Know of this crossover calculator?

[TimB]

Anyone hear of - or better yet, try - this crossover component calculator? Wonder if it looks plausible and what kind of results to expect? Rather than springing right away for an active setup thinking I will try a passive 4th order Butterworth or L-R. Will be doing a front screen array of three two-ways incorporating a single 2226j woof and 2446h comp driver and 2385a horn. Thinking of crossing at 600 Hz.

any other thoughts, advice, schematics also more than welcome! I have made a lot of sawdust, but this is my first foray into solder fumes.


http://www.ajdesigner.com/crossover/crossoverfourth.php

[NickH]

I haven't used that one but I've used the one on erse audio's website. Worked quite well.

Nick

[TimB]

Interestingly, while the Erse one doesn't say what filter it is using for its calcs, all its values returned match what the AJ says for a L-R EXCEPT one inductor L2 returns a value exactly double that of the AJ calcs. Whats up with that??

[TimB]

Oh, and would it be wise to insert an L-pad in the HF circuit (or not just wise but mandatory)? These are wired essentially in parallel with the tweeter, are they not (acting as an additional but variable inductor), so how do I account for their impedance in the crossover design, or do I ignore it?

[fpitas]

I have used the AJ Sealed and AJ Vented calculators, which give sensible answers, so that one is probably fine. A couple caveats. You will then have a "textbook" crossover, which may not be optimum if the drivers don't have flat responses in the crossover region. Also, the simple passive crossover won't allow adjustment for acoustic center offset; i.e., the horn driver is generally set back from the woofer, so delay on the woofer is appropriate for phase coherency. One can play games with the phase of each crossover section, using different orders on the woofer and horn etc., to get a reasonable phase agreement between the woofer and horn, but once again the simple 4th order won't do that for you.

[TimB]

And why should I think anything I touch could be that simple?:banghead:
guess there's a reason for active crossovers/DSP, eh? May try the passive route anyway, but seems there's a MiniDSP in my future.

[fpitas]

And why should I think anything I touch could be that simple?:banghead:
guess there's a reason for active crossovers/DSP, eh? May try the passive route anyway, but seems there's a MiniDSP in my future.

There are a few alternatives now. A friend uses a Steinberg UR824 as a USB input, multi-output DAC:

http://www.steinberg.net/en/products/audio_interfaces/ur_series/ur824.html

http://www.steinberg.net/fileadmin/files/PRODUCTS/Audio_interfaces/UR_Series/UR824/Downloads/UR824_Technical_specifications.pdf

His computer runs Jriver, which performs all the crossover and EQ functions.

http://www.jriver.com/

The woofer and tweeter channels run by USB link to the Steinberg, and then to the power amps. Very flexible system, and good sounding. There's a bit of a learning curve. We are looking into the possibility that the Steinberg's DSP can run the crossover and EQ functions internally. If we achieve that, I'll probably start using one in my setup.

I use a DCX2496, which I modified by changing the coupling caps. Whatever others' experience, mine sounds very good now, although I give it balanced inputs, and its balanced outputs run to balanced high-impedance (about 5k/side) pads and balanced amp inputs, with an eye to making the most of its rather primitive circuitry. That's another alternative except for Behringer's spotty reliability and the necessity to do a little surgery.

[TimB]

Really interesting product. Has a 200 rebate now also (though still more expensive than a minidsp). Have to figure out if it has other capabilities I would use.