Probably pin numbers, some schematic drawing programs assign pin numbers to all components. Please ignore them.
The reason I asked is that I wonder how useful the 50 Hz high-pass will be. Due to the constraint that it should only consist of Rs and Cs, it has a very smooth roll-off and only gives a good suppression at frequencies far below 50 Hz (a 50 Hz first-order high-pass is roughly at -7 dB at 25 Hz, -3 dB at 50 Hz and -1 dB at 100 Hz). Some typical sources of frequencies far below 50 Hz are church organs, synthesizers, warped records and audiophile live recordings made outside or in a place with a draft. Anyway, you can try and see.
I hadn't thought about that - I just assumed it would allow me to increase the volume without lower Hz causing problems- I'll try it anyway with a switch and see if it makes any perceivable difference above and below 50.
Which do you think would be the better approach to take a stereo signal and make a mono signal before your circuit as there seems to be several approaches that I have researched from the internet?
1. make "Y" with a 4.7k resistor on each arm before into the single leg.
Or 2. a suggested resistance of 10% of the amplifier input impedance which in my case would be anywhere from 1.3K to 3.6K
or 3. or 1k (headphone output ) to 5K (Line output).
On my full range (right channel) , if I want to lower the volume to match the woofer output, could I place a log/tapered pot after the mono resistors above and before your circuit. If so, what size, ie, 5k, 10K, 20 K or ?
Would another pot be able to vary the cutoff, ie from 100 to 200 hz vs your circuit 150 hz cutoff? If so , what size and where to place in your circuit?
Thanks
Which do you think would be the better approach to take a stereo signal and make a mono signal before your circuit as there seems to be several approaches that I have researched from the internet?
1. make "Y" with a 4.7k resistor on each arm before into the single leg.
Or 2. a suggested resistance of 10% of the amplifier input impedance which in my case would be anywhere from 1.3K to 3.6K
or 3. or 1k (headphone output ) to 5K (Line output).
On my full range (right channel) , if I want to lower the volume to match the woofer output, could I place a log/tapered pot after the mono resistors above and before your circuit. If so, what size, ie, 5k, 10K, 20 K or ?
Would another pot be able to vary the cutoff, ie from 100 to 200 hz vs your circuit 150 hz cutoff? If so , what size and where to place in your circuit?
Thanks
None, because the stereo to mono conversion is already included in my circuit. In the schematic in post #14, the 390 ohm resistors take care of that for the woofer and the 47 ohm resistors and 2.7 uF capacitors for the full-range channel. At the same time they also filter.
At the output of the lower branch of the circuit (the high-pass part of the crossover filter), you could change the 1 kohm resistor to ground into a 1.2 kohm resistor and shunt it with a 5 kohm potmeter that drives the right channel of the amplifier.
No, you would need five ganged potmeters with different values for that. That doesn't sound very practical.
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Thanks for checking. I'm in the design process of building 15 near-field speakers for gifts to my friends (actually it has been over 6 months researching and designing - I think I like that more than the actual build.) I will be using your circuit that you so graciously spent time designing as it is going to make these speakers have a real nice "large" sound from the small 4 liter boxes.
I'm making the first demo box really adjustable so I can place any 2", 3" or 4" speaker/baffle in any or all four areas of the portable box with an internal bluetooth/usb battery/110volt amp. Then make a quick easy change to the inside of the box so I can test the spl for: sealed, Br, DCR, bandpass 4th order, bandpass 6th order, a 3" woofer two chamber ported into an external passive radiator (ie like the logitech 640) and all ports will have the option of aperiodic stuffing. Once I get the best sound, then I'll build 15 of them.
I'm making the first demo box really adjustable so I can place any 2", 3" or 4" speaker/baffle in any or all four areas of the portable box with an internal bluetooth/usb battery/110volt amp. Then make a quick easy change to the inside of the box so I can test the spl for: sealed, Br, DCR, bandpass 4th order, bandpass 6th order, a 3" woofer two chamber ported into an external passive radiator (ie like the logitech 640) and all ports will have the option of aperiodic stuffing. Once I get the best sound, then I'll build 15 of them.
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