Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Did I make a good purchase? First time DIY. W12P from ApexJr
Did I make a good purchase? First time DIY. W12P from ApexJr
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 11th January 2006, 01:55 PM   #1
CFC is offline CFC  United States
diyAudio Member
Join Date: Dec 2005
Location: H-Town
Default Did I make a good purchase? First time DIY. W12P from ApexJr

Hey guys,

Yesterday I bit the bullet and bought a W12P 12" woofer from ApexJr. It is a surplus from Hales Design group.
You can take a look at it over here in the middle of the page.

Here are its T/S specs:

Fs = 22Hz
Qms = 7.06
Qes = 0.374
Qts = 0.355
Vas = 4.78 cu. ft.
Xmax = 0.177"
Xmech = 0.266"
Sd = 113.2 sq. in.
Re = 3.6 Ohm
Znom = 4 Ohm
SPL = 91.37 dB (2.83V)
SPL = 87.9 dB (1W)

Modeling in WinISD Pro gave me a nice response using a QB3 alignment with an F3 around 26Hz or so and a 3 cu. ft box.
My main concern was the low Xmax, but I will be using a 70W sub amp, and again the modeling shows that it would hit just below the limit with SPL output around 100 db (much louder than I would ever hit). Was my thinking correct? That is the value I inserted in the "Signal" tab in WinISD.
Was this a wise choice for a first project? I figured I would start with something a bit more affordable to get my feet wet, but if in the process I build something decent then all the better .
What is "Xmech" by the way?

I appreciate any input.
  Reply With Quote
Old 11th January 2006, 02:25 PM   #2
sreten is offline sreten  United Kingdom
Join Date: Nov 2003
Location: Brighton UK

Xmech is the mechanical limit of excursion, the driver is
linear within Xmax and then distorts its way to to Xmech.

Just my opinion but Fs is too low (Vas too high) to make
an ideal driver for reflexing, the result will not be too hot
at handling sub-sonic stuff - so if you use vinyl a subsonic
filter is a very good idea - hopefully built into the phono stage.

The driver parameters suggest its ideal use is as a sealed box
bass driver for a multiway speaker. Around 2 cuft will give a well
damped roll-off that can exploit room gain for good bass extension,
and as a low Q sealed box alignment excellent transient definition.

  Reply With Quote


Did I make a good purchase? First time DIY. W12P from ApexJrHide 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Its time one of you guys make some money! dcfis Class D 35 10th April 2006 11:51 PM
Your first time - Was it good? :D ShinOBIWAN Multi-Way 10 23rd July 2005 04:01 AM
Apexjr capacitors for gainclones? Which ones are good? nick_g_evans Chip Amps 4 14th December 2004 03:27 AM
Its finally time for SkinnyBoy to make an amp... SkinnyBoy Solid State 8 9th June 2004 04:35 AM
For a good time call Thatch_Ear Multi-Way 2 21st August 2002 08:03 AM

New To Site? Need Help?

All times are GMT. The time now is 04:30 AM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 16.67%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio