rebuilding speakers with different voicecoils, what changes? - 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 16th November 2012, 07:34 PM   #1
FE3T is offline FE3T  Norway
diyAudio Member
Join Date: Dec 2004
Location: Close too Lillehammer
Default rebuilding speakers with different voicecoils, what changes?

I have been playing with some speaker baskets and after market recone parts, and wonder if someone can help me predict the results of using different voice coil lengts.

All parts identical EXCEPT the voice coil.

If reconed with orginal parts:

Very ligth cone, accordian surround, and 14mm long coil
fs 85hz
Vas 14,2 L
sens 97 db/1w
qts 0,35
xmax 3mm (one way)

In my version i currently use a thick stiff cone with foam surround and a 19mm long coil
Here i belive that fs drops a lot, maybe as far as down to the high 30`s

Vas should rise to 30-50L

sensitivity should drop 6-9 db (mated with a 93 db tweeter they get slitghly overpovered by the tweet so my guess are 89-91 db/1w)

But what happens with qts? i know a heavier cone should rise qts but are unshure what a loser surround does and how does a longer coil change qts?
Here i have checked out a 10" with even heavier cone,and softer surround but the same voice coil and motor and these have a qts of 0,36. Am i totally wrong in assuming that my drivers are in the same ballpark?

So let me put together a guestimate for my drivers

This is with a 19mm long coil

fs 38hz
Vas 45L
sens 89 db/1W
qts 0.35
xmax 6mm (one way)

What if i build a version with a 16mm long coil?

Fs should rise a bit due to a ligther coil and former, but what other changes would the shorter coil give? will a shorter coil give greater force and even higher fs?

Vas shouldnt change should it?

What about sensitivity? shouldnt it be a tad higher?

Qts what about it? will it drop a bit like i belive?

xmax drops to 4,5mm

I can also build this drivers with a 14mm coil, but i guess that will only take the changes from gong from 19mm to 16mm a notch more in the same direction.

I know i should be getting a woofer tester, and plans to do so, but if you can enligthen me about basic driver understanding by answering my questions i would really appriciate it.

Last edited by FE3T; 16th November 2012 at 07:42 PM.
  Reply With Quote
Old 16th November 2012, 07:47 PM   #2
sreten is offline sreten  United Kingdom
diyAudio Member RIP
Join Date: Nov 2003
Location: Brighton UK

If you shorten the coil but keep Re constant with the same wire :
(e.g. convert a long 2 layer to a shorter 3 layer)
- Fs, and Vas don't change
- Xmax drops (obviously)
- Qts drops, BL and sensitivity goes up

For all drivers a less stiff suspension causes Fs and Qts to drop. In most
boxes with Vbox < Vas the differences in Fbox and Qbox will be minor.

rgds, sreten.
  Reply With Quote
Old 16th November 2012, 08:02 PM   #3
FE3T is offline FE3T  Norway
diyAudio Member
Join Date: Dec 2004
Location: Close too Lillehammer
The Re will rise with the shorter coils i can chose from since they all will be 2 layer.

The raw baskets i have played with are JBL`s 2118
i even did a pair with 116H-2 aftermarket parts, (rather thin and ligth foam edged cone) but i found the midrange a bit intense.

its the version with 127H-1 aftermarket parts cut down in diameter and refoamed with 116H-2 foams i think are most suited for a planned XPL based center channel (using the 116H-3 woofer found in the XPL 140`s would require a sealed solution if an acceptable size are to be obtained, but i desire a ported center)

Last edited by FE3T; 16th November 2012 at 08:06 PM.
  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
Rebuilding "Kabuki" speakers Wilade Multi-Way 8 15th December 2009 05:12 PM
Rebuilding crossovers from old ADS speakers Slanski62 Multi-Way 5 17th January 2007 03:26 AM
&quot;rebuilding&quot; stock speakers? mrunexpected Multi-Way 4 30th October 2004 08:30 AM
rebuilding a speaker Bill Fitzpatrick Multi-Way 3 21st July 2002 07:06 PM
Driver rebuilding jasepav Multi-Way 3 28th December 2001 12:59 AM

New To Site? Need Help?

All times are GMT. The time now is 12:48 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