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

Software Tools SPICE, PCB CAD, speaker design and measurement software, calculators

XSim free crossover designer
XSim free crossover designer
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 12th August 2019, 05:29 AM   #651
bwaslo is offline bwaslo  United States
Old guy with soldering iron
diyAudio Member
 
bwaslo's Avatar
 
Join Date: May 2006
Location: Portland, Oregon!
XSim free crossover designer
Quote:
All graphs are with zero smoothing. I feel this gives greatest resolution. Even 24db/oct seems to obscure a fair amount of detail. Am I ok in doing this unsmoothed?
Absolutely. Smoothing can always be added in in XSim. I only use smoothing during measurement when I'm not going to save the file and am trying to see through lots of 'grass'.

Quote:
Yes, I did do a double take when the DATS returned the triple hump and remeasured to only get the same result. I will pull them and measure each woofer outside of the box to isolate any individual driver issue. I figured that the triple hump was a consequence of the second woofer's interaction.
Try shorting out the terminals on the woofer not being measured. It won't perfectly take out the effect of interractions, but will be closer.

Quote:

I set out the inductors so as they are all at right angles to each other. Does this look OK?
Not really. That may not be the problem, but I can see a number of possible interractions in the layout. Try to look at inductors as if they are trying to be transformers (which is what you're trying to prevent). When they share a core (even with some air gaps) or when a dominant shared magnetic path can be traced through their axes (and that doesn't have to travel too long), they can talk to each other. If close together, they need to be not only at right angles but also symmetrical. If they are done that way, then there is no preferential magnetic path through both windings so the lines going over equal but opposite paths would cancel out (lower picture). To make that happen, they have to be at right angles, but not in anything that might approach sitting "end to end" (like in the upper picture).
XSim free crossover designer-inductor-pair-interraction-jpg

I traced out some likely shared field lines between close inductors in your photo (different colored lines scribbled on the photo):
XSim free crossover designer-inductor-interraction-jpg

Distance between inductors is your friend, maximize that and then any that still have to be close should be arranged to be perpendicular and symmetric as possible. Ferrous cored inductors couple most strongly and there are three of them in your layout that sit virtually end-to-end!

XSim free crossover designer-inductor-pair-interraction-types-jpg

Quote:
Now looking at this I realised that my inductors are going to be right under the upper woofers magnet, perhaps this is a problem?
Probably not. It would be preferable to not have iron or ferrite cored inductors in a strong magnetic field since that might tend to make the cores saturate a little earlier when driven. The air core inductors probably don't care too much unless they are REALLY close to magnetic materials (which might alter their inductance). If you have a choice, get them away from magnets and other large metal pieces but it's probably not a show stopper.
Attached Images
File Type: jpg Inductor pair interraction.jpg (48.3 KB, 286 views)
File Type: jpg Inductor interraction.jpg (180.8 KB, 290 views)
File Type: jpg Inductor pair interraction types.jpg (107.9 KB, 160 views)
__________________
[W9MJE] Horn spreadsheet SynergyCalc/; SmallSyns SmallSyns;
Crossover design Xsim; Depot diffusor super-easy diffusors

Last edited by bwaslo; 12th August 2019 at 05:42 AM.
  Reply With Quote
Old 12th August 2019, 12:14 PM   #652
mwmkravchenko is offline mwmkravchenko  Canada
Mark Kravchenko
diyAudio Member
 
mwmkravchenko's Avatar
 
Join Date: Jan 2002
Location: Perth Canada
XSim free crossover designer
Quote:
All measurements are outside in my back yard both for initial driver measurements and then a few weeks later for the system with this crossover. Same height off the ground, same position in the back yard. With the Omnimic fast sweep running I set the level to 2.8 volts. These speakers are quite efficient and at this level all of my neighbours were messaging me asking what the strange noise was! I applied as many tips as I could from Jeff Bagby's whitepaper for measuring as possible.

I have measured the KG's drivers in 6 different settings ranging from indoors, inside my workshop and then incrementally moving out into the back yard, each time doing full 0-90 degree horizontal polars. It was clear that even with 5ms gating the response got smoother and more repeatable the further outdoors I went.

So do I need to redo my measurements in my final listening room?

Bill's answer is spot on. As long as your measurement conditions are known and entered into the software you are fine.


Quote:
All graphs are with zero smoothing. I feel this gives greatest resolution. Even 24db/oct seems to obscure a fair amount of detail. Am I ok in doing this unsmoothed?

You are doing very well actually. The peaks looked like 1/24th octave resolution. So you are creating a very god crossover.


Bill has loads more crossover experience than I have. And his advice is pretty much what I thought about to. Only he is more familiar with his program ( I wonder why???)


Your inductor placement is great until you are sitting in the stray magnetic field of your woofer. Without getting into possible effects of mutual coupling with the stray magnetic field of a woofer motor it's best to keep them a about 10cm away from the woofer motor parts. Generally there is a bit of stray magnetic field at the sides and about 45 degrees off the central axis of the back plate.
__________________
Mark
www.kravchenko-audio.com
  Reply With Quote
Old 12th August 2019, 02:43 PM   #653
carlthess40 is offline carlthess40  United States
diyAudio Member
 
Join Date: Oct 2017
Location: Lake Mary Florida
Would anyone of your guys or ladies like to run this program and design a crossover for me. Just message me and Iíll give you my info on the drivers and size of the speaker cab . Iím only able to do things on my iPhone 8+ as I have not setup any of my computers sense Iíve moved into my new home. Thatís on the end of a very long list of to-do things right now. Lol
Thanks. People
Carl
  Reply With Quote
Old 12th August 2019, 07:20 PM   #654
mwmkravchenko is offline mwmkravchenko  Canada
Mark Kravchenko
diyAudio Member
 
mwmkravchenko's Avatar
 
Join Date: Jan 2002
Location: Perth Canada
XSim free crossover designer
Missed the iron core on the inductors. I'm slipping! I blame juvenile Alzheimers.
__________________
Mark
www.kravchenko-audio.com
  Reply With Quote
Old 12th August 2019, 07:44 PM   #655
bwaslo is offline bwaslo  United States
Old guy with soldering iron
diyAudio Member
 
bwaslo's Avatar
 
Join Date: May 2006
Location: Portland, Oregon!
XSim free crossover designer
carlthesis, with few exceptions (some Dayton drivers), there's not enough info on a data sheet or manufacturer supplied graph to simulate and design a crossover. You nearly always have to have measurements of actual drivers, at the correct relative distance from the listener (how much closer or farther from the mic/listener is the tweeter than the midrange, etc), on the actual baffle. A rough crossover that will at least keep the drivers from getting blown up (maybe) can be done, but it is likely to have some peaks and dips in places particularly in the sensitive lower treble.
__________________
[W9MJE] Horn spreadsheet SynergyCalc/; SmallSyns SmallSyns;
Crossover design Xsim; Depot diffusor super-easy diffusors
  Reply With Quote
Old 15th August 2019, 01:02 PM   #656
Mazza is offline Mazza  Australia
diyAudio Member
 
Join Date: Jul 2013
Default Breaking it down....

Dear Bill, Mark etal,
Many thanks for your encouragement and ongoing support here. Really appreciated.

I will try to systematically work through your suggestions to see if I can isolate the root case. Please hang in here with me!

Quote:
Originally Posted by bwaslo View Post
You can work with XSim to try to find what's wrong.

The 8dB suckout is happening at about the crossover point between the tweeter and the upper woofer so the first thing to check is whether the relative delay between those were determined correctly. If you enter a delay value for the tweeter of -0.8 inches, then the curve starts to look more like it measured. -0.8 inches would mean that the simulated tweeter is 0.8" too close to the mic (relative to the upper woofer), so moving the mic downwards (delay more positive, or 0) would be in the right direction (tweeter further from the mic).
This was very practical and helpful thank you Bill. I had a long play with my off sets and figured I needed to go back to the start.

So I made a new .dxo and added in my three drivers and also a driver for each pair's combined .frd.

So, looking at the tweeter and upper woofer I cannot get complete alignment.

Looking back to my built design, if add the additional 0.8in delay to the tweeter I get the following overlay which doesn't look great:

XSim free crossover designer-slide-5-jpg


However I can get alignment from 2khz and above with 0.68in on the tweeter:

XSim free crossover designer-slide1-jpg

About 1khz to 4khz with 1.16in on the tweeter:

XSim free crossover designer-slide2-jpg

And at 800kz in that little dip with 2.95in

XSim free crossover designer-slide3-jpg

So my questions are:
  1. any of these possible proxy Z off sets for my design?; or
  2. maybe I've done something wrong/overlooked/missing something here?; or
  3. has my measurement failed and I need to restart?

The pair of woofers on the other hand align beautifully with 2.98 on the lower woofer (zero on the upper woofer):

XSim free crossover designer-slide4-jpg

Quote:
Try shorting out the terminals on the woofer not being measured. It won't perfectly take out the effect of interactions, but will be closer.
I went back and remeasured my impedances shorting out the woof not being measured and this worked well - new ZMA's have a typical double hump and are in use here in the DXO attached.

Incidentally I measured my woofers FRD with the other woofer shorted. At 2.8v the woofer not being measured was still jumping around a bit in sympathy, even when shorted, and so, standing to the side of the enclosure, I gently pressed on the woof not being measured with my fingers to further damp its cone.

DXO attached, thank you again!
Attached Images
File Type: jpg Slide1.JPG (226.9 KB, 84 views)
File Type: jpg Slide2.JPG (231.0 KB, 84 views)
File Type: jpg Slide3.JPG (232.4 KB, 83 views)
File Type: jpg Slide4.JPG (234.5 KB, 84 views)
File Type: jpg slide 5.jpg (235.0 KB, 73 views)

Last edited by Mazza; 15th August 2019 at 01:15 PM.
  Reply With Quote
Old 15th August 2019, 02:35 PM   #657
Mazza is offline Mazza  Australia
diyAudio Member
 
Join Date: Jul 2013
Default Measurements...

So I had a minor brain fart - realised I have 6 sets of measurements!

So I went back to measurement set 5.

Quick and dirty, I add three drivers, tweeter, upper woofer and combined Tweeter/upper woofer.

Hold the combined driver FRD, unmute tweeter and upper woofer and add a smidge of delay to the tweeter and we get.....

XSim free crossover designer-slide-6-jpg

Conclusion - my sixth set of measurements are wonky?
Attached Images
File Type: jpg slide 6.jpg (271.7 KB, 65 views)
Attached Files
File Type: dxo Quick and dirty KG tweeter upper woofer Z off set.dxo (130.7 KB, 1 views)
  Reply With Quote
Old Yesterday, 10:31 AM   #658
pelanj is online now pelanj  Czech Republic
diyAudio Member
 
Join Date: Jul 2008
Thank you very much for this brilliant piece of software! This will make the tuning of my MF/HF horn crossover a breeze.
  Reply With Quote

Reply


XSim free crossover designerHide 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
Update to Windows Passive Crossover Designer available dlr Software Tools 1 15th May 2014 10:46 PM
Windows Passive Crossover Designer v1.2 available for download dlr Software Tools 15 13th December 2013 11:48 PM
Active Crossover Designer version 2 released CharlieLaub Software Tools 1 12th November 2012 09:08 PM
Orcad/AutoTRAX EDA - free schematic capture/PCB designer Ilija Everything Else 3 16th July 2003 11:11 AM


New To Site? Need Help?

All times are GMT. The time now is 02:18 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki