hello everyone. im going a little slow building my MOX active crossover, so i had a thought. i already have matched stereo amps to passively bi-amp my front speakers. i was curious if i can remove the crossovers from the speakers, put them BEFORE the amp, and use them in place of the active crossover im building. would i really benefit from this? my speakers are pretty inefficient and power hungry (magnepan tympani 1D's).
i already have an outboard box i could use that will house the active crossover... so, if i just toss the guts of the current passive crossover in there, will it give me some of the benefit of the active crossover?
thanks!
i already have an outboard box i could use that will house the active crossover... so, if i just toss the guts of the current passive crossover in there, will it give me some of the benefit of the active crossover?
thanks!
any reason why?
magnepan actually sold early pairs of their tympani's with EXACTLY that. its a little box that is passive, has one pair of RCA's in, and two pairs out. it has full range in, and low and high out... it goes between the pre-amp and the amps. what is so different about that?
magnepan actually sold early pairs of their tympani's with EXACTLY that. its a little box that is passive, has one pair of RCA's in, and two pairs out. it has full range in, and low and high out... it goes between the pre-amp and the amps. what is so different about that?
Because for the crossovers to work as they should the load on them needs to be the same as the speaker, 8 ohms or so. But if you load them that way your preamp won't be able to drive it.
interesting. if there any way to make a passive xover that can be driven this way, or does it have to be an active one?
cool, thanks! if i remember correctly, my speakers only have a 6db/octave 2-way crossover. so doing a simple passive line level xover would be easy and cheap. ill look into it. thanks again.
This kind of RC-filters do not allow for steep(er) filter slopes as with CL-filters used in most "usual" passive crossovers.
It is possible though to use CL- filters in passive line level circuits when the load is lower than the 5k to 10kOhm loads as presented in the RC-filters from the link above (or as it is a common load value in many active crossovers too).
With let`s say 600 Ohms load the necessary big inductor values (up to about max. 100mH) for the LC-filters are still avaiable as small ferrite core inductors.
The load presented by this kind of passive filters may be to low to be driven properly by some preamps. with a wimpy output stage but with a suitable buffer (BUF634, LT1010 etc.) which can provide some "juice", this isn`t a problem.
Works fine!
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