Help with Room Treatment (with DIY mentality) - Page 2 - AVS Forum
Forum Jump: 
Reply
 
Thread Tools
post #31 of 40 Old 03-30-2013, 05:28 PM - Thread Starter
AVS Special Member
 
tuxedocivic's Avatar
 
Join Date: Feb 2010
Location: Ladysmith, BC
Posts: 4,529
Mentioned: 4 Post(s)
Tagged: 1 Thread(s)
Quoted: 235 Post(s)
Liked: 497
Yup
tuxedocivic is online now  
Sponsored Links
Advertisement
 
post #32 of 40 Old 03-30-2013, 06:40 PM
AVS Special Member
 
Bill Fitzmaurice's Avatar
 
Join Date: Nov 2009
Location: New Hampshire
Posts: 9,479
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 1284
That looks to be a lot higher Q than .65, but not knowing the driver or alignment I can't render an opinion.

Bill Fitzmaurice Loudspeaker Design

The Laws of Physics aren't swayed by opinion.
Bill Fitzmaurice is online now  
post #33 of 40 Old 03-30-2013, 06:47 PM - Thread Starter
AVS Special Member
 
tuxedocivic's Avatar
 
Join Date: Feb 2010
Location: Ladysmith, BC
Posts: 4,529
Mentioned: 4 Post(s)
Tagged: 1 Thread(s)
Quoted: 235 Post(s)
Liked: 497
CSS trio 12 sealed in 75L. Can't remember of it was 75L but pretty sure. Well stuffed to.

Doesn't really matter. Actually kind of nice knowing I can put more LT onto the low end than I was planning. Thanks for taking a look though. Maybe I modelled wrong...
tuxedocivic is online now  
post #34 of 40 Old 03-30-2013, 07:26 PM
AVS Special Member
 
Bill Fitzmaurice's Avatar
 
Join Date: Nov 2009
Location: New Hampshire
Posts: 9,479
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 1284
If the specs are accurate 60L net gives a Q of .7, with no hump. I suspect stuffing the cab over damped it. F3 looks right, response above 70Hz doesn't, and over damping can kill the midbass.

Bill Fitzmaurice Loudspeaker Design

The Laws of Physics aren't swayed by opinion.
Bill Fitzmaurice is online now  
post #35 of 40 Old 03-30-2013, 07:40 PM - Thread Starter
AVS Special Member
 
tuxedocivic's Avatar
 
Join Date: Feb 2010
Location: Ladysmith, BC
Posts: 4,529
Mentioned: 4 Post(s)
Tagged: 1 Thread(s)
Quoted: 235 Post(s)
Liked: 497
You think I over stuffed it? I suppose that could be it.

How about the steep roll off though? Much steeper than 12db/oct.
tuxedocivic is online now  
post #36 of 40 Old 03-30-2013, 07:59 PM - Thread Starter
AVS Special Member
 
tuxedocivic's Avatar
 
Join Date: Feb 2010
Location: Ladysmith, BC
Posts: 4,529
Mentioned: 4 Post(s)
Tagged: 1 Thread(s)
Quoted: 235 Post(s)
Liked: 497
Impedance matches the model ok. A little higher impedance actually smile.gif

tuxedocivic is online now  
post #37 of 40 Old 03-31-2013, 05:29 AM
AVS Special Member
 
Bill Fitzmaurice's Avatar
 
Join Date: Nov 2009
Location: New Hampshire
Posts: 9,479
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 1284
Quote:
Originally Posted by tuxedocivic View Post

You think I over stuffed it? I suppose that could be it.

How about the steep roll off though? Much steeper than 12db/oct.
You only stuff when you want to lower Q. If Q is already low enough you just line the cab. The rolloff from 40 to 20 looks fine. Below that I'd question the accuracy of the testing hardware.

Bill Fitzmaurice Loudspeaker Design

The Laws of Physics aren't swayed by opinion.
Bill Fitzmaurice is online now  
post #38 of 40 Old 03-31-2013, 07:38 AM - Thread Starter
AVS Special Member
 
tuxedocivic's Avatar
 
Join Date: Feb 2010
Location: Ladysmith, BC
Posts: 4,529
Mentioned: 4 Post(s)
Tagged: 1 Thread(s)
Quoted: 235 Post(s)
Liked: 497
Hmm, you're right about 40 to 20. The mic is an ECM8000 calibrated by cross spectrum to their highest standards. I suppose it could be the Dayton T amp I used. Convenient for outdoor work. I'll try a near field indoors with a higher end setup when I have a chance and see if that's a problem. Thanks!
tuxedocivic is online now  
post #39 of 40 Old 03-31-2013, 07:41 AM - Thread Starter
AVS Special Member
 
tuxedocivic's Avatar
 
Join Date: Feb 2010
Location: Ladysmith, BC
Posts: 4,529
Mentioned: 4 Post(s)
Tagged: 1 Thread(s)
Quoted: 235 Post(s)
Liked: 497
There was visible excursion way down at least at 5hz. 2hz starting frequency though.
tuxedocivic is online now  
post #40 of 40 Old 03-31-2013, 09:21 AM
AVS Special Member
 
Bill Fitzmaurice's Avatar
 
Join Date: Nov 2009
Location: New Hampshire
Posts: 9,479
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 1284
Quote:
Originally Posted by tuxedocivic View Post

Hmm, you're right about 40 to 20. The mic is an ECM8000 calibrated by cross spectrum to their highest standards. I suppose it could be the Dayton T amp I used. Convenient for outdoor work. I'll try a near field indoors with a higher end setup when I have a chance and see if that's a problem. Thanks!
I have my HolmImpulse calibrated with the power amp in the loop. It's a simple affair, you just have to be sure the power amp is set at unity gain so it doesn't toast the sound card input.

Bill Fitzmaurice Loudspeaker Design

The Laws of Physics aren't swayed by opinion.
Bill Fitzmaurice is online now  
Reply DIY Speakers and Subs

User Tag List

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


Forum Jump: 

Posting Rules  
You may not post new threads
You may not 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 code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off