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 8th January 2012, 12:55 PM   #1301
diyAudio Member
 
Join Date: Jun 2007
Quote:
Originally Posted by tb46 View Post
I found a good source with sound power level and sound pressure level calculators (engineeringtoolbox.com):
Hi Oliver,

This also appears to be an excellent reference:

Loudspeaker Impedance, Series & Parallel Connection Basics — Reviews and News from Audioholics

Kind regards,

David
__________________
www.hornresp.net
  Reply With Quote
Old 8th January 2012, 02:36 PM   #1302
tb46 is offline tb46  United States
diyAudio Member
 
Join Date: Jan 2006
Location: Texas
Hi David,

Looks to me that the radiator size dependent change in radiation resistance V. frequency was not taken properly into account in this article. Also, the table on P.2 seems to indicate that no matter how many times we double the number of radiators in the series connection the output SPL will not change, but the consumed power will divide by 2 for every doubling (if the author's assumptions would hold true for going from 1 speaker to 2 speakers, it should hold true going from 2 to 4, and so on....as long as the speakers are "co-located"); that just doesn't seem likely.

Regards,
__________________
Oliver
  Reply With Quote
Old 8th January 2012, 06:12 PM   #1303
diyAudio Member
 
Join Date: Jan 2008
Quote:
Originally Posted by David McBean View Post
Hi Art,

It seems that it will not be necessary to make any special adjustment for multiple tapped horns - the proposed new multiple speakers response calculation method appears to correct the problem automatically :-).

Kind regards,

David
Good!

It will still likely be years before people don’t expect an increase in LF relative to upper response for multiple TH, but glad that that misconception may be dissuaded once the code change is implemented.

After no response to my questions from Wayne, still wondering how his measured increase of 1.5 dB at 30 Hz for a pair of his FLH compares to the “old” and “new” code ?

Art
  Reply With Quote
Old 8th January 2012, 09:13 PM   #1304
djk is offline djk
diyAudio Member
 
djk's Avatar
 
Join Date: Feb 2001
Location: USA
EAW KF940:

Click the image to open in full size.

(from EAW)
__________________
Candidates for the Darwin Award should not read this author.
  Reply With Quote
Old 8th January 2012, 09:21 PM   #1305
diyAudio Member
 
Wayne Parham's Avatar
 
Join Date: Feb 2004
Quote:
Originally Posted by weltersys View Post
After no response to my questions from Wayne, still wondering how his measured increase of 1.5 dB at 30 Hz for a pair of his FLH compares to the “old” and “new” code ?
Not sure what you're asking for, Art. I posted measurements and Hornresp models, at least in the form that they are links in post 1288. I even wrote where to find what in each link, e.g. "Hornresp models in the following link", "measurements in the following link", and so on.

I always attributed the extra "boost" at low frequencies to the increased mouth size when going from one unit to two. The horn is physically large, but it isn't acoustically large. I would expect this behavior until the group was acoustically large, at around four units for the 12Pi. Same thing happens for LABhorns up to six units. Beyond that, I would expect SPL increases, but not "bass boost" from grouping. Once the FLH group is made acoustically large, it is most efficient all the way through the passband.

Click the image to open in full size.
Single 12Pi v1 Basshorn

Click the image to open in full size.
Pair of 12Pi v1 Basshorns

Click the image to open in full size.
Single Bassmaxx Tripp Basshorn

Click the image to open in full size.
Pair of Bassmaxx Tripp Basshorns

Click the image to open in full size.
Single Tuba 36 Basshorn

Click the image to open in full size.
Pair of Tuba 36 Basshorns

Click the image to open in full size.
Group of four Tuba 36 Basshorns
__________________
Visit the π Speakers website
High-quality audiophile loudspeakers and kits

Last edited by Wayne Parham; 8th January 2012 at 09:38 PM.
  Reply With Quote
Old 8th January 2012, 10:07 PM   #1306
Djim is offline Djim  Netherlands
diyAudio Member
 
Join Date: Dec 2009
Location: 'Ollanda
Click the image to open in full size.
  Reply With Quote
Old 8th January 2012, 11:33 PM   #1307
Djim is offline Djim  Netherlands
diyAudio Member
 
Join Date: Dec 2009
Location: 'Ollanda
Click the image to open in full size.
  Reply With Quote
Old 8th January 2012, 11:59 PM   #1308
NEO Dan is offline NEO Dan  United States
diyAudio Member
 
NEO Dan's Avatar
 
Join Date: Jun 2008
Location: N.E. Ohio
Quote:
Originally Posted by David McBean View Post
Hi Art,

It seems that it will not be necessary to make any special adjustment for multiple tapped horns - the proposed new multiple speakers response calculation method appears to correct the problem automatically :-).

Kind regards,

David
Glad to hear this. Finally a solution that make sense, can't wait.
__________________
Regards,
Dan
  Reply With Quote
Old 9th January 2012, 12:27 AM   #1309
diyAudio Member
 
Wayne Parham's Avatar
 
Join Date: Feb 2004
Thanks, Djim, for bringing the measurements and the models together, side-by-side. Easier to compare than pouring through all the threads linked from post 1288. Looks like there's pretty good agreement between the Hornresp model and the measurements. Beyond the 6dB increase, there's a smidge more from 45Hz to 65Hz and a smidge less from 65Hz to 100Hz. Maybe 1dB more down low and 1dB less up high, a total of ~2dB difference. That's pretty much what the Hornresp model shows, about 2dB less slope in the overall trend.
__________________
Visit the π Speakers website
High-quality audiophile loudspeakers and kits
  Reply With Quote
Old 9th January 2012, 01:00 AM   #1310
Djim is offline Djim  Netherlands
diyAudio Member
 
Join Date: Dec 2009
Location: 'Ollanda
Your welcome Wayne, the differences are very small and in my view based on real life differences such as losses (driver) not represented by the model. However one thing I like to add, the model I used is based on your measurements to get an as close as possible model for 1 cab to see the difference between 1 and 2 cab measurement/modelling.
  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
Here is a Challenge latala Solid State 41 12th May 2011 01:13 AM
Renovation Challenge ZirconiumZephyr Multi-Way 16 1st September 2009 08:38 AM
Design Challenge #1 kgillies Subwoofers 12 13th June 2007 03:20 PM
a challenge --or I need help lawrence99 Car Audio 0 9th March 2005 04:44 AM
The challenge ! thylantyr Solid State 51 24th July 2003 08:41 PM


New To Site? Need Help?

All times are GMT. The time now is 03:02 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