15" kicker l7 30hz box design help !! - Page 4 - diyAudio
Go Back   Home > Forums > Loudspeakers > Subwoofers

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 16th November 2011, 11:40 PM   #31
bjorno is offline bjorno  Sweden
diyAudio Member
 
Join Date: Mar 2005
Location: Jacobsmountain
Send a message via MSN to bjorno
Quote:
Originally Posted by NEO Dan View Post
Hey bjorno,
Where did you get those specs?
T/S Parameters | KICKER
Hi NEO Dan,

I looked here:

Kicker Product Manuals | KICKER

+ used parameters from post# 16 and 17 here-above.

b

Last edited by bjorno; 16th November 2011 at 11:43 PM.
  Reply With Quote
Old 16th November 2011, 11:47 PM   #32
NEO Dan is offline NEO Dan  United States
diyAudio Member
 
NEO Dan's Avatar
 
Join Date: Jun 2008
Location: N.E. Ohio
I C
__________________
Regards,
Dan
  Reply With Quote
Old 17th November 2011, 12:03 AM   #33
NEO Dan is offline NEO Dan  United States
diyAudio Member
 
NEO Dan's Avatar
 
Join Date: Jun 2008
Location: N.E. Ohio
Quote:
Originally Posted by bjorno View Post
Submitting a picture showing the HR result if S4 is ~992 cm^2 ,not as the built S4 that is more than 23% larger.

b
S4 is ~992
Attached Images
File Type: png S4.png (24.6 KB, 171 views)
__________________
Regards,
Dan
  Reply With Quote
Old 17th November 2011, 04:29 PM   #34
bjorno is offline bjorno  Sweden
diyAudio Member
 
Join Date: Mar 2005
Location: Jacobsmountain
Send a message via MSN to bjorno
Quote:
Originally Posted by NEO Dan View Post
S4 is ~992
Hi Dan,

Thank you... Your design is IMO a ...perfect... T-TQWT design using the Kicker_08-15inch-L7D2 driver, not the one I previously simulated here-above(discard that picture!) using wrong T/S.

Here is a MJK simulation that show (your design) the benefit of using (mandatory) damping.

My recommendation is using a fiber density somewhere between min. 0.35 to max. 0.5 kg/m^3 in a T-TQWT or a T-QWP if a driver of this type is used:

b
Attached Images
File Type: jpg Kicker_08-15inch-L7D2_T-TQWT-as-OD-TL.JPG (861.7 KB, 170 views)
  Reply With Quote
Old 17th November 2011, 07:00 PM   #35
NEO Dan is offline NEO Dan  United States
diyAudio Member
 
NEO Dan's Avatar
 
Join Date: Jun 2008
Location: N.E. Ohio
Hi bjorno,
Thanks for the kind words. Your comprehensive postings have always interested me, and now seeing it done to one of my own designs I find it especially insightful. How long does it take to enter data from Hornresp to MJK worksheets to see this data?
__________________
Regards,
Dan
  Reply With Quote
Old 17th November 2011, 07:39 PM   #36
bjorno is offline bjorno  Sweden
diyAudio Member
 
Join Date: Mar 2005
Location: Jacobsmountain
Send a message via MSN to bjorno
Quote:
Originally Posted by NEO Dan View Post
Hi bjorno,
Thanks for the kind words. Your comprehensive postings have always interested me, and now seeing it done to one of my own designs I find it especially insightful. How long does it take to enter data from Hornresp to MJK worksheets to see this data?
Hi Dan,

I guess it normally takes less than a minute..up to 10 minutes at most for the more comprehensive models to be completed.

b
  Reply With Quote
Old 18th November 2011, 12:47 AM   #37
justint is offline justint  United States
diyAudio Member
 
Join Date: Jan 2010
Location: wisconsin
so am I supposed to stuff my box.. not to chime in the middle but just trying to scan thru these posts quick.
  Reply With Quote
Old 18th November 2011, 12:55 AM   #38
bjorno is offline bjorno  Sweden
diyAudio Member
 
Join Date: Mar 2005
Location: Jacobsmountain
Send a message via MSN to bjorno
Exclamation Kicker 08 15" L7D2 T-TQWT modeled as an OD TL

Here is another MJK simulation using Neo Dan's HR data in more detail:

b
  Reply With Quote
Old 18th November 2011, 03:00 AM   #39
NEO Dan is offline NEO Dan  United States
diyAudio Member
 
NEO Dan's Avatar
 
Join Date: Jun 2008
Location: N.E. Ohio
Quote:
Originally Posted by justint View Post
so am I supposed to stuff my box.. not to chime in the middle but just trying to scan thru these posts quick.
I believe so, bjorno's model has a stuffing density of ~.5lbs³' if I am reading it correctly. I think the red traces represent the improvement of the stuffing over the un-stuffed(grey) trace. Although some efficiency is lost when stuffed the transformation from resonant to well damped alignment would be of great interest to those who listen critically to their systems. In this case it appears ~6dB is cut from the low end of the response. You may want to try a few of the cheap pillows from walmart, they used to have some for $2.50 called deep pockets they had ~21oz of polyfill in them that could be unrolled into a long bat. You could unroll it and re-roll it into a long but thin shape that could be installed in your box one in each of the four compartments should be "perfect" . I think I would use a plastic garbage bag as a liner so you could work the stuffing into place to save yourself lots of grief from snagging on the rough wood. But once you have it in place remove the bag.

Thanks bjorno, now I am very curious to model more of my design catalog with the MJK worksheets. I am now reminded why I don't already have the MJK worksheets - MathCAD is $$$/I have. What version do you use or recommend I use?
__________________
Regards,
Dan
  Reply With Quote
Old 19th November 2011, 07:26 PM   #40
bjorno is offline bjorno  Sweden
diyAudio Member
 
Join Date: Mar 2005
Location: Jacobsmountain
Send a message via MSN to bjorno
Quote:
I believe so, bjorno's model has a stuffing density of ~.5lbs³' if I am reading it correctly. I think the red traces represent the improvement of the stuffing over the un-stuffed(grey) trace. Although some efficiency is lost when stuffed the transformation from resonant to well damped alignment would be of great interest to those who listen critically to their systems. In this case it appears ~6dB is cut from the low end of the response.
If targeting SQ too, it's IMO necessary for any type of quarter-wave designs to partly damp the internal airways besides true horns,waveguides of course.

For this design I think that 5 lbs/ft^3 is a maximum density to be used.
Good result is achieved if evenly stuffing the first of suggested sections using normal advertised damping materials starting counting from the largest CSA of the T-TQWT.See the picture:

If choosing mineral wools like 'Rock-Wool' or similar denser materials:
Another stuffing scheme should be used where the applied material always should leave a free airway path through the entire enclosure, never being allowed to physically block the volume more than 40%.

Quote:
You may want to try a few of the cheap pillows from walmart, they used to have some for $2.50 called deep pockets they had ~21oz of polyfill in them that could be unrolled into a long bat. You could unroll it and re-roll it into a long but thin shape that could be installed in your box one in each of the four compartments should be "perfect" . I think I would use a plastic garbage bag as a liner so you could work the stuffing into place to save yourself lots of grief from snagging on the rough wood. But once you have it in place remove the bag.
First:Start stuff the immediate volume behind/close to the driver = ~a ¼ of the internal length + evaluate by a listening test and if found not enough continue to fill but not more than half of the total airway length.

Quote:
Thanks bjorno, now I am very curious to model more of my design catalog with the MJK worksheets. I am now reminded why I don't already have the MJK worksheets - MathCAD is $$$/I have. What version do you use or recommend I use?
I'm still using all the different MJK worksheets he ever have published from the very first ones , MJK recommends using versions from MathCAD version 8.

Sorry for my bad english..

b
Attached Images
File Type: gif NeoDan_Kicker_08 15inch L7 D2_T-TQWT_OD-TL_opt.damping.GIF (52.9 KB, 106 views)
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
kicker l7 help Chaoticdopey Subwoofers 5 10th December 2010 12:52 PM
building my 1st ported box,kicker L7 scampo77 Subwoofers 28 2nd January 2010 06:31 PM
kicker L7 rebuildable? scampo77 Car Audio 1 16th June 2009 01:51 PM
Kicker L7 skooter Car Audio 5 25th September 2008 11:36 PM
15" box design ideas?? warnsey Multi-Way 4 19th June 2008 01:01 PM


New To Site? Need Help?

All times are GMT. The time now is 11:23 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2