Hi, I own a pair of ADS L1590/2 speakers. These speakers sound nearly perfect, except for a little mid-bass boom. There is an "Umm" sound in the male voice, which is a little bit annoying to me.

The low-pass filters on the woofers are pure second-order, without any other circuits, consisting of a 3.5 mH and a 100 uF capacitor. I have a 4 mH coil and a 130 uF cap for spare parts. I'm thinking of modifying the crossovers by using these components.

Then, I tried simulation on the old and new crossovers, and there were no problems with the results at all—smooth frequency responses and impedance curves.

However, my friend suggested to me that, in the second-order filters, the inductor value should not exceed the driver's impedance, which here is 3.8 ohms. So, I wonder whether his statement is true. Anyone could confirm, please?

The low-pass filters on the woofers are pure second-order, without any other circuits, consisting of a 3.5 mH and a 100 uF capacitor. I have a 4 mH coil and a 130 uF cap for spare parts. I'm thinking of modifying the crossovers by using these components.

Then, I tried simulation on the old and new crossovers, and there were no problems with the results at all—smooth frequency responses and impedance curves.

However, my friend suggested to me that, in the second-order filters, the inductor value should not exceed the driver's impedance, which here is 3.8 ohms. So, I wonder whether his statement is true. Anyone could confirm, please?

Last edited: