My friend bought these types of resistors for the L-Pad in his crossover. His tweeter needs a fair bit of attenuation. At a theoretical white noise load at 20V RMS, I think it was about 20-40W through the resistors. This design already uses two parallel resistors to split the load. link to similar product, not necessarily this exact listing
I believe that such a load is very unrealistic in everyday use. To my understanding higher frequencies need less voltage for the same perceived loudness. If we simulate the crossover with pink noise instead, the power of all components drops significantly (total power around 4W).
My question boils down to:
1. Are there any reasons related to the sound quality to not use this type of resistors?
2. How much power could these resistors handle without being attached to a heatsink?
3. Should we even worry about the power dissipation? Will they ever see such a large load?
Bonus question: Why does simulating with pink noise in VituixCad reduce the power usage of components by a factor ~10-20? It seems like too big of a difference.
(Below not his exact system, but similar. I do not have his files. Black = resistors, Red = Woofer)
I believe that such a load is very unrealistic in everyday use. To my understanding higher frequencies need less voltage for the same perceived loudness. If we simulate the crossover with pink noise instead, the power of all components drops significantly (total power around 4W).
My question boils down to:
1. Are there any reasons related to the sound quality to not use this type of resistors?
2. How much power could these resistors handle without being attached to a heatsink?
3. Should we even worry about the power dissipation? Will they ever see such a large load?
Bonus question: Why does simulating with pink noise in VituixCad reduce the power usage of components by a factor ~10-20? It seems like too big of a difference.
(Below not his exact system, but similar. I do not have his files. Black = resistors, Red = Woofer)
You want something with low inductivity. The listing you provide does not show inductivity. 10 W rating is ample for a tweeter L-pad. I always use Visaton resistors, either MOX or ceramic will do. And they're about the same price, and proven to be OK for this application. Why re-invent the wheel?
Besides being inductive, the rated power is only available with a large heat sink.
Otherwise the part must be substantially derated according to the mfr specs.
Pink noise rolls off at -3dB per octave, so there's no mystery why there is less power.
Use white noise instead.
Otherwise the part must be substantially derated according to the mfr specs.
Pink noise rolls off at -3dB per octave, so there's no mystery why there is less power.
Use white noise instead.
Looking again, the description does say "There is no inductive winding for low-reactance components" whatever that exactly means. They also mention audio as a use case and 50W dissipation without a heatsink. Maybe my friend's build will be fine.
There's no way those can safely dissipate 50W each without a substantial heat sink.
In fact the rating is likely with an infinite heat sink (25C).
In fact the rating is likely with an infinite heat sink (25C).
Well, I'm not saying I fully trust AliExpress listings, I'm just repeating what they put in the description. They claim the 100W model can do 50W without a heatsink
Should be fine
20 volts wont be constantly applied at normal listening levels.
Even if so, they are rated well above that power level for a tweeter pad.
20 volts wont be constantly applied at normal listening levels.
Even if so, they are rated well above that power level for a tweeter pad.
