Hi Everyone,
I've been thinking about something. I use L Pads and Zobels a little unconventionally, and I don't see it discussed often.
L-Pads
The usual reason for an L-Pad is to decrease the volume of a driver (usually a tweeter) while maintaining the same impedance. This reduces parts cost if you are buying exotic caps. Doubling the impedance means doubling the capacitance needed for a filter, which in some cases, can mean 2X the money. Of course, in general, speakers with flat impedance curves are more amplifier friendly too.
However, another reason to use an L-Pad in my mind is to design a speaker when you aren't sure about the final tweeter level. Using an L-Pad to keep a constant impedance while varying the level of the tweeter means we don't have to rethink the filter each time. So it's kind of a convenient vestige.
Zobels
Zobels can be tweaked a great deal, and still provide a relatively stable impedance to the low-pass filter. I like to use them sometimes to nudge the phase matching between a mid-woofer and tweeter. Am I being too fussy?
Best,
E
I've been thinking about something. I use L Pads and Zobels a little unconventionally, and I don't see it discussed often.
L-Pads
The usual reason for an L-Pad is to decrease the volume of a driver (usually a tweeter) while maintaining the same impedance. This reduces parts cost if you are buying exotic caps. Doubling the impedance means doubling the capacitance needed for a filter, which in some cases, can mean 2X the money. Of course, in general, speakers with flat impedance curves are more amplifier friendly too.
However, another reason to use an L-Pad in my mind is to design a speaker when you aren't sure about the final tweeter level. Using an L-Pad to keep a constant impedance while varying the level of the tweeter means we don't have to rethink the filter each time. So it's kind of a convenient vestige.
Zobels
Zobels can be tweaked a great deal, and still provide a relatively stable impedance to the low-pass filter. I like to use them sometimes to nudge the phase matching between a mid-woofer and tweeter. Am I being too fussy?
Best,
E
Also in a low pass filter, doubling the impedance, means halving the capacitance but doubling the inductance. Working low impedance can lead to more expensive components unfortunately.
C.M
C.M
I don't think so. It's one thing if you are fixing the load for an amplifier where it makes less sense to go for anything but resistive. Making a driver impedance flat to make it easy to work with is another, but in this case the RC simply becomes a part of the crossover so if you can change it and make it work for you I would.
Speaking of fixed pads, investigating the available extremes of result can open opportunities for amplifiers or crossover parts.
I have found that an L-Pad doesn't always make the impedance flat enough that it can be ignored. Eg, a compression tweeter, even with heavy padding is better with separate fixing around Fs.
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