I have an ESS Eclipse 2241am 2-way electronic crossover unit for the AMT-1am and AMT Monitor loudspeakers. It was manufactured with an 800 Hz crossover point at a 12dB per octave slope. After reading numerous threads about the monitors sounding better if crossed over at a higher frequency, I would like to change cap and resistor values to try crossing over at 1kHz and 1.2kHz. In later versions of the AMT Monitor, ESS had raised the crossover to 1kHz. Can someone kindly look at the attached schematic and calculate values for 1 and 1.2kHz? ESS no longer has schematics for the revised 1kHz version. Thanks so much in advance.
Rick
Rick
It is 2nd order Butterworth and 6 db boost around 32Hz. Do you want Butterworth or LR at 1k and 1.2k? Changing 18k to 9k1 (or//18k) on HF and .02 to .01 on LF will do LR around 1.1k.
Thank you for your response. I so do appreciate it! I would like to keep it as Butterworth but just change required C & R values for both 1.0 kHz and 1.2 kHz crossover frequency so I can try them. Are the values shown correct for 800 Hz?
The schematic must not be complete as there is a variable pot for 0 to 6dB bass boost.
The schematic must not be complete as there is a variable pot for 0 to 6dB bass boost.
Attachments
Changing caps only is most likely to DTRT if you don't have a circuit schematic - not all resistors are setting time constants, and changing only capacitor values leaves the impedance unchanged at the roll-over point.
I do not know what DTRT is and know next to nothing about crossovers especially active types. Schematic is shown in the first post. I am looking to raise the 800 Hz cross to 1000 Hz (or 1200 might be better).
DTRT = do the right thing. To raise the frequency from 800 to 1000 reduce all cap values to 80% of their original values, to raise from 800 to 1200 reduce all caps to 67% of their original value. Problem is caps tend to come in a smaller range of standard values, that might constrain things a bit. And you have to beware of tolerances, resistors with 1% tolerance are common, less so for film capacitors.