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testing my rooms acoustics ?
Posted: Thu Oct 28, 2010 5:25 am
by Karma_blitz
I just wanted to know if there was a program or vst that could help me correct the bad acoustics in my room. Im getting a really boxy sound. I think this is due to reflections from my bass off the walls. I have heard of programs and hardware like krk's ergo and ARC but is there one that allows me to use my mic. (Rhodes NT1 lol) my soundcard has a eq on the master output so i was thinking i could just adjust it accordingly ? Please can someone help. Thanks
Re: testing my rooms acoustics ?
Posted: Thu Oct 28, 2010 8:29 am
by macc
ARC and ERGO are very good, but
only as the last piece of the puzzle, in addition to good placement of the speakers (the first thing) and room treatment (the second but most work-intensive). You can't fix a reflection electronically.
I can't write a whole room treatment tutorial as I just don't have time, but to summarise;
- optimise position of speakers and listener, paying attention to (almost exclusively) response under 300Hz. Bear in mind the equilateral triangle thing for imaging
- treat room for bass - bass traps in corners typically, and other build-up spots
- use Energy Time Curve in Room EQ Wizard to hunt down and brutally murder reflections affecting the listening position with trapping
Only once you have the room fully under control will any correction software be any real use. To measure your room you need to get Room EQ Wizard from Home Theater Shack (you have have to register), and a suitable microphone that has an omni pattern. The Behringer ECM8000 is £30 and does the job well enough, you'll need a preamp on your soundcard though.
There's a wealth of info on the net - the gearslutz acoustics forum is quite good. It can be soul-destroying, especially the first measurement, and when you tweak something only to make it worse, then can't get it back as good again

I say this as someone who has just spent a solid week of time re-adjusting my room for my new monitors (PMC IB2S

). It was pretty depressing at points but came very good in the end!
Don't expect a perfect room but do expect to feel like you bought new monitors.
Re: testing my rooms acoustics ?
Posted: Thu Oct 28, 2010 2:15 pm
by Karma_blitz
thanks bro. I had a feeling there was no easy solution. Any suggestions on how far my speaker should be from the wall ? Thanks
Re: testing my rooms acoustics ?
Posted: Thu Oct 28, 2010 5:14 pm
by the get down
Speakers at minimum one foot off the walls. Your listening position should form an equilateral triangle with the speakers and be at one third the length of the room
Re: testing my rooms acoustics ?
Posted: Thu Oct 28, 2010 5:27 pm
by macc
the get down wrote:Speakers at minimum one foot off the walls.
Not true.
Your listening position should form an equilateral triangle with the speakers
True, more or less.
The measuring position, but it is impossible for the ears to both be at that point (unless you have an extremely small head

). The head should be just inside the triangle, ears in line with the sides of the triangle, ideally. So the speakers are just firing over your shoulders to the triangle's point (sort of like . Though a lot of it depends on speaker dispersion, and how bad your room is - the response is fairly likely be totally different even a few inches away from the measuring point.
and be at one third the length of the room
Not necessarily true - that's only a theoretical starting point really. 38% of the length in a standard cuboid room is a good starting point as
in theory it has the best balance of all modes. But wall material, speaker placement and dispersion etc etc etc all have a very big say in how that works in actuality. Plus then there are boundary effects to consider, blah blah. Measuring is the way.
Re: testing my rooms acoustics ?
Posted: Thu Oct 28, 2010 9:04 pm
by gkmusic
measure your room and work out the the room modes using some simple mathematics OR
http://supermegaultragroovy.com/products/FuzzMeasure/
cop this follow the instruction and get some analysis
Re: testing my rooms acoustics ?
Posted: Thu Oct 28, 2010 9:31 pm
by collective
macc wrote:the get down wrote:Speakers at minimum one foot off the walls.
Not true.
Hey macc, just moved into a new spot unfortunately I can't be that far from my walls. How close is too close and what can be done to correct any problems this might have?
In my current spot, I am unfortunately a half-foot away from the wall at most. This has not posed any problems so far (learning my room seems key here), and my last location was a bit better and my mixes translated well. Just wondering if there is anything to do. To be honest I found referencing to be the biggest help to a poor listening environment.
Re: testing my rooms acoustics ?
Posted: Fri Oct 29, 2010 1:24 am
by Trebek
There is a program called Smaart, which I believe you can get for a free demo for a certain amount of time. This is to get your speakers in phase with one another, which should help some, but getting some acoustic treatment for your walls will help too.
But what this program does is allow you to play pink noise through each speaker one at a time and have your mic hooked up where your main mixing position would be(not sure if you can use a NT1 though...I know theres specific mics...Like analyzer mics) But basically you play pink noise through each speaker 1 by 1 then you can take a snapshot in Smaart of its phase trace which will be stored on the screen, you then move to your second speaker play pink noise through it and you will have to manually re-align it to make the 2 phase trace lines align.
You will need some basic equipment....But I think that it definitely helps.
Re: testing my rooms acoustics ?
Posted: Fri Oct 29, 2010 6:46 am
by lowpass
Trebek wrote:There is a program called Smaart, which I believe you can get for a free demo for a certain amount of time. This is to get your speakers in phase with one another, which should help some, but getting some acoustic treatment for your walls will help too.
But what this program does is allow you to play pink noise through each speaker one at a time and have your mic hooked up where your main mixing position would be(not sure if you can use a NT1 though...I know theres specific mics...Like analyzer mics) But basically you play pink noise through each speaker 1 by 1 then you can take a snapshot in Smaart of its phase trace which will be stored on the screen, you then move to your second speaker play pink noise through it and you will have to manually re-align it to make the 2 phase trace lines align.
You will need some basic equipment....But I think that it definitely helps.
I've not seen Smaart used this way outside of live engineering, not sure how effective it would be in setting up in a studio environment as I've not used it myself.
Demo according to the website is 30 days though
Re: testing my rooms acoustics ?
Posted: Fri Oct 29, 2010 8:43 am
by vviiper
You must place your speakers so that the spot you are sitting in, both speakers are facing each ear, and the tweeter is level with your ear. The distance from your ear should be between 4-5 feet. <-- Treat that as a guide, you'll have to tweak.
As for acoustic treatement, using soft absorbing materials (such as blankets, eggs containers, cushions, sofas all kinds of crap) will absorb the sound and stop it bouncing off walls. You can buy special square foam that sticks to walls and is designed to absorb, diffuse and defract sound. Also, make sure your listenning environment isn't cold, as sound travels slower in colder enviroments, making the bouncing around in the room your sound does, more audible, as it travels slower.
Re: testing my rooms acoustics ?
Posted: Fri Oct 29, 2010 9:01 am
by macc
vviiper wrote:As for acoustic treatement, using soft absorbing materials (such as blankets, eggs containers, cushions, sofas all kinds of crap) will absorb the sound and stop it bouncing off walls. You can buy special square foam that sticks to walls and is designed to absorb, diffuse and defract sound.
Really bad advice. I mean... egg cartons, really? Blankets etc absorb high frequencies but do nothing to address anything below, ohhh, about 1kHz - leaving the room dull and muddy without actually addressing the problems. Acoustic foam isn't much better. I've seen it advertised as absorptive but not seen a foam diffuser - as in, a proper diffuser (not just something with a jaggedy front edge).
Also, make sure your listenning environment isn't cold, as sound travels slower in colder enviroments, making the bouncing around in the room your sound does, more audible, as it travels slower.
I've heard it all now. Ok, it is true that sound travels slower at lower temperature. But not
that slow. The rest is just guff, and shows a total lack of understanding of the principles at work.
Sorry to be harsh, but...
Re: testing my rooms acoustics ?
Posted: Fri Oct 29, 2010 9:11 am
by vviiper
macc wrote:vviiper wrote:As for acoustic treatement, using soft absorbing materials (such as blankets, eggs containers, cushions, sofas all kinds of crap) will absorb the sound and stop it bouncing off walls. You can buy special square foam that sticks to walls and is designed to absorb, diffuse and defract sound.
Really bad advice. I mean... egg cartons, really? Blankets etc absorb high frequencies but do nothing to address anything below, ohhh, about 1kHz - leaving the room dull and muddy without actually addressing the problems. Acoustic foam isn't much better. I've seen it advertised as absorptive but not seen a foam diffuser - as in, a proper diffuser (not just something with a jaggedy front edge).
Also, make sure your listenning environment isn't cold, as sound travels slower in colder enviroments, making the bouncing around in the room your sound does, more audible, as it travels slower.
I've heard it all now. Ok, it is true that sound travels slower at lower temperature. But not
that slow. The rest is just guff, and shows a total lack of understanding of the principles at work.
Sorry to be harsh, but...
I have a good understanding of acoustics and the physics of sound, but to be honest, I've never really experimented with room acoustics too much - just my contribution.
Re: testing my rooms acoustics ?
Posted: Fri Oct 29, 2010 1:31 pm
by paradigm_x
macc wrote:vviiper wrote:As for acoustic treatement, using soft absorbing materials (such as blankets, eggs containers, cushions, sofas all kinds of crap) will absorb the sound and stop it bouncing off walls. You can buy special square foam that sticks to walls and is designed to absorb, diffuse and defract sound.
Really bad advice. I mean... egg cartons, really? Blankets etc absorb high frequencies but do nothing to address anything below, ohhh, about 1kHz - leaving the room dull and muddy without actually addressing the problems. Acoustic foam isn't much better. I've seen it advertised as absorptive but not seen a foam diffuser - as in, a proper diffuser (not just something with a jaggedy front edge).
Also, make sure your listenning environment isn't cold, as sound travels slower in colder enviroments, making the bouncing around in the room your sound does, more audible, as it travels slower.
I've heard it all now. Ok, it is true that sound travels slower at lower temperature. But not
that slow. The rest is just guff, and shows a total lack of understanding of the principles at work.
Sorry to be harsh, but...
beat me to it. sorry vviiper, but thats really bad advice.
Just in a 'wanting to stop misinformation' kinda way.
Some acoustic foam is ok but the vast majority of stuff marketed as 'acoustic foam' is shite. Rockwool is a far better, and far cheaper alternative.
For diffusion to work effectively it needs to be at 1/4 of a wavelength* so any foam 'acoustic panels' with a 10mm diffusion is almost useless. And diffraction is just unpredictable diffusion and really not desirable.
Sorry
* ie schroeder type diffusers, by far the most common, and what you are referring to. Curved ones are different but you cant buy curved foam afaik, and since its permeable it wont do anything anyway.

Re: testing my rooms acoustics ?
Posted: Fri Oct 29, 2010 5:21 pm
by Neff
ive always been confused as to why this is a big deal i mean looking at some peoples set ups they are so dam ghetto with equipment on draws and stuff yet they still comeout with high quality songs is that down to the mixdown?
but it must be a big deal if everyone talks about it like this
Re: testing my rooms acoustics ?
Posted: Fri Oct 29, 2010 5:22 pm
by AJGR
this is a good start. how can you sort the acoustics out if you don't know what's wrong with them? just putting bass traps in the corners is asking for trouble. if you have a standing wave at 44Hz and you put a bass trap that is tuned to a different frequency, your room will be less accurate. same as just putting foam on the walls, it can really mess things up if you do it wrong.
Re: testing my rooms acoustics ?
Posted: Sat Oct 30, 2010 8:11 am
by macc
Nobody in this forum would be using tuned traps. You quite literally can not go wrong with broadband traps in the corners.
Re: testing my rooms acoustics ?
Posted: Sun Oct 31, 2010 10:57 am
by adamc
Ozone 4 has a nice tool you can check your room's acoustics with as long as you have a nice omni to use with it
Re: testing my rooms acoustics ?
Posted: Mon Nov 01, 2010 5:40 am
by Karma_blitz
thanks, but is there a pc version ?
Re: testing my rooms acoustics ?
Posted: Mon Nov 01, 2010 5:48 am
by Karma_blitz
macc wrote:vviiper wrote:As for acoustic treatement, using soft absorbing materials (such as blankets, eggs containers, cushions, sofas all kinds of crap) will absorb the sound and stop it bouncing off walls. You can buy special square foam that sticks to walls and is designed to absorb, diffuse and defract sound.
Really bad advice. I mean... egg cartons, really? Blankets etc absorb high frequencies but do nothing to address anything below, ohhh, about 1kHz - leaving the room dull and muddy without actually addressing the problems. Acoustic foam isn't much better. I've seen it advertised as absorptive but not seen a foam diffuser - as in, a proper diffuser (not just something with a jaggedy front edge).
Also, make sure your listenning environment isn't cold, as sound travels slower in colder enviroments, making the bouncing around in the room your sound does, more audible, as it travels slower.
I've heard it all now. Ok, it is true that sound travels slower at lower temperature. But not
that slow. The rest is just guff, and shows a total lack of understanding of the principles at work.
Sorry to be harsh, but...
Could be my problem. I have quite a lot of the 1inch thick acoustic padding around my room. Would this make sense as to why im getting a muddy sound ? If this is true and the foam is absorbing all the high frequencies would it make sense to turn them up on the back of my monitors(krk's) ? the high frequency adjust nob ?
Re: testing my rooms acoustics ?
Posted: Mon Nov 01, 2010 12:24 pm
by macc
Keep the padding but only in the essential places - don't scatter it willy nilly all over your room. You want to kill the sound in specific places - where the main early reflections are coming from - not all over the room. This will improve imaging and leave more life in the room at the same time
Make sure you get:
1- side reflection points
2 - ceiling reflection points
3 - reflection points between you and the speakers (ie, the desk or whatever is in front of the speakers)
4 - reflection points behind you
I'd suggest doubling up the padding in those places if you can. You can do it by measuring the distances and doing some simple calculations, or even the 'mirror trick' but the only real way to be sure you're hitting them is via an ETC measurement.
Regarding FuzzMeasure - as I mentioned earlier, get Room EQ Wizard which is free and for PC. You have to register at Home Theater Shack and have the appropriate mic, but it is only £30 or so. REW does ETC and is very simple to use.
