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Post by copperpipe on Sept 6, 2012 6:58:08 GMT -5
I'm not sure if "hardware crossovers" is the correct / technical term... but basically I am setting up a 12.2 channel dedicated music system in an auditorium; 12 main speakers, 2 subs. The subs of course have a filter where they ignore everything above, say, 80 or 100 hz, but is there anything I can purchase which will sit in front of the amps and discard anything below 80 or 100 hz for the 12 main speakers? The idea is to prevent the amps from wasting their time and energy playing a signal that is supposed to be played by the subs. We don't have much of a "pre / pro" (which from what I understand is ususally the hardware that handles all of this in a home theatre type setup), we are going straight from the analog out of a 16 channel computer sound card into the amps...
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Post by bobbyt on Sept 6, 2012 7:35:00 GMT -5
You're referring to an "active crossover" (preamp level), as opposed to the more typical "passive crossover" (after amplification, simply throwing away part of the amplified signal). Here's a pretty thorough article on why active is a better approach, along with being much more efficient. Standalone active crossovers are more common in the pro audio world, but active speakers or active monitors are speakers with active crossovers and separate channel amplification. Emotiva's Airmotivs are one example...I have the 6s and couldn't be happier. sound.westhost.com/bi-amp.htm |
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Post by GreenKiwi on Sept 6, 2012 9:44:30 GMT -5
You might check out the anti mode DACs.
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Post by copperpipe on Sept 6, 2012 12:38:45 GMT -5
You might check out the anti mode DACs. Thanks for the heads-up on that; unfortunately at 713 Euros a piece that is not going to be an option for us   |
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Post by jackfish on Sept 6, 2012 13:06:58 GMT -5
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Post by oppman99 on Sept 6, 2012 17:59:00 GMT -5
I've used the ones jackfish linked to. Got mine from Parts Express. Used them with a pair of Airmotive 5's and a small sub. Didn't seem to have any negative impact on the sound. Also hooked them up in my main rig. Them seem to do the job.
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Post by copperpipe on Sept 6, 2012 18:57:44 GMT -5
Thanks for the link! Are those all "active crossovers", ie all of those sit between the sound card and the amp? How would I choose what to purchase? Looks like some are "fixed frequency" and some are variable, but in both groups what's the difference? (sorry, newbie here  ) |
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Post by jackfish on Sept 7, 2012 10:07:32 GMT -5
You would get 70Hz or 100Hz FMOD High Pass Crossover Pairs depending the desired crossover point based on what you said in your first post. They are not active crossovers, they are a passive device. They would go between the sound card and the amp. You could just plug them into the amp and run an RCA cable between them and the sound card.
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DYohn
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Post by DYohn on Sept 7, 2012 10:39:45 GMT -5
Thanks for the link! Are those all "active crossovers", ie all of those sit between the sound card and the amp? How would I choose what to purchase? Looks like some are "fixed frequency" and some are variable, but in both groups what's the difference? (sorry, newbie here ) The FMODS are passive filters that yes, are used between the sound card and the amplifier. Choose a frequency that matches your subwoofer crossover frequency. |
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Post by copperpipe on Sept 7, 2012 11:34:43 GMT -5
Ok thanks. One last question, is there any noticeable effect from using these that I should be aware of... ie. do they affect the volume level, or distort the noise or do anything to the signal other than "throw away" the stuff below 70 or 100 hz etc?
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DYohn
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Post by DYohn on Sept 7, 2012 11:39:02 GMT -5
Ok thanks. One last question, is there any noticeable effect from using these that I should be aware of... ie. do they affect the volume level, or distort the noise or do anything to the signal other than "throw away" the stuff below 70 or 100 hz etc? They don't "throw away" anything, they filter the signal. Also don't expect any passive crossover to be a "brick wall." They reduce the volume of the signal below the crossover point (for a high pass filter) at whatever the slope of the filter is listed at. Most FMOD crossovers are, I believe, -12db/octave. So you may still hear sounds below the crossover point, they will just be greatly reduced in volume. No, they do not alter the passed-through signal in any significant way. |
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