inclination, nor the resources to prove it scientifically beyond any shadow of a doubt. It is rather a lot of work and time is short and better spent on other things. What I did convinced me and the other half. The differences were obvious to both of us. It would certianly be interesting to measure the differences in detail and gain some understanding of what is going on, but too late now the MDF cabinets are no longer. Everyone is entitled to their opinion, and anyone is free to build identical cabinets and do the measurements and listen themselves, and maybe come to different conclusions with different cabinets and the debate will continue. All I can say is that with my cabinets, and my cabinet design, with the 2 larger cabinets there was a significant difference in the sound of the loudspeakers, and we both preferred the Jarrah cabinets. Maybe it is wrong of me to generalise and have strong opinions on this because there is no absolute proof, but I only use MDF for prototypes now. Other people have done similar experiments and have come to similar conclusions. The last I saw was a report on one of the DIY forums where various materials were used and plywood came first, MDF last, so solid timber is not necessarily the best material.

[Slashbot_427]

One thing I have found is the quality of the sound from speakers is in the ear of the beholder. 4 years of running a music rehearsal studio for rock bands proves it. Guitar stacks or keyboard amps may not be HiFi, but studio monitors try to be. The vast numbers of different musicians and studio ppl I have spoken to and heard play, and the number of different speaker systems I have heard shows that all have their merits based on what you want to do with them. A case in point: The modern guitar sound has been shaped by 5 or 6 decades of recorded music showcasing guitars using overdriven valve amps, with transformer output stages. If the electric guitar was invented in 1983 ( transistors) instead of 1933, would it have been defined by op amps and sound like a keyboard?. Maybe? I don't know. The over-driven valve guitar sound has become part of the accoustic heritage, and if you try to use a tranny amp it sounds a bit "wrong". If you take a classic guitar speaker, such as a quad box or open backed cabinet, and play a CD it through it, it sounds crap. So why does it sound great with guitar, but crap with a radio mix.

You can run all the calibrated tests you like on a speaker system, and get fantasticly flat or crap results, but there is no calibrating a human brain. There is a lifetime of accumulated learning that goes into interpreting any sound that is heard, and the effects of various parts of any audio system will be interpreted differently by one person or another. A persons brain, in effect, is the filter for the sound that hits the ear.

You CAN make a speaker that really is crap, just look at 99% of the computer speakers out there. Its the i-generation.

There are some physics involved in the design of speaker systems, but essentially the principle is that the actual driver acts as a transducer ( ie. it converts electrical energy into sound pressure waves) and the box you put it in acts as a filter. There is also another issue which is impedance. Not the 4 ohms or 8 ohms etc electrical impedance of the wires in the voice coil, but the impedance of the air, and the impedance of the speaker system as a whole. The speaker system is a transducer, so its job is to transform electrical energy, to magnetic energy ( in the coil gap) to kinetic energy (cone movement) to sound pressure waves in the air. The degree of impedance matching between all of these energy transformations, at each frequency of interest, will define the frequency response, and sensitivity of the speaker system.

There are specific compromises involved, which can be poked in one direction or another by tweaking the design. The smaller you make the enclosure the higher the order of filter the enclosure needs to be to reproduce the bass frequencies -which increases the phase shift of the pass band. This increases the phase distortion, which is almost never quoted in specs, but results in different frequencies being reproduced by the speaker system at different delay periods.

The sound pressure levels from a phase distorted speaker system may show a "flat" response from 20-20kHz, but the various frequency bands are arriving at the listeners ear at unrelated times, due to the phase error. It is tiring to listen to.



I have a pair of full range, single driver speakers from about 1960, in cabinets with a volume of about 250 litres each. The cabinets are a direct radiated design with a rear, phase-matched bass frequency horn from the rear of the speaker cone ported to the front of the cab. I have no Idea of the specs, nor do I really care. I find them very easy to listen to for a long time ( 3-4 hours) at quite loud volumes, and really enjoy them. There is a good clarity from the speakers, so they are easy to listen to, but they are coloured by the cabinets- they have a thick midrange. The cabinets are some sort of ply, which is obviously flexing and farting with the internal sound pressures, resonating with the mid range, and absorbing some of the high frquencies. I'm not sure that replacing the ply with solid wood would have that much effect.

Cheers

[soundman]

I have to agree with slashbot, beauty is in the eye ( or ear) of the beholder ( beer holder) and it is very difficult to get any two sound guys ( even worse HIFI buffs) to agree on matters of taste. More so having knocked arround the pro sound and to a lesser extent the hifi indusrty for a couple of decades, I can tell you there are a great many out there with their ears on well and truly crooked.

back to the matter of solid timber cabinets........I have absolutly no doubt that you can build a sucessfull and reliable pair of speakers out of solid timber....BUT... you will need a great amount of care (or luck) to select an appropriately stable spiceis and suitable stock from that spicies....then employ approproate construction methods.

There are considerable advantages for the person of average understanding and skill to use typical sheet goods such as chipboard, MDF and plywood to build speakers.

The above two reasons are why in general people are advised not to build speakers out of solid timbers.

As for making a direct comparison between this speaker and that that are the same design but different materials. This is not valid unless appropriate structrual modifications are made to the design, particularly in larger speakers.

typical australian hardwoods will have significantly greater density and stiffness in comparison to most sheet goods.

MDF is a fine material for construction of (non portable) speakers and when it came out was raved about in the speaker construction press specificaly due to its density (mass) and deadness (dullness) in comparison to the popular materials in popular use at the time ( ply and chip).

However it must be understood that MDF is not particularly rigid in comparison to other materials. In comparison of like thickness, MDF has very much inferiour stuffness to both chipboard and most ply It will certainly have inferious stiffness to a nice piece of australian hardwood.
To confirm this all you have to do is build a few long span shelves. Tin munutes with a few boards and a few bricks will prove this.

If you are to get best advantage from MDF it needs to be thick and preferably well braced.
Most of the sucessfull designs I have seen in MDF have used very heavy section 20 and 25mm and even up to 32mm.

If you are to discuss the benifit of this material over that (regardless of use) correctly engineering to the best use of the material has to be considered.
So if you build two speakers of precisely the same construction but change the materials only, one of theose materials will be disadvantaged and will look inferiour.
It does not matter if it is an aluminium boat trailer V's a steel one OR a timber framed house V's steel one OR as we are discussing, Solid timber V's something else for a speaker cabinet......two products optimumly made from different materials will look very different.

As I have mentioned before...I think the suposed benifit of using "tone woods" in speaker boxes is as much BS as marking arrows on your speaker cable or painting your CD's green.

Panel resonance of any form has and always will be undesirable in speaker design. Any suposed advantage will come down to rigidity and mass.

In my experiance "dullness" experienced due to speaker box factors can always be traced to a failure in panel rigidity.
This is the main reason that almost without exception the plastic moulded "pro sound" boxes currently popular sound dull, coloured and muddy.....lack low mid presence and have poor bass transient response.
All you have to do is crank one of these up and feel how much energy is being radiated by the walls of the box energy that is lost to the speaker cone and the port.

On the subject of phase distortion......This is certainly a matter that I hear very little of these days......In the "golden age of reason" ( late seventies to early eighties) when there was a refreshing outbrake of honesty in the sound business, phase distortion and time alignment were very commonly discussed in the forums of the time, in sales material and in technical specifications.
However with the advent of computer sound and mass market HIFI and home cinema, we have gone back to sales spiel, smoke & mirrors, inparticular concentrating on and lying about POWER. Sound has passed from the hands of the bofin and enthusiast to the salesman and the ignorant consumer.

As for sayig someone is ignorant because they do not know of any brand name is an insult and displays extreem ignorance.
I am sure there are those on this forum that could sprout may significant names that most will never have heard of.....knowing or not knowing a name or brand means nothing.


Finaly.... I can not understand why someone would seek the aproval of a bunch of key punchers, before building somthing they plainly wnat to do anyway......"he go and build your solid wood speaker Youl Brunner" if it does not work you have leraned something.

Hell I have kept myself warm many winter nights burning bits of speaker box.

cheers

[rrobor]

If you build your speakers out of a wood that doesnt resonate, IE tap it, if it makes a noise like a zylophone it aint no good, I would use redgum jarra or box. Id make the boxes a bit big, then line them with MDF glued in panels. Only issue you will have is the hernia from lifting the suckers. As to the quality of sound out,. You wont care , too busy admiring the boxes.

[Sharpdon]

Interesting thread. I make speakers as part of my business, and they are almost all made out of solid woods. The wood type is not a concern as the speakers are dipoles and not box speakers. The sound is very open and natural. Siegfried Linkwitz is the designer and also gave a presentation at the most recent AES 126 Convention in Munich, speaking about Recording, Reproduction, and Delivery. You may find the information interesting. See: http://www.linkwitzlab.com/publications.htm#23 for this and much more.
I have these speakers and can say they do show flaws in recordings that I think the recording engineer would have omitted had their monitor speakers been up to the task.
You can make these speakers yourself with a documentation package and circuit boards he offers for sale. They do use active crossover networks, so require six to eight channels of amplification (60Watts per channel is recommended). I am sure you can find more information about these if you are interested. I am only suggesting this as I am a woodworker and and an audiophile who enjoys listening to music. I made all the speakers (out of hardwoods) shown in the band at the top of the Linkwitzlab page. I know there are Orion users in Australia, as I have shipped completed systems there and know there are some who have built these themselves. Some owners allow auditions of their systems, so if interested, you might inquire if someone near you would offer this kindness.