605 time delay crossover

[Alien_Shore]

OK, well, I did an inventory of my caps and coils and I don't have what I need for the LP filter. I will order some wire to wind some coils.
Do you agree with the general tips provided on this webpage?
Also, where is a good supplier of magnet wire?
For 200' of #18:
Powerwerkz $27
Amazon Small Parts $16

[donaldpatten]

Mike


The # 26 AWG Magnet wire is available from Mouser or any Belden Distributor: part # 8052 is a 1/2 pound, 800 foot spool. I got large spools with long lengths of #18 and #15 AWG from BAE Wire ( 941/309-0900 ) on eBay.
The price of copper has gone crazy.
See

www.donpatten.com

[donaldpatten]

Mike
You will want to listen to your speaker, so connect the Lowpass filter to your power amp and speaker. The woofer Zobel (10R+18F) is all ready on the circuit board.
To connect the horn you will need a 4uF cap in series and an L Pad . Connect the driver leads to the L Pad terminals 1 and 2 . Connect terminal 1 to the power amp common .Connect L Pad terml 3 to one wire of the 4uF cap and the other wire to power amp hot .

Lets check the new prototype LP filter time delay, to see what correction is needed.
Play the test signal through the filter and woofer.Trigger the scope on the input signal to the filter. Connect your test mike to pick up the on axis sound about 12 inches in front of your 604. Play the woofer . I use a dual channel in the chopped mode, sync to the power amp . Adjust the display to show the power amp output as a single pulse. The other channel shows the woofer acoustic output. Now turn on/off the horn and see any changes in the combined woofer/horn acoustic signal. When the pulse gets taller and narrower we are done. If adding the horn output causes the pulse to jump sideways ... The amount of jump is the amount of timing error.

Don

[Alien_Shore]

Don, I received the woofer TD filter today - thanks again for putting that together for me.

I've gotta run to practice, but I thought I would at least post a quick imped sweep of the woofer with the filter:



I'll do the pulse testing later tonight if I have time.

[cradeldorf]

What's a TD filter?

[Alien_Shore]

A gi-normous chunk of copper wire and little plastic cylinders


Time Delay

[donaldpatten]

cradeldorf

Most XO filters , Butterworth , etc have time delays that vary with freq. this is not what we want.
The Bessel filters have constant delay and are what the Dr ordered.
We hope to delay the low freqs , all of them, by the same delay to match the high freq delay caused by the driver being behind the woofer.
And if we are lucky, this filter will not only provide the proper amount of delay, it will have a frequency response that rolls off the high freqs to match our hi freq filter.

Don

[donaldpatten]

Mike
Please check the horn/driver frequency peak.
I want to make a filter to knock down the peak.
It looks like 1.8 or 1.9 kHz. If you can put a marker on your curve you may not have to retest
I have two Cap sub boxes:
Heath kit: 0.0022 uF to 0.22
DIY : 0.33 to 15uF in twelve EIA steps, built in a round CD box.
Have you listened to your new baby?
Don