M

Mitchell Torres

Audioholic Intern
JBL E150 subwoofer settings.....


What line level should the subwoofer be set to?

and what crossover frequency should it be set to?

AND....in the receiver set up in the subwoofer selection, should it be set to both (front and sub) or just subwoofer for the LFE?

thanks!
 
L

Leprkon

Audioholic General
Mitch,

the crossover is going to depend on your main speakers. If you have good-sized mains with a decent woofer of their own, you would probably set the crossover lower. It would make your sub more efficient.

If your mains have a small woofer, your would set the crossover higher so that your sub could fill in for the lack.

If you have the speaker manuals or the specs from somewhere on your mains, look at the lowest frequency they produce, (the frequency rating usually looks like 45 -18,000 Hz), then set your crossover about 10 Hz above the lowest number (so in my example, you would set it to 55 or as close as you could). Use that as a starting place and see how you like the sound. Try a little up and a little down to see if it matches your personal taste a little better.

Subs usually take a little more work to get them right where you want them, so take your time and don't be surprised or discouraged if you have to try several times.

I think you would want to set the LFE to sub only. Low frequency effects are "omnidirectional" and a single source can do a very good job of filling an entire room. By sending the LFE source to three different speakers, you risk some possibility of the signals cancelling each other out and causing some dead spots. The sub is best equipped to deal with LFE... let it do what it does best. :)
 
M

MDS

Audioholic Spartan
The preferred way is to connect a cable from the receiver's sub pre-out to the L(eft) line level input on the sub. This connection allows you to use the receiver's bass managment capabilities. You then have two choices for the LFE switch on the back:

1. Set the LFE switch on the sub to LFE. In this setup, the sub's internal cross over is disabled, so the position of the dial on the back of the sub is irrelevant.
2. Set LFE switch to 'normal'. In this setup, the sub's cross over is not disabled and you have two competing cross overs (the receiver and the sub). You can do this and turn the sub's crossover dial to a setting higher than the receiver's to get it out of the way. It's better to just use the LFE setting and rely on the receiver bass managment, but some people might set it to normal and fiddle with the two cross overs to achieve a good blend.

As far as the correct cross over setting, a general rule of thumb is 1/2 to 1 octave above the F3 point of the least capable speaker. The F3 point is the frequency where the speakers output is down 3 dB and can be found in the specs for the speakers where it might say something like '75Hz - 20kHz (+/- 3 db)'. An appropriate setting would be anywhere from 80Hz (right near the F3) to 120 Hz (half an octave above 80Hz).

All speakers should be set to 'small' for the above. Speakers set to small will have all bass below the cross over point you set, sent to the sub. LFE, if present, will be sent to the sub only.

Speakers set to 'large' will get a full frequency signal and any bass destined for that channel will NOT be re-directed to the sub. Only the LFE, if present, will get sent to the sub.

Settings called BOTH or LFE+MAIN will send the bass and LFE to speakers designated 'large' AND the sub. Only do this if you have very large main speakers that can play very low and/or you crave alot of bass - but beware that the bass may be too overpowering using that setting.
 
M

Mitchell Torres

Audioholic Intern
OK should the power to the subwoofer be left on?
 
M

MDS

Audioholic Spartan
It's really personal preference whether you want to leave the sub on all the time, but I would. That sub has auto turn-on when it senses a signal, and in my experience it works well. If it hasn't seen a signal in awhile (10 minutes, I think), it automatically goes into stand by mode.
 

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