Subwoofer connections?

[Ibrewster]

I'm looking into upgrading from a Logitech Z906 surround sound system to a Denon AVR-S920W based system, primarily for the HDMI inputs/switching, although any improvement in sound quality is, of course, a nice bonus. I'd like a little clarification, however, when it comes to subwoofers and how to connect them (since on my old system, the subwoofer *was* the system).

In looking at the Denon unit, I see two subwoofer jacks, from the labeling on which I infer that I could connect two separate subwoofers (as opposed to a left and right subwoofer channel or the like). Simple enough. However, in looking at subwoofers, I'm getting a little confused. Most that I look at have two sets of jacks - High-Level, and Line-in, both left and right, with one of the line-in jacks occasionally being additionally labeled "lfe". Now I know I want the line-in and not the high-level, but unless I am just mis-reading the labeling on the Denon, there isn't a right and left output for the subwoofer - so what would I connect to? Is the Subwoofer output on the Denon just another name for LFE? Do I just plug into either left or right, with no distinction? If so, why do the subwoofers *have* left and right inputs?

If someone could clarify this issue, I'd appreciate it.

On a related note, in order to save some money by building up the system in pieces, would it be possible to temporarily make use of the subwoofer on the Logitech Z906 in conjunction with the Denon by letting the Denon drive the satellite speakers and jacking the Subwoofer output of the Denon into one of the RCA inputs on the Logitech? I'm sure I could physically make the connection, but would it work properly?

Thanks!

 

[Chris Brown]

Do I just plug into either left or right, with no distinction? If so, why do the subwoofers *have* left and right inputs?

It's so that it can derive signal from regular stereo sources. Like let's say you had a stereo receiver with no subwoofer output, but it had regular stereo pre-out and main-in jacks. You could run a stereo RCA cable pair from the preamp outputs on the receiver to the stereo line-in jacks on the subwoofer, then from the stereo line-out jacks on the subwoofer to the main-in jacks on the receiver. It needs to have a left and right because it needs to be able to extract bass info from the stereo source. With a newer receiver that actually has a subwoofer output, it simply doesn't matter. Plug it into either, a specific one if it's labeled for such, or use a Y-adapter.

 

[Ibrewster]

With a newer receiver that actually has a subwoofer output, it simply doesn't matter. Plug it into either, a specific one if it's labeled for such, or use a Y-adapter.

Ok, makes sense on why the left and right, thanks! With regards to the actual connection, would there be any difference between just connecting one (say, to the "right" input) vs using a Y cable? Is the LFE jack what I should use if it is a separate jack or labeled as one of the Left/Right, or is that something special?

Sorry if I am being dense here, but I'm afraid I know nothing about audio systems - I just want good quality, immersive sound, but have no clue how to go about getting it

 

[darkblue94]

Ok, makes sense on why the left and right, thanks! With regards to the actual connection, would there be any difference between just connecting one (say, to the "right" input) vs using a Y cable? Is the LFE jack what I should use if it is a separate jack or labeled as one of the Left/Right, or is that something special?

Sorry if I am being dense here, but I'm afraid I know nothing about audio systems - I just want good quality, immersive sound, but have no clue how to go about getting it

I would suppose that the relevant information would be covered in the owner's manual which if you don't have one can be easily located on the internet.

 

[Ibrewster]

I would suppose that the relevant information would be covered in the owner's manual...

From what I've seen, not really. Typically what I see is things like "connect the speaker outputs of your amplifier to the high-level inputs, or the line level outputs to the line-level inputs". The manual for a Klipsch subwoofer I was looking at, for example, has a diagram of "low level connections" showing either a LFE output connected to the LFE input, or Left and Right pre output puts connected to the left and right line-in inputs. so no help there if you have a single "subwoofer" output - unless, of course, the "subwoofer" output *IS* a LFE output (I have no way of knowing this, since I don't even really know what LFE is). Granted, I've only pursued a couple of manuals at this point - maybe some of the others state what to do with a single "subwoofer" output. Unfortunately there are a staggering array of subwoofers to choose from, many of which have slightly different inputs, which makes it difficult. Thus the reason I came here looking for clarification.

At this point, it seems like the safest approach is to simply get a RCA Y cable to take the one "subwoofer" output and connect it to both the Left and Right inputs, unless I find a subwoofer that actually has a single subwoofer output. At least from what Chris Brown says, that should work. It would, however, be nice to know what the *proper* way of doing it is, or if there is any difference at all.

Is it at least safe to assume that if a subwoofer has a *separate* LFE jack, that that is NOT what I want, since the Denon unit only has a "subwoofer" out and not a "LFE" out?

 

[darkblue94]

LFE = low frequency effects, comes from the home theater realm. You can use a single (subwoofer) cable from the single output of the Denon AVR to the single (LFE) input of the subwoofer.