Crossover model tool

[tvrgeek]

I have spent the last three days trying to just input 4 tweeters into Sound Easy. I am getting real sick of SING errors, and it never doing the same thing twice, and changing my data when I read it back in. I bought it only for the crossover modeling and optimization tools. I am about fed up with it, so I am looking for a solid and supported passive crossover model and optimization tool. Never managed to get it to do CSD which is the other reason I bought it.

[hdspeakerman]

I am only answering to try to make you feel better. I bought Soundeasy with the user guide etc. and I could not even get the example to work right. I feel so bad that I can't get it to do anything. I know how you feel. All I want to do is be able to measure my speakers and design crossovers and I just don't seem to be able to get the job done. I feel better now. I hope you do.
Howard

[sumaudioguy]

Well it takes more than a bit of knowledge but I use MediaMatrix for all my audio modeling and it works flawlessly however it does not make passive crossover parts which must still be DESIGNED IN THE LAB to work correctly. Driver models are all first approximation and just do not work that well. I have test fixtures for the RC compensation and the LRC resonator tuning. Used with a sweep generator and an impedance measuring set up I can adjust the cap, inductor, and resistor values until the driver looks exactly like a resistor over the entire pass band. No software will come close to doing this. Once driver plus parts looks like a "resistor" in the test fixture I can measure the values of all the parts for the passive compensation. MediaMatrix is then used with driver models to design the crossover frequencies with the frequency response tool.

[chris661]

I found that Boxsim does well for this.
Tutorial here
BoxSim

It's free, and all in German, so I created that thread to go through step by step.
When you're using it, you don't need to bother with specific drivers - just look at the last tab when you've made your XO. This will show the effect of your crossover.

[dudaindc]

Originally Posted by sumaudioguy

Well it takes more than a bit of knowledge but I use MediaMatrix for all my audio modeling ...

Do you mean Peavey's MediaMatrix?
If yes, I use a similar approach using BSS London.
Cheers!

[witwald]

Originally Posted by sumaudioguy

Driver models are all first approximation and just do not work that well.

It really depends on the driver model. Not all are first order approximations. It's possible to quite accurately model the impedance of a driver in terms of both its magnitude and phase response. That includes nonlinear behaviours in the impedance at high frequencies, where the models go beyond the realms of a simple linear inductor. There have been one or two papers (maybe more) published in the Journal of the Audio Engineering Society on this topic. It's also possible to create numerical models of driver impedance that even include quite small driver resonance effects, which are sometimes evident in the impedance curve.

I have test fixtures for the RC compensation and the LRC resonator tuning. Used with a sweep generator and an impedance measuring set up I can adjust the cap, inductor, and resistor values until the driver looks exactly like a resistor over the entire pass band. No software will come close to doing this.

A software-based solution, using mathematical optimisation techniques, can actually get very close to the result that you describe. The LRC and RC compensation circuits are able to have their individual component values optimised to produce a correction that makes the equalised impedance look quite resistive, to within fractions of an ohm.

[witwald]

Originally Posted by sumaudioguy

MediaMatrix is then used with driver models to design the crossover frequencies with the frequency response tool.

How is this done? I've had a look through Peavey's MediaMatrix web site, but can't find any specific information on designing crossover filters. I'm interested to learn more about MediaMatrix's capabilities in that area.

Is the MediaMatrix software available for download from Peavey? If so, can someone please provide a pointer to it?

[Ferrit37]

MediaMatrix

[dudaindc]

Originally Posted by witwald

...
Is the MediaMatrix software available for download from Peavey? If so, can someone please provide a pointer to it?

The software is useless if you do not have the hardware...

[sumaudioguy]

Originally Posted by dudaindc

The software is useless if you do not have the hardware...

The software and frequency tools work flawlessly without the hardware. All forms of modeling and crossovers may be examined with that tool including delays and so on.

It is here for windows only : http://mm.peavey.com/assets/software..._3-3-5_493.exe

Download and install. You will need to have inputs and outputs in the program to have anything work. I use this almost exclusively because it is one of a very few programs that handle time and phase correctly.