Yes, I recommended the balsa laminate for a "lite" speaker but extra mass is fine for my own use, so I planned some lead* for my subs too.
Rather than silicone I chose a bituminous adhesive because I expect it will be lossier.
I haven't applied it yet to confirm this but it may be worth your consideration.
*Pre RoHS!
Best wishes
David
Yes, I could read that.
The wikipedia article supports the points I made earlier.
The article, like every other source I've seen, says that plastics can be absorbed by some basic organisms (worms, plankton etc), but has been observed only in the guts (and gills) of the fish that eat them.
It says that ingested plastic will "pass through an animal".
It does not support the assertion that plastic will "eventually lodge inside the cellular structure of all living creatures."
NOTE: I'm perfectly willing to believe that it could happen. But at the moment, it hasn't yet been observed, so is just speculation.
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I didn't make the assertion, why reply to me? I just provided a link with some references, at your request.
I am not keen on a dispute that feels like a troll.
Unless you let me bury my plastic trash at your place.
That would demonstrate that you sincerely believe your own position and simultaneously solve my trash problem.
And I will totally concede if you mix the small pieces in with your food, it's all unplasticised so it should be OK, just pass thru yes?
Best wishes
David
hollowboy, there are a lot of highly intelligent experienced members on this forum who really do understand what they are talking about, and old enough to know when they are being trolled. I for one, have been very patient with you, and appreciate that maybe - just maybe - you have some remedial learning difficulties, and that's fine by me. So, having established (at least in my own mind) that indeed, you are NOT a troll, then take the provided Wiki link at face value - that of entry level public domain information made for the needs of the casual enquirer. Someone like you fits the demographic perfectly.
To which I will add:- learn for yourself the differences between an atom, a molecule, a particle, a micro particle, a nano particle, a sub-atomic particle, a colloidal suspension, a slurry, a muscilage, a solution, a suspension, and after you have done all that, you can hook up with me and (maybe) Dave Zan in The Lounge for a blather about plastics. Until then, be good and be kind.
tapestryofsound
To which I will add:- learn for yourself the differences between an atom, a molecule, a particle, a micro particle, a nano particle, a sub-atomic particle, a colloidal suspension, a slurry, a muscilage, a solution, a suspension, and after you have done all that, you can hook up with me and (maybe) Dave Zan in The Lounge for a blather about plastics. Until then, be good and be kind.
tapestryofsound
Specifics aside, I think it is fair to say we all should consider the environmental footprint of our projects. Certainly fits within the scope of this thread to raise questions.
Difficult for us because "value" questions (both in the ethics and the dollar sense) are esp hard to parse for a hobby. Oops, my supper is ready and I have to go before saying more...
B.
Difficult for us because "value" questions (both in the ethics and the dollar sense) are esp hard to parse for a hobby. Oops, my supper is ready and I have to go before saying more...
B.
To troll usually means to intentionally disrupt something, at minimum effort to the troller. It is usually "inflammatory and digressive" [...] "with the intent of provoking readers into displaying emotional responses" (quoted from Internet troll - Wikipedia).
In this thread, Dave Zan (post 61) made some claims, eg "hideous if its ever burned".
I think this is untrue (when good processes are in place). I provided very clear references in post 65 to support my opinion.
Dave Zan (or anyone other reader) can simply go to those references and read them. A reasonable response would be to say "good point, it appears that Dave's claim is only true when poor practices are in place" - and move on. That's not "inflammatory and digressive".
tapestryofsound (post 70) made some claims, eg, that any plastic will "become particles tiny enough to eventually lodge inside the cellular structure of all living creatures"
I think this claim is not currently supported by any scientific literature. For example:
e.g. https://www.state.nj.us/dep/sab/NJDEP-SAB-PHSC-final-2016.pdf
"Literature searches [...] identified approximately 100 peer-reviewed references [...] No research was identified either through the aforementioned literature databases or internet searches that directly assessed either human exposure to or human health effects of micro/nanoplastics in the environment."
Again, a reasonable response would be to say "yeah, good point; TOS has made a claim that is not supported by current research" - and then move on. Dave Zen has already done this (in post 83).
That's not "inflammatory and digressive". When people agree on a point, based on the best evidence currently available, that is the opposite of digression.
IMO, providing (and accepting) information about current research and best practices is a Good Thing.
On the other hand, ad-hominem stuff is "inflammatory and digressive" with "with the intent of provoking readers into displaying emotional responses", so I'd be grateful if you'd leave that stuff out.
Ok, the OP hasn't objected so until he does...
I think this is mostly a quibble.
It may be possible to incinerate PVC cleanly but there are no such facilities in Australia, in any substantial public use.
AFAIK anyway, if you can find one then please correct me, I would love to use it.
There is currently some discussion of whether they would be desirable.
If a consensus ever is achieved then it will be many years by the time such a a facility is planned, approved, protested, appealed in court, built and tested.
So for the foreseeable future, and as far as you and I are concerned, any PVC burned will be done the hideous way - in factory or rubbish dump fires, incidentally in bushfires, by lazy backyard burners, and so on.
The best practice that you mention is practically irrelevant in Australia, so I don't understand why you want to dispute about it.
I feel similarly about your other objections, possibly debatable but I don't see the point, so I'll stop at one.
Best wishes
David
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Of course.
Millions of tons of PVC are made every year. Massive quantities of PVC plumbing are embedded in out cities and houses. We drink and shower from it. We eat food irrigated via PVC pipes. Compared to that, the environmental impact of one or two sheets used in DIY audio is definitely just a quibble
I believe that is correct. Because of the large capital costs, NIMBY stuff etc, we probably won't get one anytime soon.
However, 1 minute on google can show that we do have several recycling options. e.g. I assume this company will take PVC, since pipe is listed:
Astron also has the capability to accept post-consumer (dirty) rigid plastic. Examples include:
Hard to recycle industrial plastic packaging such as jerrycans, drums & IBCs.
Post-consumer milk bottle.
Plant pots, pipe & used wheelie bins.
This material is put through an intensive cleaning and washing process prior to conversion into recycled plastic resin.
Hard to recycle industrial plastic packaging such as jerrycans, drums & IBCs.
Post-consumer milk bottle.
Plant pots, pipe & used wheelie bins.
This material is put through an intensive cleaning and washing process prior to conversion into recycled plastic resin.
My main personal involvement is that I semi-regularly go to a recycling yard where some of these items are sorted.
I go there to buy used, intact items for use on a country property - mostly for tree planting (trying to rehabilitate some dodgy farmland), sometimes for audio*. While I'm at that yard, I sometimes drop off things for recycling. If I had a lot of scrap PVC, that's where I'd take it.
A quick search on Google found the alternative (even better practice) recycling option.
I cite the Tokyo example to show that large scale examples of good practice do exist. It might make more sense to point the finger at our poor practices rather than at the substance.
*The compression chamber on my outdoor horn is made from a used 220 litre drum (originally for transporting olives). I have the horn raised up on two heavy-duty plastic pallets (stamped as being from Kirin brewery) to keep the base dry and termite free.
Pix in post 53 & 63 of this thread:
Artichoke Horn
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I'd considered bituminous adhesive but wasn't sure it would be strong enough to hold the lead. Did you have a particular product in mind? Are you planning to use nails as well? I was looking at CT-1 silicone which specifically marks itself as suitable as an adhesive for lead. Guess I'll do a test piece anyway to check before I start putting anything in the speaker box.
Acoustic material suppliers have good stuff designed for either barrier or damping or absorption, etc.
My favourite, perhaps more easily found in Canada, is a certain pipe insulation that comes on a roll maybe 6 inches wide. It has a maybe 4 mm gooey sticky rubber layer and on top is a heavy aluminum foil. Super for wrapping dishwashers tanks and maybe in multiple layers on speakers too. Light but very dead.
I have also come to the conclusion that rigidity is much over-rated and some cabinet flex isn't terrible.
B.
an apology
This morning I looked back at what I wrote a couple of days ago and was mortified. This is not me. I am caring for someone who is about to undergo cancer surgery - again - while at the same I am suffering from a soul crushing depression trying to deal with a daily dose of what amounts to an unrelenting shitstorm of responsibility. In a situation like this it is hard to maintain a sense of perspective, mainly due to a lack of sleep, and frankly, I am truly sorry to have upset hollowboy. Anyway, I have nothing left to say and a heck of a lot to do.
Can we move on?
Kindness tapestryofsound
This morning I looked back at what I wrote a couple of days ago and was mortified. This is not me. I am caring for someone who is about to undergo cancer surgery - again - while at the same I am suffering from a soul crushing depression trying to deal with a daily dose of what amounts to an unrelenting shitstorm of responsibility. In a situation like this it is hard to maintain a sense of perspective, mainly due to a lack of sleep, and frankly, I am truly sorry to have upset hollowboy. Anyway, I have nothing left to say and a heck of a lot to do.
Can we move on?
Kindness tapestryofsound
I already have the product, it's made by Ormonoid, an Australian manufacturer so probably not available in the UK but I can check the label name if you want.
Like you, I am concerned about the adhesive bond, the stuff will probably flow very slowly, a classic physic experiment.
So I do plan to use nails or staples to keep it attached over time.
Seems sensible.
Lead has more internal loss than aluminium so it should be better but this won't matter much if the constrained losses layer dominate.
I am at work on an aluminium constrained layer face-plate for my speakers.
Interior treatment with some lead is a bit of an experiment.
You shouldn't worry that you upset him, he's an Australian, like me, and we're famously insensitive.
You have sufficient worries already, I hope the outcome is successful.
"Best wishes" is not just a formal salutation.
Best wishes
David
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Wow. After reading internet forums since the late 80's- beginning with Usenet, I can count the number of times I've seen that on one hand.
Keep your chin up and your outlook positive, you are in a tough position. I was diagnosed with stage 3-4 colorectal cancer last July. Had radiation and 2x chemo followed by a colon resection and ileostomy last month. If you need an ear to bend, or just want to fuss at someone behind the scenes, feel free to send me a PM.
I imagine that a composite enclosure would still use a solid plywood (or MDF) mounting ring for the installation of the driver(s). If the mounting is the same thickness as the foam core, it can act as an extension of the core for both outer and inner skins. Two skins of 1/8" ply with a 1" thick core ought to be pretty stiff and fairly lightweight. At that point, one could just cover the edges and corners with removable steel angles and/or reinforcements.
Don't worry about it, the ad-hominem stuff was mostly just odd (rather than offensive).
I hope the operation goes well.
Where I am, hospitals can hook you up with stuff like social workers, home nurse visits (to assist with things like changing dressings), free equipment and counseling. Also: many of the consultants will happily write letters that help to cut red tape, such as supporting applications for benefits, requesting early access to superannuation funds, stuff like that.
If you make your needs (and stress / fatigue) known, there may be similar resources you can tap into.
That's how this chap does it:
The Grand Monument Reference features heavy lead lining to all exterior surfaces. The same heavy bracing is used, but all areas between the bracing are covered by a unique sandwich lining. Heavy acoustic felt is used to separate the heavy lead sheet from the cabinetry. A further layer of heavy acoustic felt is placed over the lead and the entire sandwich is stapled to the walls of the cabinet. This result is what is effectively a box within a box. Wrapping the outside of the speaker is similar to knocking on a brick. This totally inert cabinet construction results in the ultimate sound reproduction.
Monument | Osborn Loudspakers | World's Best
Me: If I wanted to go deep into CLD, I'd avoid a rigid fastener, cos the stiffness of staples / nails would partially cancel the CLD effect. Instead, I'd make use of some sort of rubbery brace to hold the lead in place.
e.g.
1) whatever those things are called that are for bracing glass panels (pictured).
2) KEF style CLD bracing (I think this means: the brace is stiff but has rubbery edges)
3) Geddes style (I think this means: each cross brace is made from two partial braces that overlap in the middle. These don't directly touch, but are joined by a rubbery layer)
Or, the easy way out: hold the lead down with something like roofing screws (that have the rubbery washer).
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