Dayton Audio WT3 accuracy issues - diyAudio
Go Back   Home > Forums > Design & Build > Software Tools

Software Tools SPICE, PCB CAD, speaker design and measurement software, calculators

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 25th July 2012, 12:25 PM   #1
diyAudio Member
 
Join Date: Aug 2011
Default Dayton Audio WT3 accuracy issues

Hi,

I've had the woofer tester for some time and have been using the added mass method for VAS etc measurment.

Until recently I thought this was working accurately, but now I am not so sure.

I have some 8" Dynaudio woofers out of a Volvo, the aftermarket equivalent driver would be the MW180 which looks to share the same cone/VC/former and softparts (I can't see Dyn retooling these parts for a Volvo driver)-MMS of the MW180 is 36.5g, my WT3 measurement comes back with 23.80g for one driver and 22.43g for the other-well off from what I was expecting.

So I thought to try using different weights, tried a few and the MMS changes with each different weight.

Am I doing something wrong or has anyone else noticed this?
  Reply With Quote
Old 29th July 2012, 11:09 PM   #2
DrBoar is offline DrBoar  Sweden
diyAudio Member
 
DrBoar's Avatar
 
Join Date: Apr 2003
Location: Stockholm
23.80 an 22.43 are very similar, some average +/- 5%. If your weight is elastically coupled to the voice coil, by say being a mass attached to the center of the middle dome of the cone. Then some flexing could partly uncouple the mass and thus changing the measurement fo MMS.

If you run the measurement five times with the same load, do you get spot on the same value?
  Reply With Quote
Old 30th July 2012, 12:30 AM   #3
diyAudio Member
 
Michael Chua's Avatar
 
Join Date: Jul 2006
Location: Calais, ME
Quote:
Originally Posted by TheBaronGroog View Post
So I thought to try using different weights, tried a few and the MMS changes with each different weight.

Am I doing something wrong or has anyone else noticed this?
Try the Delta Compliance Method. Mount the driver to a Closed Box with a known volume. This will avoid the inaccuracies that you sometimes can encounter with Added Mass.
__________________
AmpsLab.com
  Reply With Quote
Old 15th August 2012, 11:13 PM   #4
tvrgeek is offline tvrgeek  United States
diyAudio Member
 
Join Date: Dec 2009
Location: Md
I bought a .1% 10 Ohm resistor to calibrate it with. It is just as accurate as my big bench DVM.

With T/S, within 20% you are fine. Don't sweat the details. OEM specs vary. How much glue was used varies. The slightest vibration of the mass in the mass displacement measurement, or the tiniest of air leaks in the sealed box measurement will cause much bigger issues.
  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
any updates on the accuracy of audio nirvana T/S specs? gafhenderson Full Range 109 22nd May 2012 12:42 AM
Dayton WT3 Speaker Tester Loren42 Multi-Way 37 9th November 2011 04:19 PM
Dayton WT3 testing tweeters mitchyz250f Equipment & Tools 2 28th August 2011 10:25 AM
Dayton T-Amp Issues wookie1976 Class D 0 14th April 2010 09:14 PM
Dayton WT3 Woofer Tester available next month! BHTX Multi-Way 14 30th October 2007 08:32 PM


New To Site? Need Help?

All times are GMT. The time now is 02:08 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