Can any room be effectively treated?

[sureno]

ok so i was wondering is it possible to treat any room effectively for sound? i suppose this applies to home studios where you may be limited to how you set it up or have to share it with another function e.g bedrooms/lounge studios?

[TrevCircleStudios]

No. For example, some rooms are so small that you couldnt get enough bass trapping in their. Of course you can make any room better with treatment but your in turd polishing territory if you have a bad space to start with. Square rooms, for example, are particularly difficult to deal with. I'm sure Frank will come and give you lots of reasons why any minute.

[sureno]

Originally Posted by TrevCircleStudios

No. For example, some rooms are so small that you couldnt get enough bass trapping in their. Of course you can make any room better with treatment but your in turd polishing territory if you have a bad space to start with. Square rooms, for example, are particularly difficult to deal with. I'm sure Frank will come and give you lots of reasons why any minute.

ok now if you have a big room (well not massive) what factors could hinder you achieving the optimal results?

[TrevCircleStudios]

Define big? Your idea of big might be very different from mine [fnar]

Seriously though, a square room will have nasty modes even if it is pretty big. A low ceiling will also not help. What dimensions are you talking about?

[sureno]

Originally Posted by TrevCircleStudios

Define big? Your idea of big might be very different from mine [fnar]

Seriously though, a square room will have nasty modes even if it is pretty big. A low ceiling will also not help. What dimensions are you talking about?

yeah i know what you mean, I should of said that, so im talking about a
H8ft X W11ft X L14ft room in the house? its got an indent for the windows and for my Dj bit

[TrevCircleStudios]

Like I said, Frank can give you the techy stuff. Basically, get your monitors shooting long ways down the room, monitoring position at 38% of the length, bass traps floor to ceiling in the corners, a bit of either trapping or diffusion at the mirror points and you'll see an immediate improvement.

[sureno]

Originally Posted by TrevCircleStudios

Like I said, Frank can give you the techy stuff. Basically, get your monitors shooting long ways down the room, monitoring position at 38% of the length, bass traps floor to ceiling in the corners, a bit of either trapping or diffusion at the mirror points and you'll see an immediate improvement.

great stuff, i got the monitor bit done but think i will sort the traps out, are the mirror points opposite the speakers either side and above?
cheers

btw did Frank design yours?

[TrevCircleStudios]

Originally Posted by sureno

...are the mirror points opposite the speakers either side and above?
cheers

btw did Frank design yours?

Bsically the mirror points are as follows:
if you sit in your monitoring position, where are all the points on your walls that if you stuck a mirror you'd see your monitors. Sound travels just like light (well not quite but let's not get too technical) so if you can see your monitor via a mirror point you will hear a reflection from that point.

No. Max Hodges is working on mine. You'll hear tell of him if you spend any time on SOS forums. He's a mod for the studio acoustics forum (username "Max!")

Now, gotta go to bed!

[terminal3]

Originally Posted by TrevCircleStudios

No. Max Hodges is working on mine. You'll hear tell of him if you spend any time on SOS forums. He's a mod for the studio acoustics forum (username "Max!")

OT but does he work for Focusrite as well?

[sureno]

NICE never knew that, going to get onto that, 1 more Q, does this include behind and above?

[TrevCircleStudios]

Originally Posted by terminal3

OT but does he work for Focusrite as well?

Not sure. Seeing him Saturday. Will ask if I remember. From memory he used to be at the Townhouse (some time ago now though).

[TrevCircleStudios]

Originally Posted by sureno

NICE never knew that, going to get onto that, 1 more Q, does this include behind and above?

Yes it dows. If the sound can make it's way back to your ears, it counts.

[sureno]

Originally Posted by TrevCircleStudios

Yes it dows. If the sound can make it's way back to your ears, it counts.

cool, will get the Mrs to move some mirrors around while i sit at the desk then

[Khazul]

I'll try give a simple view of room accoustics of the top of my head - Im no expert, just have a rough 'simple' idea how it works

Primary reflection points as trev described above - ie if you can see it via a single mirrror flat again a wall - then its a primary refelection - thats mainly mid/upper frequencies. generally you treat them with a combination of dispersion and absorbtion. Absorbtion is as it says on the tin. Dispersal is based upon irregular reflectors that try to bounce (higher frequeny) sound around the room in semi-random directions - to keep a natural live sound without nasty obvious resonance or fluttter echos etc, so you get a smooth decay. The absorbtion determines the rate of decay. I personally find for an average home setup, then it isnt good to over treat with absorbtion. You can end of with a rather basey and dead sounding room with really skewed overall balance.


Sound also tends form stable standing waves due to a wavelength being precisely related to a continuous path path around the room - for eg between pairs of opposite walls which is the simplest and loudest case. The next loudest type is based upon bouncing around 4 walls, after that you have to sum multiple paths around 6 walls which all get messy and probably wont tell you much you dont allready know.


To get a rough idea of the fundamental frequency of a pair of opposite walls20ft apart, the fundamental is about 28Hz or so, for 10ft apart, its double that. Also the or modes at multiples of these fundamental frequencies.

Thats normal, and on its own is a relatively small problem - the real headaches start when you have different pairs of walls where multiples of their fundamental frequencies are similar - causing a huge lift in apparent bass level across a narrow range of frequencies.

Off top of my head - your wall pair fundamentals are going to be about 40, 50 and 70Hz ( (speed of sound / 2) / distance I think, - ie 563 / distance in feet) with the being 80, 100 and 140, 70 and 80 are quite close and maybe a problem 3 x 40 is close to 140 and so that may be a problem, along with 150 to 160.

If you want to learn more about this, try google for "room modes" "axial modes" etc. There are a bunch of intersting calculators on the net that can tell you roughly what to expect, however they are a guide to potential problems frequencies within the room rather than a specific guide for you listening position and monitor places etc and dont take into account irregularities and any natural trapping. BTW - if you have certain kind of false ceiling or very thin false walls, then you may need to ignore those and measure the hard wall size. Thin fake walls may however have a greater impact upon mid and higher frequencies.

If you find you have likely huge peaking between 70 and 100Hz - then life is going to be hell getting you bass/kick mix right, or in really bad cases even being able to tell what note a bass note is.

If you have mid/high frequencies bouncing around alot - then clarity and imaging suffer alot.


Generally I would suggest sort out bass problems if you can first, then starting with absorbers on primary main reflection points - above and to sides (primary reflection of same side monitor) adding enough to bring clarity up without overdoing it.

A quick sharp clap of your hands can tell you quite alot - listen for nice smooth decay, no flutters nor nasty ringing in upper mid frequencies and try to balance to perceived response such that the high end doesnt sound too dead unless you also know the low end is very dead. Ideally you wont really hear the reverb decay, but it wont sound dead either. Anything nasty and you need some combination of additional absorbtion and/or diffusors.


And I still havnt got around to sticking proper treatment in here....

[sureno]

wow, thanks K! ok well i have not got thin walls or ceilings, i will have a problem deciding what my room needs? i think i will diffuse the mirror spots with rock wool, put the bass traps in the corners and take it from there