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

Figuring out speaker properties + Building enclosure
Figuring out speaker properties + Building enclosure
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 16th July 2018, 04:47 PM   #1
ledman is offline ledman  Germany
diyAudio Member
 
Join Date: Jul 2018
Default Figuring out speaker properties + Building enclosure

Hey everyone Completely new to building audio stuff, sorry for the wall of text ahead of time - lots of noob questions

I have two 15" GBS 1566 subwoofer chassis that fell into my lap, and i have no clue what exactly their properties are - can't find much info on the internet either.

Screenshot - 94d85bb81e40abe6602200b1d63c5edc - Gyazo Screenshot - ddb04cc11e05e655d6e72bee5ebc6dce - Gyazo

Some general questions i have are, how would i best clean these? The guy i got them from said they were sitting around for a good while, the back side of the cone and the inside of the surround is super dirty - just wipe with wet towel? the backside of the cone feels like paper mache and i am worried that they could get deformed when wet? I also assume there is some dirt inside the magnet gap and the little vent on the back - can i just remove the shiny plate? Is that just shielding or will the motor fall apart if i do that and force me to re-align everything?

Things i know about them are that they have dual 4 Ohm voice coils (3" i think) and have 1000W printed on them. I found some dodgy info online stating they do 600W rms but that is about it

I haven't dared to turn them past around 300W RMS each because the free air excursions at some frequencies are enormous and i am worried of smashing the voice coil into the magnet.
On one of them one of the tinsel leads smacks into the back of the cone at higher powers, barely happens when playing music but very noticeable on raw sinewaves - any recommendations on how to fix that?

The dustcap on one of them is slightly peeling off (still sealed and seems solid, just a spot that got unglued) - any glue recommended for fixing this?

i didn't do an exact measurement on this yet but they appear to resonate somewhere between 30 and 31hz, I estimate the Xmax to be slightly over 30mm but i am not certain on that, not sure how to measure it either.

How would i go about determining the properties of the chassis or size for a sealed box? I want to build two seperate sealed sub enclosures, maybe build something horn loaded later. I also considered Dipole but i think i'd rather have stereo bass. They will be mostly used for music.

I also want to change color of the cone and the surround at some point, can i just get an off the shelf black 15" surround and replace the blue one on these? I'd spray paint or airbrush the cones themselves since it's not like i am messing up any special characteristics by slightly increasing cone mass, given there are no specs anyways.

Last edited by ledman; 16th July 2018 at 05:31 PM.
  Reply With Quote
Old 16th July 2018, 07:10 PM   #2
Galu is offline Galu  Scotland
diyAudio Member
 
Join Date: Apr 2018
Welcome ledman!

Here are some answers for starters:

Do not wet the cones - remove dust with a soft brush only.

Do not touch the vent - hopefully no dust has got into the gap - for experts only!

Do not test the drivers at high power if not mounted in a cabinet, and certainly not with sine waves - you will overload the speaker (hence the tinsel lead smacks!).

Use Aileen's tacky glue, or similar, on dustcap.

Last edited by Galu; 16th July 2018 at 07:12 PM.
  Reply With Quote
Old 16th July 2018, 10:13 PM   #3
ledman is offline ledman  Germany
diyAudio Member
 
Join Date: Jul 2018
Alright cool
yeah i figured if it doesn't sound right it probably isn't right.
Any rough volume figures i can use for a test cabinet build?
(thinking a test cabinet made of particle board because it's basically free)

I do have experience in constructing various things, and have a good amount of metal and woodworking tools available, could also CNC some stuff.

I am pretty convinced whatever is on the surround has also gotten into that vent given how the insides of the surround look
you can see on the left how it's basically brown instead of blue like on the right Screenshot - a80d55bee8cf1cca51775789f33ffe5c - Gyazo
it is very fine sticky dust, doesn't feel very abrasive though.

So the 6 bolts on the back with the plate actually clamp the magnet to the frame?
  Reply With Quote
Old 16th July 2018, 11:00 PM   #4
MAAC0 is offline MAAC0  Portugal
diyAudio Member
 
Join Date: May 2010
Ledman


Those seem to be car subwoofers. I would try them first without a cabinet attached to the back seat of Your Volkswagen.
  Reply With Quote
Old 16th July 2018, 11:24 PM   #5
Galu is offline Galu  Scotland
diyAudio Member
 
Join Date: Apr 2018
If there was any contamination in the magnet gap, you would hear a scraping sound as you gently push on the woofer cone. If not, then leave well enough alone.

I would not undo those bolts for the reasons you, yourself, have stated!

Use a test cabinet volume of at least 2 cubic feet for one 15" driver..

We would need to know the specifications of the driver to design a final enclosure - the only references I can find are in German (picclick.de) but no parameters are given.

Last edited by Galu; 16th July 2018 at 11:28 PM.
  Reply With Quote
Old 16th July 2018, 11:32 PM   #6
Galu is offline Galu  Scotland
diyAudio Member
 
Join Date: Apr 2018
And yes, they are car subs!

Basic information:

96dB/W; 2 x 600W rms; 20 - 1,500Hz; two x 3" voice coils; 150oz magnet; 12.6kg

Last edited by Galu; 16th July 2018 at 11:42 PM. Reason: Extra info
  Reply With Quote
Old 16th July 2018, 11:49 PM   #7
ledman is offline ledman  Germany
diyAudio Member
 
Join Date: Jul 2018
Thanks for the advice so far.
I am not sure what you mean MAAC0, in which orientation? just zip ties to the headrest?
Yeah I know they are car subs - i am not going to use them in a car though.
They will be driven by a Crown 1400 CSL and annoy my neighbors

I don't have a datasheet for them either, will measure them as described here the next few days.

Will build a 60L cabinet and see what happens
  Reply With Quote
Old 18th July 2018, 09:02 PM   #8
ledman is offline ledman  Germany
diyAudio Member
 
Join Date: Jul 2018
Alright so i built two enclosures from 19mm particleboard
Screenshot - f6af7050679fd4ffefd609125bd0773b - Gyazo
Screenshot - 59cbbf7db3f644f2cc78c951aec9f0ee - Gyazo

The drivers came with this rubbery gasket/decoupler thing, i didn't have anything else on hand so i used some washers and wood screws to bolt the them in, don't like the way i had to squeeze it down to have a seal - any recommendations to get this to seal properly without feeling absolutely wrong? ring/trim over the whole rim to apply even pressure?
Screenshot - 1763509f110341c359edd8c0b7259af9 - Gyazo

I am still getting the tinsel smack on one of the drivers, even at fairly low levels - the tinsel lead in question is very close to the membrane by default (maybe 1mm gap, it's as if it is bent the wrong way, keeps going back into that position)

can i use some kind of glue to change the angle at which it sticks out of the membrane?
  Reply With Quote
Old 19th July 2018, 12:16 AM   #9
phivates is offline phivates  United States
diyAudio Member
 
Join Date: Jan 2011
Location: Willamette Valley
Good question - something both stiff and flexible is called for, and quick setting unless you can hold the tinsel lead in place while something like acrylic caulk cures. A common problem with cheaper drivers...
  Reply With Quote
Old 19th July 2018, 02:00 AM   #10
GM is offline GM  United States
diyAudio Member
 
GM's Avatar
 
Join Date: Jun 2003
Location: Chamblee, Ga.
Quote:
Originally Posted by ledman View Post
I am still getting the tinsel smack on one of the drivers, even at fairly low levels - the tinsel lead in question is very close to the membrane by default (maybe 1mm gap, it's as if it is bent the wrong way, keeps going back into that position)

can i use some kind of glue to change the angle at which it sticks out of the membrane?
Use a proper mounting gasket on the rear flange.

These folks have an assortment of quick setting glues: Aleene’s Glue Products | Craft & DIY Project Adhesives - Industrial Strength Glue

GM
__________________
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
  Reply With Quote

Reply


Figuring out speaker properties + Building enclosureHide 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
Help figuring out the Silent Speaker EmuMannen Multi-Way 55 30th May 2016 11:56 PM
Building an enclosure for an unknown speaker? KHesse Parts 4 10th November 2014 02:31 PM
need help with figuring out the connections on an old speaker yourownfree Multi-Way 12 21st December 2009 09:12 AM
Figuring out speaker problems bg4533 Multi-Way 4 22nd August 2005 06:38 PM
building an enclosure atnaat Subwoofers 16 28th June 2005 05:49 AM


New To Site? Need Help?

All times are GMT. The time now is 04:50 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki