KVR Audio

Virus-Formation · Post by **Virus-Formation** » Sun Dec 25, 2005 5:51 pm

Hi,
First want to thank all this ppl who have contributed to this excellent forum. It seems that there is almost everything in here, from the past and future of music production information.
Secondly forgive me if this is not the right place to post this, or even if this has been asked in the past, as i was unable to locate a similar thread.
ok. Basically i am looking for some info on how i can measure my rooms acoustics, and further analyze them with some pc software like from software vendor waves, or any other. I have recorded a simple set of impulse responses from my room, but analysing i found quite hard. So if anyone can share any ideas and methods i would be really gratefull. In addition i noticed that there is a plugin incorporated on logic (which unfortunately runs only on mac), the Space Designer. Is there a similar tool on a windows system (to import the original sweep and the recorded one and convolve the IR ?) i consider my self a newbie but eager and willing to learn this as i find this quite interesting.
Please post any comments and advice, would be much appreciated. Thanks.

Happy creations

Hink · Post by **Hink** » Sun Dec 25, 2005 5:57 pm

Welcome ..

I'm sure you'll get a lot of good replies...as I am stuck in the worst possible acoustic enviroments I haven't look into such software. However even though this forum deals mostly with AA/CE there are some good mids there and this is right up their alley...or at least they use to be...haven't been there recently...

Stratification · Post by **Stratification** » Sun Dec 25, 2005 6:00 pm

Good question -

I'd love to know as well; you read about this kind of thing on Sound on Sound where they go marching round peoples rooms putting up foam and eggboxes...

But how do you know that you need it in the first place and how do you know where you need it.

Is it all actually very simple, or does it require some special acoustic analysis software...

deaf dunderkwac · Post by **deaf dunderkwac** » Sun Dec 25, 2005 6:51 pm

ETF 5
is what I still use... but I think you can find free-be and possibly easier software to use.
The real trick to these types of software is learning to interput the results.
Real acoustics presents real challanges, but ususally simple solutions can be found (unless you live next to a bizzy highway/airport/train station/bus line/ etc...
The one thing most of us forget is that training yourself to really hear is the most important tool we have

Virus-Formation · Post by **Virus-Formation** » Sun Dec 25, 2005 7:10 pm

hello again and thanks for the replies. the thing is that i get quite confused on how the acoustic properties or a room can vary, and on that matter as Stratification pointed out, how can we know through IR's where there is a problem in the room? I recorded 6 sweeps and the graphs on all vary according to their posistion obviously. But from them how are we supposed to know where there needs to be some "fixing" like with isolation material, duvets/foam/eggboxes.... ? For instance i could have a bit more high frequencies on the right side wall than the left. There would be probably some reflections and standing waves, but nontheless, how do i distinguish where the materials should be applied?
Sorry if i make nosense, but its quite confusing to understand this.

again thanks for this rappid responses

happy Christmas everyone

deaf dunderkwac · Post by **deaf dunderkwac** » Sun Dec 25, 2005 8:42 pm

by using a real-time analyzer like the ETF or any spectrum analyzer, you interput what are the reflections etc.

I'm assuming you want to properly set up your speakers... so the first thing you do i 'play' the impulses (with my software(s) I can play any type of signal and do realtime subtractions of the impulse waveform. I have no idea if this is available cheaply, cause I have the expensive stuff, and don't need to know)
By looking at the signal on a spectrum analyzer (built in to the ETF etc) you are seeing the results of electronics distortion (hardly will see this) acoustical distortion (the BIG ONE) microphone distortions and speaker distortions (not as apparent as the acoustic distortion, but the next largest component of the speactrum's picture)
Using the 2-dimensional mode you should be able to see the main impulse. (that will be the strongest pulse, generally.
You will see smaller pulses preceding the impulse, known as "early reflections" caused by sound traveling along a surface. The stuff afeter the impulse is the spreaker resonances and ray reflections from the room.

as you move about the room you can 'see' yourself. Using this picture you can move large objects and 'see' them also.

The whole subject is the cause of many books.

Harry Olsten was the first and most recognized expert in this field of study.

Anyway I'll get back to you, as it's time to ake dinner

RZ · Post by RZ » Mon Dec 26, 2005 12:11 am

I know you're looking to make a space for monitoring - but let me share an anecdote which I liked.

I met an acoustics expert - who actually worked with folks in concert halls. And he would put together reports and graphs. The biggest factor about sound quality in a space is the people's mood when they enter a space. There is no definition of a good or bad sounding space - its up to the person to make their own opinion. Their opinion was more influenced about their mood than anything else. So sometimes to best way to improve a rooms acoustic was simply to have a calm and pleasant conversation before walking into the space.

G-Ro124 · Post by **G-Ro124** » Mon Dec 26, 2005 12:22 am

RZ wrote:I know you're looking to make a space for monitoring - but let me share an anecdote which I liked.

I met an acoustics expert - who actually worked with folks in concert halls. And he would put together reports and graphs. The biggest factor about sound quality in a space is the people's mood when they enter a space. There is no definition of a good or bad sounding space - its up to the person to make their own opinion. Their opinion was more influenced about their mood than anything else. So sometimes to best way to improve a rooms acoustic was simply to have a calm and pleasant conversation before walking into the space.

Thats so absurdly weird and so absurdly correct, now that i think about it

deaf dunderkwac · Post by **deaf dunderkwac** » Mon Dec 26, 2005 12:33 am

great story and really is true!

back to making a monitor space, one of the simplest to do and not have to become an expert in the field of acoustics is to pull your speakers away from a wall by about 3 ft, put at ear level using stands or even a table of sorts.
Now go out and purchase a 'kit' from one of the many suppliers of room treatment material (think, location, location, location... of the supplier, that is.)
treat the corners of the room for bass standing waves.
And poof...
It's close enuff, now get out your favorite music and start listening to it. I'm sure someone else here would recommend something if you don't have any clear choices.

IF...
you don't have money for kits you can treat bass-standing waves by hanging banners made of heavy vinal or cloth in the room (away from the wall surface by an inch or more.)
This will also break up some of the flutter echo prevalent in small rooms.
If you're using home stereo speakers, start saving money for a resonable pair of studio monitors that have more accurate mid-range, and you will hear things you've never heard before.

Good luck...

and this is just my opinion, m sure there are many others.

dunder(head)

Virus-Formation · Post by **Virus-Formation** » Mon Dec 26, 2005 6:26 pm

Hi all,

thanks for the points and ideas so far. The story with them mood sounds really ideal, especially when u come to think of that music itself will change ur mood, so i am a firm believer of this 2.
A thing that gets me now confused is how is it possible when a room has many low frequencies on its corners be treated so that all this extremee bass will fade away?
I have a few small pieces of isolation material that got from my mate to test the difference and although i placed them on the corner, i have massive bass going on to them. I cant try and record a mic on that positions either cause at around 30-125Hz there is a huge spike. Is that normal? even with some sort of acoustic treatment? I read somewhere on the web that there are some bass tubes that help to prevent that. Dunno really. Open to any suggestions. I was thinking of getting some decent monitors but i am torn inbetween a virus c and the monitors, which is another story.

Anyways, thanks for the help till now.

PS: is there a way to calculate exactly the levels of frequencies that i should get in some specific places ?

cron · Post by **cron** » Tue Dec 27, 2005 12:10 am

Try analysing your impulse response in SPEAR. You should then have a straightforward visual representation of any nasty resonant frequencies in your room.

deaf dunderkwac · Post by **deaf dunderkwac** » Tue Dec 27, 2005 12:53 am

Virus-Formation wrote: A thing that gets me now confused is how is it possible when a room has many low frequencies on its corners be treated so that all this extremee bass will fade away?
I have a few small pieces of isolation material that got from my mate to test the difference and although i placed them on the corner, i have massive bass going on to them. I cant try and record a mic on that positions either cause at around 30-125Hz there is a huge spike. Is that normal? even with some sort of acoustic treatment? I read somewhere on the web that there are some bass tubes that help to prevent that.
PS: is there a way to calculate exactly the levels of frequencies that i should get in some specific places ?

This is normal room reaction... to have the bass build-up in the corners.
You can abuse mis-use this information to your advantage.
It should be apparent that you would place any bass absorbers in the corners.

But have you read about the use of materials at acoustics suppliers?
If not you might start with Acoustic Solutions, RPG and/or just do an overall google-search on "sound-treatment". Read the FAQs and white papers.
Get the info first, then make a decision.
And remember that rugs, beds and overstuffed chairs make darn good absorbers. Shelves stuffed with stuff can scatter sound waves etc.

I've been told that you CAN calculate all the things that can happen, but acoustics is tricky, because the medium of atmoshpere is an ever-changing one.

Measuring and criticizing Room Acoustics ?