# Sticky  REW YouTube Tutorial



## Sonnie

Compliments of GIK Acoustics. We would like to thank GIK Acoustics for preparing a very nice YouTube Tutorial on how to use REW. GIK tells us it is the first of several we can look forward to seeing. Thank you GIK!


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## Phillips

Sonnie said:


> Compliments of GIK Acoustics. We would like to thank GIK Acoustics for preparing a very nice YouTube Tutorial on how to use REW. GIK tells us it is the first of several we can look forward to seeing. Thank you GIK!
> 
> Room EQ Wizard: REW Room Measurement Tutorial - YouTube​




Hi Sonnie, i agree thanks to GIK and yourself for posting this.

Hopefully there will be more tutorial videos, personally i would rather watch a video than read a book.

It would be great to watch tutorial videos, to what is best used for a certain application, and frequency range. 

Keep it up


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## Greg Midi

So the REW is a free program?


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## Sonnie

*FREE FREE FREE!*


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## Phillips

Greg Midi said:


> So the REW is a free program?



Yep the program itself is FREE, but you need measuring hardware e.g. Mic + Preamp/Soundcard with phantom power.
I use the Omnimc mic + laptop soundcard that has its own software, read my thread MIC THOUGHTS.


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## bpape

A good mic is certainly desirable for best effect. That said, even something as simple as the Radio Shack meter, USB external sound card, and the correction file for the RS meter will still get you a long way. When you're looking for relative change, we can still see that even with the inconsistencies in that sort of setup. 

..... and there will be more videos.

Bryan


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## S_Chowd38

*Re: REW YouTube Tutorial, loopback query*

Thank you for the in-depth video! It definitely helped.

It's just one of those things, though--I am still not sure if I have set up my little 2-channel M-Audio Fast Track Audio Pro to successfully complete the soundcard calibration...

Was hoping you could help me kill the confusion about 1) what my soundcard and the line input/outputs should look like beforehand, and 2) how to set up the Preferences/Soundcard settings to successfully complete the calibration test in REW.

Channel 1 ('left') has a 1/4" jack looping back to the Channel 1 output. In effect, my left monitor speaker is now disconnected from the sound card, yes? I've run the 'Levels' test using Main Speaker to Check Level, and I've got my Channel 1 input level boosted to match the -12dB noise from the software, which is only coming out the right monitor speaker. Clicked ok finish.

Channel 2 ('right') has an XLR leading to my Beyerdynamic MM1 Electret, input level at 0, phantom power on.

Have also ticked the 'Use Loopback as a Timing Reference' box under 'Analysis'.

I'm pretty sure I'm supposed to set 'Input Channel' to Right and then hit Calibrate, but...I feel like I"m missing something! And the result back from the sine sweep test is always "You're about -34 dB short." Any help on this?

Much obliged if you could point me in the right direction elsewhere if not. Thank you much


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## eurovybez

Can you do this with steinberg ci1?


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## bpape

I'm not familiar with that. I spoke with Glenn and he had the same thought that I did - as long as it shows as a soundcard and is bi-directional, it should be fine.

Bryan


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## Phillips

bpape said:


> I'm not familiar with that. I spoke with Glenn and he had the same thought that I did - as long as it shows as a soundcard and is bi-directional, it should be fine.
> 
> Bryan



Hi i am alsp interested about the Steinberg CI 1.

When you say bi - directional, please can you elabarate.

Thank you


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## bpape

A bi-directional sound card simply means that it's capable of playback and recording at the same time.

Bryan


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## aackthpt

What Bryan refers to as "bidirectional" is actually what is usually known as "full-duplex". Full duplex is the norm these days and it would be very unusual to find a sound card or audio interface that was not full duplex, so typically you don't have to worry about it.


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## rscheirer

Could I get some assistance regarding how i might use your REW software in conjunction with my DBX Driverack 260? Thanks!


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## Wayne A. Pflughaupt

Among other things, REW can help you determine where to set the crossover frequencies for your PA system as well as equalize it. Hard to be more specific without more details on your system and/or intended application.

Regards, 
Wayne


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## HTCare

hi, need to know the difference between xtz room analyser and REW software. which one is more accurate and user-friendly. will appriciate comments.


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## Dale Rasco

Accuracy of these systems can be dependent on outside dependencies such as hardware, product and subject familiarity and even weather/climate. I personally use a combination of REW for my main measurments and XTZ for validation if something does not look correct to me.


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## Dale Rasco

Also, with REW you can capture down to 0 Hz and XTZ only to 16.


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## oyo

Thank you, thank you, thank you!
I used to use REW a few years ago. This video will bring me back up to speed in no time, (well, about 9 minutes and 34 seconds!)


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## Wayne A. Pflughaupt

Great video! However, there is a significant error at about 3:25 when it says to perform the measurement with the mic in an upright position, but neglects to mention that *this requires a special calibration file for 90-degree orientation.* Traditionally horizontal orientation has been used for frequency response measurements in minimally-reverberant free-field environments like we find with the typical home theater. It should be mentioned the our generic calibration files for the  Behringer ECM8000 and Dayton EMM-6 mics  are 0-degree files for horizontal orientation. More reading on mic orientation in the links found in this post.

Regards, 
Wayne


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## bpape

Hi Wayne

Here is a quote from the REW download link where they talk about mics and calibrations:

"For listening position measurements we recommend that the meter or mic be oriented vertically with a forward angle of about 10 - 20 degrees to capture a good mix of direct and reflected sound for 'room' measurements.

For near-field measurements we recommend a horizontal position to give the most accurate high frequency readings."

Since we're doing listening position testing, the vertical orientation is what is recommended.

Bryan


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## Wayne A. Pflughaupt

Hey Brian,

Unfortunately, the REW Downloads page – and the video - neglects to mention the need for a proper calibration file when taking measurements with the mic in an upright position. 

It’s a well-known fact that the mic’s off-axis response is depressed in the upper frequencies compared to its on-axis response. For reference, see the graph below of measurements for a Dayton EMM-6 mic as performed by Herb Singleton of Cross Spectrum Labs. As you can see, when the mic is oriented 90-degrees of-axis from the signal source, its response at 20 kHz is a full 8 dB down. 

Thus, room measurements taken with the mic upright, _without the proper 90-degree calibration file,_ will show a droop in response above ~2 kHz that will not accurately reflect the speaker’s response or what the user actually hears. We've seen it happen here many times over the years, REW users perplexed about their poor measured response in the upper frequencies, only to find out that they weren't using the proper calibration file when they measured with the mic upright.









*Dayton EMM-6 On and Off Axis Frequency Response*​Courtesy of HiFi Zine​ Regards, 
Wayne


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## bpape

Above 2k i'm not too worried about. What we're trying to really tame is primarily below say 400Hz where the response is pretty much identical. If a 90 degree file is required, then it's something we should have on the site. 

Bryan


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## tusoli5

Isn't the iso curve used by many professionnals supposed to decrease gently above 2K ?
This would mean that the given curve (as wayne highlighted) is near to what it should idealy be and poor measurements of the treebles doesn't mean that it simply doesn't exist or that you can't hear it. 
A treeble uprising its power above 2k measured at 90 degrees would be dreadfull to hear and challenging to listen to more thant a few minutes. 

After mesuring, when you start equalizing your room, feel free to push it up a bit just to have your own idea, it sometimes can make beautifull enhancements and sometimes can make everything sound really bad. It depends of the tweeter quality/softness/crisspiness. ;-)
Everything may sound good out of the ideal curve, just give it a try after you've reached it.

Ideally for me, I try to flattent the more I can to stick to the ideal curve and then I unleash it to different point from what I am hearing and what I wish to reach.

So reaching the ideal curve is simply where the real work begins for me.


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## tusoli5

I'd like to ask a question, when I understand that Room eq can allow to put cut frequencies for each speaker, can I consider this software as a full active filter ?


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## Wayne A. Pflughaupt

bpape said:


> Above 2k i'm not too worried about. What we're trying to really tame is primarily below say 400Hz where the response is pretty much identical. If a 90 degree file is required, then it's something we should have on the site.


At 400 Hz and below the mic is omnidirectional, which makes upright orientation of the mic - and the proper calibration file - moot.




tusoli5 said:


> ...can I consider this software as a full active filter?


REW is a measurement program, not an equalizer program.

By the way, welcome to the Forum!

Regards, 
Wayne


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## dRwOOD73

Great video, thanks for posting.. got my uMIK a couple months ago and my DSP1124 is on it's way.. now I just need to wrangle up the necessary cables and I'm off and running.. :bigsmile:


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## dRwOOD73

Great video, thanks for posting.. got my uMIK a couple months ago and my DSP1124 is on it's way.. now I just need to wrangle up the necessary cables and I'm off and running.. :bigsmile:


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## pddufrene

I'm definitely going to check out this video, I'm curious as to how this all works and would like to try it out but not before understanding how to use it. From reading all the post above it sounds complicated.


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## dRwOOD73

pddufrene, I was right there with you.. I've been sitting on my uMIK for months now.. but, I've finally made moves to get started, got my DSP1124 today - my monoprice order of wires is coming in tomorrow.. so hopefully with some help from videos like these and the Shack/AVS forums I can get up & running in no time.. fingers x'd :gulp:


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## pddufrene

dRwOOD73 said:


> pddufrene, I was right there with you.. I've been sitting on my uMIK for months now.. but, I've finally made moves to get started, got my DSP1124 today - my monoprice order of wires is coming in tomorrow.. so hopefully with some help from videos like these and the Shack/AVS forums I can get up & running in no time.. fingers x'd :gulp:


I wish u luck, ill end up giving it a try once I figure out everything I need to get it going. Maybe by then you'll be able to coach me through it. Lol


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## swissmiss

Holy Moly, there is a lot that goes into acoustics. Thank you for the video, going to try this out for my car audio.


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## stereo247

I have a UMIK-1 and MBP. I was wondering how and if one needs to you perform the sound card calibration and level setting procedure as depicted in the video.


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## bpape

Yes to both. Especially the level setting.


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## stereo247

bpape said:


> Yes to both. Especially the level setting.


So how do I achieve the equivalent of calibrating ones sound card. In the MBP+ UMIK1 it's using the MBP sound card. Do I just plug a line in to line out cable on the MBP and then run the calibration?


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## bpape

I'm not a studio guy so I'm not familiar with that equipment - sorry. Basically you need to let the system measure whatever equipment will be used to record and generate the sound by creating a loopback for the calibration.


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## informel

stereo247 said:


> I have a UMIK-1 and MBP. I was wondering how and if one needs to you perform the sound card calibration and level setting procedure as depicted in the video.


In REW 5.01 beta page 30, it says:
Calibrating the Soundcard
This step is not required when using a USB microphone as the input, skip directly to
Check levels


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## informel

In fact, with a USB microphone, it is a lot simpler
quote from REW 5.01 beta page 28:
The initial steps required to make room measurements are:
1. Choose the audio input and output
2. Calibrate the soundcard (not required when using a USB microphone)
3. Check levels
4. Calibrate the SPL reading (not required when using a USB microphone that has
REW-compatible sensitivity cal data)


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## bpape

My mistake. Don't understand WHY one would still not be concerned about the frequency response of the sound card though.


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## informel

bpape said:


> My mistake. Don't understand WHY one would still not be concerned about the frequency response of the sound card though.


You are right about that, I do not think that it would be flat down to 10 Hz, sound card has probably a high pass filter on the low range (DC- protection) and a low pass filter at the high end for anti-aliasing


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## informel

informel said:


> You are right about that, I do not think that it would be flat down to 10 Hz, sound card has probably a high pass filter on the low range (DC- protection) and a low pass filter at the high end for anti-aliasing


I just had a second thought, the output is not completely flat across the range, but the input reading is not ruler flat either, so if you calibrate it, you will still introduce an error because with a USB mic, you do not use the input of the sound card.

If there was a cal file for the sound card input, then it would be perfect


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## stereo247

Thanks a lot guys for the replies. Literally figured this out just an hour ago after going through countless threads. Much appreciated.

Still it doesn't appear there's a way to calib the card of the MBP. If I do find it I'll post back.


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## Phillips

stereo247 said:


> Thanks a lot guys for the replies. Literally figured this out just an hour ago after going through countless threads. Much appreciated.
> 
> Still it doesn't appear there's a way to calib the card of the MBP. If I do find it I'll post back.


I would post it on the "REW forum" to get more exposure.

Any particular reason why you aren't using the laptops soundcard? How old is your laptop?


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## Phillips

> you do not use the input of the sound card.


Correct


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## informel

stereo247 said:


> Thanks a lot guys for the replies. Literally figured this out just an hour ago after going through countless threads. Much appreciated.
> 
> Still it doesn't appear there's a way to calib the card of the MBP. If I do find it I'll post back.


a generic file could be provided by the manufacturer, not the perfect solution, but better than nothing.
or one could use another PC to produce sound at different frequency and adjusting the level at every frequency using an oscilloscope then record the level on the test sound card, but that would be very time consuming.

So practically, you either use a USB microphone and forget about the error from the input of the sound card or you use a regular microphone and go through the whole process


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## RueyBang

Hello, I couldnt get the program running straight. I did everything step by step. this is a brief video of my problem, if anyone can help i would really appreciate it.


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## JohnM

RueyBang said:


> Hello, I couldnt get the program running straight. I did everything step by step. this is a brief video of my problem, if anyone can help i would really appreciate it.


You need to use the beta version of REW to get audio interfaces working properly on the Mac (Apple's version of the Java runtime had a lot of bugs in its audio handling, the beta version has a working Java runtime in it). You can get the beta version here. Note that you need OS X 10.7.3 or later and you should remove REW before you unzip the beta version bundle and drag it into the Applications folder.


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## RueyBang

JohnM said:


> You need to use the beta version of REW to get audio interfaces working properly on the Mac (Apple's version of the Java runtime had a lot of bugs in its audio handling, the beta version has a working Java runtime in it). You can get the beta version here. Note that you need OS X 10.7.3 or later and you should remove REW before you unzip the beta version bundle and drag it into the Applications folder.


Wow worked wonderfully! Thank You very much


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## wes

Ok I just downloaded REW new version how do I use my Mac to measure my room!


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## Wayne A. Pflughaupt

Did you see the link for the YouTube Tutorial in the first post?

Regards,
Wayne


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## Krogstad89

Thanks for the video! It was very helpful.

Much easier then attempting to figure everything out by trial and error!


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## ESD Network

Thank you for the great program and tutorial as well.

This will allow to do amazing discoveries about chamber resonance and much more.

Best vibes to all, much love and light for all


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## dave.riley3

WOW!! Didn't know that sound was this complicated...

I find the U-Tube presentations very fine... Also the REW docs are easy to get to and a good read...
Looks like another trip to 'DONATE' :wave:

By the several tips already received here it looks like I can keep the small laptop ( portable ) to take with a few patch cords to the hall...
Now to add help to possible good info, I read that a USB i/o for mike out and line in seems very dooable...

Going to U-Tube now to try and find best equipment to fix a room...
Maybe I misread some of the DSP adds, but it sounds like ( no pun ) that a dedicated DSP box just stays in the line to amp. for a most perfect room... Eh??

TNX from DaveR


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## bpape

DSP is fine to address frequency related issues. It cannot address reflections or decay time nor can it address modal nulls. Those things need to be addressed by treating the room.


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## dave.riley3

OK, and thanks for that, bpape.. Then I take it that a DSP rig or 31 band EQ will do about the same with the exception of maybe the DSP cuts the bands into smaller widths each...
Now I have to ask if there is also a device that will correct for the timing as well??

Unknown territory me me, so TNX again from DaveR


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## bpape

Timing in terms of what?


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## dave.riley3

Sorry, I meant reflections or decay time... Understand that is a physical room fix...

To start off should I find a 'smart' dsp unit like the feedback destroyer or in my case since the application is permanent for one type of use would the 31 band EQ box suffice?

TNX again from DaveR


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## bpape

DSP is more flexible and it's a parametric vs a graphic fixed type of EQ.

The drawback is that being analog in but providing digital processing, that is adding another A/D and D/A step. Depends on how picky you are bout your sound. If it's just for the LFE channels, it's fine. Personally, I wouldn't put something like that on my main channels. 

There are also all analog parametric EQ's available - just that you have to do the tweaking yourself as opposed to running a sweep and letting the unit make the changes (which I'm not really fond of anyway - but that's just my opinion).


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## dave.riley3

TNX much Bryan,

That sets me in the right direction and I am greatful for your advice.
Right now it looks like staying with the 31 band mono EQ set for the only room that it will be playing in, and possibly something like a feedback destroyer down stream of the manual EQ just to take care of any 'surprizes'...

DaveR


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## bpape

Like I said, the BFD is fine on the LFE channels. I just wouldn't use it in my mains chain.


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## Hopetownsound

Hi Bryan! Sorry you haven't heard from me this week. This is part of why . 

I've been attempting to use the DBX M mic that comes with the DBX Driverack. By all accounts it's an omni mic made for doing measurements. I'm following the GIK-supplied video (much thanks!). The problem I'm having is that when I attempt to do the initial soundcard calibration I'm getting an error telling me that the level is varying by way too much - typically 57db and that I shouldn't use the calibration created.

I'm on Mac OSX 10.9.5 using an old RME Fireface. The Fireface has a software mixer (Totalmix) which allows for creating loopbacks. I've checked VERY carefully and repeatedly that I'm not accidentally looping the output to the input. When I get the initial input level calibration anywhere close to the output level - the resulting sweep measurement clips. I have to have it about 20db lower than the output to make the sweep stay in the green. 

BTW, I tried selected the actual (ASIO) driver for the Fireface and the level variation was a LOT higher. in the 90's. 

If it matters, my monitoring system is a presonus central station feeding a JBL subwoofer which in turn is feeding a pair Quested v2108 speakers.

Any help would be greatly appreciated. Thanks so much in advance for the great software and the assistance!

Pier Giacalone


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## akltam

Thanks for the video. I at least have a clue how to start. Many Thanks. 

Just one request. I appreciate if the speaker can speak slightly slower so that those viewer with English as second language (like me) can follow easier. 

Many Thanks. 

Alan


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## bpape

I'm not a Mac guy so really can't help much. Not familiar with that microphone. That said, I've never done a mic calibration. As long as the mic is decent, you shouldn't have to. We really don't care if the very top or bottom end are down a couple of db. We're looking for relative variation and relative change as seating, speakers, and subs are moved in the room to get the best starting point and identify the frequencies at which problems occur. Don't really care if that null at 120Hz is -10db or -12db - just that it's a null and it's at 120Hz.

Wish I could help with your issue but I wouldn't let that hold up measuring as long as you can get a good reading. It will be pretty clear in the measurement if it looks to be a valid one or not.


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## Wayne A. Pflughaupt

Hey Pier,

This thread is specific to the YouTube tutorial, not ironing out REW issues. You’ll have better luck getting answers to that by opening a new thread.

Regards, 
Wayne


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## Hopetownsound

I'll try that. I figured since I'm having trouble following the directions in the video it applied, but I'm happy to try whatever will lead to fixing the problem. I was also working directly with Bryan before I even found this thread.

Bryan. I tried it on PC as well. Same issue. I also tried it on a different mic. Same issue. I'm pretty stumped. I'm getting a fairly consistent reading though so, I guess it's ok. I'm still learning how to read all the different data. 

I'll try starting a new thread. 

BTW - I found the video moved a bit too fast too . 





Wayne A. Pflughaupt said:


> Hey Pier,
> 
> This thread is specific to the YouTube tutorial, not ironing out REW issues. You’ll have better luck getting answers to that by opening a new thread.
> 
> Regards,
> Wayne


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## Steve Piazzo

Thanks for posting the video


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## PearlJam

Thanks. A great starting video


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## yosh7

Thanks very much for the video. I look forward to using rew.


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## yosh7

I am ordering my microphone today!


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## asere

I've used REW before with RCA cables and the UMIK 1. To be sure with the Mini DSP UMIK 1 there is no need to calibrate any sound card correct?


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## Wayne A. Pflughaupt

Correct, just load the calibration file for the mic and you're good to go.

Regards,
Wayne


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## asere

Wayne A. Pflughaupt said:


> Correct, just load the calibration file for the mic and you're good to go.
> 
> Regards,
> Wayne


Thank you!


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## Lumen

GIK, thank you for the video! It helped me understand more than I thought I knew. 

At the beginning, the narrator mentions that, for instructional purposes, both mains will be measured at the same time. He then goes on to say that (real-world) individual measurements will be made later. I don't think the second video has been made yet, so I looked for help and found it from new member "ntran" in Post #8 of this thread. 

The document is a step-by-step guide to REW and holds a wealth of information in a wrritten version as easy to follow as the video!.. Topics like computer setup with HDMI and ASIO4ALL, measuring speaker/sub combinations, and all the workings of REW itself.

Thank you, ntran!


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## RazorRay

It was very helpful to learn from this thread that Soundcard calibration is not required for a USB mic. I am using a Dayton Audio UMM-6 mic and did download the calibration file and included it in the REW preferences setup. Currently when I run "Check Levels" I cannot get the input meter to indicate in the recommended range of -24db to -12db FS even with my mic input level set to 100% (in Windows control panel). In indicates about -35db FS and this is based on a 75db signal as measured by my stand alone SPL meter. Is this a problem I should be concerned about?


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## JohnM

Nope, nothing to worry about, per the REW help on checking measurement levels: _If using a USB mic the signal may be much lower, below -50 dB, this is OK_


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## Zee

Just wanted to thank those involved in the video and the software. 

Z...


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## asere

I've used REW before with AV connections but now that I tried with hdmi I cannot open the channels on the REW output to select. I am using the Umik 1 mic with the calibrated file. I go to preferences on REW and made sure I selected Asio4, then on input I selected umik1 but for output it says Not Connected. The hdmi is connected to the back of the avr and I can see/display the PC/REW info on the tv screen.
Any thoughts please?


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## JohnM

asere said:


> I've used REW before with AV connections but now that I tried with hdmi I cannot open the channels on the REW output to select. I am using the Umik 1 mic with the calibrated file. I go to preferences on REW and made sure I selected Asio4, then on input I selected umik1 but for output it says Not Connected. The hdmi is connected to the back of the avr and I can see/display the PC/REW info on the tv screen.
> Any thoughts please?


Could try following the miniDSP article to see if that helps, it covers it all well: http://www.minidsp.com/applications/acoustic-measurements/umik-1-hdmi-on-windows


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## asere

JohnM said:


> Could try following the miniDSP article to see if that helps, it covers it all well: http://www.minidsp.com/applications/acoustic-measurements/umik-1-hdmi-on-windows


Thank you. I read it before and I can get every step but somehow I cannot get the output window to display the speaker channels. I know the hdmi has to be set for multi channel output.
How can I verify the hdmi multi channel output?


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## JohnM

I don't know, sorry. Were you able to select both the UMIK and the HDMI output on the ASIO4All control panel? Did you restart REW after doing that? What output devices does REW show? Might be worht posting a couple of screenshots of the ASIO4All panel and the REW soundcard preferences. I guess there's also a chance the HDMI behaviour may depend on the surround mode the AVR is set to.


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## asere

JohnM said:


> I don't know, sorry. Were you able to select both the UMIK and the HDMI output on the ASIO4All control panel? Did you restart REW after doing that? What output devices does REW show? Might be worht posting a couple of screenshots of the ASIO4All pane and the REW osundcard preferences. I guess there's also a chance the HDMI behaviour may depend on the surround mode the AVR is set to.


I was able to select umik for input and for output it says not connected or it says hd something. I needed to check the avr hdmi settings.


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## FargateOne

asere said:


> I was able to select umik for input and for output it says not connected or it says hd something. I needed to check the avr hdmi settings.


I am just an amateur in all computers things but I went through many problems before being capable to use rew with my hdmi output.
The problems I had were:
first) related with drivers (intel, nvidia,realtek etc), firmware, software, windows not updated to last version, adobe flash reader java etc must be updated and 
second) having downloaded updates or programs (rew or Asio4all) without having stop antivirus,firewalls web protections etc before. 
All my problems resolved after that.
Rew is a fantastic piece of machinery and I hope soon be able to post some graphs to get help to interpret all the infos provided.


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## asere

FargateOne said:


> I am just an amateur in all computers things but I went through many problems before being capable to use rew with my hdmi output.
> The problems I had were:
> first) related with drivers (intel, nvidia,realtek etc), firmware, software, windows not updated to last version, adobe flash reader java etc must be updated and
> second) having downloaded updates or programs (rew or Asio4all) without having stop antivirus,firewalls web protections etc before.
> All my problems resolved after that.
> Rew is a fantastic piece of machinery and I hope soon be able to post some graphs to get help to interpret all the infos provided.


Thank you! I was able to get the channels to show on REW after I connected the mic to a different usb input on the pc. I will post graphs once I get my sub fixed. It went caput the other day.


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## Mike Hirsh

Hi 
My names Mike and I am a "dumbo" newbie 
I have been trying for weeks, yes weeks to setup the REW software, with various hardware, mic, speakers in my studio control room and I am getting no-where fast. 

1. I have a Apple Mac OSX 10.8 Mountain Lion
2. REW software for mac
3. Behringer ECM8000 with calibration file
4. M-Box 410 firewire interface 
5. Digi design 003 interface 
6. Mackie ProFX16 mixer with USB output 
7. DynAudio BM6 speakers routed thru a Mackie 32 8 buss mixer.
8. Miles of cables and adapters in any configuration one desires....!!!!

I even have a very old analogue REALISTIC/Radio Shack SPL meter 

I have read, re-read and re-read again the the REW manual on set up and on how to take measurements 
I have printed both set up pictures 
I have listened to the GIK video 3 times and another one on Youtube

And still I get the REW software telling me my audio levels are too low to take measurements...grrrrr

EVEN THOU ALL MY LEVELS ARE UP FULL AND I MEAN UP FULL on everything INPUTS AND OUTPUTS on my mac 
mic inputs up full.... mixer outputs from speakers up FULL( well with out blowing them up and causing my ears to bleed) 

and I still get this rotten message from EQ wizard telling my my levels are too low.

At the beginning when I found this amazing software, I just plugged in my EC8000 mic straight into the input of my apple mac and the output to my Mackie 8 buss where the DynAudios are connected and I received no message telling me the levels were to low, and took some measurements and thought that was it... 

However, that was until I watched the GIK video telling me that I needed an audio interface.
Well that's ok I thought as I have 2 of them as mentioned above...!!! 

1. Digidesign 003
2. Mackie ProFX16

Unfortunately, after setting up my Digidesign 003 it didn't seem to work, so I tried my Mackie ProFX16 with USB and that didn't seem to work either.

So I went through the GIK video again and thought since on the video they are using a Prosonus Firewire Studio, I though ok I'll go out and buy a firewire interface, thinking it was the answer to my prays...
So on ebay i saw this secondhand M-audio 410 Firewire interface and bought it all because the 003 and the Mackie mixer didn't do the job 

So when my M-Audio Firewire interface arrived I thought "you beauty" I'll set it up and all will be GREAT hahahah 

Well guess what... I STILL got this rotton message from from eq wizard telling me that my audio input is too low and that I should check all inputs outputs, outputs, mute button, ect, ect, ect which I have checked re-checked and checked again on various hardware and still the readings are too low and nothing I do seems too work... Grrrr 

So now I have only succeeded in adding to my growing hardware and am $100 poorer and still NO joy only EQ wizard telling me I'm a failure  

So if there is anybody in the world that can help me here, I would really appreciate it, as I am just about stuffed and ready to commit suicide 
Mike from Oz


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## JohnM

You don't need an external audio interface to use REW, if you have a phantom power+mic to line converter for the ECM8000 there is nothing at all wrong with connecting it directly to your Mac. Simpler is often better as far as soundcards and interfaces are concerned, acoustic measurements don't place high demands on a soundcard. Cards with multiple stereo inputs can be difficult to get routing properly, not sure whether that is an issue with the Javasound implementation or something else.


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## Mike Hirsh

Hi John 

OM goodness how simple was that 
I ended up using my Zoom H4N to connect the mic using the onboard 48V phantom supply 
straight into my mac.

opened REW took the sound card measurements and "whalla" no messages 
In fact REW told me my levels were good 

Thanks a lot, you saved my life ...lol

Now all i need to do is find out how to set the limits in REW so I will read the manual on that 
again many thanks

Mike


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## Ilpo

Is it possible to set one measured response flat (on axis, for example) and others as difference to that? This is a good feature in MLSSA.

Thanks,
Ilpo


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## JohnM

Ilpo said:


> Is it possible to set one measured response flat (on axis, for example) and others as difference to that? This is a good feature in MLSSA.


Not directly, but you can divide responses by a reference using the trace arithmetic controls on the All SPL graph. The responses should be appropriately time aligned.


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## HiFiStereo

Great tool!
How to position the microphone at the listning position? Upward or horisontal towards the speakers?


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## bpape

Kind of depends on the type of mic. I generally just do it at 45 degrees.


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## Wayne A. Pflughaupt

If it’s a standard measurement mic, most pros recommend aiming it the speaker. However, vertical orientation seems to be popular with the non-pro home theater set. You can _usually_ get acceptable results doing that, as long as you’re using a 90-degree calibration file.

Regards,
Wayne A. Pflughaupt


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## Cal68

I'm a newbie with REW too and have one really dumb question for all of you. When using REW to generate a curve for subwoofers, do you use pink noise to generate the curves or sine wave? And should one use the same when generating curves for the remaining speakers as well? I could not easily find the answer to this basic question in the instructions. I just want to be sure that I'm feeding the sub and the speakers the correct signal. Thanks.

Cal68


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## Wayne A. Pflughaupt

Typically you want to use the sine wave sweep when taking measurements. Pink noise is useful with the Real Time Analysis feature along with an equalizer. It lets you adjust the equalizer and see the results instantly on the screen. Pink noise graphs can be saved just like sine-wave graphs.

Regards, 
Wayne


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## Cal68

Wayne A. Pflughaupt said:


> Typically you want to use the sine wave sweep when taking measurements. Pink noise is useful with the Real Time Analysis feature along with an equalizer. It lets you adjust the equalizer and see the results instantly on the screen. Pink noise graphs can be saved just like sine-wave graphs.
> 
> Regards,
> Wayne


Thank you very much Wayne. I was using Pink Noise to take measurements so I am glad to see your response because now I can correct my mistake.

Cal68


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## rolomoto

I've looked around here but can't find an answer. How do you interpret these graphs once they're made? I have no idea what I'm looking at. Here's the file if that will help.

thanks


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## bpape

That doesn't look right. If that's a sub reading it's the best I've ever seen. It's basically within 1-2 db up to almost 200 Hz which really isn't realistic in pretty much any situation. Plus the level is VERY high. Should be in the 70-80 db range.


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## rolomoto

bpape said:


> That doesn't look right. If that's a sub reading it's the best I've ever seen. It's basically within 1-2 db up to almost 200 Hz which really isn't realistic in pretty much any situation. Plus the level is VERY high. Should be in the 70-80 db range.


One mistake I think I was making was leaving the feedback cable in so that when I did the test the sound was only coming out of one speaker. When I "check levels" before the test I get around 75db from the speakers, so I don't know why it shows up so loudly on the graph. Does this test look better? I removed the feedback cable so the sound was coming from both speakers.


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## bpape

I can't open that for some reason.


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## JohnM

What REW version are you running, Bryan?


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## rolomoto

JohnM said:


> What REW version are you running, Bryan?


5.19 beta 3


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## JohnM

I was meaning Bryan Pape, wondering why he might have a problem opening the file.


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## JohnM

rolomoto said:


> When I "check levels" before the test I get around 75db from the speakers, so I don't know why it shows up so loudly on the graph.


Looks like you need to run the SPL calibration process so the graph appears at the right level - doesn't affect the result though, just what numeric SPL figure it sits at.


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## bpape

I am running 5.14. I actually did get it to open but it's just the soundcard calibration in the file.


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## JohnM

Odd. Just installed 5.14 and it opened the file OK (2 measurements in the file, soundcard cal and the room measurement). There is probably an error in the REW log files that may give a clue what hasn't worked, but a lot has changed since Dec '15.


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## bpape

I'll update and see what happens. Haven't been having problems.


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## bpape

Very strange. That time before I even updated it opened just fine. Gremlins.


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## madermat

thanks for the video got my mic in on Thursday.cant wait to get into the calibration


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