Low Freq. problem!

[5Elements]

Hello guys.

Not long ago I've started to build a studio room. Made 2 DIY panels, put them to the left and to the right. A thick rug is on the back wall. Thought the sound will be awesome, because I have to do mixing and it's really important! But the problem lies solely in low frequency range.

The room is pretty empty, I mean no furniture at all. Can this be an issue?
Will panels in the corners and on the ceiling save me?
Or the wall from my back can cause some problems?


This is how my room frame looks like)) I'm not a paint master actually))
And English is not my native language, so sorry If I made some mistakes.

All kind of advices would be much appreciated!

 

[GIK Acoustics]

Hello!

Your english is excellent, no worries there.
How thick are your sidewall panels?
Are they placed at your first reflection points? ( Video Early or First Reflection Points - GIK Acoustics )
When you say rug on the back wall, are you referring to the green box you drew in the drawing? This is usually referred to as the "front" wall in acoustics as it's in front of you.
The rug won't do anything at all for low frequencies, and likely your first reflection point panels won't do much for low frequencies either, as they'd need to be at least 6" thick or more to get under 100 Hz. For better bass control, you should be looking at corner absorbers that you can use in the corners of the room, and thicker panels on the wall behind you.
You can use the following as a guide: Acoustical Room Advice - GIK Acoustics

 

[5Elements]

First of all, thank you for the answer!

my sidewall panels, made of fiberglass, are 3" at much, not very thick at all. Yes, I placed them at first reflection points
The green box I drew is the rug) shame it won't affect the bass.. would you suggest to put over the rug some absorbers?

btw, thank you once again for your advice, I will make some more panels and will treat the room as you recommend!

p.s. thank you for the links)

 

[bandcoach]

What are the dimensions of your room? either in feet or meters? this will help to advise you on the area(s) to treat.

The corners do need some bass trapping, but without knowing the dimensions the actual target frequencies are difficult to determine....

 

[5Elements]

So, length of the room is 4,5m and width 2,5m.
Made 2 bass traps today, put them in the corners of the front wall. there is a little improvement, but I still miss the bass)



here's the wall behind me, is this the main problem of losing low frequencies?
some advices how to treat it?

 

[bandcoach]

Room height? yes it really does matter....

as for the odd bump in the back wall, because the lengths appear to be small we treat the room as though it were a complete rectangle rather than two rectangles tacked on to each other

 

[5Elements]

Room height is 2,4m.
I tried to listen in that "small rectangle" area and there's much low end)

 

[bandcoach]

So base resonance frequency issues are:

H	W	L	SoS
2.4	2.5	4.5	343.2
Axial Modes
Dimension	H	W	L
Frequency	71.50	68.64	38.13
Pitch	C[sup]#[/sup]/D[sup]b[/sup][sub]1[/sub] +50.49 cents	C[sub]1[/sub] +78.48 cents	D[sub]0[/sub] +61.63 cents
Tangential Modes
Dimension	HW	HL	WL
Frequency	99.11	81.03	78.52
Pitch	G[sub]1[/sub] +18.07 cents	D[sup]#[/sup]/E[sup]b[/sup][sub]1[/sub] +66.36 cents	D[sup]#[/sup]/E[sup]b[/sup][sub]1[/sub] +15.09 cents
Oblique Modes
Dimension	HWL
Frequency	106.20
Pitch	G[sup]#[/sup]/A[sup]b[/sup][sub]1[/sub] +36.25 cents

Every frequency given then has whole number (integer) multiple nodes of resonance, i.e. x2, x3, x4, x5, etc...

treating the low frequency energy will require bass traps constructed to match the range of frequencies. This can be done using a tapered profile on the trap or by constructing multiple panels tuned to each fundamental resonance frequency. The John L Sayers site has a suggested form you could use.

 

[GIK Acoustics]

First of all, thank you for the answer!

my sidewall panels, made of fiberglass, are 3" at much, not very thick at all. Yes, I placed them at first reflection points
The green box I drew is the rug) shame it won't affect the bass.. would you suggest to put over the rug some absorbers?

btw, thank you once again for your advice, I will make some more panels and will treat the room as you recommend!

p.s. thank you for the links)

The rug is fine as a decoration or for the floor but won't give you any use on the wall.
You said you've placed bass traps in the front corners - how did you build them? For the panels, I recommended doing 6" to start to absorb under 100 Hz - but thicker corner absorbers like TriTraps or Soffit traps are the types of porous absorbers that really work well under 100 Hz. The weak bass is usually caused by nulls either from your speaker positioning or your position in the room. Thick traps on the back wall will bring up those weak bass notes if its mode related - panels between the speakers and the wall will help if its SBIR related (SBIR is the interaction between the speakers and a wall).

 

[bandcoach]

One thing that strikes me from your initial drawing is that your monitors are facing straight into the room - they should be angled so that the focus point of each is your seated position at ear height- You then treat first reflection points on the lines projected from each monitor to the side walls as well as the bass issues you have noted.

treating the bass may be as simple as creating a false wall for the bumped area and hanging panels of different sizes within to handle the bass build-up.

Go back to the John L Sayers site and review his basic control room layout Acoustics 2.

Reread this section as well Acoustics 1

Angled side walls either through construction or by judicious use of broadband traps/diffusers on both side walls will improve response of the room.

bass traps on the rear wall as well as other absorption will also improve the rooms behaviour.

Flying some traps/diffusers/absorbers above starting at the front of the room should also address some of the issues.

 

[Zil]

I'm interested in acoustics, and have browsed a lot of sites for sound foam. I did see some places selling short foam at a 45 degree angle for the edge of the floor opposite the speakers and also some waist height foam to absorb bass frequencies in the corners of the room. I haven't actually tested all of this, but it might be something to look into. Actually I think the acoustic foam is too expensive and have been looking into ways to create similar structures that do the same work.

 

[5Elements]

In response to GIK acoustics.
Bass traps are 5" thick, but I think 1 additional inch won't give me the result I want
Positioning of the speakers are like in "studio rescue" videos, I mean there's a perfect triangle between me and the two. (1m)
As I understood from your reply, I have to build thick panels to put them on the front wall (SBIR as your said)

I think it's the last thing I'll do to treat my room. If it will not work, then the best way to hear what's going on at low frequencies are headphones (Beyerdynamic DT770 are the go to)


In response to our Mad Scientist
As I've said above, there's a perfect 1m triangle between me and speakers, and the speakers are positioned strainght to my ears.
Yes, on the rear wall I've put 2 panels, but there's not much difference)
As for creating a false wall, I've made something like this, the wall was a pellicle, but a strong and stiff one. No effect

One thing that's just ridiculous is that my previous room had an awesome bass without any treatment)) it was a small kitchen )) I think it is all about furniture, isn't it?


Thank you all for warm responses and for helping me to understand better acoustics and stuff, even if I still have problems))
Namaste! _/\_

 

[GIK Acoustics]

One thing that's just ridiculous is that my previous room had an awesome bass without any treatment)) it was a small kitchen )) I think it is all about furniture, isn't it?

Not really about the furniture, but wall construction has a lot to do with it (and it's also possible the kitchen was open instead of being a small closed off room, yes?

I'm interested in acoustics, and have browsed a lot of sites for sound foam. I did see some places selling short foam at a 45 degree angle for the edge of the floor opposite the speakers and also some waist height foam to absorb bass frequencies in the corners of the room. I haven't actually tested all of this, but it might be something to look into. Actually I think the acoustic foam is too expensive and have been looking into ways to create similar structures that do the same work.

Acoustic foam doesn't do much for broad control in the first place. Works well for reducing echo, but not much more than that -and in most rooms, low frequency problems need to be taken care of. You could always build some traps yourself, there's a good bit of info floating around on the web for building acoustic treatment, though it is hard to do right and have them look great if you don't have the time or tools!

 

[bandcoach]

I note that you did not try to drop in different broadband absorbers behind the false wall (or at least you make no mention of trying this, as was suggested) - that will make a difference

 

[5Elements]

to GIK Acoustics:
you know, the walls were thin in the kitchen. btw, maybe it's not just about thickness )
I don't know what do you mean by closed or open, but there were 2 doors, one going to the balcony and one to the other room, and also one big window.

to badcoach:
the thing is that I've broken the false wall, because it just didn't work) after that, I've put 2 panels in the corners, and without much difference)

is the false wall vital? I could build one, but don't know which material will work for me some recommendations maybe?