# First Measurement with REW/EMU0404/ECM8000



## ths61 (Jan 14, 2010)

Here is my 1st measurement of my Right Front speaker measured at the primary listening position using 1/12th smoothing and a REW/EMU0404/ECM8000 rig.

The soundcard and SPL has been configured, but I have to still add the ECM8000 calibration file. I still need to get the appropriate Y-connector to measure both fronts and the sub.

What smoothing level should be used to evaluate in-room measurements?

Thanks,
Tim

Right Front Speaker. No EQing. Corner broadband traps. 1/12th smoothing.


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## glaufman (Nov 25, 2007)

Opinios vary on this somewhat... for bass only scans, I prefer no smoothing at all. Others prefer a little (I'm sure they'll chime in with their exact preferences)... for full range scans, I prefer as little as possible just to the point where you can see the general trend... some prefer to say 1/3 octave... sometimes depends on how much experience you have reading noisy graphs... some of us are used to mentally filtering the noise from our day jobs, and prefer knowing that what we're looking at is as unadulterated as possible. So feel free to experiment a little bit and see what works for you here... when you post, let us know what smoothing you applied, and if we'd like to see it another way we'll let you know!

As an aside, I don't understand something... if you're already making measurements, why would you need another adapter to measure sub+mains? If you don't have a Y-adapter, how'd you do these measurements?


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## ths61 (Jan 14, 2010)

glaufman said:


> ... when you post, let us know what smoothing you applied, and if we'd like to see it another way we'll let you know!
> 
> As an aside, I don't understand something... if you're already making measurements, why would you need another adapter to measure sub+mains? If you don't have a Y-adapter, how'd you do these measurements?


These posts were at 1/12th smoothing.

I am using the EMU0404 with a XLR balanced mic cable and a XLR balanced cable going to the Pre/Pro's Right XLR input with no optional Y-adapter (see diagram below). The EMU0404 has a built-in mic power supply and I used a RatShak meter to set the SPL.

The XLR input on the Pre/Pro bypasses all DSP and bypasses the sub (Pure 2-Channel). I need to go into another AUX(L/R) input using an appropriate Y-splitter so I can measure both L/R fronts and sub simultaneously.

http://www.hometheatershack.com/forums/spl-meters-mics-calibration-sound-cards/10001-rew-cabling-connection-basics.html


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## glaufman (Nov 25, 2007)

OK. Makes sense that way. Most people's inputs enable bass management so you're at least running 1 main+sub. forgot about the L+R... guess it's time for me to pack it in for the week.


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## Wayne A. Pflughaupt (Apr 13, 2006)

> What smoothing level should be used to evaluate in-room measurements?


Like Greg, I prefer 1/3-octave for full range measurements. 

Response looks pretty poor above 9 kHz. Are you going to use our generic file for the ECM8000, or does your mic have a custom calibration?

Regards,
Wayne


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## ths61 (Jan 14, 2010)

Wayne A. Pflughaupt said:


> Like Greg, I prefer 1/3-octave for full range measurements.
> 
> Response looks pretty poor above 9 kHz. Are you going to use our generic file for the ECM8000, or does your mic have a custom calibration?


Here is the 1/3 smoothing.

I have to dig up the CD that came with the ECM8000 and determine if it's calibration file is in a compatible format that REW can use.

The current graph shows a 4dB peak at 8.4K and 3dB peak at 12.4K (above the 75dB target). I will be experimenting with some first reflection traps to see what they do.

The speakers are Magnepan 3.6's with XO points at (bass 250Hz/mid 200Hz) and (mid/tweeter)1,700Hz. Neither of the peaks correspond to the XO points.

Curious, I am comparing the REW charts to the ones produced by the Anthem Room Correction (ARC) graphs and neither have a lot in common. Hopefully, the correction file will help.


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## Wayne A. Pflughaupt (Apr 13, 2006)

> I have to dig up the CD that came with the ECM8000 and determine if it's calibration file is in a compatible format that REW can use.


 Look for the file that says “narrow band response, 0 degrees.” That’s the file to use for pointing the mic directly at the signal source, which is generally preferred for full range measurements (the orientation of the mic matters little with subwoofer-only measurements). Copy the file to your REW folder, then change the extension to *.CAL.

Regards,
Wayne


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