First measurements....Need help making sense of the graphs.

busdriver13

Registered
Thread Starter
Joined
Feb 14, 2021
Messages
10
More  
Preamp, Processor or Receiver
Legacy Wavelet
Main Amp
ATI AT544NC
Additional Amp
ATI AT542NC
Front Speakers
RBH SVTRS
Hi all. I'm just getting my system situated and took my first measurements. The room is 22L x 18W x 8H. I have acoustic treatments form GIK acoustics. Each corner is treated with soffit traps, I have (2) 244 bass traps behind the listening position on the back wall, and (2) 244 on the front wall behind the speakers, 2 at first reflection points and 2 mid wall. Any advice would be greatly appreciated. Thanks.
 

Attachments

  • SVTR-100hz.mdat
    10.5 MB · Views: 111

DanDan

Moderator
Staff member
Joined
Mar 10, 2018
Messages
743
REW has become very complex as more and more features were added. It' pretty much an Acoustic Lab now, so put on that Lab Coat and Safety Glasses!
There are plenty of Primers and Guides, but of course mine is the bestest by a bigly shot. https://www.avnirvana.com/threads/some-guides-to-rew-and-acoustic-measurement.121/page-2#post-49827
For now I note that you don't seem to have much Bass. Perhaps there was a High Pass Filter somewhere in the Recording, REW, chain?
I recommend moving the speakers to kiss the front wall. Remove those 244s temporarily so we can have almost contact. Might help with the LF.
 

busdriver13

Registered
Thread Starter
Joined
Feb 14, 2021
Messages
10
More  
Preamp, Processor or Receiver
Legacy Wavelet
Main Amp
ATI AT544NC
Additional Amp
ATI AT542NC
Front Speakers
RBH SVTRS
Not that i'm aware of. The subs are crossed at 100HZ. All other settings are normal or off. No tone controls or anything. Where could I find if there was a high pass anywhere in the chain?
 

DanDan

Moderator
Staff member
Joined
Mar 10, 2018
Messages
743
No pasa nada.... you will get into it. The subs must have been omitted from the sweep. You are about 40dB down at 30Hz.
 

busdriver13

Registered
Thread Starter
Joined
Feb 14, 2021
Messages
10
More  
Preamp, Processor or Receiver
Legacy Wavelet
Main Amp
ATI AT544NC
Additional Amp
ATI AT542NC
Front Speakers
RBH SVTRS
I have REW set to start from 10hz-20000 hz for the sweep. So you're thinking it's a processor setting or in the REW settings? When playing music, the subs are working. :dontknow:
 

JStewart

Senior AV Addict
Supporter
Joined
Dec 5, 2017
Messages
2,040
Location
Central FL
The subs must have been omitted from the sweep.

Sure does look that way. With XO at 100hz .

@busdriver13 , a couple quick things I noticed.
1. The sweep level is 115dB. If correct that's much much louder than needs be.
2. It appears the UMIK 90degree cal file is being used for the computer sound card calibration file. If I'm correct that will throw off your readings.
 

DanDan

Moderator
Staff member
Joined
Mar 10, 2018
Messages
743
+1 The Cal file needs to be applied to the Mic. That would probably explain the HF boost and the very odd level. In REW/Preferences/Soundcard/Input Options, there is a HPF available.
 

busdriver13

Registered
Thread Starter
Joined
Feb 14, 2021
Messages
10
More  
Preamp, Processor or Receiver
Legacy Wavelet
Main Amp
ATI AT544NC
Additional Amp
ATI AT542NC
Front Speakers
RBH SVTRS
Thanks fellas. As soon as I can make some noise ill make those changes and post the new measurements.
 

busdriver13

Registered
Thread Starter
Joined
Feb 14, 2021
Messages
10
More  
Preamp, Processor or Receiver
Legacy Wavelet
Main Amp
ATI AT544NC
Additional Amp
ATI AT542NC
Front Speakers
RBH SVTRS
Alright, I think I fixed it thanks to you guys. Here are the new measurements.
 

Attachments

  • New REW measurements.mdat
    5.7 MB · Views: 81

busdriver13

Registered
Thread Starter
Joined
Feb 14, 2021
Messages
10
More  
Preamp, Processor or Receiver
Legacy Wavelet
Main Amp
ATI AT544NC
Additional Amp
ATI AT542NC
Front Speakers
RBH SVTRS

DanDan

Moderator
Staff member
Joined
Mar 10, 2018
Messages
743
LOL, the world has in fact ended busdriver. It's just you and me. I'll get back to you lat.......
 

busdriver13

Registered
Thread Starter
Joined
Feb 14, 2021
Messages
10
More  
Preamp, Processor or Receiver
Legacy Wavelet
Main Amp
ATI AT544NC
Additional Amp
ATI AT542NC
Front Speakers
RBH SVTRS
Hahaha. Too funny. Thanks for the help!!
 

DanDan

Moderator
Staff member
Joined
Mar 10, 2018
Messages
743
Well, there we go. I see big nulling around 50Hz, it would probably be worth moving the subs about to see if you could minimise that.
Open to debate here but I reckon that subs can be turned sideways to get the cone much nearer to the wall. Or even pointed at the wall or floor, with an air gap obviously.
Your measurement facility is now functioning, so try the things I suggested early,
 

busdriver13

Registered
Thread Starter
Joined
Feb 14, 2021
Messages
10
More  
Preamp, Processor or Receiver
Legacy Wavelet
Main Amp
ATI AT544NC
Additional Amp
ATI AT542NC
Front Speakers
RBH SVTRS
Thanks!! Been playing with things but it's a pain moving these things around. I moved the speakers 6 inches back from the original position. That puts the face of the driver 43 inches from the back wall and side of the speakers 30 inches from the side walls. I also moved the rear soffit traps to the front corners and one horizontally behind each speaker. The listening position is 9 feet away from the face of the drivers, 7 feet from the back wall, and speakers are 8 feet 4 inches apart.
 

Attachments

  • New speaker position.mdat
    11.3 MB · Views: 43

DanDan

Moderator
Staff member
Joined
Mar 10, 2018
Messages
743
I am not sure what back or front means here. My way is to call the Front Wall, well, the Front Wall. There are speakers and subs here right? Which is where? Why place traps behind the speakers?
 

busdriver13

Registered
Thread Starter
Joined
Feb 14, 2021
Messages
10
More  
Preamp, Processor or Receiver
Legacy Wavelet
Main Amp
ATI AT544NC
Additional Amp
ATI AT542NC
Front Speakers
RBH SVTRS
Yea now that I read it, it wasn't very clear. So the front of the speakers are 43 inches from the front wall, the sides of the speakers facing the side walls are 30 inches away and the speakers are 8 feet 4 inches apart. I sit 9 feet from the speakers, the back wall is 7 feet behind me.. The speakers are on top of the subs. It's an RBH SVTR.
 

Jon330

Registered
Joined
Jan 27, 2021
Messages
2
More  
Preamp, Processor or Receiver
Yamaha
Subwoofers
Klipsch Polk
Watch this tutorial and it will help you greatly!
 

Nordo

Member
Joined
Oct 7, 2019
Messages
137
More  
Preamp, Processor or Receiver
Denon AVR X1500H
Additional Amp
Sub amp - Behringer EP2500
Universal / Blu-ray / CD Player
Panasoic BD35
Front Speakers
DIY
Center Channel Speaker
DIY
Surround Speakers
DIY
Surround Back Speakers
DIY
Front Height Speakers
-
Rear Height Speakers
-
Subwoofers
Four 15" infinite baffle drivers
Other Speakers or Equipment
HTPC (windows 10 with Kodi)
Video Display Device
Epson EMP-TW2000 projector
Screen
Matt white "blockout" curtain liner
Yea now that I read it, it wasn't very clear. So the front of the speakers are 43 inches from the front wall, the sides of the speakers facing the side walls are 30 inches away and the speakers are 8 feet 4 inches apart. I sit 9 feet from the speakers, the back wall is 7 feet behind me.. The speakers are on top of the subs. It's an RBH SVTR.
A plan of your room layout with dimensions might help.:)
 

busdriver13

Registered
Thread Starter
Joined
Feb 14, 2021
Messages
10
More  
Preamp, Processor or Receiver
Legacy Wavelet
Main Amp
ATI AT544NC
Additional Amp
ATI AT542NC
Front Speakers
RBH SVTRS
Here is my best attempt at being an artist!! I moved the speakers a bit and managed to get better measurements. Don't understand why the roll off at the high frequencies except that I was running the test generator via airplay to a Bluesound node2I.

Room is 22 feet long. The drawing appears to show 27 but is 22' long.


Screenshot 2021-02-21 at 11.56.12 AM.jpg
 

Attachments

  • Room:1.jpg
    Room:1.jpg
    48.6 KB · Views: 42
Top Bottom