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Author Topic: Active Xover into Passive Xover  (Read 1637 times)

Whit Hutchinson

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Active Xover into Passive Xover
« on: December 21, 2006, 12:30:47 am »

Hey guys I have a question about active X-overs.  I have a pair of EV Eliminator Subs (dont bash too much please) and when I ran my DRPA into them Xing over at 100 HZ or so trying to get the sub bass response I needed, it seemed it just clipped my amps alot and ran into alot of current draw.  I first blamed the amps but then I ran them passive at a little more than RMS power and thee things have fairly good "bass" but not much "sub bass".   It seems as if they like the 80s higher end "Tone Loc" bass if you know what I mean.


My question is that if I ran an Xover of 100hz or so from an active  unint such as the DRPA into the passive Xover low pass builtin in network, am I filtering out all of the bass and only trying to reproduce the really low notes that this box wont hit?

If a cab has a passive corssover should you feed it full range signal no matter what, or does it not matter if you use an active Xover frist.   I know the best case is to remove the passive filter from the cabs and run everthing from a DRPA or similar, but this does not work when someone "Hey let me borrow/rent some subs for the dj/band this weekend" and they only have a spare 600x2 amp laying around with no way to crossover.
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Paul O'Brien

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Re: Active Xover into Passive Xover
« Reply #1 on: December 21, 2006, 10:50:15 am »

Whit Hutchinson wrote on Thu, 21 December 2006 00:30

My question is that if I ran an Xover of 100hz or so from an active unit such as the DRPA into the passive Xover low pass built-in network, am I filtering out all of the bass and only trying to reproduce the really low notes that this box wont hit?



That's entirely possible. What model Eliminators are these? The built-in passive xover is probably a 6 or 12db filter at 150hz, so it's out of the picture when the active is inline at 100hz. Do you have low cut filters engaged on the amps or DPRA? These should be set at the -3db point of the Eliminators to prevent wasting amp power trying to reproduce sub bass the boxes cannot handle.
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Paul O

Too Tall (Curtis H. List)

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Re: Active Xover into Passive Xover
« Reply #2 on: January 02, 2007, 02:36:56 pm »

Paul O'Brien wrote on Thu, 21 December 2006 10:50

Whit Hutchinson wrote on Thu, 21 December 2006 00:30

My question is that if I ran an Xover of 100hz or so from an active unit such as the DRPA into the passive Xover low pass built-in network, am I filtering out all of the bass and only trying to reproduce the really low notes that this box wont hit?



That's entirely possible. What model Eliminators are these? The built-in passive xover is probably a 6 or 12db filter at 150hz, so it's out of the picture when the active is inline at 100hz.


Do you have low cut filters engaged on the amps or DPRA? These should be set at the -3db point of the Eliminators to prevent wasting amp power trying to reproduce sub bass the boxes cannot handle.






I agree completely that a well placed hi pass on the sub for efficiency and to keep it from ripping itself into pieces is a great idea. The Eliminator series have always been about high sensitivity, not low frequency extension. You might be shocked to find out how high the high pass for the sub can go before it cuts into its low frequency reach.

150 and 100hz are so close they will “add” to each other and you will get a very steep and/or wild filter. The bad part here would be how well they combine with the woofer in the full range and for that matter how the passive and active combine for the sub below 100Hz. You have some big phase issues here and they might be lining up against you. You could be losing all the energy from 80hz to 150hz if the phase combines in a cancellation pattern.
I am not claming that it is happening, but you need to make sure it isn’t.




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