Building a low-end sub for outdoor use - 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 2nd March 2010, 07:00 PM   #1
CCU is offline CCU  Denmark
diyAudio Member
 
Join Date: Apr 2007
Location: Kgs. Lyngby
Send a message via MSN to CCU
Question Building a low-end sub for outdoor use

Hi all you wonderfull DIY'ers

I'm building a new and BIGGER setup for turing Denmarks festivals

The new one is quite large, 1 meter wide and 3 meters long.
I am building 2 DR 280 speakers from Bill Fitzmaurices website and i need 1 or 2 subwoofers to go with them. just to ad a litte UMF

Our old speaker setup used 8 Velleman VDSSP8/8 bas units and a couple of piezo tweeters. Velleman nv

I've been thinking about building a small horn for them. obviouslythere are NO designs for them, because they are ridiculously cheap/low-end

My question is. do you know of any design for a small'ish horn that those drivers might work in.

I've been thinking about building 2 of these, but 60cm wide, so that i can contain 4 units
Speakerplans.com

Will this give anything near a diesent performance,

I don't look for anything under 45hz of usable output, simply because it is a low power rig og outdoor

Would really apriciate some input for you guys

PS here's a picture of the old setup
Click the image to open in full size.

Last edited by CCU; 2nd March 2010 at 07:06 PM. Reason: Added a picture
  Reply With Quote
Old 2nd March 2010, 07:12 PM   #2
CCU is offline CCU  Denmark
diyAudio Member
 
Join Date: Apr 2007
Location: Kgs. Lyngby
Send a message via MSN to CCU
I've found more T/S specs for them than is listed on the website.

Impedance (Z) 8
Resonant frequency (fs) 35Hz
Max. frequency range f3-6,000Hz
Music power 350WMAX
Power rating (P) 250WRMS
SPL (1W/1m) 91dB
Suspension compl. (Cms) 0.25mm/N
Moving mass (Mms) 65g
Mech. Q factor (Qms) 4.95
Electr. Q factor (Qes) 0.66
Total Q factor (Qts) 0.58
Equivalent volume (Vas) 43 l
DC resistance (Re) 6,4
Force factor (BxL) 12.6
Voice coil induct. (Le) 0.8mH
Linear excursion (XMAX) 6mm

And i have no idea of how accurate they are!!
  Reply With Quote
Old 2nd March 2010, 08:01 PM   #3
diyAudio Member
 
BP1Fanatic's Avatar
 
Join Date: Jan 2009
Location: Columbus, Ohio
What is the Sd or hole cut out diameter?
  Reply With Quote
Old 2nd March 2010, 08:12 PM   #4
CCU is offline CCU  Denmark
diyAudio Member
 
Join Date: Apr 2007
Location: Kgs. Lyngby
Send a message via MSN to CCU
The cut out hole i 17.6cm. if i understand the question.
The casket has a diameter of 20.5cm
  Reply With Quote
Old 2nd March 2010, 08:12 PM   #5
diyAudio Member
 
BP1Fanatic's Avatar
 
Join Date: Jan 2009
Location: Columbus, Ohio
Quote:
Originally Posted by CCU View Post
I've been thinking about building 2 of these, but 60cm wide, so that i can contain 4 units
http://www.speakerplans.com/index.php?id=hd15horn
You need to model it in Hornresp to see if 4 of those subs will perform with good results in that modified HD15.
http://hornrespdb.com/showparameters...nresp Database

Horn Parameters
Ang : 1,0 x Pi Eg : 2.83 Rg : 0 Fta : 16.51

S1 : 544.8 S2 : 722.16 L12 : 27.38 F12 : 0
S2 : 722.16 S3 : 1054.92 Con : 15.25 F23 : 0
S3 : 1054.92 S4 : 1785.57 Con : 15.36 F34 : 0
S4 : 1785.57 S5 : 2206.16 Con : 8.97 F45 : 0

Chamber parameters
Vrc : 52 Fr : 40 Vtc : 20000
Lrc : 40 Tal : 4 Atc : 1982.4

Last edited by BP1Fanatic; 2nd March 2010 at 08:23 PM.
  Reply With Quote
Old 2nd March 2010, 08:27 PM   #6
CCU is offline CCU  Denmark
diyAudio Member
 
Join Date: Apr 2007
Location: Kgs. Lyngby
Send a message via MSN to CCU
thanks
I'm not really sure how to use that program, but i'll give a try
  Reply With Quote
Old 2nd March 2010, 08:46 PM   #7
diyAudio Member
 
BP1Fanatic's Avatar
 
Join Date: Jan 2009
Location: Columbus, Ohio
Quote:
Originally Posted by CCU View Post
The cut out hole i 17.6cm. if i understand the question.
The casket has a diameter of 20.5cm
Sd = 17.6 x 17.6 x 0.7854 = 243.29cm^2.
  Reply With Quote
Old 3rd March 2010, 02:07 PM   #8
CCU is offline CCU  Denmark
diyAudio Member
 
Join Date: Apr 2007
Location: Kgs. Lyngby
Send a message via MSN to CCU
i think i've done it right

Multiplied the sd by 4 for the 4 drivers and added the volume to the rear champer

here's how it looks...
Click the image to open in full size.

Click the image to open in full size.

Last edited by CCU; 3rd March 2010 at 02:08 PM. Reason: added some pictures
  Reply With Quote
Old 3rd March 2010, 02:10 PM   #9
CCU is offline CCU  Denmark
diyAudio Member
 
Join Date: Apr 2007
Location: Kgs. Lyngby
Send a message via MSN to CCU
for a low-end build i don't think i looks to bad with usable output to 40hz
  Reply With Quote
Old 3rd March 2010, 02:25 PM   #10
diyAudio Member
 
Join Date: Sep 2008
When I was new to Hornresp, I also made the mistake of trying to derive new values for parameters like Sd, for example, by multiplying the Sd by the number of drivers. Hornresp works much better if you use the built-in Driver Arrangement wizard. Go to the Input Parameters, fix all of the parameters as they would be for a single driver, then click Tools and Driver Arrangement. Tell it how many drivers you will have in series, then how many of those groups you will have in parallel. You want to do it this way because the electrical parameters, for example, will determine the usable bandwidth and the upper/lower end of your design.

What kind of horn are you trying to design for these?
  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
building semi-outdoor speakers, need tweeter LittleDave Multi-Way 3 20th January 2008 03:54 PM
low end woofers dalcorn Multi-Way 11 7th April 2006 08:18 AM
high end version of low end phono stage dsavitsk Solid State 20 2nd September 2005 12:51 AM
Low-End Happiness mjarve Solid State 11 1st May 2004 03:48 AM
Zenquito 5x50W : nearly the building end Idefixes Solid State 27 12th March 2004 05:02 PM


New To Site? Need Help?

All times are GMT. The time now is 08:25 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