Discrepency in Shiva White Papers - 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 8th October 2001, 04:39 PM   #1
diyAudio Member
 
Join Date: Oct 2001
Send a message via ICQ to poop
I am a newbie at speaker construction, and I was thinking about starting with a sealed sub. I noticed that quite a few people go for Shiva designs, and I went to adire audio's web site and red the sealed design white paper.

I also ran some equations to see what I could come up with on my own. I noticed some striking differences in what the equations say and what Adire Audio says.

I was looking for a Qtc of around 0.6. Using a spreadsheet I found on diysubwoofers.org, I plugged in the T/S parameters for the Shiva, and calculated for a Qtc of 0.6. I compared the numbers to the Shiva white paper, and here is what I saw:

______________White Paper: _____ My calculations:
Box Volume:___88.5 liters ______ 110 liters
Anechonic F3:_30.7 Hz __________ 39.1 Hz
Anechonic F8:_20.5 Hz __________ 23 Hz
Fb:___________34.4 Hz __________ 32.3 Hz

I realize that the box volume difference is due to the use of stuffing in the white paper's designs. I thought that stuffing simply increased the apparant box size to the driver (hence the ~25% difference). Can stuffing alter the other results this much? Or is Adire fudging on their numbers?
  Reply With Quote
Old 13th October 2001, 01:59 AM   #2
Wizard of Kelts
diyAudio Moderator
 
Join Date: Sep 2001
Location: Connecticut, The Nutmeg State
Fb? Isn't that a specification for ported boxes? You cannot tune a sealed enclosure.
  Reply With Quote
Old 13th October 2001, 02:09 AM   #3
Wizard of Kelts
diyAudio Moderator
 
Join Date: Sep 2001
Location: Connecticut, The Nutmeg State
Anyway, for a final Q of .6, I get the same numbers you do-not Shiva's numbers. Do you have a link to the white paper?

For what it is worth, if you make an 88 liter PORTED box and tune it to 13 Hz or so, you should get numbers somewhat near that.

Incidentally, the tuning ratio H for that ported box is .6. The tuning ration is defined as Fb/Fs. Has there been some confusion between H and Q? Just guessing.

[Edited by kelticwizard on 10-12-2001 at 11:24 PM]
  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
Port length calc discrepency thejoneses Subwoofers 2 10th February 2008 01:58 AM
Feedback papers... mikeks Solid State 20 21st March 2007 10:03 AM
Papers Wanted! mikeks Solid State 16 9th June 2006 07:12 AM
TIM papers darkfenriz Solid State 22 9th December 2005 04:48 AM
BBC technical papers Jonathan Bright Multi-Way 1 8th November 2004 12:02 AM


New To Site? Need Help?

All times are GMT. The time now is 10:33 AM.


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