15 Inch/38cm PA (sub)woofer - diyAudio
Go Back   Home > Forums > Loudspeakers > Subwoofers

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 27th May 2006, 07:52 AM   #1
tubee is offline tubee  Netherlands
diyAudio Member
 
tubee's Avatar
 
Join Date: Jul 2004
Location: Netherlands
Default 15 Inch/38cm PA (sub)woofer

Hi all

I found a 38cm PA speaker, they wanted to throw it away at the shop where i get my parts. The speaker was dead and the former user bought a new one. Unfortunate i don't have a camera at hand.

I measured the connection: zero ohm, but after scratching the isolation of the voice coil winding itself a 2nd measure: 6.1 ohms!! So its a bad connection, and after some soldering it plays again!

Some features: No brand name is stamped on it, only a code on (18cm ferrite!) magnet: 330772
I guess its an american or english make of late 1980's.
Steel pressed basket, textile 2 roll surrounded paper cone, at voice coil standard yellow cotton surround. Voice coil is 80 mm diameter, decompression hole in pole peace of 25mm.
Cone has rather thin (estimated 0.3/0.4 mm thick) not straight shape but has a "Nawi- membrane" or trumpet like. It plays easily to 3000hz and then rolls off. Cone dispacement is about +/- 5 mm.

Now i am figuring out what to do with it:

Could it be possible to enlarge cone mass with tissue paper/ with water mixed woodglue, to build a active subwoofer of it for my stereo/surround purposes. After that apply a dampening layer over cone (i experimented more often with speakers)

Well, what do you think?
Regards:
__________________
Daisy Bell
  Reply With Quote
Old 27th May 2006, 08:42 AM   #2
tubee is offline tubee  Netherlands
diyAudio Member
 
tubee's Avatar
 
Join Date: Jul 2004
Location: Netherlands
I have been searching for a cheap (+/-80W) sub amp.
Also any suggestions?
__________________
Daisy Bell
  Reply With Quote
Old 28th May 2006, 08:46 PM   #3
tubee is offline tubee  Netherlands
diyAudio Member
 
tubee's Avatar
 
Join Date: Jul 2004
Location: Netherlands
Well i don't get any response here.

In meantime thought things over. Its worthwile, because a friend of my, percussionist, said this PA speaker would cost around 300 Euro.

Can measure TS parameters via soundcard & poweramp (speaker workshop or Arta) and then calculate the casing for it as a subwoofer.

When TS parameters are not perfect for a sub, i could make cone some heavier with glass fibre/tissue or aluminium foil.

Thinking about 60 Litres bassreflex (+/- 42 * 42 * 50cm) with a dia 100mm pipe, length +/- 200 mm. Then have to find a cheap 100W amp or build one.

But first i will try it unmodified in a cheap made plywood box of around 60L, thinking about bassreflex (+/- 42 * 42 * 50cm) with a dia 100mm pipe, length +/- 200 mm. Then have to find a cheap 100W amp or build one later. First tests can with a standard amp here, see wat comes out of that giant.
__________________
Daisy Bell
  Reply With Quote
Old 28th May 2006, 08:55 PM   #4
Bazukaz is offline Bazukaz  Lithuania
diyAudio Member
 
Bazukaz's Avatar
 
Join Date: Nov 2005
Location: Vilnius
Send a message via Skype™ to Bazukaz
Hi,
What about leaving the speaker as it is and using a linkwitz rilley to equalise f. response, or using this http://sound.westhost.com/project48.htm
?

In my opinion , sealed box and lighter cone can have better transient response.
Regards,
Lukas.
  Reply With Quote
Old 29th May 2006, 05:50 PM   #5
tubee is offline tubee  Netherlands
diyAudio Member
 
tubee's Avatar
 
Join Date: Jul 2004
Location: Netherlands
Hi Lukas, thanks for reply.

With searching to a diy sub amp, this site came across too, but i did not look at it properly. I Agree with you, a heavy cone with port is allways "later" in time them a light one in a closed box (better transient / impulse performance) I have bass reflex surround speakers, but stuffed the ports.

With this equalizer there is problably no phase switch or pot needed anymore, but not sure about that. (all speakers are and stay in phaze without smearing) And funny enough he uses a 38cm speaker too.
__________________
Daisy Bell
  Reply With Quote
Old 22nd June 2006, 12:22 PM   #6
tubee is offline tubee  Netherlands
diyAudio Member
 
tubee's Avatar
 
Join Date: Jul 2004
Location: Netherlands
Here it is, will put it in a 60L enclosure soon.
Attached Images
File Type: jpg voor%20jan-willem%20009.jpg (30.5 KB, 296 views)
__________________
Daisy Bell
  Reply With Quote
Old 22nd June 2006, 12:26 PM   #7
tubee is offline tubee  Netherlands
diyAudio Member
 
tubee's Avatar
 
Join Date: Jul 2004
Location: Netherlands
Backside, cd is for comparison
Attached Images
File Type: jpg voor%20jan-willem%20008.jpg (34.2 KB, 277 views)
__________________
Daisy Bell
  Reply With Quote
Old 22nd June 2006, 02:58 PM   #8
diyAudio Member
 
Join Date: Dec 2005
Location: silang, cavite
Send a message via Yahoo to audiomachines
hi sir,

I think it is a celestion or a wharfedale model.

regards,
audiomachine
  Reply With Quote
Old 22nd June 2006, 03:22 PM   #9
tubee is offline tubee  Netherlands
diyAudio Member
 
tubee's Avatar
 
Join Date: Jul 2004
Location: Netherlands
Yes Audiomachines, i thougt also this would be a UK (or USA?) manufacturer.
__________________
Daisy Bell
  Reply With Quote
Old 23rd June 2006, 12:24 AM   #10
diyAudio Member
 
Join Date: Jun 2004
Location: Indiana
might want to look here for my evolving plan for a 15" MI driver.

mike
  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
Which amp for speakers with a Fountek Neo Pro 5i and 12 inch woofer boidos Pass Labs 1 24th June 2009 09:10 AM
Vifa 8 inch woofer MTruslow Multi-Way 1 8th January 2009 02:24 AM
four inch woofer enclouser? dallaire Multi-Way 15 20th December 2007 11:07 PM
Best 15 inch Woofer around 500rms?!?! WhiteBoyChriss Multi-Way 19 4th November 2002 12:29 AM


New To Site? Need Help?

All times are GMT. The time now is 10:21 AM.


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