How to balance new sub w/ system (1 Viewer)

I just got a new sub (JBL PB12) that I now need to integrate into the rest of the system which is JBL NSP1's driven by a Pioneer 511. I've got a few questions:
1. What is LFE and how is it used?
2. How do I set the crossover freq, sub level, etc. correctly? Is this just what sounds good or is there something a bit more methodical available?

sorry for a newbie type question, but the search function is disabled. If you could point me to a thread, that would be great. Thanks.

-Scott

not familiar with either bit of kit, but this should help you to get going.

1) LFE stands for low frequency effect and in a dolby/dts 5.1 setup it is the .1 because it is not a full range speaker.

2) I assume you ae only setting it up for home cinema. On the amp you should have a single phono out connection for the sub, it will probably be marked by either "sub out" or "LFE out". connect a phono lead from this to your sub, which should have a single phono input marked with something like "low input", "LFE input".

Now that they are connected on your pioneer there should be a setup menu for speaker configuration in which you can now set to having a sub. Then there should be a sound level test which sends a test signal to each speaker in turn and you can adjust the level of each so at the listening point they are all the same volume. To do this properly you really need a sound meter, but it can be done by ear.

There will also probably be an option for the sub for for "LFE" or "LFE + main". If you choose "LFE" then you sub will only be used for LFE channel, if you pick "LFE + main" then your sub will be used for the LFE and assist your main speakers. If you choose the latter you need to set a crossover frequency. Usually on AV amps the choice is pretty limited so it is best to just guess the best for your speakers, if you have large speakers - bookshelf or tower, that can handle a reasonable amount of bass then try around 80Hz, smaller speakers use a higher cross over frequency. try trial and error to see which sounds best.

Thanks for the info. I think I understand LFE now, we watched star wars epi. 1 last night and the pod races apparently used a lot of "non-audio" LFE for the pod engines as they go by. Very different from listening to it on your standard TV.

Is an audio pressure meter and some kind of test source useful for setting the crossover freq. or is just something you do till it sounds good?

-Scott

a sound meter (the same as an audio pressure meter I think) is a small hand held device (usually) that measures the volumes of sounds. They can cost hundreds of pounds for proffesional ones, but for home cinema a cheap one is ok. Radio shack do one which I own (click here).

Your AV amp should have a option for setting the sound levels where it will send a test signal through each channel in turn and you hold the sound meter where your head would be if you were watching films. You adjust each individual channel until all channels read the same level on your sound meter at that point.

It is a useful tool and when I first got one I found my speaker levels were out quite a bit.

This will not help you with crossover frequency though, I'm not sure if there are any tests you can do to set it correctly as opposed to just trying several and picking the one you like.

the pod race is certainly a good choice to put the sub through it's paces.