Lets say I want two sets of outputs from a preamp. Can I just run two wires from my output stage? I assume this will split the available power between the two sets of outputs, are there other potential consequences?
Same question for adding an LFE channel. Could I split out a third line from my output and run it through a low-pass filter? Or split out a line from each channel, run it through a summing circuit, then a low-pass filter?
Same question for adding an LFE channel. Could I split out a third line from my output and run it through a low-pass filter? Or split out a line from each channel, run it through a summing circuit, then a low-pass filter?
Long runs of RCA cable, say 4 m each leg, can pick up RF noise like sports talk radio or CB's. 2 m is okay.
A useful device is the electronic crossover. I picked up a used one for $50 a Nady. Has inputs & outputs for stereo line level. Then mixes the two inputs for the bass channel, single output. Crossover frequency for the sub is settable with a dial. Below 20 hz cutoff for woofer protection from footsteps built in.
Check ebay or craigslist, gumtree in UK.
A useful device is the electronic crossover. I picked up a used one for $50 a Nady. Has inputs & outputs for stereo line level. Then mixes the two inputs for the bass channel, single output. Crossover frequency for the sub is settable with a dial. Below 20 hz cutoff for woofer protection from footsteps built in.
Check ebay or craigslist, gumtree in UK.
a] for RCA analog unbalanced interconnects. Using good shielded coax cables, RF interference should not be a problem. With cables more than 10 meters long, power line noise might be noticeable.
b] for RCA digital interconnects, in theory they should not be split, but in practice it will probably be OK.
c] for XLR balanced interconnects, splitting is OK, but both inputs need to be balanced inputs.
In any case, turning off power to one of the inputs, may do strange things.
b] for RCA digital interconnects, in theory they should not be split, but in practice it will probably be OK.
c] for XLR balanced interconnects, splitting is OK, but both inputs need to be balanced inputs.
In any case, turning off power to one of the inputs, may do strange things.
Are you guys bringing up cable length and shielding because splitting the signal will reduce the voltage level and thus increase susceptibility to interference?
This would be single-ended analog only, and just outputs.
EDIT: And while I'm here, is summing a stereo signal to mono to be sent to a subwoofer really this simple? (A low-pass filter would have to be added)
This would be single-ended analog only, and just outputs.
EDIT: And while I'm here, is summing a stereo signal to mono to be sent to a subwoofer really this simple? (A low-pass filter would have to be added)
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Well, no. Your resistance mixer is 1/3 the solution. you need to boost the signal back up to the 1.5 vac or 2 vac level or whatever the loads expect. This 2 resistor mixer works for sources that are 50 ohms capable, rare outside an electronics lab. Then the filter will take more current than a 10000 kohm input, unless active (involving transistors or op amps). 50 ohm sources can handle it, 2000 ohm sources like 4558 or 33078 cannot. You can build a mixer with a power supply , RF shielding case, RF filters in & out, and some op amps or transistors. Or you can buy one for ~$50 used. Called for this purpose an electronic crossover.
I have experienced AM sports talk radio at the end of a 4 m RCA cable into a power amp. Nearest AM radio station is about 3 miles. Driver in mixer was a 2000 ohm capable op amp. 4558 originally and changed to 33078 later to reduce hiss. I had to increase bypass capacitor of that power amp from 68 pf to 120 to filter out the radio station.
I currently have a different power amp 2 m away by RCA cable from the mixer, with 12 ga speaker cables running across the floor 4m to speakers. Cables are a bad trip hazard, and running the speaker cables under the floor would involve drilling 1.5 cm diameter hole since the phone plug connector is that big. The Speakon connector on the speaker is even bigger.
I have experienced AM sports talk radio at the end of a 4 m RCA cable into a power amp. Nearest AM radio station is about 3 miles. Driver in mixer was a 2000 ohm capable op amp. 4558 originally and changed to 33078 later to reduce hiss. I had to increase bypass capacitor of that power amp from 68 pf to 120 to filter out the radio station.
I currently have a different power amp 2 m away by RCA cable from the mixer, with 12 ga speaker cables running across the floor 4m to speakers. Cables are a bad trip hazard, and running the speaker cables under the floor would involve drilling 1.5 cm diameter hole since the phone plug connector is that big. The Speakon connector on the speaker is even bigger.
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