AR-90 Crossover Electrical Simulation

[johnfalc]

I was describing how crossovers work, in a general way, to a friend and decided a graphic portrayal would work best.  I use LTSpice when I'm doing simple amplifier circuits and the like but I found an online tool which impresses me with its Java/JavaScript quality and suitability to the task of explaining multi-way speakers.

The application site (a beauty of this is that it is a site, not an application you need to install on your PC or Mac) is http://www.falstad.com/circuit/circuitjs.html .  If you click on this it will take you to the site with a simple RLC circuit already loaded. 

To take a look at the AR-90 crossover, you just need to load the parameters from a text file which I've attached.  Here's the drill:

* Once on the www.falstad.com site, click on <File>, then select <Import from Text...> to open a small dialog into which you'll paste the text file's contents.

* Open the attached "4 Way Circuit - AR 90.txt" file using something like Notepad (the Windows app).  Select the entirety of the file by using <Ctrl><A> and <Ctrl><C>, then paste the contents into the small dialog box opened in the first step above.  Click <OK> and the model of the AR-90 crossover will appear.

* Click the button labeled "Run / STOP" to see the frequency run from 20Hz to 20KHz while the simulation shows both the activity in the circuit and the resulting voltage delivered to each of the drivers (or in the case of the woofers, the pair of drivers).

Note that I simplified things by only plugging 4 ohm resistors in rather than making any attempt to model the drivers ... remember this was just a simple teaching exercise.

You may toggle the switches to see their effect on the voltages presented to the driver's surrogate resistors.  Here's a picture of what you should see if you follow the directions above.

Editing the circuit is very easy so, if this intrigues you, you may choose to model other crossovers by altering the topology/components.  

Thanks to RLowe for his contribution of the AR-90 crossover layout from which it was much easier to read component values than the other documents in the library.

John

4 Way Circuit - AR 90.txt

[Pete B]

Have you looked at Xsim by Bill Waslo?

Best way is to measure the input impedance of the drivers in system, saved as a .ZMA file.

Xsim will read in those files.

[johnfalc]

Hi Pete, No, I haven't, but I will take a look.  Thanks, John

[Pete B]

I used it here, it is free by the way: