JL e110 sub

hi guys,
I just bought a JL e110 sub.  I understand that it has a low pass filter.
When the active crossover is on, the low freq signal is filtered into the sub.
But I also get low frequency signal into my main speakers?

Is that the way it's supposed to be?  Anyone with experience with this sub?

Try reading this thread. Congrats on the great sub purchase.


actually i read that thread. 
But it's still not very clear.

I put the subwoofer between the preamp and amp, utilizing the JL's internal crossover.

When I set the sub crossover at 60 hz, and when I play a test track of 50 hz, am I supposed to hear output from the speakers also?  or should they be dead quiet, since all the signal is going to the sub?

thanks again
Dead quiet? I don’t think so.

I would imagine there would be some sound coming through at a much lower level than otherwise. The further down you listen from the crossover frequency, the SPL from the main speakers should drop off dramatically. 80dB per decade (or 24dB per octave) according to what I’ve been reading.

Can you describe your setup?

i am using a locally built tube preamp and amp

there is no sub output from the preamp so i need to place the sub in between and use the internal crossover

speakers are totem hawks for now but getting new ones soon

i don't quite get how crossover works.  I thought if you set the freq to say 60 hz, then there is no signal going to the main speakers.  If there is, then essentially i am running the speakers full range, and supplementing freq below 60hz with the sub.  How do people connect to subs at line level without crossover.....so confusing
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From page 15 of the e110 manual...

Crossover Switch
The “crossover” selector switch determines the operating mode of the E-Sub’s built-in active crossover.

“Off” defeats the crossover filter, completely removing this circuit from the signal path and is most useful when using a receiver or preamp/processor’s filters and bass-management features.

“On” activates the on-board active crossover. This crossover consists of a 24 dB/octave low-pass filter for signals feeding the E-Sub’s internal amplifier, plus a 24 dB/octave high-pass filter feeding the “Line-Outputs” on the E-Sub’s rear connection panel. This is most useful when integrating the E-Sub into a two channel audio system.

Crossover Frequency Knob
The “crossover freq. (Hz)” selector knob allows the user to choose the crossover frequency of the E-Sub’s built-in, active crossover. It has no effect when the “crossover” switch is in the “off” position. The frequency is variable from 25 Hz (full counter-clockwise) to 130 Hz (full clockwise). 80 Hz is a commonly used filter frequency and usually serves as a good starting point for adjustments.


So you would connect the preamp outputs (variable level; i.e., volume controlled; NOT record outputs) to the line level inputs on the sub and then connect the line level outputs on the sub to the inputs of your amp. I assume that is what you have done.

With the Crossover Switch set to On and the Crossover Frequency Knob set to 60 Hz, the sub will receive frequencies below 60 Hz and the amp/speakers will receive frequencies above 60 Hz. However, the slope of the filter is not infinite, so near the crossover frequency you will still be able to hear the attenuated signal in both the sub and main speakers. However, if you go out to one octave on either side of the crossover frequency, 30 Hz and 120 Hz in this case, the signal will be attenuated 24 dB and you probably will not be able to hear it unless you turn the volume quite loud and the room is quiet.

Does that help?

 I thought if you set the freq to say 60 hz, then there is no signal going to the main speakers.  If there is, then essentially i am running the speakers full range, and supplementing freq below 60hz with the sub. 

Your thinking is correct IFF the slope of the filter is infinite, effectively a brick wall filter. You are not running the speakers full range. The signal you hear is actually attenuated. If you have an SPL meter, you can verify that. But, because 50 Hz is so near the crossover frequency it has not been attenuated very much.

You'll find 1st, 2nd, 3rd and 4th order filters used in speakers which have slopes of 6, 12, 18 and 24 dB/octave respectively. So there is always some overlap on either side of the crossover frequency. The steeper the slope, the less the region of overlap.

Got it
thanks for the explanation 
Yes you just need to turn the cross over on. There is no low pass filter only a crossover. If you don't want to use it as a crossover just use the line in with no line out and it will work the same as a filter but have an adjustable slope. 

I have two jl112es