605 time delay crossover

[donaldpatten]

L1 1.4605425
C2 17.41598667
L3 0.80942775
C4 12.58409333
L5 0.6199425
C6 9.364906667
L7 0.42345225
C8 5.516826667
L9 0.18948525
C10 1.133253333
Mike

Look at the fourth image a pr of red & blue freq resp curves, and the text with them. Can you trigger the scope (dual ch'l) on the amp out and look at the mike preamp out on the other ch'l ? Your traces show a large LF pulse followed by a smaller HF pulse, repeated 6 times.
Try to reduce the time base by 5 or 6, to show only one pr of pulses. Now turn off the HF driver. Turning the HF on/off will help iD the two pulses.

www.donpatten.com

New coil & cap values See my web site


L1 1.4605425
C2 17.41598667
L3 0.80942775
C4 12.58409333
L5 0.6199425
C6 9.364906667
L7 0.42345225
C8 5.516826667
L9 0.18948525
C10 1.133253333

[donaldpatten]

Mike
The CPU list of coils & caps is 1 to 10
The schematic is C1 to C5. Sorry about that
C1 = 12 + 5.6
C2 = 12 + 0.33 + 0.22
C3 = 4.7 + 4.7
C4 = 3.3 + 2.2
C5 = 0.33+ 0.33+ 0.47

For the schematic and text see:

www.donpatten.com

[Alien_Shore]

Great - that clarification helps Don.
I'll get the other breadboard out and start putting the test rig together.

I also have an active XO which provides the ability to play with time delay - I might look into that to do some prototyping.

[donaldpatten]

Mike
When you tune L1 & C1:
Connect 12uF and the 5.6 in parallel to make C1 . Connect C1, L1 coil, and a. resistor all in series, Try the DAT by measuring a sweep impedance. To tune a coil add or remove turns of wire.L1 & C1 should bottom out at 998 Hz.

Don

[donaldpatten]

Mike
I suggest to test the breadboard board low pass filter you run a sweep freq resp.with the woofer and Zobel connected as a load. Do not connect the HF driver. The sweep tone is connected to the power amp input. The measurement connection is to the woofer terminals ..Take care as not to short the speaker line, since both the tone source and measurement connection are probably common thru your PC.
When your make a measurement like this be very Quiet as your Super Duplex is a super microphone.
Don

[Alien_Shore]

Hmmm, ok so I don't use a mic for the measurement? I attach both the amp out and the PC soundcard input to the woofer terminals?!?

[donaldpatten]

Yes Mike
This is a test of the freq resp of just the coils & caps. WE will include the drivers next. To keep the filter happy we need the Zobel and woofer as the load. Try a sweep curve to see how we are progressing
Don

[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