Need fast answer please - What do I cover absorbers in so they only absorb bass?

[Kola]

Hi,

I know the difference between bass traps and broadband absorbers is the fact one absorbs everything and the other mainly bass.

I have a friend coming tomorrow to help me build my traps but I still haven't a clue what to cover the Rock wool in to leave as much mid and treble out.

Everyone here bangs on about a special kraft paper that you just cant get in the UK.

Will plastic sheeting do? Or will this block bass also rendering traps I make useless? If it will do how thick will I need?

Need a speedy reply as friend is coming tomorrow. Sorry if title sounds pushy. Not meaning to come across like that.

[matt thomas]

anything that reflects highs but isn't very dense or thick should do it. Like craft paper, cardboard, plastic sheet, foil sheet, single ply of plywood, etc..

People won't be able to suggest how much to use because it will depend on what exactly it is you use, and how you use it. you can use your ears, or get some measurement software to measure the room.

Of course you might want to look at how to build a panel bass trap, these only absorb bass http://www.ethanwiner.com/basstrap.html

matt

[Kola]

Hi matt, thanks for speedy reply. Appreciated.

Im getting a calibrated mic to measure my room using room EQ wizard but have to import from the US so looking at a week until I can do that.

Ill use plastic sheeting as its easily bought from my DIY shop. Cardboard too. Any clue as to what thickness I should use?

[matt thomas]

OK, this is just a guess, but maybe the kind of cardboard a greeting card would be made out of, judging only by what I've heard others say they have used.

matt

[Kola]

Thanks mate.

[Glenn Kuras]

I would go with the cardboard myself.

[Kola]

Thanks Glenn. Any exact thickness?

[Glenn Kuras]

Originally Posted by Kola

Thanks Glenn. Any exact thickness?

Don't know the thickness but a single walled cardboard should be fine.

[Kola]

So sort of what Matt said, greeting card thick should do it?

[Weasel9992]

Originally Posted by Kola

So sort of what Matt said, greeting card thick should do it?

I think that would work fine.

Frank

[SAC]

oh.......

...and I was thinking 'magic bass dust'...

[Weasel9992]

Originally Posted by SAC

oh.......

...and I was thinking 'magic bass dust'...

The 70's were a long time ago man.

Frank

[tINY]

Can you get pegboard in the UK?



-tINY

[Kola]

Hi tINY,

Sorry, I didn't realise you had replied.

Not sure about peg board, ill have a look around.

Can I ask will tin foil do the trick?
And also why is card better than plastic? (Out of interest)

[tINY]

Cardboard is less stiff than plastic sheet - though either one may work in your application.

Cardboard is cheap....



-tINY

[Kola]

I was thinking though with the plastic sheeting I could wrap the entire Rockwool in it. I have already realised how much crap comes of these things if you accidentally knock them.

Due to my room doubling up as where me and the wife sleep some of the trap I make will constantly be being put up and down.

How thick is too thick for the plastic sheeting mate? Or does it not matter?

[SAC]

The common utility ~4mil plastic sheeting commonly found in rolls in hardware stores and Wal-Mart, etc. should work fine.

[Kola]

Cheers SAC.

4 mil is very thick for plastic sheeting though isn't it? Wont it become more like rigid plastic at that point?

The stuff I have in my mind is see through and at its thickest around 2 mil.

[SAC]

4 mil is by no means rigid!

2 mill should work fine too - any of the utility rolls of plastic sheeting commonly available in sizes such as 3' x 100' or 10' x 25', etc., should work fine.

[Kola]

Thanks SAC. Great, ive got a clear picture in my head now.

Thanks to all who have helped. By way of thanks Ill put some pics up at when done.

[Glenn Kuras]

Just a note that you only want to put this to the fronts, not the backs, of the panel.

[Kola]

Why is that Glen?

[Glenn Kuras]

Originally Posted by Kola

Why is that Glen?

You want the sound to pass through the back of the panel as easy as possible.

[SAC]

Glenn is correct. To make them more reflective to mid/high frequencies, you only treat the front incident surface.

Regarding the fear of Fiberglas - Semi-rigid Fiberglas is coated with a binder! And you only effectively generate dust by crushing the bound structure and then by doing something additional to accelerate the particles!!!- which makes me wonder what one is doing if someone is actively able to accomplish such a feat!?!?!

Just a casual comment, as this fear seems to be pervasive about the forum! I have dealt with Fiberglass panels for years, and I have never had a situation where innocent passive panels suddenly start shedding Fiberglas dust in the manner many seem to claim to routinely encounter from simply looking at them.

Semi-rigid Fiberglas panels are industry standard, and I suspect you encounter them in the real world far more often than you are aware - and in commercial and office spaces even more than one might imagine, as they are the norm. In fact, they are so common that you may not even be aware of them.

Unless you are using them to pad a mosh pit, I would suggest that you should be fine.

[Kola]

Thanks guys.

[DanDan]

In the UK you should be able to source Isover Duct Cladding Slabs, High performance version. They are better performers than 703 and have Foil on them.
DD

[Kola]

All ready got RW3 mate.