Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Multi-Way Conventional loudspeakers with crossovers

Asymmetrical crossover
Asymmetrical crossover
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 19th March 2017, 05:48 PM   #1
LightBit is offline LightBit  Slovenia
diyAudio Member
 
Join Date: Aug 2016
Default Asymmetrical crossover

Hi, I have a question about asymmetrical order and frequency crossover.

I have Visaton BG 20 "full-range" driver, but since it is very poor above 10kHz I have decided to add tweeter Visaton TW 6 NG.

BG 20 has bump from 1kHz to 9kHz so I came up with idea of using 6db low pass filter at 1kHz on BG 20 and 12db (LR2) high pass filter at 4.5kHz on TW 6. It works quite well in simulation, but I'm worried it might not work well due to some side effects (phase, ...). BG 20 would definitely need notch filter, if used above 1kHz.

Here is simulation:
Click the image to open in full size.

Would this work?
Do you have any considerations or suggestions about this?
  Reply With Quote
Old 19th March 2017, 05:58 PM   #2
eriksquires is offline eriksquires  United States
diyAudio Member
 
eriksquires's Avatar
 
Join Date: May 2013
Hi !

Sure, you can use your low pass filter to also minimize or remove resonances in the woofer.

Your crossover design needs to include the acoustic offsets before you can deal with phase matching properly.

Best,

E
__________________
All of my successes and failures can be explained by my attempts at getting a girlfriend. All of them.
  Reply With Quote
Old 19th March 2017, 06:20 PM   #3
eriksquires is offline eriksquires  United States
diyAudio Member
 
eriksquires's Avatar
 
Join Date: May 2013
I should have answered your question a little more.

Assymetrical crossovers are very common, but the details are driven by phase AND amplitude matching. You will need to examine both closely as you design.

There is a thread in the software section for XSim, which includes some designs. You can use them to learn about what is involved, or you can start here:

https://speakermakersjourney.blogspo...f-version.html

Look at the last two links under "Design Documents"
__________________
All of my successes and failures can be explained by my attempts at getting a girlfriend. All of them.
  Reply With Quote
Old 20th March 2017, 11:00 AM   #4
LightBit is offline LightBit  Slovenia
diyAudio Member
 
Join Date: Aug 2016
I get similar results in XSim.
So, I have to measure acoustic offset first and include it in simulation (as delay).

What about vertical distance between drivers?
For 1kHz it should be 34.6 cm, for 4.5kHz it should be 7.7 cm.
  Reply With Quote
Old 20th March 2017, 04:59 PM   #5
eriksquires is offline eriksquires  United States
diyAudio Member
 
eriksquires's Avatar
 
Join Date: May 2013
Right!

Also make sure the FRD data includes phase, XSim won't create it, and it must be there. Same for your impedance data. So, Distance, FRD/acoustic phase and impedance with electrical phase, all must be in your sim to get accurate results.

There is no absolute requirement of distance. What there is are rules of maximum distance at given frequencies, but these are not set in stone, and often challenged, since they will integrate better with longer listening distances.

Best,

E
__________________
All of my successes and failures can be explained by my attempts at getting a girlfriend. All of them.

Last edited by eriksquires; 20th March 2017 at 05:02 PM.
  Reply With Quote
Old 20th March 2017, 05:07 PM   #6
eriksquires is offline eriksquires  United States
diyAudio Member
 
eriksquires's Avatar
 
Join Date: May 2013
When you have all of this in, reverse the tweeter in your sim and examine the FR. Should create a dip that is deep, wide and symmetrical.
__________________
All of my successes and failures can be explained by my attempts at getting a girlfriend. All of them.
  Reply With Quote
Old 20th March 2017, 05:20 PM   #7
eriksquires is offline eriksquires  United States
diyAudio Member
 
eriksquires's Avatar
 
Join Date: May 2013
BTW, I did not mean to say you should only use XSim. Rather, that any simulation you use to design a crossover should include all this data to reach accurate conclusions.

My examples area all in XSim however.
__________________
All of my successes and failures can be explained by my attempts at getting a girlfriend. All of them.
  Reply With Quote
Old 21st March 2017, 01:15 PM   #8
system7 is offline system7  United Kingdom
diyAudio Member
 
system7's Avatar
 
Join Date: Aug 2008
Location: Portsmouth UK
I don't see why you should use anything but Visaton Boxsim for this.

I had a look at the issues here, and they are fierce.
BG 20 - 8 Ohm
The TW70 seemed a much better idea, BTW.
TW 70 - 8 Ohm

Best idea I saw was a Troels Gravesen project:
Monacor SP200X +

But you're not going to like it. 4th order on First Draft! Lots of impedance correction too. Nothing wrong with that, but hard to build.
Attached Images
File Type: png First Draft Fullrange 8 inch FR.PNG (18.3 KB, 281 views)
File Type: png First Draft Fullrange 8inch TW70.PNG (10.3 KB, 278 views)
__________________
Best Regards from Steve in Portsmouth, UK.
  Reply With Quote
Old 21st March 2017, 08:12 PM   #9
LightBit is offline LightBit  Slovenia
diyAudio Member
 
Join Date: Aug 2016
I didn't use Boxsim and XSim, because they are not for Linux.

TW 70 only gets to ~15kHz, TW 6 NG gets to 20kHz easily.

Hm, looks really good, but such crossover would be too expensive (for cheap drivers). Why two TW 70? For better power handling, because they are crossed low?
  Reply With Quote
Old 21st March 2017, 08:15 PM   #10
LightBit is offline LightBit  Slovenia
diyAudio Member
 
Join Date: Aug 2016
Quote:
Originally Posted by eriksquires View Post
There is no absolute requirement of distance. What there is are rules of maximum distance at given frequencies, but these are not set in stone, and often challenged, since they will integrate better with longer listening distances.
As close as possible would be best than?
  Reply With Quote

Reply


Asymmetrical crossoverHide 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Asymmetrical Synergy Horn Patrick Bateman Multi-Way 12 7th March 2017 05:48 AM
Preamp stage is going very asymmetrical. Why? dfg Instruments and Amps 11 28th February 2015 01:48 PM
Asymmetrical crossover question gainphile Multi-Way 8 13th August 2009 04:39 AM
Asymmetrical amplifier Thoru Solid State 0 26th January 2004 07:00 PM
Aleph asymmetrical clipping? (help) panos29 Pass Labs 9 8th October 2003 11:54 AM


New To Site? Need Help?

All times are GMT. The time now is 01:23 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio
Wiki