Poll on PCD change - give me your input

[Jeff B.]

OK. As many know I am revising the Passive Crossover Designer. One of the things that I changed was correcting the vertical panning, which was upside-down. You would have thought that a dummy like me would have caught that one, but I am really surprised that it got by all you smart guys too. :rolleyes:

Now, in my tests it matches my off-axis summations and phase in CALSOD exactly (which I thought I tested before, but it must have escaped me somehow). That brings me to the Z offset.

Should I change the way it works so that it matches CALSOD, LspCad, SoundEasy, Speakerworkshop and all of the other excellent simulaton tools out there - meaning that the woofer offset would be a negative value if it is behind the 0 plane? Sheesh Jeff, it's about time, already.

Or, do I leave it as it is (+ for most woofers) because this is what you are used to working with and you have all these former project files that will be screwed up if I change it. It will mess up everything, including my brain.

Give me your pick, please.

Thanks,
Jeff

[dcibel]

Re: Poll on PCD change - give me your input

I would like if you changed Z offset so negative is behind the 0 plane. It makes more sense that way, and people new to the software will be less likely to enter the wrong value here. Previous project files will be screwed up, but I can live with that.

Another welcome change would be to use something like mm for driver offsets instead of meters.

Btw, thanks a lot for your excellent spreadsheet. My speakers would not exist without it ;)

[Mark65]

Re: Poll on PCD change - give me your input

Having it be a positive value is the only way I know , since I've only used your app, but if all of the other programs use a negative, then that might be a worthwhile change, plus it seems more intuitive for that value to be negative, since it's farther away from the listening point.

Short answer: I dunno...:D

Edit: Wouldn't it be a relatively simple matter of changing z offsets from positive to negative in the project files (for us, that is, once you're done screaming and gnashing your teeth over the changes in phase)?



Mark

[Zilch]

Re: Poll on PCD change - give me your input

You would have thought that a dummy like me would have caught that one, but I am really surprised that it got by all you smart guys too. :rolleyes:

Y'all are too smart, is all; it requires someone CERTIFIABLY dumb to catch this stuff, like me asking the appropriate question: "WTF...?" :p

That brings me to the Z offset. Should I change the way it works so that it matches CALSOD, LspCad, SoundEasy, Speakerworkshop and all of the other excellent simulaton tools out there - meaning that the woofer offset would be a negative value if it is behind the 0 plane?

Conceptually, driver acoustic centers are behind the measurement plane, the front of the baffle, typically. Yes, they are added to the measurement distance, but we think of them as being negative offsets from zero.

Now that I have the Y offsets in correct polarity, I am able to dial Z in quite precisely, knowing where the inverse null is located by measurement....

[[email protected]]

Re: Poll on PCD change - give me your input

as long as you change the explanation balloon, it should be no problem to change to a negative. could you add more of these balloons? they could be most useful. for instance, for the x and y. thanks.

[charlielaub]

Re: Poll on PCD change - give me your input

Jeff-

Could you place one or more characters in the PCD file that indicate the version so that you can automatically revise parameters such as this or prompt the user to do so when opening a file created in an older version?

-Charlie

[davidl]

Re: Poll on PCD change - give me your input

Change it so it matches Calsod please

[mzisserson]

Re: Poll on PCD change - give me your input

Certinly one step to making it more intutiave. Though, it is clearly explained in the instructions so no biggie.

[gordoncalder]

Re: Poll on PCD change - give me your input

Hi Jeff,

I'd vote for using the negative (for woofer behind tweeter) if it matches other software, and is more intuitive for new users.

And while I'm at it, many thanks for those amazing programs!

[dlr]

Re: Poll on PCD change - give me your input

That brings me to the Z offset.

Should I change the way it works so that it matches CALSOD, LspCad, SoundEasy, Speakerworkshop and all of the other excellent simulaton tools out there - meaning that the woofer offset would be a negative value if it is behind the 0 plane?

One vote YES. But you knew that would the case for me.

Everything relative to a single coordinate system origin.

dlr

[gordoncalder]

Re: Poll on PCD change - give me your input

Hey Jeff,

Just noticed yesterday what looks like a bug in the woofer box and circuit designer program.
In the box volume and vent calculator area I have
'English Units: English"
"Volume-Vab (Litres) = 46.01"
"Volume-Vab (Ft^3) = 1.63"
and "Tuned Port Fb = 22.8 Hz"

If I then switch to "Metric Units: Centimeters" I get:
"Volume-Vab (Litres) = 2.81"
"Volume-Vab (Ft^3) = .1"
and "Tuned Port Fb = 58. HZ"

If I then hit the "Transfer Vab" button, it transfers to the upper part of the spreadsheet and totally throws off the charts below.

Just thought I should mention it..

[Jeff B.]

Re: Poll on PCD change - give me your input

Hey Jeff,

Just noticed yesterday what looks like a bug in the woofer box and circuit designer program.
In the box volume and vent calculator area I have
'English Units: English"
"Volume-Vab (Litres) = 46.01"
"Volume-Vab (Ft^3) = 1.63"
and "Tuned Port Fb = 22.8 Hz"

If I then switch to "Metric Units: Centimeters" I get:
"Volume-Vab (Litres) = 2.81"
"Volume-Vab (Ft^3) = .1"
and "Tuned Port Fb = 58. HZ"

If I then hit the "Transfer Vab" button, it transfers to the upper part of the spreadsheet and totally throws off the charts below.

Just thought I should mention it..

Sorry Gordon, I'm not following you here. Everything you described above is exactly as the program was meant to function, so I don't see a bug being described. Please elaborate on the problem I'm not seeing.

Jeff

[Jeff B.]

Re: Poll on PCD change - give me your input

One vote YES. But you knew that would the case for me.

Everything relative to a single coordinate system origin.

dlr

Somehow I thought I might see you in this thread. ;)

[Jeff B.]

Re: Poll on PCD change - give me your input

Jeff-

Could you place one or more characters in the PCD file that indicate the version so that you can automatically revise parameters such as this or prompt the user to do so when opening a file created in an older version?

-Charlie

Interesting idea. It may take a little trickery, but I might be able to make that work.

[Paul W]

Re: Poll on PCD change - give me your input

From the LspCAD 5.25 pro manual, page 59: "...a positive dZ is further from the listener than a negative dZ." Personally, I don't care, provided it is made very clear...preferably as part of the input screen (make it very obvious for dummies like me).