Hi folks,
I'm runnings some floorstanders and a subwoofer. At the moment, I'm running high level in and out of the sub at 80hz Butterworth (order not specified in manual). I want to build a pair of passive subs eventually.
I'm looking at how to best crossover the sub(s) and floorstanders. I'm not interested in miniDSP (though may do some REW in the digital domain) and am looking at active crossover options. I won't go into it, but the speaker designer has indicated an improvement in the mids (and max SPL) with an 80hz LR4 crossover.
I'm particularly interested in ESP P09 (https://sound-au.com/) and the DIY Biamp 6-24 Crossover. The idea would be to place the active crossover between pre and power to split mids/highs (mains) and lows (sub).
My pre-amp has very low output impedance (2ohm) and power amp has low input impedance (1kohms). Ideally, according to the manufacturer, the output impedance of anything driving the power amp should be 10ohms or less ideally up to 50ohms. This is a bit higher than the typical 1:10 ratio but I'd prefer to stick with ~10ohms.
Both active crossovers have an output resistor to reduce high frequency oscillations from opamps/JFETs (respectively) and as far as I can tell, this largely determines the output impedance. I've tried searching and I can't quite figure out a few things...
Any assistance would be much appreciated. I'm a way off building something but good to plan and understand my options.
I'm runnings some floorstanders and a subwoofer. At the moment, I'm running high level in and out of the sub at 80hz Butterworth (order not specified in manual). I want to build a pair of passive subs eventually.
I'm looking at how to best crossover the sub(s) and floorstanders. I'm not interested in miniDSP (though may do some REW in the digital domain) and am looking at active crossover options. I won't go into it, but the speaker designer has indicated an improvement in the mids (and max SPL) with an 80hz LR4 crossover.
I'm particularly interested in ESP P09 (https://sound-au.com/) and the DIY Biamp 6-24 Crossover. The idea would be to place the active crossover between pre and power to split mids/highs (mains) and lows (sub).
My pre-amp has very low output impedance (2ohm) and power amp has low input impedance (1kohms). Ideally, according to the manufacturer, the output impedance of anything driving the power amp should be 10ohms or less ideally up to 50ohms. This is a bit higher than the typical 1:10 ratio but I'd prefer to stick with ~10ohms.
Both active crossovers have an output resistor to reduce high frequency oscillations from opamps/JFETs (respectively) and as far as I can tell, this largely determines the output impedance. I've tried searching and I can't quite figure out a few things...
- Can the output resistors be reduced to something like 10ohms in either option? Would this be opamp-dependent in the case of P09?
- Are the high frequency oscillations affected by input impedance of the load the crossover will drive at the power amp?
- ESP notes that the resistor is partly to reduce current, how does this requirement to reduce current change with a lower than typical impedance load at the power amp?
Any assistance would be much appreciated. I'm a way off building something but good to plan and understand my options.
1) Fristly no, stick with the value given, it will have been tested as stable. Too low and the circuit could be unstable into a cable load.
2) There won't be any oscillations unless you ignore point 1)
3) That's only for short-circuit protection, nothing to do with normal operation. RCA plugs are easy to accidentally short.