What is the best way to MEASURE speaker displacement? - diyAudio
Go Back   Home > Forums > Design & Build > Construction Tips
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Construction Tips Construction techniques and tips

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 7th September 2013, 01:05 AM   #1
eqjive is offline eqjive  United States
diyAudio Member
Join Date: Jan 2013
Default What is the best way to MEASURE speaker displacement?

What is the best way to MEASURE speaker displacement, i,e volume occupied by speaker inside a box, including cone, magnet, structure etc? I've found a number of 'caculators' and ways to estimate this, but what amount empirical measurements?

- Saran wrap and amount of water displacement?

- How about using a VAS box with the magnet inside, instead of out as would normally be done for the VAS measurement?

- Something else?
  Reply With Quote
Old 7th September 2013, 01:21 AM   #2
diyAudio Member
Join Date: Mar 2007
Location: California
Odd shape is difficult to measure.

I don't recommend trying to Saran wrap your driver and then playing Archimedes.

Most people are satisfied calculating the cone volume using the formula for a truncated cone, and adding in the magnet volume, which is more or less a cylinder for most woofers.

You don't need to be all that exact. Almost everything about a driver's alignment is subject to variation by temperature (voice coil and ambient) as well as cone excursion so getting the box volume calculated to within +/- 10% is more than good enough (assuming that is why you want to know the driver volume).

If your question pertains specifically to measuring the driver to determine Vas from a resonance change when mounted in a box of known volume, perhaps you should consider the added mass method instead. There is no need to know the driver volume when doing it that way.
  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
How to Measure Speaker Distortion Correctly? megasat16 Multi-Way 46 14th July 2016 02:19 PM
Speaker measure required-Help. Martin300B Multi-Way 0 28th October 2012 05:32 PM
measure speaker T/S parameter, what do I need? gychang Equipment & Tools 20 10th July 2012 04:32 PM
How to measure an active speaker system? Tyson Multi-Way 2 4th January 2010 04:42 AM
Speaker Workshop - using "Measure -> Passive Components" to measure ESR ? percy Multi-Way 0 12th March 2006 09:18 PM

New To Site? Need Help?

All times are GMT. The time now is 03:24 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