Alpair7/Scanspeak 18WU/8741 Fast - diyAudio
Go Back   Home > Forums > Loudspeakers > Full Range

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 17th May 2013, 10:54 AM   #1
markre is offline markre  Finland
diyAudio Member
 
Join Date: Jan 2012
Default Alpair7/Scanspeak 18WU/8741 Fast

Some time ago I built my first speakers based on alpair 7 and modified pensils. They sounded very good but after a while a started to want a little improvement in the bas region and it also seemed that it missed a lot of detail when there was music with more bas. However there was a lot that I liked with the alpairs so I decided to give them a little help with some woofers.

With the kind help by Dave Dlugos we decided on scanspeak 18WU/8741-T00 in a push-push configuration and a 46L vented enclosure with the alpair in a aperiodic transmission-line about 5-6L.
I built it from inside out. After constructing the t-l for the alpair I made the bracing and a frame. Over that I laminated two layers of 4mm birch-plywood (vhv), after that a 8mm board used to damp floors, after that plywood (hvh) and last mdf. It turned out to be a very stiff construction without any vibrations even when playing very loud.

Click the image to open in full size. Click the image to open in full size. Click the image to open in full size. Click the image to open in full size.

One technical challenge was how to fix the elements to each other to get the most of the push-push configuration. Obviously it has to be done when the elements are in place and a hole would not be a satisfying solution. I decided to do aluminum pieces that I could attach to the elements and that would click into each other. It turned out to work very well.

Click the image to open in full size.Click the image to open in full size.

A big thank to Dave for all his valuable help,
Markus
  Reply With Quote
Old 17th May 2013, 11:37 AM   #2
zman01 is offline zman01  Bangladesh
diyAudio Member
 
Join Date: Feb 2011
Location: Dhaka
Nice build.

Bi-amped?
  Reply With Quote
Old 17th May 2013, 11:39 AM   #3
Squeak is offline Squeak  Denmark
diyAudio Member
 
Squeak's Avatar
 
Join Date: Jul 2007
Location: Frederiksberg
Wow that is one hell of a speaker! Obviously a LOT of work and thought went into this.
I hope it sounds accordingly.
Where is the crossover point?
  Reply With Quote
Old 17th May 2013, 12:03 PM   #4
markre is offline markre  Finland
diyAudio Member
 
Join Date: Jan 2012
Cross-over point 213 Hz/second order (happened to fit with the values). In the future I may bi-amp it.
Well my goal was that a symphony orchestra should sound like a symphony orchestra and a funk band like funk band without giving up details. I must confess that I’m satisfied. The alpairs also seems a bit happier without struggling with the bas.
  Reply With Quote
Old 17th May 2013, 03:12 PM   #5
diyAudio Member
 
tuxedocivic's Avatar
 
Join Date: Jan 2011
Location: Ladysmith, BC
Very nice build. The curves are incredible. 200hz seems like a good spot. Where is the box tuned to?

Edit - is that a passive or active cross over?
  Reply With Quote
Old 17th May 2013, 06:51 PM   #6
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
Good to see these go public. Excellent work Markus

dave
__________________
community sites t-linespeakers.org, frugal-horn.com, frugal-phile.com ........ commercial site planet10-HiFi
p10-hifi forum here at diyA
  Reply With Quote
Old 17th May 2013, 08:10 PM   #7
chrisb is offline chrisb  Canada
diyAudio Member
 
Join Date: Aug 2002
Location: victoria BC
Quote:
Originally Posted by tuxedocivic View Post
Very nice build. The curves are incredible. 200hz seems like a good spot. Where is the box tuned to?

Edit - is that a passive or active cross over?

"in the future I may bi-amp it" sounds to me like currently passive XO
Markus - gorgeous freaking work on the machining of interlocking aluminum coupling parts - glued to drivers' magnets , I guess?
__________________
now on sabbatical
  Reply With Quote
Old 17th May 2013, 08:42 PM   #8
diyAudio Member
 
Join Date: Jun 2011
Location: Canton Michigan
What a great job you did buildign these boxes with the dirvers you used. Dave is a super guy. Glade he could help out it shows and again good Job enjoy. N.S.
  Reply With Quote
Old 17th May 2013, 08:45 PM   #9
diyAudio Member
 
vinylkid58's Avatar
 
Join Date: May 2005
Location: Victoria, B.C.
Quote:
Originally Posted by chrisb View Post
Markus - gorgeous freaking work on the machining of interlocking aluminum coupling parts - glued to drivers' magnets , I guess?
Very creative, but far too complicated for me personally, I would have used a simple bolted flange. Very impressive build nonetheless.

jeff
  Reply With Quote
Old 18th May 2013, 05:20 AM   #10
markre is offline markre  Finland
diyAudio Member
 
Join Date: Jan 2012
The scanspeaks has the magnet attached to the frame by screws. I just extended them to go through the aluminum parts. I would not trust glue in the long run. There was some work with the aluminum parts, guess 3d-printing would be the easy way out.


If I understand Dave’s calculations right the box is tuned to 41Hz.
  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
FS: ScanSpeak Illuminator 18WU/8741T 1fspd Swap Meet 7 21st January 2013 01:47 PM
Kubotech -- Alpair7.3? planet10 Full Range 8 19th October 2012 12:21 AM
ESS Sabre ES9012, ES9023 or Wolfson 8741 ??? LinuksGuru Digital Source 9 16th March 2012 11:49 AM
FS: BNIB Single Scanspeak 18wu/4741T Driver bikinpunk Swap Meet 0 27th September 2010 04:11 PM
Scanspeak Illuminator 18WU/4741T00 xmax? kkant Multi-Way 9 22nd March 2009 03:39 AM


New To Site? Need Help?

All times are GMT. The time now is 04:51 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2015 DragonByte Technologies Ltd.
Copyright 1999-2015 diyAudio

Content Relevant URLs by vBSEO 3.3.2