Reverse Xover Calculator

[ss007]

I've found many calculators that suggest components for xover design. I'm trying to figure out where my high pass is set in the speakers I have.

First There is a 5.1 ohm resistor in line then a 6.2 uf cap also in line then a .30mh inductor across a Dayton 1 1/8 silk dome tweeter that has a nominal 8 ohm rating.

Does anyone know of a calculator where you enter in what you have and it gives you your current crossover point.

[Pano]

the Passive Crossover Designer will do the job.
Not a simple calculator, it runs in Excel. Haven't seen the reverse you want in a simple calculator. Would be handy, tho.

Loudspeaker Design Software

FWIW.
PCD says your filter = 2nd order Bessel at 2.8KHz with 4dB attenuation. Plotted on the tweeter impedance.

[ss007]

Thanks Panomaniac. Passive crossover designer looks great. Problem is I use a Mac. My wife has a pc but without excel. I think I'll get excel for her laptop and install it there.

2.8K!!! That makes sense, The speakers are missing the upper mids. I know the woofer rolls off about 2K. All the calculators say I need a 6uf cap and a .8mh inductor. Does your program say that will get me closer to 2K?

I'm wondering if the .3 coil was put in there by mistake

[Pano]

Looks to me like 5uF + .5mH and 5R in series ought to get you to 2K Bessel electrically.

5-5-5 Or drop to 4uF and be at a 2KHz L/R curve, more or less.

We have the Home Edition of MS office. Much cheaper than the business version and you can run it on 3 computers.

[ss007]

Cool! Great info! Can I bother you for the 2nd order butterworth so I can compare them all.

Thanks for the tip on the MS Office Home, I think that's what I'll do

[Pano]

OK, 2nd order Butterworth @ 2KHz (electrical) with 4dB attenuation looks like:
9uF, 0.4mH, 4R series

The values get tricky because of the big impedance peak at 650Hz. But PCD says this is what is needed.
That said, spreading the x-over freqs. but just 800Hz is probably a good thing. But you can try lower on the tweeter to find out.

[krzys]

Originally Posted by ss007

Thanks for the tip on the MS Office Home, I think that's what I'll do

You can just download the totally free Open Office (open source) software and run any Excel file on it .
OpenOffice.org - The Free and Open Productivity Suite

Chris

[bassmeknik]

Originally Posted by krzys

You can just download the totally free Open Office (open source) software and run any Excel file on it .
OpenOffice.org - The Free and Open Productivity Suite

Chris

Open Office works and is free I am using it instead of Microsoft Word for document processing.

[Pano]

I have not gotten Passive Crossover Designer to work in Open Office. Has anyone?

[ss007]

I got a copy of Office Home Student at Fry's for $89.00. Not bad, Staples wanted $149.


I'm going to try open office on my mac, It will be great if that works!


It's all up and running. I printed out the user manual and will read through that a couple times.

Is there an online library for FRD and ZMA files? I'm using the Dayton Classic 8" woofer and the 1 1/8 Silk Dome tweeter.

That said, spreading the x-over freqs. but just 800Hz is probably a good thing. But you can try lower on the tweeter to find out.

Pano, I'm not understanding what you meant by this.

Slightly off topic-- Does the 6 ohm series resistor change the nominal imp. of the tweeter. For example if I was using one of the simple online crossover calculators would I now enter something other than 8 ohms specified by the manufacturer when calculating?