The Advantages of Floor Coupled Up-Firing Speakers

[markus76]

Originally Posted by gedlee

In the end all that matters for a dead hanging absorber placed away from a wall is its thickness and flow resistance and distance from the wall. Pleating the fabric makes its "virtual thickness the same as the fiberglass and its flow resistance is comparable. Hence, in theory (and here the theory is quite accurate), the two will act the same if done correctly.

To be as effective as fiberglass you'll probably need a lot of fabric which would increase cost?
What fabric properties would one want to look for when choosing drapes for absorption?
How to calculate the optimal depth of a pleated drape?
Would absorption benefit from hanging multiple layers at different wall distances instead of hanging one single pleated drape?

Best, Markus

[gedlee]

Originally Posted by markus76

To be as effective as fiberglass you'll probably need a lot of fabric which would increase cost?
What fabric properties would one want to look for when choosing drapes for absorption?
How to calculate the optimal depth of a pleated drape?
Would absorption benefit from hanging multiple layers at different wall distances instead of hanging one single pleated drape?

Best, Markus

Of course - the fabric can easily get to be much more expensive than fiberglass, I usually look for deals. The velour knid of heavy thick weave that is not very tight is best. To optimize pleat size and fabric density etc. you would have to go to Ingards book. Multiple layers is also dealt with in the book - there is a section on "multi-layer" absorbers. Orignially the bookk came with software to to the calculations, but the soiftware is now obsolete and the code was never available. A windows program that did the same things would be very cool.

Oh yea, about the Antonio book, I'm not a big fan. They present the ideas as best promotes their products. There are lots of ways of doing the same things without the excessive costs of their products. Like the stone walls that I use in most of my rooms. They are not going to tell you about that and how its just as effective, lots cheaper and far better looking than what they sell.

[markus76]

Originally Posted by gedlee

Oh yea, about the Antonio book, I'm not a big fan. They present the ideas as best promotes their products. There are lots of ways of doing the same things without the excessive costs of their products.

I'm not like some people here that tend to believe everything they read and then feel betrayed when they find out that there's more to the story than they were told
From what I could read at Amazon, the book seems to be a good overview of acoustic treatments presented with a solid theoretical background.

[Elias]

Originally Posted by markus76

Get 6" thick fiberglass and mount it

You recommend using fiberglass inside you living room?!

It's a free ticket to the asthma clinic

[terry j]

Originally Posted by Elias

You recommend using fiberglass inside you living room?!

It's a free ticket to the asthma clinic

I don't get this! and I hear it often.

So, it turns out f/glass is 'radioactive', for some reason unknown to science the f/g particles have a 'half life' and decide to defy the second law of thermodynamics and just eject themselves from the surface at random!!

There they are, left alone and untouched, and the particles are exploding off the surface spontaneously.

Don't buy it myself. Cutting f/glass is of course a different story, but even then they stop dispersing into the air once you stop cutting.

Wrapping f/glass then it is even more crazy to suggest asthma etc (esp one would use compressed f/glass, if only to make the job easier for themselves) cause now not only do they spontaneously eject from the surface, they undergo 'quantum tunneling' and burrow thru the material.

Anyone is free to worry about things they want to worry about, and god knows I tend to worry about different things than most people into audio, but the health risks of f/glass is not one of the things I personally would worry about, YYMV.

Tho sometimes I sit there eating my hamburger, drinking my beer and smoking the cigarette and look at the f/glass thinking to myself 'that is so unhealthy you really should do something about it' haha.

[MaVo]

No, they dont eject themselves or are radioactive.

They have a half live in terms of biodegradability, which means the stuff you get into your lungs wont sit there forever, but can be dissolved by your body - at least the newer rock wool has to have this attribute.

[gedlee]

Fiberglass has been proven to not be carcinogenic, but it is know to be highly alergenic to many people. If undisturbed for a long time this is not an issue. Put putting it in AND taking it out is a real issue for many people - myself included. And it doesn't take much to "disturb it" to the point where it is irritating. It can be a big problem for people with asthma - getting to be about 1/2 the population from what I understand.

[markus76]

There are also "green" alternatives to fiberglass with very similar properties made from wood fibers, polyester, cotton, etc.

[gedlee]

Cotton, Polyester? Sounds like "fabric" to me. I thought that's what I recommended!

[MaVo]

This stuff for example: Thermo-Hemp i got a sample once and it feels nice, very similar to rock wool, but without the fine fibers that itch so much. And no evil stench of glues or solvents at all.