@Wolf said: @dcibel- I don't see the issue some people have with placing the series resistor at the input. The advantages are that it does not tilt the FR, and that it helps keep the impedance phase more linear. Being that the post filter still highpasses the bandwidth, the resistors do not get hot, nor is it a direct load prone to such a result.
Here's the power dissipation for the circuit above. Both series and shunt resistors are similar values at 13 and 12 ohm respectively. Series resistor is the worst offender for power dissipation, not the shunt, although both are "bad". That is all.
Removing the shunt resistor, the 13 ohm series resistor alone is much happier, fine in most cases for a tweeter circuit and a shunt alone would be much worse (similar to above), but I would still tend to avoid just as a "best practice", there is always another way to achieve the FR goal.
First one looks like shunt is before the highpass since it is gobbling up a steady amount of power at lower frequencies until the highpass kicks in. Second one is with shunt removed since no power is drawn until the highpass allows current to flow.
If I'm not mistaken, Xsim power requirements also do not factor in the decreasing scale that higher frequencies actually require less power, and therefore it operates at same linear power scale required for all frequencies, correct? This means that required power handling in the treble is actually less than shown, and that this is a worst case scenario. I'm pretty sure I read this at one point, but please correct me if I'm wrong.
As it sits, i still see no issue with the fore series resistor.
@Steve_Lee said:
Is the OP happy with the FR of the XO at this point?
That crossover was made with the actual woofer measurements, but the tweeter frd was made from the manufacturer's data (ran through response modeller). I did this to see if I could make the tweeter work with this particular woofer before I ordered them. The final tweeter response will be nowhere near that flat as they are destined to be installed in the Sansui speakers I am working on, behind the speaker grills of death, where flat frequency response goes to die
@jr@mac said:
I don't agree with the parallel resistor before the XO, but the woofer will shit the bed long before a 10W resistor will.
I'm trying to imagine both a bedridden/decrepit woofer and resistor accomplishing this feat of utter contempt for getting up and going to the bathroom in audio terms, JR.
Can you please put this into context for us still able to bark like a woofer and resist the temptation to do so?
Woofers almost always run out of mechanical power handling before anything else has a chance to get hot. Most playback occurs in the 3-10W range - full spectrum, meaning even padding before a crossover in a tweeter circuit means it needs to dissipate jack-shit.
@jr@mac said:
Woofers almost always run out of mechanical power handling before anything else has a chance to get hot. Most playback occurs in the 3-10W range - full spectrum, meaning even padding before a crossover in a tweeter circuit means it needs to dissipate jack-shit.
Much ado about nothing.
"Mechanical power handling", like exceeding Xmax at 3 ~ 10 Watts ?
@jr@mac said:
Woofers almost always run out of mechanical power handling before anything else has a chance to get hot. Most playback occurs in the 3-10W range - full spectrum, meaning even padding before a crossover in a tweeter circuit means it needs to dissipate jack-shit.
Much ado about nothing.
"Mechanical power handling", like exceeding Xmax at 3 ~ 10 Watts ?
Yep. Surprising how few watts it can take to unload a ported woofer below tuning. Also surprising how few ways it takes to get to high volume.
Comments
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In which position is the shunt, fore or aft?
InDIYana Event Website
See schematic in 1st post.
First one looks like shunt is before the highpass since it is gobbling up a steady amount of power at lower frequencies until the highpass kicks in. Second one is with shunt removed since no power is drawn until the highpass allows current to flow.
Correct. It's fine, so I agree with Wolf's assessment.
If I'm not mistaken, Xsim power requirements also do not factor in the decreasing scale that higher frequencies actually require less power, and therefore it operates at same linear power scale required for all frequencies, correct? This means that required power handling in the treble is actually less than shown, and that this is a worst case scenario. I'm pretty sure I read this at one point, but please correct me if I'm wrong.
As it sits, i still see no issue with the fore series resistor.
InDIYana Event Website
Is the OP happy with the FR of the XO at this point?
There is a VERY SLIGHT difference in the modelled HPF response in the second Xsim pic than in the OP.
I don't agree with the parallel resistor before the XO, but the woofer will shit the bed long before a 10W resistor will.
That crossover was made with the actual woofer measurements, but the tweeter frd was made from the manufacturer's data (ran through response modeller). I did this to see if I could make the tweeter work with this particular woofer before I ordered them. The final tweeter response will be nowhere near that flat as they are destined to be installed in the Sansui speakers I am working on, behind the speaker grills of death, where flat frequency response goes to die
I'm trying to imagine both a bedridden/decrepit woofer and resistor accomplishing this feat of utter contempt for getting up and going to the bathroom in audio terms, JR.
Can you please put this into context for us still able to bark like a woofer and resist the temptation to do so?
Thanks, man.
Woofers almost always run out of mechanical power handling before anything else has a chance to get hot. Most playback occurs in the 3-10W range - full spectrum, meaning even padding before a crossover in a tweeter circuit means it needs to dissipate jack-shit.
Much ado about nothing.
I'ts pretty amazing how people can get so wound-up and excited over a simple question and the answers given, isn't it?
I don't think anyone here was pissy. I hope I didn't come off that way, if so it was never my intention.
The conversation took a turn when I said:
"Mechanical power handling", like exceeding Xmax at 3 ~ 10 Watts ?
Yep. Surprising how few watts it can take to unload a ported woofer below tuning. Also surprising how few ways it takes to get to high volume.
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