View Full Version : FMOD Inline rca low pass crossovers?
11-28-2009, 02:02 PM
I'm presently using a 150Hz low pass filter (speaker level output) for my subwoofer. I'm thinking about using the 150Hz FMOD line level fiter instead...Are these things any good?
11-28-2009, 02:07 PM
they do what they say. i have used the 30 hz high pass with success.
11-28-2009, 02:23 PM
go to harrison labs website and click on crossovers. they have a subsonic filter(hp-sub) w/selectible 5hz values, i believe 20,25,30,35.
11-29-2009, 12:22 AM
They are dependent on impedance, same as a passive. Not all pre-amps and amps have the same impedance, so the fmod will not always work as advertised.
11-29-2009, 06:11 AM
johnny is right.
I had lots of them in lots of systems.
they are geared towards a 10k ohm amp or maybe a 22k amp I forgot i have not used them for a long time.
. if your amp has 47k impedance they will sound wrong.
buy this instead. you can adjust volume with it and adjust crossover freq. you don't need to use the satellite part just use the sub part. it also has a subsonic feature to protect the sub from too deep bass, 15hz or so.
11-29-2009, 04:56 PM
I'm running a small 12VDC powered portable system and these FMODs suits my need. I will give them a shot and see what happens.
In regards to amplifier impedances....Is is safe to say that consumer grade amplifiers/recievers will have 47K ohm input impedances, will audiophile grade amps have lower input impedances?
I'm using the Boston Acoustic LCAi220 local control amplifier I purchased here to power my portable system, but it doesn't state much specs. I'm planning to use one FMODs between the output of my portable CD player and this amp. The left channel for sub bass and the right for full range.
DARN!!!...What i need is a 12VDC active subwoofer crossover!...Does anyone know of any?
11-29-2009, 06:13 PM
12VDC electronic crossovers are, well, extremely common.
More money, more features. (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=267-822)
I have a 3-way Coustic electronic crossover (XM6) I can sell. It works pretty good, quiet. I powered it with a computer power supply, but that was only because I also had a small 2 channel amp. This could be powered by a 1 amp 12V wall-wart.
11-29-2009, 10:02 PM
this would also work.
I have one sitting in a box somewhere.
I have a lot of fmods sitting around somewhere I have some of hlabs better passive crossovers. sitting around
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