2.5-way crossover design - Page 2 - diyAudio
Go Back   Home > Forums > Loudspeakers > Multi-Way

Multi-Way Conventional loudspeakers with crossovers

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 16th July 2008, 04:40 PM   #11
sreten is offline sreten  United Kingdom
diyAudio Member
 
Join Date: Nov 2003
Location: Brighton UK
Quote:
Originally posted by Puppetnation

I was believing , due to common designs have both woofers sharing the first LP stage, they were parallel (also if actually only in the overlapping freq. range), that's why...
.

thanks
Hi,

They can share the mid/treble LP stage but at the c/o point the 0.5
way should well down due to the series 0.5 way inductor and so
high impedance, not affecting much the other drivers impedance.
That is : the c/o is much nearer one driver values than 2 parallel.

FWIW 2.5ways can be problematic if the drivers are
not suitable, hence presumably JWJ's question.

/sreten.
  Reply With Quote
Old 16th July 2008, 04:48 PM   #12
diyAudio Member
 
Join Date: Jun 2007
Well, I'm no expert certainly, but I think we need some clarification.

Are you starting with two bass speakers and a tweeter, and later planning to add a third bass speaker, OR are you planning to later convert the second existing bass speaker to the new .5 aspect of your speaker system?

If you are adding a third woofer to convert from a 2.0 to a 2.5 that is a completely different ballgame than using the existing two woofers in a 2.0 and later converting those same two woofers from a 2.0 into a 2.5.

I would say that if you are adding a third woofer for the .5 aspect, then you can calculate the 2.0 crossover aspect now and it should work later.

But if you are going to convert one of the existing woofers to the .5 aspect, then the load impedances on the crossover completely change and the original 2.0 crossover is worthless.


Or am I missing something?

Steve/bluewizard
  Reply With Quote
Old 16th July 2008, 05:51 PM   #13
diyAudio Member
 
Join Date: Apr 2007
Here is how I have done it. I use a cascaded XO layout for the woofers. AFAIK, Jeff Bagby was the first DIYer I remember using this.

I use a low pass for the full range woofer and off the driver side of the XO I cascade the .5 way XO and driver. What this does is give me the roughly first order low pass for the .5 way driver, which then transitions to a steeper slope as it approaches the MT XO point.

Zaph uses this approach in his new ZRT design (the 2.5 way version) seen here:

http://www.zaphaudio.com/ZRT.html

Please note though that this isn't something that can be gotten right with just textbook formulas. Getting the proper baffle step compensation along with proper integration of the mid and tweeter really requires actual measurements and XO software.

Regards,

Dennis
  Reply With Quote
Old 16th July 2008, 09:58 PM   #14
diyAudio Member
 
Join Date: Mar 2008
Quote:
Originally posted by Jay_WJ
What kind of drivers are you working with?
Two Morel MW166 and one Morel MDT32S

Cabinet total volume is 33 liters, divided in 2 x 16.xx liters separate chambers, sealed.
  Reply With Quote
Old 16th July 2008, 10:00 PM   #15
diyAudio Member
 
Join Date: Mar 2008
Quote:
Originally posted by BlueWizard
.....are you planning to later convert the second existing bass speaker to the new .5 aspect of your speaker system?

....

But if you are going to convert one of the existing woofers to the .5 aspect, then the load impedances on the crossover completely change and the original 2.0 crossover is worthless.

Steve/bluewizard
That's right!
tnx
  Reply With Quote
Old 16th July 2008, 10:28 PM   #16
tpsorin is offline tpsorin  Romania
diyAudio Member
 
Join Date: Jun 2005
Location: Timisoara
You can use a program that "knows" 2.5 way. Like "Passive Crossover Designer". It is a excel sheet. Excellent.
No need to design a 2way than add 0.5.

Don't use directly the driver graphs from data_sheet. Measure the drivers on actual baffle. If you have no measurement microphone than use a baffle simulator. You can find all tools at http://www.pvconsultants.com/audio/frdgroup.htm
  Reply With Quote
Old 17th July 2008, 11:46 AM   #17
sreten is offline sreten  United Kingdom
diyAudio Member
 
Join Date: Nov 2003
Location: Brighton UK
Quote:
Originally posted by Puppetnation


Two Morel MW166 and one Morel MDT32S

Cabinet total volume is 33 liters, divided in 2 x 16.xx liters separate chambers, sealed.

Hi,

Have you bought the drivers ? If so no comment, but if not .....

/sreten.
  Reply With Quote
Old 17th July 2008, 01:57 PM   #18
diyAudio Member
 
Join Date: Mar 2008
Quote:
Originally posted by sreten



Hi,

Have you bought the drivers ? If so no comment, but if not .....

/sreten.

I just own one pair of MW166, the rest will come.

They're among the few midwoofers good for a sealed enclosure (nowadays most loudspeakers are made with bass-reflex in mind).

Other stuff (Dyns, Eton etc.) were too expensive for me.

Anyway, please express your opinion, I'm here to learn...
  Reply With Quote
Old 17th July 2008, 03:07 PM   #19
diyAudio Member
 
AdamThorne's Avatar
 
Join Date: Oct 2006
Location: Los Angeles, CA
On the topic of 2.5 cross design, but off of the current project...

Can you make a series .5 cross design? For example if you have two 4 ohm drivers? I was thinking you might just bypass one driver with a cap, but then I wondered if that would screw up the rest of the setup.

Just wondering.
  Reply With Quote
Old 17th July 2008, 03:47 PM   #20
sreten is offline sreten  United Kingdom
diyAudio Member
 
Join Date: Nov 2003
Location: Brighton UK
Quote:
Originally posted by Puppetnation



I just own one pair of MW166, the rest will come.

They're among the few midwoofers good for a sealed enclosure
(nowadays most loudspeakers are made with bass-reflex in mind).

Other stuff (Dyns, Eton etc.) were too expensive for me.

Anyway, please express your opinion, I'm here to learn...

Hi,

Well actually it is not my opinion, check out the test of
the MW166 at zaphaudio.com , its not great at $107.

I do not know of any independant test of the $80 MDT32S,
the known / tested benchmarks for DIY softdome tweeters
are the $40 Seas 27TDFC / and $80 Peerless 810921.

/sreten.
  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 do you design a crossover?????? legendaryfrog Multi-Way 25 19th November 2006 09:23 PM
I need to design a crossover. j.burtt Multi-Way 3 11th May 2006 09:10 AM
crossover design keroo Multi-Way 1 1st May 2005 12:03 AM
crossover design Dave Jones Multi-Way 10 21st September 2003 07:38 PM
Crossover design Bose(o) Multi-Way 23 11th February 2002 07:22 AM


New To Site? Need Help?

All times are GMT. The time now is 10:07 PM.


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