NEWBIE Need help with a two way 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 10th November 2012, 09:52 PM   #11
just another
diyAudio Moderator
 
wintermute's Avatar
 
Join Date: Aug 2003
Location: Sydney
Blog Entries: 22
well if you were using ruler flat FR's then something is going very wrong with the modeling!

I just put your first circuit into speaker workshop with my DMS37 tweeter FR and Impedance (real in box measurements) and I see NO peaking at all. The only thing that is off is that speaker workshop is boosting the higher frequencies by around 2db (which I see every now and then and I think is a bug).
FR plots below. Blue is original raw response. Black is with your filter. Second image is with black adjusted to reflect reality (with respect to the levels).

I didn't model the bass part of the circuit, so I guess it might be interacting...

edit: ok I added my MW144's (with impedance double to nominally 8 ohms) and put in the bass part of the circuit as well. Note that the tweeter response is 2db higher than what it would be in real life. Surprisingly good all things considered, and NO peaking... all inductors were modeled with zero series resistance as per the OP, but realistically they should have at least 0.1ohms.

Tony.
Attached Images
File Type: png response1.png (26.0 KB, 58 views)
File Type: png response2.png (25.5 KB, 54 views)
File Type: png tweeter_network.png (8.7 KB, 54 views)
File Type: png full_network.png (31.9 KB, 53 views)
__________________
Any intelligence I may appear to have is purely artificial!
Some of my photos

Last edited by wintermute; 10th November 2012 at 10:10 PM. Reason: added full network...
  Reply With Quote
Old 11th November 2012, 05:21 PM   #12
diyAudio Member
 
Join Date: Jul 2004
Location: Austin, TX
ok , first of all thanks everybody for your help ...
after a bad start i start over with 2 included drivers in boxsim
visaton al170 and ke25sc as tweeter .
I chose crossover point for 2000hz and start with it , after i put my calculations in sw and after adding some filters anywhere i saw a peak () here s the results , what do you think ? and how it can go simpler and better and why ..
thanks in advance

edit : there s a peak around 6200 that s annoying me , i know it s the tweeter respond but can i get rid of it ?

again thanks all
Attached Images
File Type: jpg freq respond.jpg (165.0 KB, 53 views)
File Type: jpg Crossover.jpg (125.7 KB, 19 views)
__________________
Marge, don't discourage the boy! Weaseling out of things is important to learn. It's what separates us from the animals! Except the weasel.

Last edited by Ahmad_tbp; 11th November 2012 at 05:24 PM.
  Reply With Quote
Old 11th November 2012, 06:09 PM   #13
system7 is offline system7  United Kingdom
diyAudio Member
 
system7's Avatar
 
Join Date: Aug 2008
You're getting the hang of it, Ahmad. The amazing "optimise" button helps too!

I got something not a million miles away. 20L cabinet. Of course, I lost the stupid LCR filter on the tweeter. It has one built in, as it goes. Just the 6kHz bass notch needed. Give you a tip. Take out the resistor on the bass notch to see where it hits.

Your crossover is a bit low, IMO. But that particular tweeter might get away with it. Keep an eye on phase, and try to get the impedance as high as possible. It makes life easier for the amp.
Attached Images
File Type: png Visaton_AL170_crossover.PNG (15.9 KB, 16 views)
File Type: png Visaton_AL170_FR.PNG (21.3 KB, 12 views)
File Type: png Visaton_AL170_Phase.PNG (24.0 KB, 9 views)
__________________
Good Night, and Good Luck. Best regards from Steve in Portsmouth, UK.
  Reply With Quote
Old 11th November 2012, 07:42 PM   #14
diyAudio Member
 
Join Date: Jul 2004
Location: Austin, TX
Quote:
Originally Posted by system7 View Post
You're getting the hang of it, Ahmad. The amazing "optimise" button helps too!

I got something not a million miles away. 20L cabinet. Of course, I lost the stupid LCR filter on the tweeter. It has one built in, as it goes. Just the 6kHz bass notch needed. Give you a tip. Take out the resistor on the bass notch to see where it hits.

Your crossover is a bit low, IMO. But that particular tweeter might get away with it. Keep an eye on phase, and try to get the impedance as high as possible. It makes life easier for the amp.
mmm , very interesting , i know it ll sound stupid but i didn't think of a third order crossover for tweeter ... lemme redo all that again
__________________
Marge, don't discourage the boy! Weaseling out of things is important to learn. It's what separates us from the animals! Except the weasel.
  Reply With Quote
Old 11th November 2012, 07:59 PM   #15
diyAudio Member
 
mondogenerator's Avatar
 
Join Date: Sep 2009
Location: City Of Villans
Blog Entries: 1
i agree with Steve, 2khz is too low for the KE20.

In my tower I found the G20SC and KE20 almost interchangable. The G20SC is actually flatter in my design so the option for the KE got shelved.

I used 5uF and 0.33mH for 2nd order, L pad on the driver side.

A small tip. I always add an R to every component, in series, sometimes in parallel or T filter configuration. As steve says the 'Optimise' button is useful, as long as you optimise a couple of components at a time. The extra Rs I add can either stay or are removed depending on if theyre worthwhile.
__________________
Every new piece of knowledge pushes something else out of my brain - Homer.....................Simpson

Last edited by mondogenerator; 11th November 2012 at 08:06 PM.
  Reply With Quote
Old 11th November 2012, 08:11 PM   #16
diyAudio Member
 
Join Date: Jul 2004
Location: Austin, TX
took out the bass resistor
__________________
Marge, don't discourage the boy! Weaseling out of things is important to learn. It's what separates us from the animals! Except the weasel.
  Reply With Quote
Old 11th November 2012, 08:16 PM   #17
diyAudio Member
 
Join Date: Jul 2004
Location: Austin, TX
i tried to tweak it for a while and that was my best result (until steve showed me the bright light ) it s my very first try and even that i m trying to tweak i don know exactly what i m doing have to spend a lot of time on it , have to learn it gonna build some studio monitor for my self one day
__________________
Marge, don't discourage the boy! Weaseling out of things is important to learn. It's what separates us from the animals! Except the weasel.
  Reply With Quote
Old 11th November 2012, 08:20 PM   #18
diyAudio Member
 
mondogenerator's Avatar
 
Join Date: Sep 2009
Location: City Of Villans
Blog Entries: 1
I suggest the component values in my last post as a starting point for the KE20. Once you get into using your own .frd and .zma data for the drivers you're actually going to use then things really get far more interesting

Also, some peaking may be present due to the baffle diffraction. Id recommend experimenting with offsetting the tweeter from the centreline of the baffle. Just 1cm can make all the difference. Height and inter-driver spacing has similar effects.
__________________
Every new piece of knowledge pushes something else out of my brain - Homer.....................Simpson

Last edited by mondogenerator; 11th November 2012 at 08:24 PM.
  Reply With Quote
Old 11th November 2012, 08:40 PM   #19
diyAudio Member
 
Join Date: Jul 2004
Location: Austin, TX
thanks mondogenerator i sure will test ur suggestions and i m tweaking with different baffle setting as well .
i tried something different this time , instead of passive crossover i tried active filters and with a 24db lpf at 2200 with q of 0.4 and a 12db hpf at 2200 and with q of 0.8 , i got the results as you see , but when the phase respond looks wierd , is it me or i m doin somethin wrong ??!

edit : is there any way to get rid of that annoying 5200 peak ??
Attached Images
File Type: jpg active fre res.jpg (170.4 KB, 13 views)
File Type: jpg active phase res.jpg (132.5 KB, 10 views)
__________________
Marge, don't discourage the boy! Weaseling out of things is important to learn. It's what separates us from the animals! Except the weasel.

Last edited by Ahmad_tbp; 11th November 2012 at 08:44 PM.
  Reply With Quote
Old 11th November 2012, 08:50 PM   #20
diyAudio Member
 
mondogenerator's Avatar
 
Join Date: Sep 2009
Location: City Of Villans
Blog Entries: 1
it looks like that peak is either due to the woofer breakup peak, OR the baffle placement of the tweeter.

Thats all i can think of, UNLESS the slope of the HP is 'doglegged' with a 1st order slope between the 2nd pole and 5khz.
__________________
Every new piece of knowledge pushes something else out of my brain - Homer.....................Simpson

Last edited by mondogenerator; 11th November 2012 at 08:54 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
[NEWBIE]Amplifier Design[NEWBIE] KernelPanic Solid State 13 7th December 2011 02:32 AM
Newbie Design seekingwisdom Multi-Way 4 27th April 2005 02:44 AM
Newbie speaker design Wingfeather Multi-Way 3 23rd June 2004 01:59 AM
Newbie design mikec Multi-Way 7 5th April 2004 02:03 AM
Newbie design ideas cohort36 Multi-Way 5 18th September 2003 08:59 PM


New To Site? Need Help?

All times are GMT. The time now is 03:37 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