I often see the modified second-order crossover topology, as I call it myself, used in many speakers. Notice the R1; it is usually found on low-pass filters in both 2- and 3-way systems.

The simulation showed that the R1 is used to modify the slope of the low-pass filter, or someone could define it, in other words, as a Q adjuster.

According to observations, its value usually stays in a range of 0.5 to 2 Ohms. I believe the manufacturers don't put it there randomly. Despite my research into many of Loudspeaker's cookbooks, I found little to no mention of them.

Therefore, I'd like to ask directly: Is there a formula or calculation method for R1?

The simulation showed that the R1 is used to modify the slope of the low-pass filter, or someone could define it, in other words, as a Q adjuster.

According to observations, its value usually stays in a range of 0.5 to 2 Ohms. I believe the manufacturers don't put it there randomly. Despite my research into many of Loudspeaker's cookbooks, I found little to no mention of them.

Therefore, I'd like to ask directly: Is there a formula or calculation method for R1?

#### Attachments

Last edited: