Hi thank you for the very interesting advice
When we agree on the importance of stiffness and compare the stiffness of various materials it's clear that metals win hands down
And this explains why someone use them facing all technical issues
I am already in crisis with wood
But i am thinking to stiffeners like bracings but made of bolted metal bars
It could be a decent compromise
Hi yes maybe above 300 Hz could be decent satellites
But the bass range is the real challenge
I have many friends who use towers with small woofers
They don't know what a real bass is really
@ginetto61
Speaking of different materials and different stiffnesses, one of the first compromises to be faced with is the consequence of the fact that the more rigid a material is, the more it will transmit vibrations.
Yet you need a rigid material so that the driver remains as immobile as possible.
I'm glad to read about your penchant for metal (just because it can be a motivation), but I really don't like it as a material for loudspeakers, and even less for a subwoofer cabinet.
Also because if the metal does not have an adequate thickness then it flexes and transmits a lot of vibrations (read "noise") to the outside.
Take a sheet of metal and take a sheet of MDF and bang them both and you will make my point.
Furthermore, if it has sufficient thickness and an adequate size then how much will it weigh? 😉
However, even if said here it might seem out of place, even if in my opinion it isn't at all, the materials with which the (counter)top of modern kitchens are built could in my opinion be very interesting to analyze in their characteristics.
Among many, have you ever considered Corian?
https://en.wikipedia.org/wiki/Corian
https://www.corian.com/
Speaking of different materials and different stiffnesses, one of the first compromises to be faced with is the consequence of the fact that the more rigid a material is, the more it will transmit vibrations.
Yet you need a rigid material so that the driver remains as immobile as possible.
I'm glad to read about your penchant for metal (just because it can be a motivation), but I really don't like it as a material for loudspeakers, and even less for a subwoofer cabinet.
Also because if the metal does not have an adequate thickness then it flexes and transmits a lot of vibrations (read "noise") to the outside.
Take a sheet of metal and take a sheet of MDF and bang them both and you will make my point.
Furthermore, if it has sufficient thickness and an adequate size then how much will it weigh? 😉
However, even if said here it might seem out of place, even if in my opinion it isn't at all, the materials with which the (counter)top of modern kitchens are built could in my opinion be very interesting to analyze in their characteristics.
Among many, have you ever considered Corian?
https://en.wikipedia.org/wiki/Corian
https://www.corian.com/
The steel boat Princess II and the plate alloy Silver Lady here back in the day were both similar size. The alloy boat banged hard while the steel was super dampened
With your example, place a finger on the MDF and steel. It will quieten the steel but make zero difference to MDF
So what?
I would never build a subwoofer cabinet out of metal, steel, sheet metal, iron or anything else.
Apart from perhaps tungsten, which is the stiffest existing material AFAIK?
I'm joking about tungsten of course, but I didn't realize the boats example compared to the subwoofer cabinet.
How much do "Princess II" and "Silver Lady" weigh respectively? 🤔
I would never build a subwoofer cabinet out of metal, steel, sheet metal, iron or anything else.
Apart from perhaps tungsten, which is the stiffest existing material AFAIK?
I'm joking about tungsten of course, but I didn't realize the boats example compared to the subwoofer cabinet.
How much do "Princess II" and "Silver Lady" weigh respectively? 🤔
Not very good for enclosures, we have used it to “decorate” some boxes (ie a top of such on a pair of mFonkens, because not sufficient veneer to finish the job.
dave
May be, but not for me, thanks.
I would never build or want one, of any shape.
And I didn't even like the various "metallic" Canton from ages ago...
Just my personal preference.
Really?
I really like that material though.
"Corian consists mainly of aluminum trihydroxide (55-60%) and polymethyl methacrylate (34-45%) with trace elements of iron oxide black, carbon black, titanium dioxide, colorants and methyl methacrylate".
The physical characteristics look promising for speaker cabinet construction.
One in particular intrigued me a lot:
"Thermoformable: Flexible when heated, Corian can be shaped and molded into generally limitless forms which can be used in commercial and artistic projects through a process called thermoforming".
I've never used it anyway.
However, I completely realize if the aesthetics must not have been exactly the best.
I believe that today they have also improved from an aesthetic point of view, though.
Corian and similar materials have pretty good stiffness - similar to the best plywood, I believe, and at least double that of mdf. Density is approx double that of hardwood plywood. Damping is difficult to get info on. I'd say that it's good for subs.
Large cabinets will be heavy, though.
Large cabinets will be heavy, though.
hi thanks again Instead of perfection i prefer to think about ideality Like the ideal behaviour of a component and how much a real component approaches ideality
The closer to ideality the better Unfortunately i have a feeling that the materials can be very good for one property and not so good for others
For instance a very stiffness material can be very bad at damping vibrations
The solution could be a combination of materials ideal for one property and another
One material that impresses me much is the bullet proof glass It is a combination of a very stiff one and a plastic layer
It is impressive how it blocks noise coming from the streets
Unfortunately working on it is out of reach for many diyers
Never hear a speaker made with this kind of material
you got me It is so hard to accept compromise I guess this is what is called maturity ? then at 63 i am still quite immature
Of course it depends on the object of discussion
For instance i see a mains transformer in a amp that i am thinking to mod and so destroy It looks nice But if i look at its secondary so thin i get sad
I am quite sure that there are much better transformer out there in terms of regulation and the desire of replacing and throw it in the garbage bin becomes strong
the mature guy accepts this Any cheap commercial product is designed and built with costs in mind
I am pretty sure that i will replace it A mains transformer is the first and more important bottleneck in an amp
Like i am sure that most transformer in cheap amps are garbage Unfortunately measuring their regulation is not easy
on the basis of what i have learned increasing stiffness moves resonances up in frequencies It could be that high Hz resonances are easier to cancel
Maybe just little absorbing pads placed strategically will solve the problem
you are very right and the evidence is that metal cabinets are more an exception than a rule Like multilayers glasses concrete carbon fiber and so on
By far the most common material is MDF Easy to work cheap Unfortunately very far from ideal I even start to hate it
Why ideality must be so difficult to achieve ?
By its very nature.
it is a creation of the mind when you set a goal.
We can even call it a "dream" if you want.
Then there is the reality (of the laws of physics to deal with). and most of all of what is there. 🙂
Now I'll continue reading your comment. 😉
hi thanks for the hint I should find a guy with cutting machine and a welder It would be really nice I believe in stiff materials now completely
at the point that i wonder why many keep on using MDF that is such a poor material This choice leaves me puzzled
Yes ! with the right drivers these could be a great option for mids and highs I paid almost nothing for them and they do sound nice
from 300 Hz up i would place them side by side with the famous Rogers and listen if the difference is so great I really doubt
Bass solution is the problem The challenge The nightmare
If I may, just because MDF represents the compromise of compromises.
And that's no small thing.
If it is so widespread even among the most famous manufacturers and if it still offers acoustic results that satisfy those manufacturers and their customers there must be a good reason.
If you want something that comes close to ideality and you follow that path you will find exactly what you are finding.
No certain and definitive answer.
Because of the inevitable compromises.
And you return to the starting point.
Maybe, I repeat maybe, you should reconsider your ambitions and goals.
And most of all, make your choice, because none of us will be able to make it for you. 😉
IMO
nice 😢
let me be more precise My final system will be a satellite from 2-300 Hz up and a 12-15" woofer in a separate box One per channel
no additional subwoofer will be needed A good 40 to 18kHz response and i will be done for ever
While the sats are really not a problem the bass solution is and a lot
on the basis of what i have learned here cheap commercial units are garbage especially considering the cabinet execution
While good woofers are available off the shelf cabinets are not This is the very challenging task
actually to build a great cabinet for a single powerful woofer is the most challengig of all tasks
at the point that using two woofers back to back seems the only viable solution really
4 woofers will be needed
😀
I understand what you mean, but you possibly would be wrong, imo.
However, I just saw a Stereophile positive review of a subwoofer that costs over 10,000 bucks and weighs nearly 50 lbs.
Why does it cost so much?
Because in my opinion it maybe will be very technological.
Is the cabinet made of iron?
Or glass?
Or concrete?
Frankly I don't know, but it doesn't seem like it though.
Why does it cost 10,000 bucks?
I don't really even know, but I know that it was placed into a system that at a rough estimate cost no less than a pair hundred thousand bucks.
This is why I asked you earlier in which system you would have placed your subwoofer.
Because in my opinion the quality of the pieces of equipment should be homogeneous enough, in order to obtain an optimal result in SQ.
However, using a 15" woofer would be another thing to look at, in my opinion.
Maybe, I repeat maybe, you didn't quite realize what you were getting yourself into.
I believe that by pursuing your ideality (which I understand and respect, also because I also like oversized and quality things) you could run the risk of losing contact with reality (I called it "common sense" before, I think).
Especially because yours is a DIY project, not the top of existing technologies in subwoofers, I respectfully think.
And yet the 10.000 bucks subwoofer mentioned above is perhaps very technological.
And I don't think you would be able to mimic their behavior and the knowledge behind it, at least not in a reasonable amount of costs and time.
Yours is a DIY project and as such it has the duty to be very realistic, rational and with your feet firmly planted on the ground, imo.
Otherwise...
Hey man, you can make the most ideal cabs out of metal if you wish. But maybe try to develop a culture of teaching yourself exactly how to implement it yourself. Get a lil AliExpress angle grinder and start from there. Teach yourself how to use it. You don't need to weld metal all the time. For speaker use, learn how to use epoxy correctly from the documents on the West Systems site and the Gougoun bros handbook there
Relying on others to make your ideals for you is not what DIY is about. I have the experience to create metal shapes, but for a sub, I would make a dual steel skinned body filled with concrete if I were real;y set on metal. Get rid of the ringing. To experiment, try placing one metal tubes inside another and fill that gap with a mix of epoxy and sand, Bamboo chopping board baffle and back. Make some satellites and a lil computer type sub with 3" FR drivers and cheap 5" sub driver from Ali and get used to using the grinder and a jigsaw or lil router trimmer
You need to get hands on with some tools for your ideals, ideally. That's where the DIY satisfaction is. Plenty here who will move you along if they see you working systematically towards arming your self and learning the skills for the task as you push your project along
MDF?
You will find on this very site the same folks talking MDF down in one thread and suggesting Sonotube in another. I consider them both paper boards and, just like any other rigid material, engineer it to the required duty
This will give you a mental spasm, right now I am engineering an external 80L cab for a 1kwrms 12" sub with 7kg of magnet and running 600wrms on each of its dual voice coils. I am using 12mm MDF, but I have taught myself very very well how to work and engineer with MDF over a period of 35yrs