Birch ply is relativiely cheap & available. It isn’t so much the specific material, it is the numbe rof plies and teh quality of construction.A step up is stranded/fossilized bamboo plywood. I hav esome RIchlite which is quite interesting.
dave
As a general rule of thumb, I go for: stiffness for subs; damping for mids.
If only it were that simple...
If only it were that simple...
This is very interesting. Where do you find graphite sheets big enough to make a speaker out of? Wouldn’t they be extremely messy?
I’m intrigued by fiberglass and composites in general mostly because you can build loudspeakers in any shape. This opens up many possibilities to the DIY’er. Making something that looks like the KEF Blade is in the realm of the possible for someone who doesn’t have a CNC machine. I’m glad that loudspeaker designers are finally taking into account the shape of the cabinet. And no, my wife wouldn’t like a propeller blade shaped speaker either. 😤
Definitely interesting, maybe a bit beyond ‘noob’ capabilities though. Maybe OP is a boat builder? I remember fiberglass speakers, they never took off. Walnut veneer over particle board was way more popular than space aged plastics. My wife would never stand for a bright blue auto lacquered loudspeaker, she’s funny that way.
I’m intrigued by fiberglass and composites in general mostly because you can build loudspeakers in any shape. This opens up many possibilities to the DIY’er. Making something that looks like the KEF Blade is in the realm of the possible for someone who doesn’t have a CNC machine. I’m glad that loudspeaker designers are finally taking into account the shape of the cabinet. And no, my wife wouldn’t like a propeller blade shaped speaker either. 😤
Wow! Thanks for that. Richlite is very interesting. used for non-wearoutable fret boards. I need to try some. They even have bamboo and ply laminates. https://www.richlite.com/partialsheets?page=2
I’m definitely going to try that in my next build. I assume it glues up with epoxy. It would make a great top for a router table too. Downside is … it’s expensive! $54 per square foot of 3/4” or $1,700 for a 4x8 sheet.
I am mostly doing FR single driver loudspeakers. Only have the option of the first. I take advantage that in music there is VERY rarely sufficient continuos HF energy in a narrow enuff bandwidth to set off the potential box resonances. And that the thickness of material vrs the wavelengths that would excite them, there is much more effective damping. It is easy to show that this energy falls off 2nd order as in the blue line in the chart in post #39. Further iformation suggests it may be 4th order — red curve.
I typically turn the music up and listen to the box with a mechanics stethescope. Rap the boxes with a hammer just right and you can set them off. If became evident that the time-smeared grunge coming off the MDF boxes was masking the small detail, robbing DDR.
dave
Fiberglass, carbon fibre inside and out dramatically stiffens things.
I did use it on some horn PA builds, but the stuff is nasty to work with. I also did HDF boxes lined with laminate/arborite. That was before i discovered BB. Late rwe switched to a higher quality version detailed in OR.
dave
I did use it on some horn PA builds, but the stuff is nasty to work with. I also did HDF boxes lined with laminate/arborite. That was before i discovered BB. Late rwe switched to a higher quality version detailed in OR.
dave
Your rudeness is definitely stiffer than your laminates, at the end of the day use what you feel is the better material man, that's how voodoo works
More advanced construction techniques may sound intimidating, but I did try to convey the reassurance that it's actually easier and less messy than traditional once taken through the process
I'll leave you be
Hi.
First, living in the city in a condo means no workshop.
I'd have to join a local 'maker shop' that has the equipment and space.
While I am a software engineer, its an engineering degree. So looking back some ~35yrs ago at my strength and materials course...
1) All things resonate if enough energy at the right frequency is applied.
2) Depending on the density and type of materials , energy would either be absorbed or reflected back.
That said... there are 'densified' laminates (d-lam) which would reduce vibrations. More expensive than mdf or birch ply.
Using different materials. D-lam for cabinet, hardwood for internal support(s) or maybe a laminate of some other materials.
I would suppose you don't want that to resonate either.
I am considering using either a full range or a coax driver.
For example
Tang Band W8-2314 8" Coaxial Full-Range Woofer
I've noticed that outside of the Fyne F1 series (Their 'flagship' design) They have gone to more traditional box or shaped box designs.
(So not so much of a translam design, but could be done w layered d-lam , birch, or mdf. )
Even their F1s look like you could take this approach, only using translam for the cylinder but then the trick would be in the cutout for joining the cylinder to the box. Or just take a more practical design like their F-701's.
The other thing they talk about is an internal box for the downward port. I saw a cutout diagram on one of their tower designs. Essentially its a rectangular box w a port hole inside the speaker. then the port and tube are at the bottom of the speaker So you would get a chamber within the box.
Any thoughts on that?
Or could go smaller w a 4" driver
Tang Band W4-1879 4" Full-Range Driver
But would then need a small powered sub...
The benefit here is that it would be a small bookshelf unit.
First, living in the city in a condo means no workshop.
I'd have to join a local 'maker shop' that has the equipment and space.
While I am a software engineer, its an engineering degree. So looking back some ~35yrs ago at my strength and materials course...
1) All things resonate if enough energy at the right frequency is applied.
2) Depending on the density and type of materials , energy would either be absorbed or reflected back.
That said... there are 'densified' laminates (d-lam) which would reduce vibrations. More expensive than mdf or birch ply.
Using different materials. D-lam for cabinet, hardwood for internal support(s) or maybe a laminate of some other materials.
I would suppose you don't want that to resonate either.
I am considering using either a full range or a coax driver.
For example
Tang Band W8-2314 8" Coaxial Full-Range Woofer
I've noticed that outside of the Fyne F1 series (Their 'flagship' design) They have gone to more traditional box or shaped box designs.
(So not so much of a translam design, but could be done w layered d-lam , birch, or mdf. )
Even their F1s look like you could take this approach, only using translam for the cylinder but then the trick would be in the cutout for joining the cylinder to the box. Or just take a more practical design like their F-701's.
The other thing they talk about is an internal box for the downward port. I saw a cutout diagram on one of their tower designs. Essentially its a rectangular box w a port hole inside the speaker. then the port and tube are at the bottom of the speaker So you would get a chamber within the box.
Any thoughts on that?
Or could go smaller w a 4" driver
Tang Band W4-1879 4" Full-Range Driver
But would then need a small powered sub...
The benefit here is that it would be a small bookshelf unit.
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I have a pair of those, cheap. They measure (T/S) as if each driver were a different model. And they are kind of coloured.
dave
Dave,
That's good to know.
The 4" TangBangs are ~$230 each... not exactly cheap.
(But that's relative. I guess, especially since there's only 1 driver and no crossover)
I guess finding the right driver will help determine the size and somewhat the shape of the cabinet.
Again, its a thought exercise that may never go anywhere, day job work is picking up.
But I guess the fun is thinking thru the design and seeing what goes into a speaker build.
Thx again for the input.
That's good to know.
The 4" TangBangs are ~$230 each... not exactly cheap.
(But that's relative. I guess, especially since there's only 1 driver and no crossover)
I guess finding the right driver will help determine the size and somewhat the shape of the cabinet.
Again, its a thought exercise that may never go anywhere, day job work is picking up.
But I guess the fun is thinking thru the design and seeing what goes into a speaker build.
Thx again for the input.
Damping is always a good thing.
Some people have reservations that chasing one property compromises another. It's not necessarily like that. Damping is not reactance, it doesn't simply soften other materials or inherently cause more movement. It does respond to existing movement of course, the very movement which is the problem in the first place 😉
Hey man, if you are interested, keep an eye out for my Tiny40s test box build. The construction process actually addresses your points and then some. Since I am making one with MDF and one in foam, if I change the material over to marine ply instead of MDF, then it will be a good example of how I have been recommending to work with FRP
The only issue is that I feel that I haven't been able to acoustically model the test box, as I don't have the experience to tell how well I am reading the results from Hornresp and Winisd. The consensus is that my modelled boxes are acoustically poor, so haven't been too eager to waste materials and time until I get that right
I found this... https://www.tb-speaker.com/products/PR10-A
Which is the 5" w a passive radiator
also see: https://www.tb-speaker.com/uploads/files/d3541016ff29a511aaf9afe8da14ea26.pdf
If I'm reading the spec correctly its a 3.6L box?
Also I'd need to figure in an amp.
I'm trying to picture a rough size of a 3.6L box? I mean that's fairly small. The passive radiator is ~8"
Something like 9x9x6 or something like that???
If one whole side is a passive radiator... that would make bracing interesting. (Would it even need bracing? )
Thx
For my small home office... This would be perfect for a 2.1 solution.
Are we talking about these:
https://www.parts-express.com/Tang-Band-W4-1879-4-Full-Range-Driver-264-903?quantity=1
Where did you get them or when?
I mean if I did these in cabinet w a downward port... I think I could do something neat.
Sorry. It appears I quoted two different posts. If you think I’m rude you should move to Boston.
https://www.diyaudio.com/community/threads/tiniest-40hz-sub.407158/post-7574293. Next box I model will be the 4L with 2x 6.5" Dayton reference alloy cones and be build to keep an eye out for. The cross-section is almost egg shape on that and the internal volume can be adjusted by any amount even after completing initial build and listening tests. My bass driver is expected to arrive this Friday and I am really looking forward to putting it through its paces