Newbie sub question

I have never messed with the Sub before so I really need some help from the forum member here. I just ordered the LFM-1 B-stock last Friday. After reading the LFM-1 and my Onkyo TX-RS 500 owner’s manual, I have a question regarding the crossover frequency for my main speakers.

My receiver crossover frequency is from 80 Hz to 120 Hz and my main speakers are Klipsch RF – 35. The frequency response for these speakers is from 37Hz to 20 KHz +-3db. Because my receiver crossover only goes as low as 80Hz, can I disable the receiver internal cross over and use the LFM-1 cross over? I’d like to hear how it sound at 40 and 60 Hz cross over. My receiver owner’s manual does not mention anything about allowing using external crossover.

I have a feeling that I’m stuck at 80Hz .

Thanks

I don't know about your receiver, but typically a sub like the LFM1 will do a lot better job of reproducing an 80hz signal than the average speaker. Not because the speakers can't handle it, but because the receiver does not have the output to drive them properly without something else suffering. The LFM1 has its own amp, and therefore will leave the receiver with a bit of headroom for the rest of the speakers in your system.

Also, usually on a receiver you can tell it you have no sub and send the line level output through the LFM1 and use its crossover and continue on to your front channel speakers from there.

Thanks trikos, I feel very good about setting my crossover at 80Hz now. My receiver definitely needs help with the amp.

On my receiver, the subwoofer has 4 different modes.

1. To output low frequencies of all channels from the sub
2. To output low frequencies of the center and surround from the sub.
3. To output only the LFE channel.
4. Subwoofer off

Can I just set the subwoofer off and play with the LFM-1 crossover? I was wondering if this is the case, how can I select to output low frequencies of all channels or just the front or just the rear from the sub?

Thanks again with all your help.

do you mean:send the speaker level out from receiver to lfm,then from the lfm on to the mains? but i am not sure if the lfm high passes the speaker out or not,the manual would say

If I am correct, what Trikos is saying is exactly how I had my old pro logic yamaha set up with my sub.

I had to remove the receiver's jumpers between the line out and line in signals for left and right mains. then I cabled the outs to the sub ins, sub outs back to the receiver ins, thereby using the sub's crossover.

On a 5.1 setup, however, this wouldn't help filter further from the surrounds or center channel, which carry a good amount of LF signals.

Newbie, the one thing to keep in mind is that Low Frequencies are non-directional, in other words the human ear can't pinpoint the source as with high freqs, so you won't find much advantage to using the LFM's crossover unless your receiver is doing a poor job. Trikos speaks the truth, though; using the receiver's internal crossover and letting the LFM take the <80hz signals will likely improve the performance of your receiver and your speakers.

If you want your speakers to run full range, just set the sub to run LFE only. If I recall correctly, this will only send the .1 signals in 5.1 [7.1, etc] digital signals to it. All lower frequencies intended for the other speakers will go on through without using the Onkyo's crossover.

ahhh,greg,i remember the pre out/main in jumpers.it has been awhile.and newbie,80 hz is a pretty common point.mine stays there for movies but when i'm crankin' some heavy bass music then i set to 60hz just because the output of my sub and my basement like to clash at times

Audio Newbie

If you checkout the manual for the LFM1, which is online. Go to page 6 - Diagram2. This will show you that your front left/right channels of your reciever can be connected directly to the LFM1. You use the LFM1 to adjust your crossover frequency and also send the high frequency (80hz and up) output from the LFM1 to your front left/right speakers also shown on that diagram.

As far as your reciever, you can pick number 1,2 or 4 and see how your receiver puts out. Since you have limited power in your receiver, you will probably find not sending the low frequencies to your other speakers will be best. But this does depend a lot on the efficiency of your speakers.

Keep in mind that your brain/ear cannot figure out what direction sound is coming from below about 100hz, so don't worry about not outputting those frequencies to the other speakers. In a normal room, the LFM1 should have plenty of output.

Do some listening tests and see what you like best..

The LFM-1 has no Line Out jack, therefore you must use the high level(speaker) connection inorder to use the LFM-1's crossover.

Thank you so much for all of your inputs. I've received tracking information from Outlaw last night. I just can't wait to play with the sub.

Thanks again for all your helps.