Interest check - REW Demo

EndersShadow

This is an interest check only right now.

The biggest influencing factors as to how your speakers sound is your room. Normally this is the last thing people deal with and in all honestly it should be the first. It sometimes can be hard to see what changes you may need to make to your layout regarding toe in, what size and where to place room treatments, etc.

A long time ago thsmith posted a thread about REW that peaked my interest. This program allows you to get some graphical representations of how your front Left/Right and sub are integrated in your room. This can be very helpful for seeing what room modes you have in your main listening position, helpful in determining what depth of room treatments to get, place your sub, set crossovers manually, etc. Its honestly a pretty cool program.

In addition for anyone who has purchased a Mini-DSP, the REW measurements can be loaded directly into that device allowing for a very good room calibration either in addition to whatever auto calibration you have, or on its own.

Somewhere along the way I discussed that interest in this program with codyc1ark. Cody mentioned he had the stuff to use REW and didnt have any need for it. He graciously sent what he had to me. The package included a SoundBlaster Live 24bit external USB soundcard and a bunch of cords, basically everything but the laptop, SPL meter, and suggested tripod.

I being the slacker I am finally got things setup and here shortly I should be able to run some sweeps to help determine placement of my sub and some other things. I want to look at visually how my room interacts with the frequencies to determine the best course of action in regards to sub placement, moving my main forward, backward, side to side ect. I am hoping to have it help me pinpoint my dips and peaks and possibly help me adjust my rooms layout accordingly, both in my main HT and also my 2 channel room.

Once I am done with it, I will have no immediate need of the equipment. As such I figured I would see if others might be interested in demo’ing the product.

Here is some info straight from the website:

Room Acoustics Software

REW is room acoustics analysis software for measuring and analysing room and loudspeaker responses. It includes tools for generating audio test signals; measuring SPL and impedance; measuring frequency and impulse responses; generating phase, group delay and spectral decay plots, waterfalls, spectrograms and energy-time curves; generating real time analyser (RTA) plots; calculating reverberation times; calculating Thiele-Small parameters; determining the frequencies and decay times of modal resonances; displaying equaliser responses and automatically adjusting the settings of parametric equalisers to counter the effects of room modes and adjust responses to match a target curve. The audio analysis features of REW help you optimise the acoustics of your listening room, studio or home theater and find the best locations for your speakers, subwoofers and listening position.

New in REW V5

• Phase & Group Delay (measured, minimum and excess)
• Phase wrap/unwrap, minimum phase generation
• Step Response and Spectrogram plots
• Impedance measurement and Thiele-Small parameter calculation from impedance measurements
• Impulse Response delay calculation and adjustment
• Measurement arithmetic functions, add/subtract/multiply/divide/merge measurement
• Separate windows for overlays, RTA and EQ functions
• Sound level meter with full integrating functionality including equivalent sound level and sound exposure level; mic/meter and soundcard calibration corrections applied; A, C or Z weighting
• New algorithms for EQ adjustment offering exceptional tracking of target responses, can be used over any frequency range
• Waterfalls of predicted results of EQ can be viewed in the EQ panel and can update live as filter settings are adjusted
• Support for QSC DSP-30, Crown USM 810, Behringer DCX2496 and MiniDSP parametric filters
• Room resonance analysis to determine the frequencies and decay times of modal resonances with pole-zero plots of the response and any filters applied
• "Modal" filter setting provided for parametric EQ filters to aid in correcting modal decay

Carried over from REW V4

• Free!
• Frequency response measured using logarithmically swept sine signals for fast, accurate room acoustics and audio analysis measurements using either an SPL meter or measurement microphone
• Real Time Analyser with up to 1/48th octave resolution
• Spectral decay plots, waterfalls and energy-time curves
• Reverberation times derived in accordance with ISO 3382 in octave or one-third octave bands with results for Early Decay time (EDT), T20, T30 and an optimal fit RT60 figure, impulse response can be displayed with octave or one-third octave filter applied
• Signal Generator offering sine waves, square waves, linear and logarithmic sine sweeps, random pink noise (full range, speaker calibration, sub calibration and custom filtered) and periodic pink and white noise
• Frequency response import from and export to text files
• Impulse response import from WAV or AIFF files
• Export impulse responses of measurement or filter settings to WAV files with 16, 24 or 32-bit resolution
• Automatic identification of peaks in the response, automatic assignment of filters to peaks and optimisation of filter parameters to counter the peaks
• Support for the Behringer Feedback Destroyer Pro models DSP1124P and FBQ2496, including filter setup via Midi (Midi interface required)
• Support for the TMREQ equaliser in the TAG McLaren AV32R DP and AV192R AV processors, including filter setup via RS232
• Compensation for C-weighting when using an external SPL meter as the input, calibration files can be loaded for soundcard, microphone or SPL meter
• Comprehensive help files within the application and on-line

Here is the list of items you need in order to use REW properly:

• Laptop - whatever you have on hand but it must have either Windows 7, 8 or XP and meet the requirements found in the quote below
• REW software - its free to download, but you must create a Home Theater Shack account to download it, but its a good forum and useful for questions and help interpreting the data. They do also have beta versions that are newer than the one at this link. They are easy to find.
• Creative drivers - free. I am using the Creative Sound Blaster Driver 01.02.00 drivers
• Tripod (optional, but you really want to use one) - 15-25 bucks
• Radio Shack Digital SPL meter - 25 bucks IIRC
• Cords - included

This demo would be setup similar to the MIT demo. Each person would pay shipping to the next. It needs to be sent insured for 100 dollars with signature required. It’s a fairly small and light package, it could probably fit in a medium flat rate box.

All I would ask is that you post your graphs, what it taught you about your room and what changes if any you plan to make. Each person will have it for a month in an effort to ensure that it doesn't just sit for years (like it did with me). That should allow you enough time to set it up, run it a couple few times and get help with interpreting the data it provides you.

THIS IS A INTEREST CHECK ONLY. I anticipate this starting around December, or the first of next year so I can get enough time to run everything and interpret the data and see what changes I need to make.

If you are interested in this demo, please post interest in this thread. If there is enough to justify this I will get things ready after I am finished.

thsmith

Great idea ! The RS SPL meter using the REW calibration file will be good enough for a sub only. To measure full range speakers will require a better mic than the RS SPL contains. I believe Beringer is the one the site recommends and they have a calibration file for it as well.

I have not even ran a sweep since moving to KS last year. I should break out the gear and check my sub.

Phasewolf

The Radio Shack meter is not going to give very good measurements at all which is why I got a MiniDSP UMIK-1 Microphone and got it calibrated at Cross-Spectrum Labs. Looking at the before and after with both there is no comparing the two.

The thing I like about it is that you plug it into a usb port and your good to go. Import the cal file and all is set on that end.

If you want I can loan it out for this so people can get good readings.

Let me know.

John..

Msabot1

I used a device called a Pink Noise Generator to show anomalies in acoustics,speaker performance,crossover performance and the like. Probably wouldn't need to do this in your average listening room though.

thsmith

A lot of you here have talked about wanting to try REW, here is your chance.

EndsShadow has made it easy for you.

If you are really into HT, this is a must try. Even minor changes to rasing a dip will be felt and heard. Get your sub as flat as possible THEN run your AVR calibration and you will be floored on how much tigher and the presence your sub has.

Phasewolf

I ran my sda's and seen a 25db dip at 150hz I moved the speakers back a inch at a time and now it is gone. Running the program can help you fix lots of issues. It really allowed me to find the best places for each speaker and then find the best locations for my room treatments.

Polk&Beans

Sounds like a way better way than the old school SPL meter and trial and error ways I did it in the old days. Now I am old, tired and lazy. So I got a Marantz with Audessey XT-EQ32??? It does all that with several microphone placements.

Phasewolf

Maybe but with this software you get your speakers in the best location before you run your auto correct software and less needs to be fixed and the less that needs to be tweaked the better it sounds.

thsmith

Phasewolf wrote: »

Maybe but with this software you get your speakers in the best location before you run your auto correct software and less needs to be fixed and the less that needs to be tweaked the better it sounds.

Exactly and if you look at what Audessy does, it really does not address dips or peaks just tries to level adjust.

strider

Great opportunity here, guys. Not just for HT, either. With some time invested in it you can really get some good results.

EndersShadow

thsmith wrote: »

Great idea ! The RS SPL meter using the REW calibration file will be good enough for a sub only. To measure full range speakers will require a better mic than the RS SPL contains. I believe Beringer is the one the site recommends and they have a calibration file for it as well.

I have not even ran a sweep since moving to KS last year. I should break out the gear and check my sub.

Hmm, I thought it would be good enough to get some decent measurements. I may look at something else then for measuring my mains. Wanted help with seeing how they interact with their placement from the side walls as well as how far out from the wall they are.

Phasewolf wrote: »

The Radio Shack meter is not going to give very good measurements at all which is why I got a MiniDSP UMIK-1 Microphone and got it calibrated at Cross-Spectrum Labs. Looking at the before and after with both there is no comparing the two.

The thing I like about it is that you plug it into a usb port and your good to go. Import the cal file and all is set on that end.

If you want I can loan it out for this so people can get good readings.

John, I might indeed be contacting you in regards to this, we can talk via PM about that possibility.

Polk&Beans wrote: »

Sounds like a way better way than the old school SPL meter and trial and error ways I did it in the old days. Now I am old, tired and lazy. So I got a Marantz with Audessey XT-EQ32??? It does all that with several microphone placements.

As mentioned by others, Audyseey can only do so much to fix the problems in your room. It cant totally eliminate dips and peaks in your system that doing something as small as moving speakers a couple inches or feet one way or another could fix.

I look at speaker placement as 90% of the battle. If you place them right to begin with (if you can given WAF and room layout problems) then the auto cal cant take it that extra 10%.

strider wrote: »

Great opportunity here, guys. Not just for HT, either. With some time invested in it you can really get some good results.

Yup, going to use this with my 2 channel system....

ZLTFUL

Call me interested Dan...

Phasewolf

I have a very bad room with using a mic it allowed me to maximize things. I ended up moving my couch forward 8" where I had it before was in a room mode and there was a massive dip and the speakers went back some really made things overall better.

Sure there is work I need to do still but that comes with time and trial. The nice thing is you can see things all you do is place the mic at the height of your head where you would be sitting and measure each speaker. Then move a speaker say 2" and measure it again and see if your going the right way or if it made a issue worse and then you can move it the other way.

Once speakers are each placed in there best location you can play it you like with the seating and see if there is anything that can be done there.

I did all of this with no room treatments in the room. Once things are where you need them I started adding room treatments back into the room. This allowed me to micromanage things and get the most with a bad room.