Originally Posted by jim19611961
(.2 ms smoothed)
Purple = 4k
Green = 2k
Gold = 1k
Black = 500hzI figured out how to get ETC sliced smoothed plots to overlay in REW.
1) You open the file multiple times (4 in this example)
2) Go to filtered IR
3) Click on the filter options ( I like to use 500hz, 1k, 2k and 4k) and check envelope
4) Smooth each (.2 ms)
5) Do steps 2-4 for each slice
6) THEN go to overlay.
These graphs look different than how they look in Omnimic. Importing the wav file from Omnimic into REW for ETC has always had some substantial variances. But that point aside, you guys measuring WITH REW should get accurate data.
Although a bit less accurate, 1 ms smoothed makes interpretation easier.
In any case, you all should be able to get your sliced ETC's to look like the above in some fashion. Once done, I think interpretation is pretty strait forward.
Jim, thanks for detailing the process. Since I usually respond from a computer without REW and seem to forget details I could lock away in a vault and regurgitate ad nauseam years later, I recall back when we first started discussing ETC's and slicing that I had actually done this procedure before in REW! Apparently, the only bit I retained from that exercise was the importing of a measurement multiple times...sorry to make you go through the process when I had already completed it several months back.
Anyway, with all of these "pristine" ETC's being posted in what I would consider to be heavily treated rooms (since I have bare walls!), I thought it might be a good idea for us "regular Joe's" to see what a completely untreated room looks like in comparison (especially one that has used Audyssey XT32 and achieved a relatively flat FR from 20-20k Hz):
All plots are created as described above including 0.2ms smoothing applied. Also, each speaker is set to full band (sub off) and I kept the color scheme consistent (e.g. Red is 500Hz, Green is 1000Hz, Gold is 2000Hz and Blue is 4000Hz):
Left Speaker Only Full Band:
Right Speaker Only Full Band:
Center Speaker Only Full Band, 0.2ms Smoothing:
Now I've already stated that for my listening space (99.9% movies), I'm starting out with an approach that will not emphasize taming high gain early ipsilateral reflections but rather focusing more on the left and right speaker contralateral reflections as well as front wall absorption (to tame reflections from surrounds) and back wall absorption (for the mains). I will also mention that during these measurements I discovered an audible echo in my listening space that I plan to address with my latest treatment plan.
Anyway, I didn't post these graphs with the intent of soliciting ideas on how to identify and treat these reflections but more as a reality of what a typical room with no treatments might look like for those taking measurements and wondering why their ETC's aren't as pretty as what Jim, Keith and Jerry are posting! HST, I welcome any and all feedback.