Oh, for God's sake......

 

To anyone interested in broadband absorbers, I can't recommend enough building them yourself. I did my math recently and 15 8" thick absorbers cost me around 300$. And it's 1st class wool going bellow 120hz which not every does. If I were to buy premade ones, it'd be around 600$ or more.

 

Last edited: Aug 30, 2016

I made my basstraps with plywood and fyberglass, 2 panels of 120x60x3 cm, from 40 to 70 kg m3 of density (yes they absorb till 70 Hz broadband) I ve also used thicker panels, with a bitume foil, fyberglass 120x100x5 cm density 125 kg m3 for the external leak out (plasterboard) of a floating room with a 14 cm wooden floor full of rockwool, 100 kg m3 density. Double door and window, no air passages etc
the basstraps aren t expensive, I don t know... could be 50€ of wood, 25 of rockwool, screws, nails, glue
if you use a cardboard box, even less

there are many projects online, I use a system, Leide system

the deep basstraps are 240x60x10 cm the 10 cm section is:

front panel, 2 cm of space, fyberglass panel, 5 cm of space, rear panel
the front panel and the 2 cm of space are the first hostacle, while the fyberglass transforms the sound pressure into heat to cool down in the 5 cm back space
the front panel must be 0.6 cm
fyberglass density 70 kg m3

high basstraps
same as deep basstraps, but 240x60x5 (no space on the rear)
the front panel must be 0.4 cm
fyberglass density 40 kg m3

Owens Cornill 703 and 705 have similar specs to my Iberna fygerglass

the scheme is, starting from a corner:
deep bass trap, pyramidal foam, high basstrap, foam, deep, foam, high and so on
of course you d need less, 60 cm for the traps and 100 for foam in early reflection points, 60 in other point
never put 2 traps of the same kind side by side
never put foam for more than the 40% of the overall walls surface
wooden floor and absorbing ceiling, human ears are used to thsi and react well

https://audiosex.pro/threads/basstraps-and-acoustic-chamber.22948/

 

Yes, more than that 40% it starts to even feel weird in the room. It is as if your energy field keeps needing to recalibrate your bodies place in the physical space. To be in an anechoic chamber, a special room designed for sound measurement of speakers and microphone tuning and the like, where there are NO reflections, in a very, very short time it becomes frightening to many people as well as hallucinatory.

http://www.alternet.org/story/91472/what_does_silence_really_sound_like
http://phys.org/news/2009-10-sensory-deprivation-hallucinations-minutes.html

 

I've been using dirac live room correction for six months, i knew some pros use ARC2 system, when i read its manual&specs, i found it's basically frequency adjusting, a buddy who posted here before me and said ARC2 is a toy, i guess it is ture. But dirac do impulse&phase correction in addition, this is important, an ordinary speaker sounds bad isn't mostly because its frequency response curve are wired, i tried to even the curve before but it doesn't sound nice, this reminds me a lot, but dirac corrects the sound, suddenly the sound stage opens up, everything is like placed in real world, X/Y/Z axis in front of you goes transparent and vivid, f*cking clear in a word, also it evens the freq. curve or we can edit the curve, the sound is really really good, if there's other thing that affect the sound i think is the speaker's price, i'm using such sound as reference on krk speakers, i guess dirac tripled the price of sound by krk.

i saw people said u should count on your ears, my opinion is ears are easy to be confused/influenced, u don't hear instruments in real world everyday, u may hear people talking everyday, then leaving your mind as impressions of sound, but your ear cannot remember them accurately, then a common speaker plays those sounds, your ears will think this is the right sound after a few hours, next time u will be confused on which is a right sound, then u listen to a real instrument or vocal to turn your ears right, but a song is mostly a complex mixture, so it goes difficult and it's waste of time.

 

FYI you cant put the cart before the horse. You have to measure & analyze your room's frequency response first along with it's decay across the entire freq spectrum, RT60 & calculate the nodes & modes. Then & only then can you make an educated guess as to what & how much reinforcement you will need.

Before you get in too deep, set your monitors up first if its a mixing room & take all movable furniture out. You can calculate a starting point from here - http://noaudiophile.com/speakercalc/. Next follow this to a T http://realtraps.com/art_measuring.htm - Ethan is a veteran when it comes to measuring room acoustics & building reinforcement. He owns a company called Realtraps & has had dozens of articles published in AES. Another man I trust is Rod Gervais. Both Ethan & Rod have plenty of info up on Gearslutz. Rod's book on studio building is second to none.

We have a decent thread started in the link at the bottom of this reply. But for brevity sake - project studios/mixing rooms built without acoustics in mind (like your parents basement or a spare bedroom) typically have peaks & nulls as much as 30-40db. The hardest thing to achieve is an even response in the 1-2nd octave in small/medium rooms. In these smaller rooms broadband & bass absorption is what you want. Diffusion can be a nice touch, but isn't typically necessary in smaller spaces. The goal in these types of rooms is to achieve an even frequency response with peaks & nulls no greater than 10db across the full audible spectrum along with a smooth even decay time across the full spectrum. People tend to over look the decay part & its just as important if not more than an even room frequency response because you can adjust your ear to a frequency response. That's why people prefer certain speakers to others, but you cant adjust your ear to frequency over time because the frequencies that decay longer mask other frequencies. Making what you hear inconsistent at different levels of volume & frequency. So your mixes are basically crap shoots... I highly recommend you take as many measurements as you can & check out the thread below. CHEERS

https://audiosex.pro/threads/room-correction-eq.28499/#post-239401

Oh & Room EQ Wizard is free!!