PCD and a few general crossover questions.

[killersoundz]

Ok I want to thank the people here for sparking my interest in designing my own crossovers. Well I downloaded PCD for excel 2007. I do want to say off the bat as far as software goes the layout seems a bit hectic. :) Are you supposed to be able to input driver specs into this program, because I cannot tell where. :confused:

The only thing I've messed with in it so far is the textbook crossover calculators. I did read the instructions. Ok only maybe half the way through...I'll go back and read the rest.

Let me ask a lot of newbie crossover questions:

Lets say I want to make a passive crossover for a high powered pa speaker to handle 1000W. Are there inductors out there that will do this or would I be putting two in series? What about the power handling of capacitors?

Is a first order crossover going to naturally have better power handling than a second order? Should I ever even attempt to use a first order crossover for a PA speaker (or anything else)? Is it going to be rubbish? (I kind of assume)

Are there any clear schematics on how crossovers are wired up? It's simple enough to me (I get it) but the only part I need to visualize is splitting the negative.

That's all for now. Thanks.

[Chris Roemer]

Ok I want to thank the people here for sparking my interest in designing my own crossovers. Well I downloaded PCD for excel 2007. I do want to say off the bat as far as software goes the layout seems a bit hectic. :) Are you supposed to be able to input driver specs into this program, because I cannot tell where. :confused:

The only thing I've messed with in it so far is the textbook crossover calculators. I did read the instructions. Ok only maybe half the way through...I'll go back and read the rest.

Let me ask a lot of newbie crossover questions:

Lets say I want to make a passive crossover for a high powered pa speaker to handle 1000W. Are there inductors out there that will do this or would I be putting two in series? What about the power handling of capacitors?

Is a first order crossover going to naturally have better power handling than a second order? Should I ever even attempt to use a first order crossover for a PA speaker (or anything else)? Is it going to be rubbish? (I kind of assume)

Are there any clear schematics on how crossovers are wired up? It's simple enough to me (I get it) but the only part I need to visualize is splitting the negative.

That's all for now. Thanks.


Straight 1st order XOs (single cap for a tweeter or a single coil for a woofer) practically NEVER work (they can't really do the job you're hoping they due, very often due to the actual driver's impedance profile - woofer's substantial rise with frequency, and tweeter's resonant freq. - especially those w/OUT ferrofluid).

2nd order can often work out well, especially with non-problematic drivers.

[davepellegrene]

You can't load TS parameters into PCD. You firts have to make up FRD and ZMA files or find someone that have them already for the drivers you want to simulate.

Here (http://techtalk.parts-express.com/showthread.php?t=210439) is a link to a tutorial from Max Andrews on how to get started. It explains how to make FRD files using graphs imported into SPL Trace. You then load them into Jeff B. Response Modeler, you can get at his site as well. Response modeler is were you put your TS parameters into along with box volume. Once you do that you make FRD and ZMA files to load into PCD. Once you learn PCD it will all make sense how it is set up. Max explains it pretty well. At least it will give you a starting point to ask questions from.

Dave

[killersoundz]

You can't load TS parameters into PCD. You firts have to make up FRD and ZMA files or find someone that have them already for the drivers you want to simulate.

Here (http://techtalk.parts-express.com/showthread.php?t=210439) is a link to a tutorial from Max Andrews on how to get started. It explains how to make FRD files using graphs imported into SPL Trace. You then load them into Jeff B. Response Modeler, you can get at his site as well. Response modeler is were you put your TS parameters into along with box volume. Once you do that you make FRD and ZMA files to load into PCD. Once you learn PCD it will all make sense how it is set up. Max explains it pretty well. At least it will give you a starting point to ask questions from.

Dave

Thank you. Sounds like a very long drawn out process but probably worth it. :)

I'll give it a shot and ask some more questions later I'm sure.

[killersoundz]

Straight 1st order XOs (single cap for a tweeter or a single coil for a woofer) practically NEVER work (they can't really do the job you're hoping they due, very often due to the actual driver's impedance profile - woofer's substantial rise with frequency, and tweeter's resonant freq. - especially those w/OUT ferrofluid).

2nd order can often work out well, especially with non-problematic drivers.

Ok that's what I figured. Besides a 6db/octave roll off would have an overlap for days!

So now about 2nd order power handling. How could you manage to get a huge power handling (1000w) out of a second order crossover with a capacitor and inductor on each filter.

[fastbike1]

??? Every published design has a crossover schematic included. I'm not sure what you mean by splitting the negative. Every crossover ultimately gets to what is basically a common ground. That line goes to the negative terminal.





Are there any clear schematics on how crossovers are wired up? It's simple enough to me (I get it) but the only part I need to visualize is splitting the negative.

That's all for now. Thanks.

[jclin4]

??? Every published design has a crossover schematic included. I'm not sure what you mean by splitting the negative. Every crossover ultimately gets to what is basically a common ground. That line goes to the negative terminal.

Not sure, but maybe the OP means how to turn a schematic into an actual crossover. Curt C provides this info (also linked in the speaker-building-bible sticky)

http://speakerdesignworks.com/nodal_analysis.html

With any crossover, a lot of wires end up going to ground (negative). To keep things neat, I like to use strips with a jumper that connects all the terminals:

http://rsk.imageg.net/graphics/product_images/pRS1C-2266710w345.jpg

[davepellegrene]

Thank you. Sounds like a very long drawn out process but probably worth it. :)

I'll give it a shot and ask some more questions later I'm sure.

From a remodeling contractors point of view.
I can say in the time it took me to learn how to use spl trace, response modeler and PCD, to get to the point that I am comfortable building the crossovers for a three way speaker, I could have built a house from the ground up myself. The few speakers I have built so far I would say are just ok. It will probably take me at least three of four more houses to get good at it. :eek: :D
It sure is fun though.
Dave