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Discussion Starter · #1 ·
I've got to say that the learning curve using REW is much longer than I expected! I've spent several hours reading the REW Help (not really a help...more of a college textbook) and the Getting Started (much more help) as well many forum searches & posts.

I purchases a calibrated UMM-6, a BFD1124 & the required cables, etc.

I was able to follow the Getting Started to produce some graphs yesterday, but can't get it working today. I realized that many of the settings did not stick, so I have re-booted several times & gone through every setup option step by step.

Problem 1: When I open up the SPL meter it is registering about 30 or 40db higher than reality. For example, a 75db test tone will register as 115db.

Problem 2: I connected the BFD properly & found some procedures to reset it. The filter indicators are blinking constantly...not sure what the that thing is doing. I guess it's searching for feedback. I could really use some help with the proper settings to keep this thing in bypass mode until I learn how to transfer eq settings from REW.

Thanks for any help getting me started in the right direction!
 

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- Here's the DSP1124P user manual.

- This document will help you learn about the hardware which you just bought .

- ( Depending on experience ), REW demands more than "several hours" of study before one will get much from it .
- I suggest being patient, going slow & giving yourself a couple of months ( to come to terms with it all ) .

:sn:
 

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^^^
Agreed. I am newbie myself and would suggest maybe to forget about the BFD1124 for the time being and just use the setup consisting of UMM-6 with assorted connections. Just to limit variables.

Run some SPL sweeps from 20Hz to 200Hz and play with mic position. I use 3'3" as standard ear height based on me and my furniture. Also documented some set points for initial SPL calibration. All in hopes to understand how repeatable the measurements are from day to day.
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I am on my third session of use. Figure about 2-4 hours per session in my case. Several more hours spent reading user guides beforehand. Today I just measured SPL of my sub with and without poly fill. Last week was SPL of bass on various seating positions and orientation of sub. Basic stuff but good ways to ease into it. I have been recording three sweeps for each individual test so as to confirm nothing funny is going on.

In addition to the REW manual there is another user guide at the below link specific to USB microphone setup.

http://www.avsforum.com/t/1449924/s...and-how-to-interpret-graphs/270#post_22823228

So far I still have to go into the preferences section and select the input mic manually for each session. Cal SPL everytime too but that is normal I believe. Also I have been making it a habit to confirm windows playback and recording device settings in hopes to be able to remember without having to reference the literature.

I just have the UMM-6 from cross spectrum on a boom stand.
 

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I purchases a calibrated UMM-6
Where from Cross - Spectrum or Parts Express?
First check the mic calibration file is loaded + at the top of the file (first line) there should be something like SENS FACTOR -7db, REW recognizes this. If this line is missing, quite on the cards if you purchased from CS then you download the original from Dayton and copy and paste the first line.

I was able to follow the Getting Started to produce some graphs yesterday, but can't get it working today. I realized that many of the settings did not stick, so I have re-booted several times & gone through every setup option step by step.
Make sure the mic is plugged in before opening REW.

Problem 1: When I open up the SPL meter it is registering about 30 or 40db higher than reality. For example, a 75db test tone will register as 115db.
See above
 

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I've got to say that the learning curve using REW is much longer than I expected! I've spent several hours reading the REW Help (not really a help...more of a college textbook)...
Did you check the REW Youtube Tutorial video?

Re the BFD, you might find the BFD Guide more intuitive than the Behringer manual.

Regards,
Wayne
 

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Also, you must use REW 5.01 Beta 17.

The earlier versions may not properly apply the UMM-6 mic calibration file. This can lead to erroneous SPL levels being set.
 

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Discussion Starter · #7 ·
Thanks for your help...turns out the calibration issue was a brain fart - I didn't quite understand that you use the Rat Shack sound level meter to set the REW SPL. It sometimes helps when you put it away & start fresh the next day!

Here are the few initial decay & waterfall graphs - these are with L+R+ 2 subs and Audyssey turned off. Both subs are in the front of the room at 25% from each side wall and are both equal distance from the listening spot. One is a DIY & the other is an SVS. I currently have 4, 24"x48", 4" deep linacoustic panels. I plan on purchasing 4 GIK Monster Bass panels & building 3 or 4 additional DIY panels to help treat the room.

Thoughts?
 

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