Help with REW needed. - Home Theater Forum and Systems - HomeTheaterShack.com

 1Likes
Reply
 
Thread Tools
post #1 of 11 Old 10-09-16, 07:58 AM Thread Starter
Shackster
 
Prize78's Avatar
prize
 
Join Date: Aug 2009
Location: Midlands, UK
Posts: 99
Help with REW needed.

Hi all. I'll try to keep a very long story short! Basically, I have a DIY subwoofer: two drivers (Acoustic elegance av12's) mounted in a push pull configuration, sealed box. Powered by Behringer EP4000 power amp. I have recently upgraded a couple of items, namely, speakers to Monitor Audio Silver 6's and AV amp to Yamaha rxa3050. I had noticed that the bass was a little underwhelming, so decided to run REW to see what was going on. I'm having a nightmare of a job to get rew going. I've got a laptop that has line in and out, so I thought i'd be able to use these. Seemingly not as REW tells me that the 'impulse peak isn't in the right place - check settings'. So I have wound up wit a USB adaptor box, offering mic in, line in, front out, rear out and cen/bass out. So. I hooked up red rca to spl meter (radioshack analogue) into mic in (it doesn't work with line in) and left and right RCA's from 'front out' on splitter box into Yamaha video aux in on the front of receiver. I downloaded the calibration file from this forum and entered that accordingly. On running a measurement, i get a clipping message at the end telling me that input is too high (clipping), but persevered anyway.
Well, i'm getting all sorts of graphs now, and the last two measurements taken, gave exactly the same graph, when one of the measurements had the SPL meter on, and one didn't! So how does that work??!

This leads me to believe that I have a dodgy connection somewhere. Any ideas folks?
Prize78 is offline  
Sponsored Links
Advertisement
 
post #2 of 11 Old 10-09-16, 08:30 AM
REW Author
 
JohnM's Avatar
John
 
Join Date: Apr 2006
Location: UK
Posts: 6,353
Re: Help with REW needed.

There shouldn't be any problem using line out and line in on the laptop, so you'd be better sorting out why that wasn't working than just trying a completely different setup.
JohnM is offline  
post #3 of 11 Old 10-09-16, 08:44 AM Thread Starter
Shackster
 
Prize78's Avatar
prize
 
Join Date: Aug 2009
Location: Midlands, UK
Posts: 99
Re: Help with REW needed.

Quote:
JohnM wrote: View Post
There shouldn't be any problem using line out and line in on the laptop, so you'd be better sorting out why that wasn't working than just trying a completely different setup.
It says 'None' on the soundcard calibration section and i don't know how to get a file in there? Have tried the loop thing to calibrate but it just freezes?? Is there another way round??
Prize78 is offline  
post #4 of 11 Old 10-09-16, 09:46 AM
REW Author
 
JohnM's Avatar
John
 
Join Date: Apr 2006
Location: UK
Posts: 6,353
Re: Help with REW needed.

Freezing is unlikely. Calibrating the soundcard goes through a series of steps, click the Next button at the bottom of the soundcard preferences to go to each successive step. The overall process is described in the help.
JohnM is offline  
post #5 of 11 Old 10-09-16, 10:44 AM Thread Starter
Shackster
 
Prize78's Avatar
prize
 
Join Date: Aug 2009
Location: Midlands, UK
Posts: 99
All I keep getting now is "soundcard didn't provide any data, make sure it's connected"?
Prize78 is offline  
post #6 of 11 Old 10-10-16, 06:02 PM
REW Author
 
JohnM's Avatar
John
 
Join Date: Apr 2006
Location: UK
Posts: 6,353
Re: Help with REW needed.

Probably best if you post a screenshot of your REW Soundcard preferences to see what you have selected and let us know what OS you are running and what the connections to/from your laptop are.
JohnM is offline  
post #7 of 11 Old 10-11-16, 07:06 AM Thread Starter
Shackster
 
Prize78's Avatar
prize
 
Join Date: Aug 2009
Location: Midlands, UK
Posts: 99
Re: Help with REW needed.

RIght, after lots of messing about, I have finally got REW working as it should. Turns out the line in was muted!! Anyhow, have taken a few measurements with interesting results. (See graph)

Purple line is from a measurement taken from on the floor.
Pink line is from the main listening area.
Blue line is from the spl meter virtually touching the subwoofer cone.
Green line is from an alternative listening area.

Seemingly, from the main listening area, I am losing bass altogether in the 93Hz region, but only in that one spot, as from the alternative listening position, no such dip is present.

Am I best to have a go at the manual PEQ on the Yamaha for a start?
What alternatives are there to get rid of the dip??
Attached Thumbnails
Help with REW needed.-cornerlistening.jpg  

Prize78 is offline  
post #8 of 11 Old 10-11-16, 02:20 PM
REW Author
 
JohnM's Avatar
John
 
Join Date: Apr 2006
Location: UK
Posts: 6,353
Re: Help with REW needed.

Anything you do with EQ will have the same effect at all listening positions, so if you try to lift a dip at one position you will create bumps anywhere there isn't a dip. EQ also cannot do anything about sharp, deep features in the response. The best starting point is to experiment with listening positions and speaker positions. A relatively quick way to explore that is to use REW's signal generator to play the Pink PN signal and look at the response on the RTA using the settings below, move the mic/meter or sub/speakers to different locations to see how the response changes.

Name:  rtasettings.jpg
Views: 57
Size:  17.2 KB
Prize78 likes this.
JohnM is offline  
post #9 of 11 Old 10-11-16, 03:50 PM Thread Starter
Shackster
 
Prize78's Avatar
prize
 
Join Date: Aug 2009
Location: Midlands, UK
Posts: 99
Re: Help with REW needed.

Quote:
JohnM wrote: View Post
Anything you do with EQ will have the same effect at all listening positions, so if you try to lift a dip at one position you will create bumps anywhere there isn't a dip. EQ also cannot do anything about sharp, deep features in the response. The best starting point is to experiment with listening positions and speaker positions. A relatively quick way to explore that is to use REW's signal generator to play the Pink PN signal and look at the response on the RTA using the settings below, move the mic/meter or sub/speakers to different locations to see how the response changes.

Attachment 129481
Thanks for the suggestion. I shall give it a go. No idea where the real low end stuff has gone as I've seen this sub go down to about 7Hz (albeit in a different room). It's as though there's a filter on it cutting the low end out?
Prize78 is offline  
post #10 of 11 Old 10-11-16, 05:59 PM
REW Author
 
JohnM's Avatar
John
 
Join Date: Apr 2006
Location: UK
Posts: 6,353
Re: Help with REW needed.

Sub position, measurement position and room can have a very dramatic effect on the sub's measured LF extension.
JohnM is offline  
Reply

Bookmarks

Tags
needed , rew

Quick Reply
Message:
Options

Register Now




PLEASE COMPLETE ALL REQUIRED FIELDS BELOW... THANKS!

REQUIRED FIELDS ON THIS PAGE
YOU MUST COMPLETE ALL OF THESE

Username
Password
Confirm Password
Email Address
Confirm Email Address
Random Question
Random Question #2




User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
PLEASE READ BELOW PRIOR TO ENTERING AN EMAIL ADDRESS!

ATTENTION!

YOU MUST ACTIVATE YOUR ACCOUNT!

Activation requires you reply to an email we will send you after you register... if you do not reply to this email, you will not be able to view certain areas of the forum or certain images... nor will you be able download software.

AN INVALID EMAIL ADDRESS WILL CAUSE YOUR ACCOUNT TO BE DELETED!

See our banned email list here: Banned Email List

We DO NOT respond to spamcop, boxtrapper and spamblocker emails... please add @hometheatershack DOT com to your whitelist prior to registering or you will get nowhere on your registration.


Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML is not allowed!
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 


For the best viewing experience please update your browser to Google Chrome