Anyone ever attempted an 8th order bandpass? - 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 22nd June 2015, 09:32 PM   #1
diyAudio Member
 
Join Date: Nov 2009
Default Anyone ever attempted an 8th order bandpass?

Since david updated hornresp I'm curious on this one....

How were the results?
  Reply With Quote
Old 22nd June 2015, 09:54 PM   #2
sreten is offline sreten  United Kingdom
diyAudio Member
 
Join Date: Nov 2003
Location: Brighton UK
Hi,

AFAIK practical bandpasses go up to 6th order.

rgds, sreten.
__________________
There is nothing more practical than a really good theory - Ludwig Boltzmann
When your only tool is a hammer, every problem looks like a nail - Abraham Maslow
  Reply With Quote
Old 22nd June 2015, 11:16 PM   #3
GM is offline GM  United States
diyAudio Member
 
GM's Avatar
 
Join Date: Jun 2003
Location: Chamblee, Ga.
Hmm, the original Karlson [K15] is a practical 8th order alignment.

GM
__________________
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
  Reply With Quote
Old 23rd June 2015, 01:31 AM   #4
diyAudio Member
 
Join Date: Jan 2008
Location: Toronto and Delray Beach, FL
Quote:
Originally Posted by GM View Post
Hmm, the original Karlson [K15] is a practical 8th order alignment.

GM
Is it true to say that with enough alignments, you can model anything however complex?

Ben
__________________
Current projects: motional feedback woofing and large ESL panels. HiFi aspirations since 1956
  Reply With Quote
Old 23rd June 2015, 01:36 AM   #5
GM is offline GM  United States
diyAudio Member
 
GM's Avatar
 
Join Date: Jun 2003
Location: Chamblee, Ga.
Sure, AkAbak uses definable ducts you chain together to create as many series, parallel interlocking chambers as you want.

GM
__________________
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
  Reply With Quote
Old 23rd June 2015, 02:01 AM   #6
diyAudio Member
 
Join Date: Nov 2007
I'd love to try one, just to see what the design process is like and how accurate the sims are.

My concern is that the HornResp sim doesn't include the impact of losses, and there's also the question of port lengths being affected by their actual position in the box, something that's not addressed in Hornresp.

It's Ok if you design for A and get something approximately like A, which is what happens when most people use Hornresp for designing bass horns. It's another thing to design for A and get B, something totally different, due to an "accumulation of errors" caused by what I indicated above.

There's also the question of design methodology, i.e. how would be your start point for designing such a thing? e.g. given a particular driver, how would you go about designing the best 8th order BP for it? How does one choose a driver for such an alignment anyway?
__________________
www.diysubwoofers.org
  Reply With Quote
Old 23rd June 2015, 05:47 AM   #7
diyAudio Member
 
Matthew Morgan J's Avatar
 
Join Date: May 2011
Location: Arizona
Lightbulb For what it's worth


I have toyed around with the idea of 8th order alignments and i came up with a few good sims, and possible foldings and layouts .... I mentioned it over at the Mass Loaded Transflex / Karlflex discussion a few times but never got around to building one of these 8th order cabs ...

As far as drivers are concerned, Low VAS , Mid Q drivers with strong motors seem to work well for this .... Beyma 15p1200ND/n , B&C 18TBW100 , Eminence Definimax 4012 , and dual Alpine SWE-10S4 (no longer available) all simulated very well in this type of cabinet .. .

Efficiency and output is decent for a smallish box however this is not the design of choice if you are shooting for extreme bass extension or ultimate cone control ..... This design is all about efficiency in a cabinet that would be smaller than a FLH for a given driver .... According to simulations this design looks like it competes well in terms of size/performance when compared to other popular DIY configurations such as Tapped Horns, but real world performance has yet to be tested because nobody has built one yet..

Click the image to open in full size.

Click the image to open in full size.

Click the image to open in full size.

Click the image to open in full size.

Click the image to open in full size.
  Reply With Quote
Old 23rd June 2015, 07:58 AM   #8
diyAudio Member
 
Join Date: Jun 2007
Quote:
Originally Posted by Brian Steele View Post
My concern is that the HornResp sim doesn't include the impact of losses, and there's also the question of port lengths being affected by their actual position in the box, something that's not addressed in Hornresp.
Hi Brian,

As indicated some time ago in my Post #5472 on the Hornresp thread, the predictions should hopefully be reasonably accurate at bass frequencies. We won't know for sure though, until some brave soul decides to have a go at building and testing one :-).

For some reason, I gained the impression that these alignments were being used for car sub-woofer designs, but perhaps I was mistaken in thinking this. I am starting to wonder why the feature was requested at all, if no one is building these speakers. I hope I didn't spend time developing new simulation models that nobody intends using :-).

Kind regards,

David
__________________
www.hornresp.net
  Reply With Quote
Old 23rd June 2015, 07:20 PM   #9
GM is offline GM  United States
diyAudio Member
 
GM's Avatar
 
Join Date: Jun 2003
Location: Chamblee, Ga.
Hmm, I thought it was requested to sim K15s except with a basic vent cutout, then use the cutout's area to reshape it to an expo, hypex/whatever Karlson slot without having to resort to using AkAbak or at least getting 99% of it into AkAbak to fine tune the K-slot.

It can also be used to extend a TH's [6th order] usable BW, so between the two it seems a worthy upgrade if folks can figure out how to input it and use the LW to tweak it.

GM
__________________
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
  Reply With Quote
Old 23rd June 2015, 07:26 PM   #10
freddi is offline freddi  United States
diyAudio Member
 
freddi's Avatar
 
Join Date: Aug 2005
it should do a good job of catching K15's characteristics where it counts - I'm not feeling well enough to give a go - it should be great to make general predictions to avoid wasting wood with new K's

K15 by Carl's estimation

vf = 2.3 cu ft
vb = 4.0 cu ft (before driver displacement)
sb = 32 sq inches
sf = 222 sq inches

The rear shelf creates a port area of 52.5 sq inches with the back of the cabinet.

The front shelf creates an area of 73.5 sq inches with the front panel.

Last edited by freddi; 23rd June 2015 at 07:30 PM.
  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
How to build DIY 8th order 48db active crossover?? Hybrid fourdoor Multi-Way 16 25th April 2014 03:52 PM
LR 4th order vs LR 8th order crossover redliner Subwoofers 1 7th January 2009 11:32 PM
Problems with calculating an 8th order (SubSim) zoofelix Subwoofers 3 27th January 2006 11:29 PM
4 Sale 36pcs LM2876/LM3886 + 8th order active crossover Bent Swap Meet 10 31st March 2005 11:44 AM
6th-order Bandpass BAM Subwoofers 1 24th September 2001 05:51 PM


New To Site? Need Help?

All times are GMT. The time now is 03:29 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2015 DragonByte Technologies Ltd.
Copyright 1999-2015 diyAudio

Content Relevant URLs by vBSEO 3.3.2