Foam Core Board Speaker Enclosures? - Page 12 - 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 29th November 2012, 07:49 AM   #111
xrk971 is online now xrk971  United States
diyAudio Member
 
xrk971's Avatar
 
Join Date: Oct 2012
Location: Virginia
Nice job! That was a good idea to start from inside, I started from outside to make sure the mouth had a 30 in long piece. Looks awesome! Congratulations on getting the channels completed.
  Reply With Quote
Old 29th November 2012, 07:55 AM   #112
diyAudio Member
 
Join Date: Dec 2010
Location: Coffs Harbour NSW 2450
I started my foamcore project today. Ill have to wait for my internet to be connected before i can upload pics. I just estimated horn length so i hoping it sounds acceptable. Using 4x3inch instwad of the 4inch drivers. They sound fresher than the bigger ones. Which i think will be better suited for what ill be using them for.
__________________
  Reply With Quote
Old 29th November 2012, 07:59 AM   #113
diyAudio Member
 
Join Date: Dec 2010
Location: Coffs Harbour NSW 2450
Just to add its a 75cm horn path and mountng the drivers in the mouth facing out hoping for it to just boost the bass output. Not aiming for deep deep response but a good bass output will be nice.
__________________
  Reply With Quote
Old 29th November 2012, 09:01 AM   #114
xrk971 is online now xrk971  United States
diyAudio Member
 
xrk971's Avatar
 
Join Date: Oct 2012
Location: Virginia
Quote:
Originally Posted by klampykixx View Post
Just to add its a 75cm horn path and mountng the drivers in the mouth facing out hoping for it to just boost the bass output. Not aiming for deep deep response but a good bass output will be nice.

Driver at the mouth like the B&W Nautilus where the horn is acting as an infinite tube? I guess we will see when you post pics. 75 cm has a characteristic freq of only 114 Hz, is that low enough bass for you?
  Reply With Quote
Old 29th November 2012, 09:13 AM   #115
xrk971 is online now xrk971  United States
diyAudio Member
 
xrk971's Avatar
 
Join Date: Oct 2012
Location: Virginia
Quote:
Originally Posted by Cal Weldon View Post
Speaker widow was in a good mood so I got a start. I found it easier to begin on the inside and spiral out, making sure I waited at each corner to catch up with the next piece so as to give my working room but I made sure I used a full piece at the mouth to cut down on visible seams.

I forgot to mention that I also double up on the glue by liberally applying white, or in your case, yellow glue on top of the hot melt just in case there are any cracks that need to be sealed, plus it ensures that if hot melt ever gives you have a backup bond. I assume you are waiting for cap to bond right now. You are right about getting the approval of the OWMBO prior to starting new campaigns.... This particular speaker has a very high WAF though.
  Reply With Quote
Old 29th November 2012, 11:06 AM   #116
diyAudio Member
 
Join Date: Dec 2010
Location: Coffs Harbour NSW 2450
Im not familair of the cab you described but to the "tuning" frequency, no thats not really low enough but it was the longest i could draw up in the space i have as well as keeping it stereo and fitting four drivers in there... Lol it will more than do the job me thinks.
__________________
  Reply With Quote
Old 29th November 2012, 12:40 PM   #117
xrk971 is online now xrk971  United States
diyAudio Member
 
xrk971's Avatar
 
Join Date: Oct 2012
Location: Virginia
Quote:
Originally Posted by klampykixx View Post
Im not familair of the cab you described but to the "tuning" frequency, no thats not really low enough but it was the longest i could draw up in the space i have as well as keeping it stereo and fitting four drivers in there... Lol it will more than do the job me thinks.
75 cm (29.5 in) is actually adequate for a mass loaded transmission line like the TABAQ (circa 32 in) which uses a restriction on terminus to 'mass load' the TL to bring the resonant tuning frequency down to about 55 Hz. You really should take a look at the TABAQ TL thread. The design has been built by many folks over the years (I think the thread has like 130,000 views) and was designed for small 3 to 4 in drivers to get deep bass. Your requirement of 4 drivers does make it more difficult to fit all that in.

The design can be found here:

http://coolcat.dk/bjoern/TABAQ_TL_for_TB.pdf

http://www.coolcat.dk/bjoern/TABAQ%2...et%20build.pdf
  Reply With Quote
Old 29th November 2012, 12:45 PM   #118
Speakerholic
diyAudio Moderator
 
Cal Weldon's Avatar
 
Join Date: Jan 2004
Location: Near Vancouver
Quote:
Originally Posted by xrk971 View Post
I assume you are waiting for cap to bond right now.
Goodness no. WYSIWYG, I will try and do the other spiral today. We'll see about doing the caps. Yes, I used some hot glue where there are gaps but I'm not too worried, there is a similar SPL on either side of the channels inside the the horn isn't there?
__________________
Next stop: Margaritaville
Some of Cal's stuff | Cal Weldon Consulting
  Reply With Quote
Old 29th November 2012, 01:18 PM   #119
xrk971 is online now xrk971  United States
diyAudio Member
 
xrk971's Avatar
 
Join Date: Oct 2012
Location: Virginia
It's not about SPL (as there is very little pressure build-up in horns in general since they are so open) but I worry about small air leaks which can cause the low frequencies to have a hard time in establishing a standing wave. If you have played a flute or any other woodwind instrument you know that a tiny leak on the finger seal above the low note you are trying to play causes the note to collapse. I am just being careful and using plain hot melt is fine as long as there are no obvious leaks.
  Reply With Quote
Old 29th November 2012, 01:38 PM   #120
Speakerholic
diyAudio Moderator
 
Cal Weldon's Avatar
 
Join Date: Jan 2004
Location: Near Vancouver
I tried to be careful and added extra where I saw gaps as I went along so I'm hoping I have done it well enough.
__________________
Next stop: Margaritaville
Some of Cal's stuff | Cal Weldon Consulting
  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
Speaker damping: Foam or expanding foam akunec Multi-Way 4 11th February 2014 01:14 AM
Replace speaker foam with this odd material? flyingsquirrelman Subwoofers 7 25th July 2010 01:32 PM
concrete board for enclosures? alandarkdale Multi-Way 6 31st March 2007 08:35 AM
Foam core construction for subwoofers morbo Subwoofers 19 30th August 2005 08:09 PM
speaker foam dave k Multi-Way 2 24th June 2003 05:05 AM


New To Site? Need Help?

All times are GMT. The time now is 01:01 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