What Volume to use for a 4-way with 18" woofer? - diyAudio
Go Back   Home > Forums > Loudspeakers > Multi-Way
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Multi-Way Conventional loudspeakers with crossovers

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 30th May 2012, 07:23 PM   #1
diyAudio Member
Join Date: Feb 2012
Default What Volume to use for a 4-way with 18" woofer?

Hi folks!

How can I know / calculate the "preferred volume" (in cubic feet or cubic centimeters) for the enclosure of my 18" woofer speaker?

Its for my 4-way speakers (consisting of an 18"woofer, a Kef B200, a midtone and a ribbon tweeter)

Dayton Audio PA460-8 18" woofer Specifications

Thanks very much!

Click the image to open in full size.

Last edited by Eftegari; 30th May 2012 at 07:37 PM.
  Reply With Quote
Old 30th May 2012, 07:29 PM   #2
tt398 is offline tt398  United States
diyAudio Member
Join Date: Jan 2004
Location: Montana
Default T/S parameters

You must obtain the Thiele / Small parameters for the woofer and design an enclosure for it using some design software. This is a start..
  Reply With Quote
Old 30th May 2012, 07:40 PM   #3
diyAudio Moderator
Cal Weldon's Avatar
Join Date: Jan 2004
Location: Near Vancouver
The parameters are listed on the link he provided.

There is free software for this. Not sure how good it is though. Do you know if you want vented or sealed? What are you doing for the crossover?

AJ Audio Subwoofer Box Enclosure Design Software - Sub Speaker Cabinet Building Program Downloads
planet10 needs your help:
Let's help Ruth and Dave
  Reply With Quote
Old 30th May 2012, 08:17 PM   #4
CCU is offline CCU  Denmark
diyAudio Member
Join Date: Apr 2007
Location: Kgs. Lyngby
Send a message via MSN to CCU
Hold on!

Designing a 4 way system is NOT an easy task.. and i gather that you don't have a lot of experience.
I would start with a kit if i were you OR do it as an active system, so it easy to tweak your way out of design "fault"
  Reply With Quote
Old 30th May 2012, 09:48 PM   #5
diyAudio Member
Join Date: Feb 2002
Location: Western Sydney
UniBox - Unified Box Model for Loudspeaker Design - Kristian Ougaard
Impedance varies with frequency, use impedance plots of your drivers and make crossover calculations using the actual impedance of the driver at the crossover frequency
  Reply With Quote
Old 30th May 2012, 10:57 PM   #6
tvrgeek is offline tvrgeek  United States
diyAudio Member
Join Date: Dec 2009
Location: Md
CCU, dead on.

If anyone does not believe how difficult it is to build a speaker system well, just go to the store and see how many build and sell speakers that are terrible. (most). Then go pick a speaker that is done well. Vanderstein 2Ce for example. Look carefully and ask yourself, "Now what am I going to do better?" It is not easy.

A few tips for first timers:
Build an established design. The place to start is to pick up Joe DeApollito's book on measuring speakers.

I do my box modeling in WinIsd even though I have SoundEasy. I do my T/S measurements with WooferTester II. I actually use TrueRta for acoustic testing more than I should ( paid high res version). At some point, you are going to buy a mic. Do not mess around, get one that is calibrated first. It will save you a lot of money.

Now here is what beginners do not want to know. 90% of the result is the crossover. Not the drivers, not the box. The crossover. Stick with cheap drivers and unfinished boxes until you understand this. I can design and build a box to be optimum for the problem in a couple of days. I can (and do) just send ScanSpeak or Seas lots of money and buy fantastic drivers. I have spent 35 years trying to understand crossovers for just a two-way. ( subs are easy. Electronic, 4th order at least)
  Reply With Quote
Old 31st May 2012, 07:46 AM   #7
diyAudio Member
Join Date: Feb 2012
Thanks very much for all info!

Indeed, I will be using ACTIVE 4-way crossovers (from minidsp.com which are widely applauded by experienced users who only believed the quality after they compared these to expensive pro crossovers) with 4 amplifiers. so I have lots of room for tuning and adjustments.

The online free software over here


advises an optimum of 80 as Vb, for a closed box which is what I want. But is this Cubic Feet or Cubic Centimeters??
  Reply With Quote
Old 31st May 2012, 12:06 PM   #8
This speaker DIY thing, it's pretty addicting!
diyAudio Member
mikejennens's Avatar
Join Date: Feb 2008
Location: Bismarck, ND
I can't open the software you linked to on my work computer, but I'd guess the 80 is liters, since it appears the website author is European.
Another great resource for DIY speaker building is the Parts-Express techtalk forum Techtalk Speaker Building. There are a lot of very knowledgeable and helpful members on techtalk. I've met several of them and have built some of their designs.
If you solicit some advice from some of the "gurus" for your build, you'll end up with a very good speaker. If you go it alone, you're missing out on a valuable resource. There is a LOT of physics involved with a properly designed speaker. There is a LOT of gratification in applying the principles correctly.
Jolida SJ502A, Squeezebox Touch, Paul Carmody's Sunflowers, Jeff Bagby's Continuums; Planet 10 HiFi's MarkAudio A 7.3 Frugalhorns and MarkAudio CHP-70s, Bjorn's PS95 TABAQs
  Reply With Quote
Old 31st May 2012, 12:41 PM   #9
diyAudio Member
Inductor's Avatar
Join Date: Feb 2006
Location: Cascais
It's not a good candidate for sealed, but maybe you can find it possible.
Test here. EBS Software.
Their site is wrong "Compliance Equivalent Volume (Vas) - 473.50 cu. ft.". It says Cuft instead of liters. You can find good Vas (liters) data on the pdf.
If you go on with the choice for your sub you can use it like this in a BR,
DAYTON PA460-8 18, VB = 154.0 L, FB = 28.8 Hz, 97.6 dB2.83Vm.
F3=44 Hz, F6=34 Hz, F12=24 Hz 05.2012
but be advise that you can get better l.f. extension with this 5" woofer in a 8 liter enclosure. TangBand W5-1138SM
PA woofers are not that great l.f. champions reproducers.
(This is advise for others as of course you can manipulate with dsp and equalization, but I don't have the experience. Please post your findings)
  Reply With Quote
Old 31st May 2012, 02:30 PM   #10
diyAudio Member
Join Date: Feb 2012
Thanks for your advise! I will go for a closed box indeed. I trust my 4-way active crossovers and driver quality within my budget range.

I assume that a given VOLUME van be freely divided between whidth, height and deppth?

If so, then I am really in love with the following pproportions that would give me the perfect volume and a very compact tall speaker. See my drawing below.

Is this very possible or very utopian?

Click the image to open in full size.
  Reply With Quote


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
Please help ID this 18" woofer airegin Subwoofers 10 10th November 2011 01:12 PM
Huge 2-way with 18" woofer and 2" exit compression driver? BHTX Multi-Way 15 23rd June 2011 10:59 AM
Hartley 18" Woofer thetubeguy1954 Subwoofers 27 1st December 2007 09:46 PM
Rate this Pro 18" Woofer sonu Multi-Way 6 3rd July 2005 06:41 AM
Dayton pro 18" woofer w/4" VC rcavictim Multi-Way 8 27th November 2004 03:32 AM

New To Site? Need Help?

All times are GMT. The time now is 05:31 AM.

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

Content Relevant URLs by vBSEO 3.3.2