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

Multi-Way Conventional loudspeakers with crossovers

Goodmans Dimension 8 Speakers.
Goodmans Dimension 8 Speakers.
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 6th December 2018, 09:58 AM   #11
vishalk is offline vishalk  United Kingdom
diyAudio Member
 
vishalk's Avatar
 
Join Date: Mar 2017
Location: North London
midrange test.jpg

The above picture shows the midrange test on the dayton dat v2.

The green line showing the test before and the blue after glueing the surround down.

Click the image to open in full size.

New capacitors for crossover.

Last edited by vishalk; 6th December 2018 at 10:12 AM.
  Reply With Quote
Old 6th December 2018, 10:36 AM   #12
Mosquito is offline Mosquito  Argentina
diyAudio Member
 
Mosquito's Avatar
 
Join Date: Sep 2009
Location: Santa Fe, Argentina
Why weird? More recently, Mirage and Definitive Technology show similar arrangement..
__________________
"It is less serious than if worst"
  Reply With Quote
Old 6th December 2018, 02:54 PM   #13
Galu is offline Galu  Scotland
diyAudio Member
 
Join Date: Apr 2018
Quote:
Originally Posted by vishalk View Post
. . . over the years the glue somehow had weakened and the surround was coming away from the chassis.
That's a common problem with drivers of this age. Also worth checking that the rear suspension spider is still securely glued to the driver basket - see attachment.
Attached Images
File Type: jpg Detached Spider.jpg (117.9 KB, 111 views)
  Reply With Quote
Old 6th December 2018, 05:09 PM   #14
vishalk is offline vishalk  United Kingdom
diyAudio Member
 
vishalk's Avatar
 
Join Date: Mar 2017
Location: North London
Well spotted Galu from the graph produced it shows from around 400hz to 1.5khz isnt smooth even after glueing the surround.

I doubled checked the spider and it was fine, what i need notice though was as i moved the spider the voice coil was sliding up and down the cone/diaphragm! The glue here had also come away, so that has been glued now and hopefully i will do another test and it should be a smooth curve.
  Reply With Quote
Old 6th December 2018, 05:55 PM   #15
Galu is offline Galu  Scotland
diyAudio Member
 
Join Date: Apr 2018
Well spotted! Just don't put full power through those drivers until you're sure all's glued that's meant to be glued!
  Reply With Quote
Old 6th December 2018, 06:52 PM   #16
vishalk is offline vishalk  United Kingdom
diyAudio Member
 
vishalk's Avatar
 
Join Date: Mar 2017
Location: North London
Every Driver has been thoroughly checked with the dayton dats v2, the bass drivers i will match them up closely.

I have glued and checked all parts where needed now!, next is to tackle the cabinets and get them filled, sanded and repainted.

Not to happy about the sponge dampening material, i have lots of polyfill and wool to thinking one cabinet i will leave standard and the other use poly acoustic wadding and see which one sounds better.
  Reply With Quote
Old 6th December 2018, 07:15 PM   #17
Jonathan Bright is offline Jonathan Bright  Australia
diyAudio Member
 
Join Date: Feb 2004
Location: Queensland Australia
Re; the overall design of these speakers. They are 'different' but may well be based or serious research. There is a paper by (Roy Allison? I think) in the JAES many yrs ago ('70's?) where he did extensive testing of speakers against walls and corners etc. I recall they had woofers near the boundaries. This generated a series of graphs that showed bass reinforcement in the lower octaves. I understand he marketed models based on this research. These Goodmans may have also been designed with that in mind.
Cheers Jonathan
__________________
"It was the Springtime of the year when aunt is calling to aunt like mastodons bellowing across primeval swamps." P.G. Wodehouse.
  Reply With Quote
Old 6th December 2018, 07:23 PM   #18
Galu is offline Galu  Scotland
diyAudio Member
 
Join Date: Apr 2018
Foam alters the sound quality at high frequencies, while wool felts alter the sound quality at lower frequencies.

At least that is what it says here:

How to Use Sound-Damping Materials in DIY Loudspeakers

Perhaps you could also experiment with a mixture of the two?
  Reply With Quote
Old 6th December 2018, 07:29 PM   #19
Jonathan Bright is offline Jonathan Bright  Australia
diyAudio Member
 
Join Date: Feb 2004
Location: Queensland Australia
Yes Galu that's worth thinking about because filling the enclosure will increase the effective volume and alter the low frequency response damping etc. But after all these yrs the T/S parameters of drivers and bass radiator are likely to have drifted a bit.......so the result will be like the marriage vows.....it will effect the speaker 'for better or worse' ha ha.
__________________
"It was the Springtime of the year when aunt is calling to aunt like mastodons bellowing across primeval swamps." P.G. Wodehouse.
  Reply With Quote
Old 6th December 2018, 07:38 PM   #20
vishalk is offline vishalk  United Kingdom
diyAudio Member
 
vishalk's Avatar
 
Join Date: Mar 2017
Location: North London
haha thanks Jonathan! Thats a good link Galu one i have read many time before, i will certainly give it a go!
  Reply With Quote

Reply


Goodmans Dimension 8 Speakers.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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Goodmans Goodwood Speakers - rough sounding drivers pm2097 Multi-Way 24 27th June 2015 04:23 AM
Opinions on Goodmans Speakers bm_mode Multi-Way 10 18th April 2012 03:46 AM
small metal boxed goodmans speakers baggins Multi-Way 0 30th April 2006 12:00 PM
Help on choosing an old Goodmans speakers beta_sound Multi-Way 5 16th May 2004 08:58 PM
I have some Goodmans Mezzo SL speakers... Matttcattt Multi-Way 2 29th January 2004 03:30 AM


New To Site? Need Help?

All times are GMT. The time now is 03:32 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki