Lfe - Blu-ray Forum

watchdog · 11-03-2008, 11:38 AM

Hello....Can someone explain the difference between the LFE inputs and the left and right inputs on a sub....Ive always had mine in the LFE coming from the sub out on my avr. Im just wondering what exactly theyre used for...

Thanks!

VinnAY · 11-03-2008, 12:49 PM

Quote:

Originally Posted by watchdog

Hello....Can someone explain the difference between the LFE inputs and the left and right inputs on a sub....Ive always had mine in the LFE coming from the sub out on my avr. Im just wondering what exactly theyre used for...

Thanks!

LFE output is for a subwoofer with onboard amp (powered sub), the L/R inputs are for line level output from the AVR (sub w/o onboard amplifier).

watchdog · 11-03-2008, 11:37 PM

Cool...thanks....

Big Daddy · 11-04-2008, 01:57 AM

The easiest method to hook up a subwoofer with a surround receiver is to connect the LFE (sub out) on the receiver to the LFE input on your subwoofer using a single subwoofer cable. An audio patch cord or interconnect will work. However, it is better to use a subwoofer cable (RG6 double or quad shield) to reduce hum and hiss when the cables are moved. With this option, the crossover filter on the sub is bypassed, so the receiver or processor has control of the crossover frequency. You can perform bass management by setting the speakers to large/small, etc.

Line level inputs on a subwoofer are for older receivers or separate pre/pro components that do not have LFE output or if you decide you will get better bass performance by bypassing the AVR's crossover and bass management manipulation. If you have a spare set of Front Left and Right channel (pre-out) outputs, connect these to the low level inputs of your powered sub. If you have only one set of outputs on the receiver and they are being used to drive a power amp, use a Y cable. If you have a surround processor use the Speaker Set-up menu to select front speakers as "Large" and Subwoofer "No" or "Off."

If you do not have the option for LFE out or to separate your pre amp from your power amp, the best way to hook up your subwoofer is with speaker wire connections. Run separate left and right speaker wires from your front speaker outputs on the amp or receiver to the subwoofer. If you have a surround processor use the Speaker Set-up menu to select front speakers as "Large" and Subwoofer to "No" or "Off." Speaker level hookup is almost foolproof. You'll then have to fiddle with the variable low pass filter on the sub, as well as the level and phase controls, until it sounds right. This hookup option is also the least likely to pick up "hum" and noise.

Passive (unpowered subwoofers) do not have line level inputs. They only have speaker level inputs for connection to a an external amplifier with speaker wires.

goresnet · 11-04-2008, 07:00 AM

Big Daddy (or anyone else), can you connect a passive sub (ie from an htib) to a newer avr (denon 1909 or onkyo 606) with speaker level inputs? I'm planning to upgrade to HD audio to compliment my HDTV and PS3. Right now I just have an HTIB, which I'm in the process of upgrading. But I have to go piece by piece, due to our first baby coming on Dec. 24th! If I could do receiver and sub at the same time, I would. As it stands, it'll be receiver, then sub, then the rest in a set (Bic Acoustech in-walls, for the wife!).
Anyhow, would connecting the (unpowered) sub with the front L/R and setting the avr to "large fronts - no sub" work in this situation?

Big Daddy · 11-04-2008, 07:51 AM

Quote:

Originally Posted by goresnet

Big Daddy (or anyone else), can you connect a passive sub (ie from an htib) to a newer avr (denon 1909 or onkyo 606) with speaker level inputs? I'm planning to upgrade to HD audio to compliment my HDTV and PS3. Right now I just have an HTIB, which I'm in the process of upgrading. But I have to go piece by piece, due to our first baby coming on Dec. 24th! If I could do receiver and sub at the same time, I would. As it stands, it'll be receiver, then sub, then the rest in a set (Bic Acoustech in-walls, for the wife!).
Anyhow, would connecting the (unpowered) sub with the front L/R and setting the avr to "large fronts - no sub" work in this situation?

The answer to your question is yes. A passive subwoofer can be be used. However, a passive subwoofer needs an external amplifier to drive it. Normally, you connect the LFE (sub) output from the receiver to the external amplifier and then run two speaker wires from the amp to the subwoofer. Both of my subwoofers are passive and I use external amplifiers to drive them. External amplifiers for subs run between $50 up to $500, depending on how much power you need. In your case, you need an amplifier with low power as your subwoofer may not be able to handle it. You can buy external amplifiers from Part Express.

Subwoofer Amplifiers:
http://www.parts-express.com/webpage...ctGroup_ID=505
Regular Amplifier (can be bridged to use as a single mono amp for a subwoofer):
http://www.parts-express.com/pe/show...number=302-601

The other solution is to buy a relatively inexpensive powered subwoofer.
http://stores.channeladvisor.com/the...ers/Subwoofers

The answer to the second part of your question. You can use two front speakers with or without a sub and have the receiver send all the information to the front speakers. However, your sub still needs power.

goresnet · 11-04-2008, 04:33 PM

Thanks,
I was thinking that it would get its power from being branched off the fronts, just like the fronts themselves are powered. I know then that the sub would be trying to reproduce the full range of sound, as it doesn't have a crossover (the sub out on my current receiver handled that.)

goresnet · 11-09-2008, 06:32 PM

One more question. Instead of upgrading my receiver first, I'm looking at upgrading the speakers first. Is it possible to hook up a powered sub to an HTIB receiver that just uses speaker line outs? I got a really good deal on my speakers, and I can get a really good deal on a sub. So speakers first, and the avr when my CC has better going out of business sales!
So anyway, could I run the front L/R to the powered sub, then use its outs to the fronts?

Big Daddy · 11-09-2008, 07:43 PM

Quote:

Originally Posted by goresnet

One more question. Instead of upgrading my receiver first, I'm looking at upgrading the speakers first. Is it possible to hook up a powered sub to an HTIB receiver that just uses speaker line outs? I got a really good deal on my speakers, and I can get a really good deal on a sub. So speakers first, and the avr when my CC has better going out of business sales!
So anyway, could I run the front L/R to the powered sub, then use its outs to the fronts?

It is not the ideal setup, but it should work. Make sure the sub you are buying has speaker level inputs. Read my post #4 in this thread.

goresnet · 11-09-2008, 08:11 PM

thanks, big-d. I know it's not ideal, just trying to get everything piece by piece, and have everything working as I go, instead of buying piece by piece and having the parts sit until I get everything. Of course, it's only a couple of months, but I can't stand having stuff not hooked up!

11-03-2008, 11:38 AM	#1
watchdog Member Member since:Sep 2008 Location:Upstate NY Blu-ray collection:15	Lfe Hello....Can someone explain the difference between the LFE inputs and the left and right inputs on a sub....Ive always had mine in the LFE coming from the sub out on my avr. Im just wondering what exactly theyre used for... Thanks!

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11-03-2008, 11:37 PM	#3
watchdog Member Member since:Sep 2008 Location:Upstate NY Blu-ray collection:15	Cool...thanks....

11-04-2008, 01:57 AM	#4
Big Daddy Blu-ray Champion Top ranked HT gallery Member since:Jan 2008 Location:Southern California Home Theater Gallery:79 Blu-ray collection:122 Trading Score:1	The easiest method to hook up a subwoofer with a surround receiver is to connect the LFE (sub out) on the receiver to the LFE input on your subwoofer using a single subwoofer cable. An audio patch cord or interconnect will work. However, it is better to use a subwoofer cable (RG6 double or quad shield) to reduce hum and hiss when the cables are moved. With this option, the crossover filter on the sub is bypassed, so the receiver or processor has control of the crossover frequency. You can perform bass management by setting the speakers to large/small, etc. Line level inputs on a subwoofer are for older receivers or separate pre/pro components that do not have LFE output or if you decide you will get better bass performance by bypassing the AVR's crossover and bass management manipulation. If you have a spare set of Front Left and Right channel (pre-out) outputs, connect these to the low level inputs of your powered sub. If you have only one set of outputs on the receiver and they are being used to drive a power amp, use a Y cable. If you have a surround processor use the Speaker Set-up menu to select front speakers as "Large" and Subwoofer "No" or "Off." If you do not have the option for LFE out or to separate your pre amp from your power amp, the best way to hook up your subwoofer is with speaker wire connections. Run separate left and right speaker wires from your front speaker outputs on the amp or receiver to the subwoofer. If you have a surround processor use the Speaker Set-up menu to select front speakers as "Large" and Subwoofer to "No" or "Off." Speaker level hookup is almost foolproof. You'll then have to fiddle with the variable low pass filter on the sub, as well as the level and phase controls, until it sounds right. This hookup option is also the least likely to pick up "hum" and noise. Passive (unpowered subwoofers) do not have line level inputs. They only have speaker level inputs for connection to a an external amplifier with speaker wires. Last edited by Big Daddy; 11-04-2008 at 04:53 AM.

11-04-2008, 07:00 AM	#5
goresnet Blu-ray Guru Member since:Oct 2008 Location:League City, TX 4K collection:51 Blu-ray collection:576 Trading Score:1	Big Daddy (or anyone else), can you connect a passive sub (ie from an htib) to a newer avr (denon 1909 or onkyo 606) with speaker level inputs? I'm planning to upgrade to HD audio to compliment my HDTV and PS3. Right now I just have an HTIB, which I'm in the process of upgrading. But I have to go piece by piece, due to our first baby coming on Dec. 24th! If I could do receiver and sub at the same time, I would. As it stands, it'll be receiver, then sub, then the rest in a set (Bic Acoustech in-walls, for the wife!). Anyhow, would connecting the (unpowered) sub with the front L/R and setting the avr to "large fronts - no sub" work in this situation?

11-04-2008, 04:33 PM	#7
goresnet Blu-ray Guru Member since:Oct 2008 Location:League City, TX 4K collection:51 Blu-ray collection:576 Trading Score:1	Thanks, I was thinking that it would get its power from being branched off the fronts, just like the fronts themselves are powered. I know then that the sub would be trying to reproduce the full range of sound, as it doesn't have a crossover (the sub out on my current receiver handled that.)

11-09-2008, 06:32 PM	#8
goresnet Blu-ray Guru Member since:Oct 2008 Location:League City, TX 4K collection:51 Blu-ray collection:576 Trading Score:1	One more question. Instead of upgrading my receiver first, I'm looking at upgrading the speakers first. Is it possible to hook up a powered sub to an HTIB receiver that just uses speaker line outs? I got a really good deal on my speakers, and I can get a really good deal on a sub. So speakers first, and the avr when my CC has better going out of business sales! So anyway, could I run the front L/R to the powered sub, then use its outs to the fronts?

11-09-2008, 08:11 PM	#10
goresnet Blu-ray Guru Member since:Oct 2008 Location:League City, TX 4K collection:51 Blu-ray collection:576 Trading Score:1	thanks, big-d. I know it's not ideal, just trying to get everything piece by piece, and have everything working as I go, instead of buying piece by piece and having the parts sit until I get everything. Of course, it's only a couple of months, but I can't stand having stuff not hooked up!

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