lfe input importance in sub

[mopeer]

i`m planning to buy the jbl tlx 175 sub

1.has somebody heard about it?

2.how important is that a sub will have a LFE input ?

 

[DrPainMD]

1. no
2. very important

 

[mopeer]

i mean a sub that have LFE input compare to one that have only left/ right inputs
will i loose something by conecting the sub output from my reciever to left or right,compare to conect it to a lfe input?
i anderstand that the lfe input bypassing the frequency control
i don`t understand exactly what it gives

 

[sivadselim]

2. very important

Why do you say that?

There are many subwoofers, mopeer, that do not have an input that is, specifically, an "LFE input". With these subwoofers you simply use a single input (or you can use a y-splitter and use both the L+R inputs) and set the subwoofer's adjustable "crossover" (it's really just a high-pass filter) to it's highest available setting.

An "LFE input" bypasses the subwoofer's "crossover", altogether.

 

[MDS]

As sivadselim said, the sub does not have to have an input specifically labeled LFE. All you need is a sub with a low level input and whether it is labeled 'LFE', 'line-in', 'rca-in', 'input 1', etc is irrelevant. You want a sub with that kind of input because ideally you want to connect the receiver's subwoofer pre-out to the sub so you can use the bass management features of the receiver.

The catch is that subs vary:
- It may have only one input and it is labeled LFE. In that case there may be another switch to flip to disable the internal xover. With the switch in one position, the sub's internal xover is active and with it in the other position it is not. I forget the model number, but one JBL sub I had worked that way.

- It may have two inputs, labeled eg. LFE and Line-In. In that case using the LFE input bypasses the sub's internal xover and using the Line-in activates the sub's internal xover. You could use either one, but if you use Line-In then you want to set the xover dial on the sub to its highest setting.

 

[mopeer]

thank you for helping me since i have to make some fast dicision and "drpain md" unswer put me into pressure(sorry for spelling mistakes i`m not from the usa)
but i`m still confused becouse
there are subs that have both the lfe input and l/r inputs(3 inputs),so if it the same why they have done it?
there should be some reason they made an option to bypass the xover,
i read some review about sub that they put con.-that it have not lfe input.

i know that using the regular l/r input will work o.k reproducing the .1 chanell that comes from the reciever sub pre out,but what is the reason they made it in addition?
as you said MDS "- It may have two inputs, labeled eg. LFE and Line-In. In that case using the LFE input bypasses the sub's internal xover and using the Line-in activates the sub's internal xover. You could use either one, but if you use Line-In then you want to set the xover dial on the sub to its highest setting."
but what with the case of only l/r inputs ,i belirve in that case you can`t bypass the xover

 

[DrPainMD]

sorry for the hast response, but what MDS said

 

[MDS]

but what with the case of only l/r inputs ,i belirve in that case you can`t bypass the xover

If it doesn't have an additional switch that the manual says is used to bypass the xover, then you turn the xover setting on the sub as high as it will go and that effectively bypasses it. For example, if the highest setting on the sub is 150 Hz and you set it there, it basically means that the sub will only deal with frequencies below 150 Hz. If you set the xover in the receiver to 80 Hz, then only 80 Hz will go to the sub and 80 < 150 so the sub's xover won't touch it.

 

[mopeer]

but what is the reason for all that,i mean what advantage it will give to bypass the xover,and why they made a LFE input on the sub in addition to the L/R ?
can it be they just made it if you can get the same without it?
i realy will apreciate if you`ll help me to clear this issue today

 

[Mr. Lamb Fries]

but what is the reason for all that,i mean what advantage it will give to bypass the xover,and why they made a LFE input on the sub in addition to the L/R ?
can it be they just made it if you can get the same without it?
i realy will apreciate if you`ll help me to clear this issue today

1-in case your receiver does not have a LFE/subwoofer crossover-out built in, you can use the subwoofers crossover.
2-advantages could be if your receivers crossover is more accurate, by splitting the signal to the rest of your speakers in the receiver, you wont have any gaps in the sound (htz)
3-Having both does not cost much to integrate into the sub, but it makes it a much more versitile subwoofer for marketing. It can have more options for more customers.

Its not that big of deal. you can try different configurations and let your ears decide what sounds best to you. having both allows the manufacturer to sell the same product to a larger market with out much increase in cost (the cost is passed on to the consumer anyways) I would use your receivers LFE out and sent it to the LFE in on the sub. if you dont like it...try other configurations!

Have fun, dialing in a sub is one of my favorites.

 

[Sheep]

Sometimes, on my subwoofer for instance, turning the crossover knob all the way up is the bypass. And usually, turning this all the way up should suffice.

If all this fails, just check the subwoofer manual on the JBL site.

SheepStar

 

[mopeer]

mr. lmb fries
corect me if i`m wrong but reasons 1 and 2 you gave can be achieved also with the usual l/r inputs
the thing is that i have to choose between 2 subs and i need to know how important is to have a special lfe input

i read this but not sure fuuly understand

"The subwoofer's amplifier control/input/output panel takes up most of its rear baffle; the rest is occupied by the Sub Utopia Be's Turbulence Free Port (TFP). Both single-ended and balanced inputs are provided, for both Stereo (L/R) and LFE . I used the latter, in single-ended form, for all of my listening. This input bypasses the sub's onboard lowpass filter, which is continuously variable from 40 to 160Hz at the Stereo inputs. Many subwoofer manufacturers use the term LFE for such an input, a designation that's not entirely correct and can be confusing. This"LFE" input can be used for whatever bass comes out of an AV receiver or preamplifier-processor's subwoofer output, whether that output is set up to carry just the LFE channel (the ".1" in a 5.1 system) or, more commonly, includes bass from some or all of the other channels as well. The only requirement is that this signal has already been lowpass-filtered by the pre-pro or receiver; the "LFE" input provides no such filtering"

 

[sivadselim]

"The subwoofer's amplifier control/input/output panel takes up most of its rear baffle; the rest is occupied by the Sub Utopia Be's Turbulence Free Port (TFP). Both single-ended and balanced inputs are provided, for both Stereo (L/R) and LFE . I used the latter, in single-ended form, for all of my listening. This input bypasses the sub's onboard lowpass filter, which is continuously variable from 40 to 160Hz at the Stereo inputs. Many subwoofer manufacturers use the term LFE for such an input, a designation that's not entirely correct and can be confusing. This"LFE" input can be used for whatever bass comes out of an AV receiver or preamplifier-processor's subwoofer output, whether that output is set up to carry just the LFE channel (the ".1" in a 5.1 system) or, more commonly, includes bass from some or all of the other channels as well. The only requirement is that this signal has already been lowpass-filtered by the pre-pro or receiver; the "LFE" input provides no such filtering"

That explains it quite well. What is it you do not understand?

 

[mopeer]

maby it becouse my english is not perfect but i still don`t understand what is the reason to put a special LFE input in addition to L/R inputs on the sub,
i mean will i loose something by buying a sub that don`t have special LFE input
and have only L/R inputs?

 

[sivadselim]

i still don`t understand what is the reason to put a special LFE input in addition to L/R inputs on the sub, i mean will i loose something by buying a sub that don`t have special LFE input
and have only L/R inputs?

The LFE input bypasses the sub's "crossover" completely. This is actually the best way to connect a subwoofer if you are sending it a signal that has already has been bass-managed as is usually the case with a HT receiver.

The L/R inputs ARE affected by the sub's "crossover" setting. This would be the best way to send a subwoofer a full-range signal.

The reason both LFE input and L/R input is included is because this gives the consumer the most options, as there are many different uses and ways to connect a subwoofer.

Will you lose something if you don't have a special LFE input? Not really, because, as has been stated in this thread, when you have no LFE input, you simply set the sub's crossover as high as possible.

 

[mopeer]

The LFE input bypasses the sub's "crossover"

completely. This is actually the best way to connect a subwoofer if you are sending it a signal that has already has been bass-managed as is usually the case with a HT receiver.

by saying it is the best way to connect you mean that it`ll have some sonic advantages( compare to the sugestion of setting the sub cross as high as possible when not having lfe))or it is just more covinient?


The L/R inputs ARE affected by the sub's "crossover" setting. This would be the best way to send a subwoofer a full-range signal.

under which circumstances you choose to send full range to the sub,when listen to music or also in movies?

The reason both LFE input and L/R input is included is because this gives the consumer the most options, as there are many different uses and ways to connect a subwoofer.

Will you lose something if you don't have a special LFE input? Not really, because, as has been stated in this thread, when you have no LFE input, you simply set the sub's crossover as high as possible.

if i`m using small satilite speakers would it make diference for using the cross on the sub or bypassing it?

 

[mopeer]

sorry i didn`t send it corect

1.by saying it is the best way to connect you mean that it`ll have some sonic advantages( compare to the sugestion of setting the sub cross as high as possible when not having lfe))or it is just more covinient?
.

2.under which circumstances you choose to send full range to the sub,when listen to music or also in movies?



3.if i`m using small satilite speakers would it make diference for using the cross on the sub or bypassing it?

 

[mopeer]

TLX SUB175 – TLX Series







• Built-in Amplifiers


• Heavy-duty drivers


• Optimized sizes for incredible low frequency effects



:EA
SPECIFICATIONS
Warranty
General
System Frequency Response 35 - 130Hz
Built-in Amplifier 110 Watts
Low frequency cut-off 36Hz
High Frequency cut-off Adjustable 40 - 130Hz
Drivers woofer 210mm long throw
Cabinet Finish Brown Cherry, Beech, Black
Dimensions
(H x W x D) 350mm x 295mm x 350mm
Weight 11kg

this is one of the jbl subs i think of,those subs made in denmark,
what is the meaning of
"Low frequency cut-off 36Hz "

 

[Nick250]

I am the only one wondering about this. mooper and DrPainMD join AH the same day, they post very nearly at the same time and they both have the same bad typing habits. And according to the time thingie, post two was submitted before post one. And the thread is being dragged out by the claim of not to understanding very clear well thought out posts. I may be proved wrong but I smell a rat.

Regards,

Nick the sceptic.

 

[mopeer]

I am the only one wondering about this. mooper and DrPainMD join AH the same day, they post very nearly at the same time and they both have the same bad typing habits. And according to the time thingie, post two was submitted before post one. And the thread is being dragged out by the claim of not to understanding very clear well thought out posts. I may be proved wrong but I smell a rat.

Regards,

Nick the sceptic.

idon`t understand exactly what you mean but you are wrong,i am new in this area and english is not my mother languige so it happenes that i`ll make mistakes