In three-way speakers design, if we'd like to reduce the SPL of the midrange and tweeter, it could be easily achieved by adding the L-Pad circuits to the drivers. However, some people used to advice the resistors should be used as minimum as possible because they would introduce loss, and some distortions, to the system. Hence, I found the alternative method that is to use a single resistor on each driver and redesign the whole crossovers.
As can be seen, the modified crossovers could provide the same result as using the L-Pads on midrange and tweeter.
I wonder which way is more suitable between adding L-Pads to both midrange and tweeter, or redesign the crossovers and use only single resistor for each driver?
As can be seen, the modified crossovers could provide the same result as using the L-Pads on midrange and tweeter.
I wonder which way is more suitable between adding L-Pads to both midrange and tweeter, or redesign the crossovers and use only single resistor for each driver?
You need to use real impedance measurement data to see the difference.
In short: usually an L-pad is less driver-impedance dependent.
In short: usually an L-pad is less driver-impedance dependent.
Well, isn't loss exactly what want if one of the drivers is more efficient than the other(s)? Additionally, I don't see any reason why a resistor might introduce non-linear distortions. The resistor value(s) have to be chosen accordingly, hence there is no general rule like »as low as possible«.
Best regards!
Ignore "some people's" advice. Use as many resistors as required to achieve your target response.
There's one context where you may have read that resistors are a bad idea: I've seen some other people suggest that an easy way to modify the TS parameters (Qes in particular) of a woofer to suit a specific box is to put a resistor in series with it. This does work in a pinch but it's indeed going to waste power, always better to find a more suitable woofer for your box or a more suitable box for your woofer. This has nothing to do with padding your midrange and/or tweeter to match your woofer's response, this is standard practice and there's nothing wrong with it.
There's one context where you may have read that resistors are a bad idea: I've seen some other people suggest that an easy way to modify the TS parameters (Qes in particular) of a woofer to suit a specific box is to put a resistor in series with it. This does work in a pinch but it's indeed going to waste power, always better to find a more suitable woofer for your box or a more suitable box for your woofer. This has nothing to do with padding your midrange and/or tweeter to match your woofer's response, this is standard practice and there's nothing wrong with it.
In some cases L-pads make the impedance more consistent, so the crossover function may improve with them.
Additionally, if you don't know for sure how much you need to decrease output, the L-pad is more likely to let you adjust the level without impacting the crossover in a significant way.
If the crossover is already dialed in though, switching from an L-pad to a single resistor might make sense just because it reduces part count. It will depend on the driver, amount of attenuation, crossover, etc.
Additionally, if you don't know for sure how much you need to decrease output, the L-pad is more likely to let you adjust the level without impacting the crossover in a significant way.
If the crossover is already dialed in though, switching from an L-pad to a single resistor might make sense just because it reduces part count. It will depend on the driver, amount of attenuation, crossover, etc.