Building column absorbers today.can someone with experience take a quick look.see picture

[Dirt9]

I am wondering if leaving the paper on both sides is ok.the absorbers will go flat against the corner with the open side facing towards the listening position. front and back are open.

 

[Adhoc]

The kraft paper shouldn't make that much of a difference. Bass and midrange has enough energy to make it vibrate, so those sound waves will pass through and not be reflected to any degree to speak of.

 

[Tonto]

They will be ok, better if you could use ridged fiberglass like Owens Corning 703 or 705.

 

[Dirt9]

I thought about using Owen's corning Thermafiber rock wool that has a density of 2.5pcf.
There seems to be two camps when it comes to what people are using when the thickness of the traps get over 12".
I built 10 of these 16"x28"x4' and used R30 but I may end up using the high density rock wool depending on how these measure.
not sure if the price per performance is worth it for the rock wool when it's thick.

 

[DanDan]

703 and 705 work well from say 1"-6" Above that they become less absorptive at LF. Lower GFR/Density fibre is way better.
I am certain your Kraft paper will do no harm at all, and may actually boost LF absorption a little.

 

[Tonto]

I get the best price from local insulation installing companies. There is one here in T-Town that just about gives away his left over rock wool. He has bins in his shop where he throws his remnants and that stuff falls apart so easy he hates trying to use it on another job.

 

[Dirt9]

A few quick measurements with all four corners stacked before and after,nothing fine tuned,no other treatments,no eq or smoothing applied.
literally just stacked them and measured real quick.Not sure why the jpegs are showing the wrong resolution even though i saved them correct,you'll have to open the mdat.
They seem to be working alright?.I'll nock that 50hz hump off when I'm done treating the room.