Hopefully a simple question - 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 15th November 2010, 04:05 PM   #1
diyAudio Member
cradeldorf's Avatar
Join Date: Nov 2010
Location: Muskegon Mi.
Default Hopefully a simple question

(Quote from the noob section) All right. I'm going to get a bit technical, so hang in there with me. The first thing most often considered in a design is the box and bass alignment. The two most common bass alignments for woofers are vented and sealed, but transmission lines, horns, infinite baffles, and dipoles can sometimes be an option as well. However, every woofer is usually best suited for only one of those applications. To figure out which one, we examine its electrical and mechanical strength (Qes and Qms), and come up with a figure called its Qts, which, depending on its value will tell the designer which bass alignment will work the best. Next, we need to know the equivalent air volume (Vas) of the driver. Using this number in conjunction with the Qts and the drivers' resonant frequency (Fs), we can start designing appropriate cabinets and alignments to get the proper bass response from a driver. Getting this step wrong means that the speaker's bass will either be way too weak, or overbearing and boomy... neither of which is fun to listen to.Q: Can't you just get the best bass from a big woofer, and just sort of add stuffing or fiberglass until it sounds right?
A: It's a common misconception that a "huge" woofer is gonna make super-deep, visceral bass. Actually, the point of having a woofer with a lot of surface area is to increase its Sound Pressure Level. You'd be surprised; an 8" or 10" woofer can easily extend down to the bottom range of human hearing (20 Hz or lower), when it's in the properly tuned enclosure. Now please, pay attention. We still haven't gotten past step #1.

So, now that we have a general idea of our box volume, we can start considering how we want the cabinet to look and where we might want to arrange the drivers on the baffle. A lot of beginners (myself included, once upon a time) think you can just fenestrate drivers anywhere on the baffle, so long as it looks cool. Visions of rows of tweeters and midranges are sketched up--and often shot down by the DIY community.

Heres my question/s How do I calculate the proper bass alignment and box volume for my Altec Lansing 604 Duplex speakers?
  Reply With Quote
Old 15th November 2010, 04:14 PM   #2
Did it Himself
diyAudio Member
richie00boy's Avatar
Join Date: Nov 2003
Location: Gloucestershire, England, UK
You've already given the answer in your preamble - find Qts, VAS and Fs. Then use modelling software. There are published alignments that are good for starting points, but if you read up on what group delay is you should be able to come up with something reasonable yourself. Just keep one eye on the frequency response curve and the other on the excursion curve and thermal power curve.
www.readresearch.co.uk my website for UK diy audio people - designs, PCBs, modules and more.

Last edited by richie00boy; 15th November 2010 at 04:18 PM.
  Reply With Quote
Old 15th November 2010, 06:31 PM   #3
bjorno is offline bjorno  Sweden
diyAudio Member
Join Date: Mar 2005
Location: Jacobsmountain
Send a message via MSN to bjorno

First I Agree with richie00boy.You almost answered our own question.
See one (quick) example on how to continue using HR (Hornresponse):

Attached Images
File Type: jpg Altec-Lancing_604-X.JPG (300.1 KB, 64 views)

Last edited by bjorno; 15th November 2010 at 06:39 PM.
  Reply With Quote
Old 15th November 2010, 08:27 PM   #4
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


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
very simple question mail2vasu2004 Power Supplies 5 25th September 2010 10:36 AM
A simple question from a simple man. inteificio Solid State 5 17th October 2005 03:00 PM
Simple Question stoN_Cold Solid State 2 3rd October 2005 10:56 PM
Simple answer required for a simple question... rabbitz Multi-Way 4 31st August 2003 10:05 AM
simple question W.O.L.F. Pass Labs 6 1st August 2002 03:12 PM

New To Site? Need Help?

All times are GMT. The time now is 02:46 PM.

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