Author Topic: Free Room Measurement Software?  (Read 13141 times)

miklorsmith

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Free Room Measurement Software?
« on: January 10, 2008, 11:17:25 AM »
I have equipment that I planned to use with Inguz, i.e. microphone and USB preamp that can be used with Audacity to record straight to .wav files.

What I need is a program that outputs pink noise or test tones (should be pretty easy, like a downloaded file) and analysis software.

This is one of the TacT functions I really miss.  Obviously I'll be using cave man techniques to make corrections but having the raw data would be really helpful.

I have a ratshack meter and Stereophile test tones but this method isn't terribly precise and is a bit of a pain.

Thanks for any help,

Mike

Offline bpape

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Re: Free Room Measurement Software?
« Reply #1 on: January 10, 2008, 11:34:29 AM »
Go to hometheatershack.com and go to the Room EQ Wizard area (REW).  Free software written in Java that works very well.  Will show you frequency response, decay time, waterfalls, and impulse response.  I think it will do pink noise in addition to swept tones.

Bryan
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Offline richidoo

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Re: Free Room Measurement Software?
« Reply #2 on: January 10, 2008, 12:33:54 PM »
Yeah, it works well. Waterfalls only go up to 700Hz, maybe the new version 3 goes higher? But it is pretty easy to setup with any kind of soundcard. You can also get tones and pink noise for manual testing from realtraps.com. If you find a mode that needs exploration, the single tones come in handy. They are 30 second sine waves from 10 to 300Hz in one Hz increments. http://www.realtraps.com/test-cd.htm

I also made a quicker sweep wav from Ethan's Sonar file. It plays each freqency only for a second or two, allowing you to sit in the room in a specific spot while watching the meter as it sweeps through 10-300. The automated software is much easier, and probably more accurate too. If you have a laptop or audio computer already setup in there, that's the way to go.

I'm gonna try to do the same thing with Inguz. Tell us how it works out for ya!
Rich

miklorsmith

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Re: Free Room Measurement Software?
« Reply #3 on: January 10, 2008, 01:59:20 PM »
Thanks guys.

I have done the Inguz thing.  I think it does work but coming from a TacT, it's really not user friendly and it's a total black box system.

I'm Windows-level guy.  Running Inguz right really needs a little deeper knowledge.

Hugh is a great guy, the time he spends with folks on this voluntary project for him is amazing.  He put a semi-parametric EQ in the package just because I asked him!

If it had a measurement and correction screen, and better user interface it would be an incredible "product".

Offline richidoo

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Re: Free Room Measurement Software?
« Reply #4 on: January 10, 2008, 03:07:45 PM »
Here is another software to check out:

http://www.juicehifi.com

It is new and amateurish, but the guy is quick to respond to questions, and seems to know his stuff. I haven't played with it too much yet, but I am intrigued by the potential to do room correction and other processing completely on the PC. Meantime, you can (supposedly) use it to create customized correction (text) files that Inguz plugin can use for its correction. Much more accurate than the Inguz interface which is necessarily limited. Let us know if you find it to be of any value (or not...)

Combined with a multi channel sound card it can be a digital crossover too. Handy lookin tool. Time will tell.
Rich

miklorsmith

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Room EQ Wizard - Boo Yah!
« Reply #5 on: February 25, 2008, 08:02:10 AM »
I've been tweaking my Definition 2 sub EQ for about two months.  The EQ is a dbx pro unit, which has self-tuning via pink noise to generate a graphic EQ curve.  You have 4 bands of parametric EQ beyond that.  There are other setups but this is the one I've been using.  This unit has a laptop interface sort of like a TacT unit, though far less sophisticated.  Still, for what it is/does it works very well.

I'm running the subs to about 125 hz where the mains start tapering from there in my room but have some output down to 40 hz.  I haven't noticed any phase issues in the bass. 

Obviously, the potential is tremendous - complete flexibility and honest ability to achieve whatever sound you want in the room.  As those experienced with EQ and the like will rue:  "Flexibility is the enemy of satisfaction - you always know there's more and will overanalyze."  While I've been happy with what I've achieved with an SPL meter, test tones, and paltry understanding of parametric EQ/acoustics, it hasn't been quite "right".  Midbass has been plump and low bass not quite as forceful as I'd like.

Well, I sat down with REW this w/e and figgered it out, to a point.  There's a ton there I won't ever need, especially since I'm using an external EQ.  I was able to get the measurement stuff working though, it's not too hard.

The short story is that in 2 hours, including the upfront learning curve of getting the software operational, I was able to EQ each speaker independently +/- 3 dB from 20 - 200 hz in my room.  The target for this exercise was to get "flat".  I will likely save this curve in my EQ as a reference and move onto others like TacT does - varying curves for volume levels and/or purpose.  Funny, I'm not sure "flat" will be my preference but whenever I need it, it'll be there.   

This tool makes quick work of evaluating the working environment and adapting strategies to achieve optimum results.  Compared with shooting in the dark it's incredibly effective.  Being able to see exactly what's happening and addressing it in a real-time environment is the bees knees - I'm sold.

Offline richidoo

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Re: Free Room Measurement Software?
« Reply #6 on: February 25, 2008, 11:08:54 AM »
The dbx has that real time tweak ability, right? They have a crossover product that worls the same way, very nice.

When I first tried Tact couple years ago, I preferred flat to all other settings. I tried to make it work with the psychologically correct EQ curves that are supposed to sound better, match the ear, etc. I didn't think it was anything special. Then I said what the hell, might as well try flat, easy enough... I rolled it -18dB below 20Hz (haha) and took it right out to 20k. Press play.... Beethoven 3rd Symphony, a moment I will remember forever. Amazing technology. The Tact was doing a lot of work to make that room flat, and after a while I had some listening fatigue. But overall a very cool box. Everyone esle I know with Tact don't have the fatigue problem. Bass EQ is an interesting way to go. I like also passive correction to avoid the fatigue, but both cost about the same by the time you are really done.

Thanks for the update Mike! It's hard to imagine how good it must sound. Carl's MC402 amp ran away from home and is hiding out over here for a couple days (shhh), trying to edumacate me about the beauty of unlimited raw power into large drivers. Wow! I am a believer. Enjoy it!
Rich

miklorsmith

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Re: Free Room Measurement Software?
« Reply #7 on: February 25, 2008, 11:28:56 AM »
This dbx is actually a 6-channel EQ of which I'm using only 2 (subs only).  Commands through the laptop are intantaneous so I was running sweeps, making corrections via laptop, new sweep, repeat.  The process was incredibly fast once I got the basic SPL levels figured out.

My mains are unfiltered, which is the biggest difference versus the TacT I had before.  I'm not a fan of messing with the signal but on the subs whatever is lost (nothing I can tell) is seriously outweighed by the gains.  I'm with you on the TacT Rich.  Even with my uber DAC doing digital conversions I could tell something wasn't right.  I won't be going back to full dsp any time soon though the Inguz solution seems pretty darn transparent to my ears.  Of course, that only applies to the SB interface where this works with all input sources.

I never liked "flat" through the TacT but believe it or not it sounds pretty good right now.  It is lean in the bass so I gave it a little bump there.  The next step will be start with a fresh slate and skip the self-EQ sequence with the dbx.  I think that gives me 7 bands of parametric to play with.  Four bands should be enough to get back to flat in-room, and three more to set for mood - jazz/classical, rockin', electronic, movies, etc.  I'll probably have 5 different curves loaded into the dbx for these different scenarios.

Having the whole thing separately powered with the gentle beast Crown amp and mega-output sub drivers means however I tune it, it doesn't affect any of the qualities above 125 hz.  In many ways it is the theoretical ideal realized.