Just to show you how i built my bass traps

I was just watching Ethan's video about diffusion... again... Well my QRD diffusor is pretty similar to those Real Traps sell, btw. I would buy one but since i am in Croatia it would cost fortune just for one... Anyway, as Ethan said, on one inch off deepness you have to be one foot away, so it means I will be good, since my deepest well is 6.7 inch and I am more than 6.7 foot away. I would really like to know more about this, any more thoughts about this? Ethan? P.S. I dont know is it just psychological thing but it seams to me that sound really did improve in the mid range.

I just find out that Tervol DP-3 is just 30kg/m3 wich i used for my corners... is it to soft for bass traping? Is 110 kg/m3 good or its to much rigid? Please help.

it will do

Ro wrote

Well, there's not enough volume in a small room (or wall volume) for the diffuser to develop a useable reverb and adds unwanted coloration. Especially in close range of the listening point, it'll only distort the sound image.

Put another way to answer your question about why diffuser are no good in small rooms. Our brain cannot decode reflexion that are too close from each other, if the said diffuser is too close, then your brain will just mix the signal comming from the diffuser (reflected) with the signal comming from the speakers (direct) , and create comb filtering Fx wich would just be percieved as being the signal comming from the speakers (bad). To be usefull diffuser must have at leats 16 ft behind the listeing point. At that distance our brain hear two different things , the signal from the speakers and a diffused "room" sound, or tail, or reverb call it what you want. I hope this is not too confused.

Thanks Eric. Not confusing at all! It makes perfect sense. Your explanation is very clear, and I think I get the idea now. So unless your room is something like at least 22 feet long in total (which would put the mix position at 16 feet from the rear wall, according to the 38% rule) then it doesn't make any sense to use diffusion on the rear wall, as it will "muddy up" the sound with comb filtering, instead of improving it. Much appreciated! - Stuart -

New speakers just came and they are really nice! Cant wait to finish my room so i can hear them like they really sound. They are little high now but sound is much, much better now, bass is soooo deep. ...about diffusion, i will live it where it is for now and whan finish with basstraps i will see what to do with it...

time for new measurements! so this is how krk sounds at my place. much better than alesis but i still have 14 dB dip at 50 hz... its time for more basstraps!

hello i had the same problem as you.. peak on a very sub range.. around 30 db. i've solved it!! :) a bit.. but i still have other problems.. anyway how i've solved? i've built 4 giant traps.. 120cm x 60 x 40!! and i've completely closed the room width between two bookshelf, that makes my bm5a going steep down at 50 hz.. i still have a bit of residue.. but is down 15db.. those traps are made with Rockwool 225 acoustic (brand named Rockwool) with another Rockwool type at 140 kg/m3 on the back and with another of 50 kg/m3 on the front.. i've done in that way "by case" because was spare piece of rockwool. but it works! :)

Hi again! I moved to a new similar but little bit better room and I am starting it from scratch :) I have few questions but lets start from the beginning... Room size L: 3.87m, W: 3.58m, H: 2.55m I included some skatchUp pics down. So first, i know I will need lots of bass trapping and I would like to presserve some HF, so I would like use eco leather for covering my absorbers, how smart would that be? Since I cant build bass traps in back corners I am planning to build big absorber on back wall, will 10cm depth be enough? I am currently waiting for custom speaker stands and then I will make some measurements and post them here so you can see in more detail whats going on in my room. But all in all I am much more happy with this room even without all the treatment :) Best regards and sorry for my bad English, Tomislav

you could consider some absorbers on stands you could move into the corners when needed or use when recording and need to make a spot in the room a bit deader.

yes, I was thinking on doing that, since right now I have about 20db dip around 60 to 80hz and I know I will need to cover as much corners as possible to get it fixed...

the dip is likely caused by a mode due to your room height. putting a cloud over your mix station is a good start, if that only starts to correct it, rebuild the cloud using a backing panel of 3/4" (19mm) MDF and plywood (for attaching screws easier and some stability) with the absorber side down. hang it on a 15 degree angle (front low- back high) if possible. have the cloud extend from the front of the mix desk to about 16-24" (400-600mm) behind you. leave at least 12" (300mm) all around the edge of the cloud to the walls. in your case, consider build several smaller clouds.

hi, thanks for help, that was helpful ;) so what do you think about this design for speaker stands? All tubes will be filled with sand.

Hello tomislav, I had the same idea. I was thinking however that the original levelling would be a bit tricky, they will also be a bit sensitive if you happen to lift or jolt the speaker tray, the sand will flow underneath and you'll have to empty them out again to go back to the original level. Did you intend to fill the outer tubes to a specific level, then insert the inner tubes and fill them with sand, then pour sand in the outer tubes to hold the inner tubes in place? Or would you seal the bottoms of the inner tubes before filling. The second may be more practical.

hi, I am thinking about filing outer tubes with sand to get the hight that I want closing inner tubes and making 3 holes on top to fill them with sand, put them in place and fill outer tubes to top, that way I will be able to isolate inner tubes from outer ones... Closing inner tubes on bottom will give much more stability and wont make them go down... Sorry on my bad English i hope you understand what i mean :)

I am thinking about filing outer tubes with sand to get the hight that I want closing inner tubes and making 3 holes on top to fill them with sand, put them in place and fill outer tubes to top, that way I will be able to isolate inner tubes from outer ones...

I don't understand how that would isolate the inner tube form the outer tube. It sounds like you would have an inner tube filled with sand that is sitting directly in the sand inside the outer tube. So there is no isolation, that I can see. Also, why would you want to isolate the two tubes? Much easier to isolate the speakers themselves from the stands. - Stuart -

Soundman2020 wrote:

I am thinking about filing outer tubes with sand to get the hight that I want closing inner tubes and making 3 holes on top to fill them with sand, put them in place and fill outer tubes to top, that way I will be able to isolate inner tubes from outer ones...

I don't understand how that would isolate the inner tube form the outer tube. It sounds like you would have an inner tube filled with sand that is sitting directly in the sand inside the outer tube. So there is no isolation, that I can see. Also, why would you want to isolate the two tubes? Much easier to isolate the speakers themselves from the stands. - Stuart -

:oops: i dont know why but i thought sand would be good isolator :) thinking about it now i see your your point... well, at least I will be able to adjust hight :)

why not make them out of cast iron pipe with a soft rubber sleeve between them for a strong friction fit but still decoupled?

Hello. I'm about to do some tests in my studio and I saw your graphics, they look very nice and make clear where are the problematic frequencies. What software have you used to test your room and how have you done your tests? pink noise??? Thanks.