REW Learning curve

0 Members and 1 Guest are viewing this topic. Read 266 times.

SoCalWJS

REW Learning curve
« on: 10 Sep 2018, 09:26 pm »
Finally got all the parts up & running to play around with REW. Got the Minidsp UMIK-1 and a Mic Boom/Stand. REW latest version. Calibration file installed. Think I have everything done correctly. Now I just have to figure out what I am doing wrong.

I tried suggested settings on the plate amps from a couple of people, and I spent a bit over an hour just running the basic sweep from 15-20,000 Hz, Left channel, Right channel, and combined.

My results were constantly changing, which was expected. What was not expected was that I seemed to be unable to change the basic shape of the curves.

I was able to tame the peak at around 30 Hz by playing around with PEQ and Phase (etc - those had the biggest effect), but...

I have serious "suck out" from about 40-120 Hz. I couldn't boost those frequencies to save my life (yes, I mostly did it by getting the peak down as much as possible at 30, then turning the overall gain of the plate amp up).

This was about the best I could do.

*******Well, I tried to save the image, now I can't find it*******

Lets just say it was ugly. About +2 db from 25-35 Hz (or so), then - 10-15 db from 40-45 til almost 120 Hz with 1/3 Octave smoothing, both channels (each channel was similar, right channel not quite as pronounced)
 :scratch:
Got tired of it. I'll try again tomorrow. Read about REW some more. Think about it.

No clue why the "Phase" portion of the sweeps was all over the place.....dropped to the bottom of the scale, then jumped to the top and started down again, only to repeat...



******Let me know if I should move this to another Forum******

Phil A

Re: REW Learning curve
« Reply #1 on: 10 Sep 2018, 10:20 pm »
You can save the file (haven't used REW in quite a bit) and you can also hit 'Alt' and 'Printscreeen' on the computer keyboard (while the image is on the screen) and then open Windows Paint and hit 'Paste' and then save the image of whatever is on the computer screen when you did it.

mlundy57

Re: REW Learning curve
« Reply #2 on: 11 Sep 2018, 05:16 pm »
I find it takes me awhile working through the instructions to make sure I have everything (e.g. computer settings, recording level above noise floor, headroom, etc.) set properly.

I don't know what sources you have checked but here are some links I found helpful

https://www.roomeqwizard.com/
https://www.roomeqwizard.com/REWhelp.pdf
https://www.avnirvana.com/forums/official-rew-room-eq-wizard-support-forum.10/
https://www.hometheatershack.com/forums/rew-forum/
https://www.hometheatershack.com/forums/rew-forum/57103-rew-youtube-tutorial.html

The third time I used REW I thought I remembered how to set everything so I tried hooking everything up and running tests without walking through the instructions. I ended up with measurements that didn't make sense (things changing when they shouldn't, not changing when they should). When I started over and followed the instructions it worked properly.

As for capturing a picture of the graph, in the measurement window that generates the graph there is an icon of a camera with "Capture" underneath it (towards the upper left about even with the row of buttons). To save a picture of the graph, click on the camera then follow the instructions to add any info and save a jpeg.

Mike

SoCalWJS

Re: REW Learning curve
« Reply #3 on: 11 Sep 2018, 07:38 pm »
I find it takes me awhile working through the instructions to make sure I have everything (e.g. computer settings, recording level above noise floor, headroom, etc.) set properly.

I don't know what sources you have checked but here are some links I found helpful

https://www.roomeqwizard.com/
https://www.roomeqwizard.com/REWhelp.pdf
https://www.avnirvana.com/forums/official-rew-room-eq-wizard-support-forum.10/
https://www.hometheatershack.com/forums/rew-forum/
https://www.hometheatershack.com/forums/rew-forum/57103-rew-youtube-tutorial.html

The third time I used REW I thought I remembered how to set everything so I tried hooking everything up and running tests without walking through the instructions. I ended up with measurements that didn't make sense (things changing when they shouldn't, not changing when they should). When I started over and followed the instructions it worked properly.

As for capturing a picture of the graph, in the measurement window that generates the graph there is an icon of a camera with "Capture" underneath it (towards the upper left about even with the row of buttons). To save a picture of the graph, click on the camera then follow the instructions to add any info and save a jpeg.

Mike
That's what I thought, so that's what I did. Yesterday. And again this morning. Made careful note of the Directory structure. It defaults to save as a jpeg.

Didn't work either time. Nothing there. :scratch:

I'll read/reread the resources you listed (thanks). Hoping to find a streamlined setup guide someplace. The one that is recommended the most frequently (dropbox document https://www.dropbox.com/s/zdhq72a1puyyxpr/REW%20101%20HTS%20Current%20Version.pdf?dl=0) gets sidetracked by things I don't have/need (ASIO) and it's not always clear whether they have come back from that particular side trip)

Tried my OmniMic and got the same basic results. Pretty sure it's speaker position/Listening position related. I was hoping to be able to place them where they fit best and are aesthetically pleasing - surprise, surprise - not going to work, so I'm repositioning things and measuring again.

I'll get it. Eventually. I'm persistent over time, but tend to get frustrated and give up after an hour or so with each attempt.

Danny Richie

  • Facilitator
  • Posts: 12130
    • http://www.gr-research.com
Re: REW Learning curve
« Reply #4 on: 11 Sep 2018, 08:55 pm »
Quote
I have serious "suck out" from about 40-120 Hz. I couldn't boost those frequencies to save my life (yes, I mostly did it by getting the peak down as much as possible at 30, then turning the overall gain of the plate amp up).

If you just turn the gain up will it produce a flat response from the woofers to the Neo 10's disregarding what is going on below 40Hz?

If the crossover control is turned all the way up and you can turn the volume up or down and you get no real gain in the 40 to 120Hz region then you have serious cancellation going on at your measuring spot.

Also, make sure the low pass switch is in the Ext/12 position.

Quote
No clue why the "Phase" portion of the sweeps was all over the place.....dropped to the bottom of the scale, then jumped to the top and started down again, only to repeat...

Phase is basically time arrival. And because you have primary, secondary, and third reflections going on in the room, it may make that type of measurement useless.

If things are really that bad in your room then you could always run one or two subs in the rear of the room in an out of phase position and do away with more of the room issues.

Another thing to consider is that if the speakers were full range passive speakers then you'd have no way of making these adjustments. You have a ton of flexibility here. It is just a matter of dialing it in.