Overstuffing?

[billfitzmaurice]

Re: Overstuffing?

Do you think the alternate location would be better?

Probably, but the only way to know for sure is to try different placements and measure the results.

[Æ]

Re: Overstuffing?

Wow, Pete, you have done something unprecedented here. You've moved me to put a TT member on ignore. You're obviously a very intelligent, experienced designer, and I admire that. Problem is, you're also an unbelievably arrogant icehole, and I have no patience at all for that sort of individual. I truly hope that I never meet you in person, I simply won't bite my tongue in the face of such arrogance face to face, and things would likely get ugly. Congrats, you're the alienation King!

All Hail!



Mark

Horrible thing to say Mark, at least in public. One should never make such tentative threats on the internet, where it becomes public domain. You know, if anything ever did happen, your statements could and would be used against you.

Making terrorist threats? Heck, I was banned from this forum for six months just because I made a statement in jest, that got interpreted the wrong way.

[Mark65]

Re: Overstuffing?

It's OK, Alan, I never threatened anyone. It would just be a shouting match, I'm a lover, not a fighter.😁

[corradizo]

Re: Overstuffing?

I pulled out a massive load of stuffing...

I pulled about a garbage bag full of r13 per sub. Each had a half of a 12lb roll in it with the backing taken out.

I'm leaving my settings all the same and will measure to see how things change. Just from listening, I think it's louder...

[corradizo]

Re: Overstuffing?

Here is the REW file. When I went into windows to check the mic level, it was set at 10.3db. I lowered it to 0db. No idea why it changed. I question where it was at 10.3db or 0 for my baseline measurement. If it was at 10.3db for the original, I think it would make things seem quiet when adjusted to 0db. It's it possible to have gained still much more spl? If you try to level match it, I think I still gained 3db. It's definitely louder.

Rew .mdat file:

https://www.dropbox.com/s/9fw5bg7yhfl7dvo/stuffing%20compared.mdat?dl=0

Edit: my data is bad. I found that the kids turned the gain all the way up on my inuke.

[andy19191]

Re: Overstuffing?

I think in a lot of physical systems there are different ways to describe it and sometimes the disagreements become more a game of semantics than anything.

Not sure I would agree. The debate was about physics which is unambiguous at the fundamental level of conservation of mass, momentum and energy, thermodynamic constraints and empiricism to work with a continuum. A reasoned discussion at this level would have settled things after a couple of exchanges.

What happened instead was that nobody debated at this level (undergraduate level for engineers and scientists) and instead based their arguments on weaker foundations. Claiming someone you consider to be knowledgeable would support your claim is more likely to provoke a giggle than agreement. People putting forward this type of argument know they haven't got a firm grasp of the topic regardless of whether their claim is true or false. What can cause a lot more problems is people basing their reasoning on design rules/parameters. Having a firm grasp of how these behave does not necessarily mean having a firm grasp of the physics they represent but people can and do confuse the two and then take decisions believing they have a solid basis for them. It is clear that some people did/do not understand how stuffing can change the pressure-volume relationship and whether the design rules they are familiar with do or do not include it in their assumptions.

[bill poster]

Re: Overstuffing?

One of the best loudspeakers I've heard were called Electrofluidics Sonolith, designed and built by a one man outfit based in Spitalfields, East London (Jack the Ripper area). I was a teenager at the time and this was early 90s. If I remember correctly they were made of a composite material used in oil rigs (die cast moulds, very expensive to produce back then) and had a modular construction so he could produce different variations. All used modded Jordan drivers/ 1st order, very flat impedance, streamlined cast ports etc.

No stuffing at all, as far as I remember. Ruthlessly revealing, to the point they kind of spun me out.

small pic of one here http://www.6moons.com/audioreviews/t...lineara_2.html

[craigk]

Re: Overstuffing?

Not sure I would agree. The debate was about physics which is unambiguous at the fundamental level of conservation of mass, momentum and energy, thermodynamic constraints and empiricism to work with a continuum. A reasoned discussion at this level would have settled things after a couple of exchanges.

What happened instead was that nobody debated at this level (undergraduate level for engineers and scientists) and instead based their arguments on weaker foundations. Claiming someone you consider to be knowledgeable would support your claim is more likely to provoke a giggle than agreement. People putting forward this type of argument know they haven't got a firm grasp of the topic regardless of whether their claim is true or false. What can cause a lot more problems is people basing their reasoning on design rules/parameters. Having a firm grasp of how these behave does not necessarily mean having a firm grasp of the physics they represent but people can and do confuse the two and then take decisions believing they have a solid basis for them. It is clear that some people did/do not understand how stuffing can change the pressure-volume relationship and whether the design rules they are familiar with do or do not include it in their assumptions.

like when you were copying and posting from other peoples responses from different sites and acting like they were your responses. this makes it all clear now.

[andy19191]

Re: Overstuffing?

like when you were copying and posting from other peoples responses from different sites and acting like they were your responses. this makes it all clear now.

I think you may need to provide evidence in the form of links to support such an accusation otherwise people might think you are just a nasty piece of work that makes stuff up.

[craigk]

Re: Overstuffing?

I think we can all go back and find it if need be. I think we know who the "piece" is too.

[mattsk8]

Re: Overstuffing?

Not sure I would agree. The debate was about physics which is unambiguous at the fundamental level of conservation of mass, momentum and energy, thermodynamic constraints and empiricism to work with a continuum. A reasoned discussion at this level would have settled things after a couple of exchanges.

What happened instead was that nobody debated at this level (undergraduate level for engineers and scientists) and instead based their arguments on weaker foundations. Claiming someone you consider to be knowledgeable would support your claim is more likely to provoke a giggle than agreement. People putting forward this type of argument know they haven't got a firm grasp of the topic regardless of whether their claim is true or false. What can cause a lot more problems is people basing their reasoning on design rules/parameters. Having a firm grasp of how these behave does not necessarily mean having a firm grasp of the physics they represent but people can and do confuse the two and then take decisions believing they have a solid basis for them. It is clear that some people did/do not understand how stuffing can change the pressure-volume relationship and whether the design rules they are familiar with do or do not include it in their assumptions.

I don't see how you could possibly disagree with what Jeff stated. Your comment here doesn't provide any evidence to back up your disagreement whatsoever. What Jeff stated is absolutely true and applies to just about every area of any debate. If you have this all figured out, then state your [absolute] position on the subject at hand... but be sure to leave semantics out of it :rolleyes:

[Jeff B.]

Re: Overstuffing?

Not sure I would agree. The debate was about physics which is unambiguous at the fundamental level of conservation of mass, momentum and energy, thermodynamic constraints and empiricism to work with a continuum. A reasoned discussion at this level would have settled things after a couple of exchanges.

What happened instead was that nobody debated at this level (undergraduate level for engineers and scientists) and instead based their arguments on weaker foundations. Claiming someone you consider to be knowledgeable would support your claim is more likely to provoke a giggle than agreement. People putting forward this type of argument know they haven't got a firm grasp of the topic regardless of whether their claim is true or false. What can cause a lot more problems is people basing their reasoning on design rules/parameters. Having a firm grasp of how these behave does not necessarily mean having a firm grasp of the physics they represent but people can and do confuse the two and then take decisions believing they have a solid basis for them. It is clear that some people did/do not understand how stuffing can change the pressure-volume relationship and whether the design rules they are familiar with do or do not include it in their assumptions.

I wish I felt more like digging into this, it seems to be a decent topic, but two surgeries in 12 days and 9 visits to the dialysis center take a lot out of me, and I really don't have the motivation. Still, if you go back over what I wrote you will see that I kept it simple intentionally because it is more important to me to be understood than sound like a scientist. However, with thirty years in precision leak testing, working with adiabatic systems and the Ideal Gas Law, I do have a pretty good understanding of that subject. And Jeff Candy, being professional Theoretical Plasma Physicist, I am sure could give you a lot of mathematics to support our position if necessary. Dr. Candy knows his stuff, of that I am pretty certain of.

Our points were simple, they are not absurd and everyone should be able to agree on them. Quite simply, stuffing is a nice way to lower system damping, but it does so with via system losses. We call that absorption. It converts acoustic energy to heat. There's no free lunch, there's no gain, there are losses, as occur anytime we lower the system Q. Carl's graph demonstrates this - if you only look at the shape of the lines you would tend to interpret it differently than you would if you laid the two lines on top of each other. Seeing the two lines together demonstrates the loss from the absorption. Sure, we can trade in efficiency for a flatter curve, and we should all already understand that.

[dlr]

Re: Overstuffing?

This thread reminds me that I hated Thermo in college.

dlr

[carlspeak]

Re: Overstuffing?

The discussion seems to be heading in a more technical direction. To that end, I submit a link (sorry, it's not my work) to a gentlemen (Phd) who derived some higher level math to explain why FG is a better stuffing medium than PET. The Author is the same person who did the AR3a and 4x stuffing comparisons I posted earlier. IIRC, the blogspot page all the math resides on is managed by Ken Kantor. Some of you might know who he is.

For your reading pleasure....

http://auralization.blogspot.com/?zx=bf1dfafee4b1d1df

[fpitas]

Re: Overstuffing?

As for FG or Acousta-Stuf being better, I'd say it depends on what you want or expect from stuffing in a particular situation. There's no doubt FG is better at very low frequencies, but sometimes the desired absorption is for midrange frequencies. Then Acousta-Stuf might be a better choice if you don't want additional low frequency damping.