I'm very interested in this kit - just how many parts do I need for my project?
2-way magnepan crossover with diffrent slopes to approximate the stick 3rd order low pass (18db/octave @ 250) and 1st order high pass(6db/octave @ 200), plus a subwoofer output (stereo if possible) at about 50hz in 4th order.
I read at the start of the thread
Does that mean I'm in for 6 boards if I want some sort of subwoofer and 4 boards for a 2way setup? What about asymmetrical slopes?
Peter
2-way magnepan crossover with diffrent slopes to approximate the stick 3rd order low pass (18db/octave @ 250) and 1st order high pass(6db/octave @ 200), plus a subwoofer output (stereo if possible) at about 50hz in 4th order.
I read at the start of the thread
Does that mean I'm in for 6 boards if I want some sort of subwoofer and 4 boards for a 2way setup? What about asymmetrical slopes?
Peter
tiroth said:I think my post was obviated, so you can ignore this.I'm sorry for the problem my mistake caused and appreciate the words of support.
You are doing a good job. Sorry for the confusion earlier, as I reinstalled my OS, and the webpage didn't refresh properly when I posted, replying to a dated message.
Thanks again for your efforts, and I hope to get some boards soon to use in my projects.
--
Brian
pburke said:
Am I understanding you correctly?
- 3rd order LP @ 250
- 1st order HP @ 200
- No bandpass needed (two way)
This requires four boards for stereo. Asymmetric slopes are not a problem.
- 4th order @ 50Hz
For the subs, you need to cascade two boards, so you need two for mono and four for stereo. Sorry...unfortunately you are using only 1 HP section and need four LP sections per channel, so there is a lot of the board that is unused. You could use one of the free HP sections to cross your mains at some point if you want to reduce excursion at low frequencies.
Second Q graph.
The noteable thing is here is that by the time we reach Q=1.7, Fc has drifted by 1/10 octave and the peaking is about 1dB higher than expected.
Why? These measurements are made with NE5532. I'm out of FET-input opamps in DIP.
The input impedance is too low, which causes the Q to affect Fc a little.
The noteable thing is here is that by the time we reach Q=1.7, Fc has drifted by 1/10 octave and the peaking is about 1dB higher than expected.
Why? These measurements are made with NE5532. I'm out of FET-input opamps in DIP.
The input impedance is too low, which causes the Q to affect Fc a little.Attachments
Here is the HP. There is something odd here; when I use the smallest capacitor (1nF) the overall level is unexpectedly down 1dB. Fc is right on target.
I have included a sweep at Fc=2.5kHz to make this more clear. I do not think this is a problem with the board, but I don't understand it.
I have included a sweep at Fc=2.5kHz to make this more clear. I do not think this is a problem with the board, but I don't understand it.
Attachments
2sk389 discontinued?
I called Toshiba Singapore today, the manufacturer, not some retailer. They also say that they discontinued 2sk389. That is a bit troubling. Where do these s2k389 from other retailers come from then? Toshiba also gave me the e-mail of a retailer here who "may have small quantities in stock".
I guess one could also use 2sk170 in this application. They're cheaper anyway... Or buy from the retailer Tiroth has on hand, and risk that they're either counterfeit (?) or not available in the future for replacements. Hmmmm.
I called Toshiba Singapore today, the manufacturer, not some retailer. They also say that they discontinued 2sk389. That is a bit troubling. Where do these s2k389 from other retailers come from then? Toshiba also gave me the e-mail of a retailer here who "may have small quantities in stock".
I guess one could also use 2sk170 in this application. They're cheaper anyway... Or buy from the retailer Tiroth has on hand, and risk that they're either counterfeit (?) or not available in the future for replacements. Hmmmm.
NE5532 not bad at all
Hi
These measurements were done using 7! cascaded NE5532 from Philips. On my other filter board....
The difference between the measured and expected response is less than 0.1dB.
Mind you, this was done using measured component values to calculate the response, but done just to see how a bipolar opamp really affects the freq response.
\Jens
Hi
These measurements were done using 7! cascaded NE5532 from Philips. On my other filter board....
The difference between the measured and expected response is less than 0.1dB.
Mind you, this was done using measured component values to calculate the response, but done just to see how a bipolar opamp really affects the freq response.
An externally hosted image should be here but it was not working when we last tested it.
\Jens
Hi Tyler,
I hate to ask this, are all the jumpers set right?
Have you tried another type of cap, or maybe there is a semi short circuit on one of the soldering pads....creating a DC path that would act like a gain offset?
Are any changes needed in the artwork I'd like to know...so I can move tracks placed inconveniently.
\Jens
I hate to ask this, are all the jumpers set right?
Have you tried another type of cap, or maybe there is a semi short circuit on one of the soldering pads....creating a DC path that would act like a gain offset?
Are any changes needed in the artwork I'd like to know...so I can move tracks placed inconveniently.
\Jens
I'm finally satisfied that the boards work. I'd like to (officially) begin accepting payments so we can get these boards made up ASAP.
Go here to pay
http://www.anidian.com/audio/construct/mox_order.shtml
I would like to have all payments made by midnight Saturday, May 8th.
I will plan on sending the order Monday, May 10th. I will continue to post tests, especially for the opamps themselves.
Thanks for all the help from folks who have pitched in so far. I'm certain additional contributions will be made as people squeeze every drop of functionality out of these boards.
Go here to pay
http://www.anidian.com/audio/construct/mox_order.shtml
I would like to have all payments made by midnight Saturday, May 8th.
I will plan on sending the order Monday, May 10th. I will continue to post tests, especially for the opamps themselves.
Thanks for all the help from folks who have pitched in so far. I'm certain additional contributions will be made as people squeeze every drop of functionality out of these boards.
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