If I install a 10K resistor in series with the XLR input to the pot - that will also provide me more range to attenuate
As presented, the range on both filters is 0 (counterclockwise pot) to
unity gain (clockwise). You should have virtually infinite relative range
between the two outputs.
Changing the trim pots to 50K does not change the maximum attenuation. With either a 50K or a 25K pot, turning it all the way down means no signal gets through to the circuit. I believe the 10K Nelson refers to is the input impedance of one channel, which consists of the high pass input pot in parallel with the low pass input pot, about 12.5K. The downstream JFET inputs are very high impedance and don't lower that number very much.
If you are having a problem setting the 25K pot to the exact level you want because the wiper range is too narrow and hard to get right, then changing to 50K pots would widen that range but it would not change the amount of attenuation available. It will also change the effective input impedance the preamplifier sees. If you change just the low pass pots to 50K, the effective input impedance will be 16.67K. Changing both high and low pass would yield 25K.
Anything above a 10K input impedance should present no problem for most preamps, some tube gear excepted. Since you are driving this crossover with a balanced source, it is probably capable of being connected to much lower input impedances, depending on its rating.
If you are having a problem setting the 25K pot to the exact level you want because the wiper range is too narrow and hard to get right, then changing to 50K pots would widen that range but it would not change the amount of attenuation available. It will also change the effective input impedance the preamplifier sees. If you change just the low pass pots to 50K, the effective input impedance will be 16.67K. Changing both high and low pass would yield 25K.
Anything above a 10K input impedance should present no problem for most preamps, some tube gear excepted. Since you are driving this crossover with a balanced source, it is probably capable of being connected to much lower input impedances, depending on its rating.
Appreciate your responses. Surprisingly I am getting a very different sound signature with the analog Lx-mini than with the DSP with same crossover point 300 Hz 12dB.
At 10K all trim pots equal, the low bass is louder, bloomy and highs recessed. I got much more details and gain control before via direct amplification to full range Lii-12 drivers vs using the Lx-mini crossover. I lost a few dB's on the highs.
How can I fix this issue and get back to perfectly blending Hi-Lo drivers outputs so they just magically dissapear?
At 10K all trim pots equal, the low bass is louder, bloomy and highs recessed. I got much more details and gain control before via direct amplification to full range Lii-12 drivers vs using the Lx-mini crossover. I lost a few dB's on the highs.
How can I fix this issue and get back to perfectly blending Hi-Lo drivers outputs so they just magically dissapear?
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LXmini with the low eq section in place adds a bump in the low bass that is not there in your DSP crossover. This is creating the sonic signature you are describing. I mentioned the bump in post #802 and then suggested you try it anyway in post #809.
If you don't like it, bypass it and you will have only the 300Hz 12dB LR filter without the low bump. The attenuator linked to in your post #829 should work just fine, although it should really not be needed. Try bypassing the bump first, then adjusting the trim pots on the PCB.
If you don't like it, bypass it and you will have only the 300Hz 12dB LR filter without the low bump. The attenuator linked to in your post #829 should work just fine, although it should really not be needed. Try bypassing the bump first, then adjusting the trim pots on the PCB.
Do I need to desolder all the parts and where is best location for jumper wire?
Actually I think you would be better off converting the Lo Eq section to a subsonic filter instead of bypassing it. For a 20Hz subsonic rolloff:
Change C1, C2, C5 and C6 to 0.1uF
Change R1, R3, R5, and R7 to 82K ohms
Change C1, C2, C5 and C6 to 0.1uF
Change R1, R3, R5, and R7 to 82K ohms
The analog crossover was fit closely to the DSP version provided by SL,
and was signed off by him. Both had the bump on the bottom.
Thanks Mr. Pass- I would prefer to keep original and faithful to your design. For now will try to feed the XO low output to a passive attenuator to a class-D amp in an attempt to blend it. The blue attenuators pots in balanced mode are tricky to adjust and will leave them to max. position
Papa:
He's using this crossover with an open baffle system. 12" woofer + 12" coax, both open baffle.
He's using this crossover with an open baffle system. 12" woofer + 12" coax, both open baffle.
I understand, and of course the original filters are not expected to be a
good fit...
Agree.. no system is perfect. In my view, trust your own ears.
Just aiming for the best OB crossover circuit for my simple 2 way set-up.. After many nights of playing with DSP, I settled down with 300Hz 12 dB for my own room and ears..and sounded pretty good. I realize all systems are a compromise the challenge I have now is to replicate digital ton analog with hopes of better outcomes.
So fat it's been trial and error. I am thankful for the community support to date
Just aiming for the best OB crossover circuit for my simple 2 way set-up.. After many nights of playing with DSP, I settled down with 300Hz 12 dB for my own room and ears..and sounded pretty good. I realize all systems are a compromise the challenge I have now is to replicate digital ton analog with hopes of better outcomes.
So fat it's been trial and error. I am thankful for the community support to date
I think the safest thing is to replace the caps and resistors in the Low Eq section with the values I list in post #832. That will give you a 300 Hz low pass with a subsonic roll off below 20 Hz and no bump in the low bass.
I have attached the LTSpice response plot the crossover will have if you do that.
I have attached the LTSpice response plot the crossover will have if you do that.