so whats the story with LFE?

[Geoffcin]

i finally got my subs hooked up last night. and plugged in a new movie but im not getting what i thought i would get from the lfe source on my h/k. each of my subs is an 8" that i have tuned the cabinets to about 40hz, with about 200 watts going into each one. with the sub adjustment turned up on my h/k to about 6 i still only get just a slight rumble not the bone crusher i was expecting. any thoughts?

If your using a splitter then each sub will only see half the signal strength. You should be able to compensate using the receivers adjustments.

LFE is very specific to the movie. Some don't have any LFE at all! Others like Star Wars, or Jurassic Park, can give your sub a real workout.

[kexodusc]

If your using a splitter then each sub will only see half the signal strength. You should be able to compensate using the receivers adjustments.

LFE is very specific to the movie. Some don't have any LFE at all! Others like Star Wars, or Jurassic Park, can give your sub a real workout.

Not exactly, voltage remains constant througout a parallel circuit, so when you use a splitter, there is no loss in signal strength to each sub. Most of those tiny signal amps have more than enough miliamperes to split an LFE cable several times before the resistive load is too much. Cool experiment to perform if you've got a multimeter and way too much free time on your hands.

I'm guessing there's a difference in output voltage between DVD and CD player in this case...a very common, and annoying occurance

[Geoffcin]

Not exactly, voltage remains constant througout a parallel circuit, so when you use a splitter, there is no loss in signal strength to each sub. Most of those tiny signal amps have more than enough miliamperes to split an LFE cable several times before the resistive load is too much. Cool experiment to perform if you've got a multimeter and way too much free time on your hands.

I'm guessing there's a difference in output voltage between DVD and CD player in this case...a very common, and annoying occurance

When I run a splitter in my velodynes? I just don't seem to get that effect from doing it.

[kexodusc]

When I run a splitter in my velodynes? I just don't seem to get that effect from doing it.

Not necessarily - depending on the subwoofer manufacturer, different things can happen. Today, the most common thing I'm seeing (my last 4 subs and most people I've asked) is that the plate amp will sum the 2 separate L/R inputs before going to the power amp. You will actually get up to 6dB of voltage gain depending on how the summing is done..

Theoretically, you could get as much as a +3 dB output increase at the woofer for a given setting.

My last few subs manuals actually recommended using the L/R with a splitter increase the input strength. The plate amp just sums the inputs into a mono signal for the woofer. In a perfect system it'd be double, but you probably lose some. It's pretty noticeable and easy to measure.

I'm not sure what the real advantages are though. I accomplished just as much for years using 1 cable. The only benefit I can think of using the Y-cable is if your receiver's LFE output signal is weak while at or near it's max limit...not likely these days.

I've heard a lot of people (usually with cables to sell) say it benefits signal purity by reducing loss. I can't see how.