Blending response of Sub and Mains - Home Theater Forum and Systems - HomeTheaterShack.com

 
Thread Tools
post #1 of 6 Old 07-25-13, 04:35 PM Thread Starter
Shackster
Rog
 
Join Date: Nov 2009
Posts: 66
Blending response of Sub and Mains

HI Everyone,

I've hit a point where I could use some help.

Here's the equipment I'm using:

Behrenger 502
Dayton Audio EMM-6 microphone with calibration file from Cross Spectrum
Windows 8 laptop interfacing to a Creative X-FI external sound card.
Behrenger 1124P
VTF3 - Mark 4 Sub
B&W 603 Mains Crossed over at 80 HZ
Sunfire Ultimate Reciver II

I am equalizing my new sub and I'm trying to use the "lean and mean" house curve outlined in this thread http://www.hometheatershack.com/foru...e-options.html

Here's the curve:

20 10
22 9
25 8
28 7
31.5 6
36 5
40 4
45 3
50 2
56 1
63 0

I've gotten close a couple of times, and overall I like the resulting sound that I get when I listen to music. But, I always seem to get stuck at the point where I try to integrate the response of the mains and the sub together.

Here's the baseline I'm dealing with:

Blending response of Sub and Mains-baseline.jpg

When I build the filters, I tell it to use filters from 20 - 60 HZ, which corresponds to the house curve. The sub response follows the curve pretty good as shown below:

Blending response of Sub and Mains-sub-equ-house-curve.jpg

Where I run into trouble is when I try to get the response of the subs and mains to blend together smoothly. I know that the response from 60 - 90 is way too high, and that what I want to get to is a response that continues as with the red line that I added below:

Blending response of Sub and Mains-what-we-want-get.jpg

I'm stumped as what's the best way to get this done. I've tried several different things, including adding filters out into 80 + hz range, and I don't seem to be able to get the response that I need. Whenever I do try to do that, I don't have any idea how to set the filters, and end up using trial and error because the subs and mains are both contributing to the overall response, but I can only equalize the sub. (Don't know if that made any sense or not)

Here's 15 - 200 hz response for the sub and left main together taken from a full range sweep:

Blending response of Sub and Mains-sub-left-main-low-frequency-response.jpg

I don't know if my assumptions about how to approach this are correct or not. If I'm way off base somewhere, please let me know and I'll reset. Are there some steps that I can follow to get this resolved ?

I'm going to attach the mdat and req files for these measurements. Here's the mdat: Test 8 measurements.mdat

Here's the REQ file: Test 8 - Limits 20 - 60.req

The mdat is a group of three measurements, and includes a full range sweep of the sub and left main.

Thanks in advance for any insight you can provide.

Rog
rogerv is offline  
Sponsored Links
Advertisement
 
post #2 of 6 Old 07-25-13, 08:04 PM
HTS Senior Moderator
 
Wayne A. Pflughaupt's Avatar
 
Join Date: Apr 2006
Location: Corpus Christi, Texas
Posts: 9,177
Send a message via Yahoo to Wayne A. Pflughaupt
Re: Blending response of Sub and Mains


Quote:
rogerv wrote: View Post
I'm stumped as what's the best way to get this done. I've tried several different things, including adding filters out into 80 + hz range, and I don't seem to be able to get the response that I need. Whenever I do try to do that, I don't have any idea how to set the filters, and end up using trial and error because the subs and mains are both contributing to the overall response, but I can only equalize the sub.
Hey Roger,

I’d first suggest finding a location for the sub that gets a better baseline response. That graph’s not the best candidate for reasonable equalization.

Beyond that, I’d suggest equalizing your house curve all the down to the crossover point, even if you want response to level out at 60 Hz. At that point, it should just be a matter of adjusting the sub level relative to the mains.

Regards,
Wayne



To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.
|
To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.

Wayne A. Pflughaupt is offline  
post #3 of 6 Old 07-26-13, 10:10 AM Thread Starter
Shackster
Rog
 
Join Date: Nov 2009
Posts: 66
Re: Blending response of Sub and Mains

Hi Wayne,

Thanks for the reply. I don' know if I've got a better place for the sub in the room. I spent a lot of time prior to this trying to find a spot that didn't have major suckouts or humps in it to start with. I eliminated lots of positions that had suckouts in them in the 40-80 hz range. What is there about the starting point that I should try and improve ? The sub has lots of different settings that change the characteristics of its response. I could modify these to get a better starting point, but don't know what to shoot for.

Unfortunately, the room is 14 ft. by 15 ft. by 8 ft, which is almost square. In addition, the mains alone generate a huge 15 db peak around 40 HZ. that seems independent of crossover settings. When I went through this a couple of years ago, no one could figure out why that behavior occurred.

I'll keep banging on this.

Thanks again,
Rog
rogerv is offline  
 
post #4 of 6 Old 07-27-13, 11:05 AM
REW Author
 
JohnM's Avatar
John
 
Join Date: Apr 2006
Location: UK
Posts: 6,710
Re: Blending response of Sub and Mains

Doesn't look like there was any output from the left main in your 'sub and left main' measurement. Basic problem is your target level is too low, and the low end of the sub output doesn't have enough level to support 10 dB more output at 20 Hz than at 63 Hz. Try removing the house curve for the moment, set the target level to 85 dB and generate filters for the range up to at least 100 Hz.
JohnM is offline  
post #5 of 6 Old 07-27-13, 12:33 PM Thread Starter
Shackster
Rog
 
Join Date: Nov 2009
Posts: 66
Re: Blending response of Sub and Mains

John,

Thanks for the reply. I'm pretty sure you have me on the right track now. Here's what did it for me:

Quote:
JohnM wrote: View Post
Basic problem is your target level is too low, and the low end of the sub output doesn't have enough level to support 10 dB more output at 20 Hz than at 63 Hz.
This sub has two adjustable parameters (called "EQU" and "Q") that affect the overall shape of its output. These settings really give a lot of flexibility for a starting point. The previous baseline was using "EQU2" on the sub. I went back and did some new baselines using EQU1 which has more output around 20 hz. Here's the starting point using EQU 1.

Blending response of Sub and Mains-new-baseline.jpg

This starting point doesn't have the sag around 20 HZ and below that you pointed out and should support a 10 DB difference between 20 and 63.

I really can't remember how I ended up with EQU 2 rather than 1. I know that I've gone through lots and lots of combinations and iterations, so I may have just flipped the wrong switch at the wrong time. Anyway, I'm going to reset with one of these as the new starting point and try again.



Rog

I just realized that the graphs that I posted were with equalization added, not baseline. Aargh. I'll post corrected baselines.

Last edited by rogerv; 07-27-13 at 12:46 PM.
rogerv is offline  
post #6 of 6 Old 07-27-13, 01:16 PM Thread Starter
Shackster
Rog
 
Join Date: Nov 2009
Posts: 66
Re: Blending response of Sub and Mains

I thought I'd better post a separate correction message rather than try and change the original. The graphs I posted in the previous message were with equlization added. I forgot to bypass the equalizer

Anyway, here are the correct baseline measurements:

Blending response of Sub and Mains-corrected-baselines.jpg

Rog
rogerv is offline  
Reply

Bookmarks

Tags
blending , mains , response

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










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