My sub project - 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 20th August 2009, 03:51 PM   #1
diyAudio Member
 
Join Date: Jun 2009
Location: Montreal, Qc
Default My sub project

My first post about this has been deleted from the Upgrade Island... I guess I'll need to retype it and restart all over again (kind of sucks).
I am planning to build my 2nd diy project which is a 12'' powered sub. I am not looking for 'WOAH!' stuff but more of a 'cool that sounds good' sub that's why I'm not going to build a 500W sub.
This is the amplifier that I want to put in:
http://www.parts-express.com/pe/show...number=300-784
This will power this Dayton driver:
http://daytonaudio.com/files/specs/S..._specsheet.pdf
It's only 51$ on Parts express and it was the one that looked the best on WinISD.
The enclosure will be vented with two 1,75'' port of 3,75'' long in an enclosure with exterior dimensions of around 20" H x 16'' W x 14,75'' D.

This should be around 70L or 2.4cu ft. This sounds awfully big for an enclosure but I guess it's ok for a 12''.

Alright... on my first post which disappeared I was talking about the bracing with another member. I wasn't able to read his last posts on it so that's why I have recreated this one. I have learned that the filling should mostly be acoustic foam on the walls and not so much polyfill since it'S a ported enclosure.
I'm not too sure about the bracing : chris661 told me that making this:

brace.bmp
on the picture it's only 2D but it would be the same thing vertically to create a type of half sphere behind the driver. IMO it's very good but since I only have 70W of power maybe it takes up some volume ( and I don't want a bigger box) and is a little too solid?
I was thinking something more like this (once again it's in 2D but would be the same vertically) : untitled.JPG
Any opinons? Have anyone used this driver before? any ameliorations? comments?
Thanks in advance

EDIT:
on PE it says that all the parameters I have used to 'design' this are wth both voice coils in parallel. And since impedance is 8 ohm per coil does this mean that total impedance would be 4 ohm? s this how I need to connect it(sorry for awful image) :P.bmp

Last edited by fouchagalaga; 20th August 2009 at 04:02 PM.
  Reply With Quote
Old 20th August 2009, 08:42 PM   #2
diyAudio Member
 
chris661's Avatar
 
Join Date: Feb 2008
Location: Sheffield
Blog Entries: 8
You nearly got the bracing right - needs bringing in a bit (in the middle) so one piece (symmetrical) slots between so you can glue it. Your wiring is correct.

When it comes to large drivers and bracing, more is always more. If you screw it in to test it, you can remove it again afterwards, to see if it makes a difference.

Like I've said before - this is your design, we can only suggest.

Chris
Attached Images
File Type: jpg Bracing.JPG (66.2 KB, 258 views)
__________________
"Throwing parts at a failure is like throwing sponges at a rainstorm." - Enzo
My setup: http://www.diyaudio.com/forums/multi...tang-band.html
  Reply With Quote
Old 20th August 2009, 09:40 PM   #3
diyAudio Member
 
Join Date: Jul 2007
I have used the 10 inch version of that driver with reasonable results. Wiring the 2 voice coils in parallel however created too low of an impedance for the amplifier which failed. I have since put a 10 watt 4 ohm resistor in series to protect the amplifier. I used the 10" DVC in left and right subwoofers and I equalized the bass response with an Audio Control Richter Scale electronic crossover/bass equalizer. I would strongly recommend some sort of 1/2 octave equalization to optimize your bass response.
  Reply With Quote
Old 21st August 2009, 11:21 PM   #4
diyAudio Member
 
Join Date: Jun 2009
Location: Montreal, Qc
Thanks chris for the response! I guess your bracing is better.... it's the same as the one I've shown (2nd image) but just more solid. The only thing is... since I have an amp in the back poking out, do I actually glue it to the back? or do I make it like I have shown (1st image) also, my driver will not be centered. 2'' from top and 10'' from bottom (where the 2 ports will be). Will the bracing affect anythng?

And what's a 1/2 octave equalizer? Does the amp I am using have anything similar to that?
Will the impedance be lower than 4 ohm if wired in parallel? (I wouldn't think so, but maybe?) the amp should be able to take it right?

Last edited by fouchagalaga; 21st August 2009 at 11:23 PM.
  Reply With Quote
Old 22nd August 2009, 06:49 AM   #5
diyAudio Member
 
chris661's Avatar
 
Join Date: Feb 2008
Location: Sheffield
Blog Entries: 8
Don't worry about the driver being off-centre. WRT the ports - drill holes around 3" diameter in various places along the pieces of bracing, so the air isn't trapped in the sections made by the bracing (in a sealed box, it wouldn't matter so much) like this, but it will be a far simpler design.

Click the image to open in full size.

The amp - to make sure the whole thing works before attacking the amp, run the speaker wire out of one of the ports, plug the amp in and give it a test. Then you can decide if you want to attach the amp to the sub.

Chris
__________________
"Throwing parts at a failure is like throwing sponges at a rainstorm." - Enzo
My setup: http://www.diyaudio.com/forums/multi...tang-band.html
  Reply With Quote
Old 22nd August 2009, 10:25 PM   #6
diyAudio Member
 
Join Date: Jun 2009
Location: Montreal, Qc
hmm.. very good thanks chris661 I now feel like I'm a bracing expert. If I have any questions I'll ask. If not, anyone else have comments?
  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
CDPRO2 Group Project (open source project) BrianGT Digital Source 147 8th August 2008 11:37 AM
My OLD Project....... cheap tube audio project!!! tube-lover Tubes / Valves 4 8th May 2008 09:26 PM
first project ceebmoj Full Range 5 23rd January 2008 07:51 AM
My first project, cool project. sorinsistem Solid State 3 19th January 2006 05:08 PM


New To Site? Need Help?

All times are GMT. The time now is 03:13 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