jbell's set of four tapped horns - Page 35 - 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 1st July 2010, 06:41 PM   #341
tb46 is offline tb46  United States
diyAudio Member
 
Join Date: Jan 2006
Location: Texas
Default Post #340

And a drawing, 1/2" material is basically the same response:

Regards,
Attached Files
File Type: pdf cube_minus_10_40.pdf (7.6 KB, 529 views)
__________________
Oliver
  Reply With Quote
Old 2nd July 2010, 12:55 AM   #342
jbell is offline jbell  United States
diyAudio Member
 
Join Date: Apr 2003
Location: .
Oliver:
Thanks for the drawings and suggestions. After my episode with a -13db@40hz flh design... I don't think I can ever bring myself to build something that doesn't have lots of oomph at 40hz. The cube is actually breaking new ground for me, as it's a design that can't do 40hz with authority in singles.

I guess the 'flat to 40' habit is hard to break.

great suggestion and layout though.
  Reply With Quote
Old 2nd July 2010, 04:24 PM   #343
FlipC is offline FlipC  United States
diyAudio Member
 
Join Date: Aug 2008
Using letter boxes always seems better.
Just more to build. (which I am a bit lazy)

magent in mouth...
So every TH I have built or theoretically played with has a better PA performance with magnet in mouth. HT setups have been the reverse. But that is probably because we model HT's in quater space rather than half and also that we want HT's to do sub sonics
and 115 DB is good. Vs 130 DB at half space at 40 Hz.

As far as mounting the driver opposite
wall. It becomes the TH Mini then. So it shouldn't cause any effect whatsoever as long as path doesn't change.

Wish I had time to knock one of these out.
Got to finish my other things first.
  Reply With Quote
Old 2nd July 2010, 09:08 PM   #344
tb46 is offline tb46  United States
diyAudio Member
 
Join Date: Jan 2006
Location: Texas
Default Posts #340/341

Hi jbell,

As food for thought I plotted Hornresp SPL and Impulse Response comparison for both boxes. I just don't like that big hole between 160 and 250Hz :-) .

Regards,
Attached Images
File Type: jpg Cube_spl_impulse_comp_small.jpg (55.2 KB, 957 views)
__________________
Oliver
  Reply With Quote
Old 2nd July 2010, 09:12 PM   #345
jbell is offline jbell  United States
diyAudio Member
 
Join Date: Apr 2003
Location: .
Yee Ha !!!!

The cube tests better at 40hz than I would have thought! With no reflectors in, it's a 'little' stuffy at 80hz -- Other than that, 99db@40, 101@50, 101@60, 100@70, 98@80, 99@90, and 100@100. Have to cycle through the 1hz tests yet. (I listen to each 1hz increment with sine waves, to determine what I do and don't like out of a sub.) I also typically 24dbLR low pass at 90-95 hz on my subs, so above 100hz is of little consequence to me. Also, it looks like it is directional, -6db at 120 degree, and about -10 at 180.

From doing this in the past, adding a reflector or two close to the driver will help 80hz at the expense of 40hz...

not sure it's worth it to add reflectors... I'm such a 40hz nut.

The cube gives up 2-3db across the board vs the big cab... But I can tell already that my back will be happier installing.

Last edited by jbell; 2nd July 2010 at 09:39 PM.
  Reply With Quote
Old 2nd July 2010, 09:41 PM   #346
diyAudio Member
 
Join Date: Sep 2008
-12dB at 180* is pretty sweet. Thanks for the measurements. Is it the same for all frequencies?
  Reply With Quote
Old 2nd July 2010, 10:47 PM   #347
diyAudio Member
 
Join Date: Apr 2007
Hey Jim ... Looks like you got another winner !
Did you add any bracing ? How about some pix ?
__________________
Don

Last edited by Don Snyder; 2nd July 2010 at 10:52 PM.
  Reply With Quote
Old 2nd July 2010, 10:57 PM   #348
jbell is offline jbell  United States
diyAudio Member
 
Join Date: Apr 2003
Location: .
Don:
'By accident' in the past, I've come up with better 40hz by not trying to keep the expansion exactly conic when building. Your drawing a few posts back is much more linear than what I did.

Here's some pics with some braces just put in. Have to wait till the glue dries before I know if they affect the sound any or not. I decided against reflectors, and to leave the 40hz alone.
Attached Images
File Type: jpg Picture 166a.JPG (61.2 KB, 948 views)
File Type: jpg Picture 167a.JPG (61.4 KB, 923 views)
  Reply With Quote
Old 2nd July 2010, 11:19 PM   #349
diyAudio Member
 
Join Date: Nov 2007
Quote:
Originally Posted by jbell View Post
The cube tests better at 40hz than I would have thought! With no reflectors in, it's a 'little' stuffy at 80hz -- Other than that, 99db@40, 101@50, 101@60, 100@70, 98@80, 99@90, and 100@100.
Not bad at all! I wonder if the "shading" of the mouth by the driver contributed to the lower F3 point?

What's the external dimensions of the box BTW?
  Reply With Quote
Old 2nd July 2010, 11:21 PM   #350
diyAudio Member
 
Join Date: Nov 2007
Quote:
Originally Posted by jbell View Post
Here's some pics with some braces just put in. Have to wait till the glue dries before I know if they affect the sound any or not. I decided against reflectors, and to leave the 40hz alone.
Those angles are so close to square, I wonder if it's possible get away with implementing it as a stepped tapped-horn instead, with little loss in the passband?
  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
tapped horns - a different perspective & an alternative vasyachkin Multi-Way 58 17th April 2014 04:53 PM
Dampening in Tapped Horns?? atilsley Subwoofers 25 20th June 2009 08:24 AM
how to model tapped horns? weikertball Subwoofers 2 11th January 2009 09:43 PM


New To Site? Need Help?

All times are GMT. The time now is 08:44 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