Tuning en Stuffing my big TL subwoofer ? Tuning en Stuffing my big TL subwoofer ? - diyAudio
Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Tuning en Stuffing my big TL subwoofer ?
Tuning en Stuffing my big TL subwoofer ?
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
Thread Tools Search this Thread
Old 18th July 2004, 03:25 PM   #1
pa is offline pa
diyAudio Member
Join Date: Nov 2001
Location: France
Send a message via ICQ to pa
Default Tuning en Stuffing my big TL subwoofer ?

Hi !
I've just finish a straight 15" subwoofer with a 15b100r Beyma driver mounted in a 15.748" diameter sonotube wich is 157.48" long. I think it could be largely more dynamic than it sounds i probably have to shorten and stuff the tube but i don't know how. I think i can use Holofill 2 fiber or whool. but if you have comments on the driver or how long the tube should be it would be cool.
Thanks in advance for your help.

Fs 25 Hz
Re 5.2 Ohms
Qms 3.32
Qes 0.35
Qts 02
Vas 400 liters
Cms 0.368 mm/N
o 1.75 %
Sd 880 cm
Xmax 3 mm
Vd 280 cm
Le 0.9 mH
  Reply With Quote
Old 18th July 2004, 04:34 PM   #2
BillFitzmaurice is offline BillFitzmaurice  United States
Join Date: May 2004
Location: New Hampshire
I'd leave the length as is; with a Qts of only .2 you need it. This driver is not well suited to TL use, but with that low of a Qts you'd be hard pressed to get strong bass from it in any alignment.

The stuffing issue is a matter of measuring the system impedance. With a bare pipe you should see a major spike at the Fb, which in your case will be around 40-50 Hz, and series of minor resonance spikes above that. Gradually add stuffing until those upper spikes disappear. What you'll end up with when it's right is an impedance chart that looks just like a sealed box, with the one spike at the Fb and a smooth line above that until it rises in the high frequencies where the effect of the coil inductance is seen. Response will clean up a lot when you're done, as the midbass resonances will be eliminated and the roll off below Fb will change from the 4th order of a vented box to the 2nd order of a sealed box. Bailey recommended using long fiber wool, but practically speaking plain old polyester pillow stuffing works just fine.
  Reply With Quote
Old 19th July 2004, 02:26 PM   #3
random_id is offline random_id  United States
diyAudio Member
Join Date: Feb 2004
Location: PA
I have tried to model the speaker in MJK's worksheets. I tried several things but I don't have an easy solution. I think right now you are getting many peaks and valleys the whole way up the frequency spectrum. You can stuff it to even out the response, but in the end, it looks like the response will be similar to the driver mounted in an infinite baffle. Try between 0.3-0.4 pounds per square foot in the bottom 1/3rd of the tube.
You might want to try different setups with the Mathcad sheets to find a better solution.

Good luck
  Reply With Quote
Old 19th July 2004, 06:05 PM   #4
qi is offline qi
diyAudio Member
Join Date: Oct 2003
Location: .
According to the AlphaTL spreadsheet that GM kindly posted on this forum, you need to stuff with ~ 1/2 lbs per cubic ft of PolyFill (pillow stuffing) and you'll get a tuning of ~21HZ at that length.

But here is the rub. Based on your driver's specs you REALLY should be using a tube with an inner diameter of 21.75" -- not 15"

BTW, are you sure Qts is .02 and not .2?

  Reply With Quote


Tuning en Stuffing my big TL subwoofer ?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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Humble Optimo TL stuffing tuning: Please help. dublin78 Multi-Way 32 6th April 2010 05:57 PM
Stuffing a subwoofer Buzzy Subwoofers 2 5th August 2008 09:22 AM
stuffing herndonb Subwoofers 6 20th May 2006 01:55 PM
Stuffing Roy Lewis Multi-Way 2 28th April 2004 06:53 PM
TL stuffing Ilianh Multi-Way 3 22nd February 2003 11:58 PM

New To Site? Need Help?

All times are GMT. The time now is 04:57 PM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio