RSW 15: LFE only/Music only?

[wstrickland1]

There's only a L & R input. My Martin Logan has LFE In and 2 channel in so that it works in 2 channel mode (music) AND for movies (LFE) So what's the deal? I guess it's one or the other. Does anyone know another way to get both?

[DrWho]

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=240-125

And here's a few more similar items in case you wanted to do some

shopping, but I see no reason to spend more money (they're all more

expensive):

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=263-360

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=263-497

http://www.radioshack.com/product/index.jsp?productId=2103861&cp=&pg=3&kw=y+adapter&parentPage=search

[wstrickland1]

so what, just wye in both the output from the pre amp and the LFE output? That seems like a rig to me. Somehow that just doesn't seem right.

[DrWho]

Maybe I'm not understanding the question...

You're trying to connect the LFE out from your reciever into the subwoofer right? And the subwoofer only has L and R inputs on the back (ie, no LFE input). I was suggesting that you take the LFE out from the reciever and plug it into that adapter. You then plug each end of the adapter into the L and R inputs.

Inside the subwoofer, both the L and R inputs get summed into a single mono signal so it really doesn't matter if you just feed one of the inputs. But sending a signal to both inputs yields a 6dB gain in volume (relative to feeding just one of the inputs).

Or are you trying to wire the LFE from both your reciever AND the outputs from a 2 channel pre amp? I wouldn't suggest this approach, because even after you figure out the wiring, you will still need to change the settings on your subwoofer as you switch between the reciever and preamp. If you're doing this approach, how are your mains connected to their amplifier(s)?

So to help you out as best as possible, we're gonna need to know what exactly you're trying to accomplish...which involves listing each piece of gear involved. Seems to me like I was barking down the wrong tree not understanding your situation.

Another possibility...are you looking to replace your martin logan sub with an RSW-15? If so, the RSW-15 has both stereo inputs and an LFE input.

[sivadselim]

Yeah, wstrickland1, I don't understand how your ML works if it is connected this way.

Does it have a toggle switch that allows you to choose between the LFE versus R+L inputs? Or do you use two completely different sources for movies versus music, perhaps?

If the answer is "no" to both of those questions, how does your subwoofer discern what is being input into it simultaneously via the LFE input versus the front R+L pre-outs when playing back LFE-containing material? Or does it not, and play back both?

I think what you may be doing, if your sub allows it, is simultaneously feeding your LFE into a non-crossed-over input and feeding your front R+L (set to LARGE) pre-outs into the subs R+L inputs and using the sub's crossover to adjust these. So what you are doing is creating redundant bass below the subs crossover setting from the sub and the LARGE fronts. This is OK as long as this is what you want to do. HOWEVER, bear in mind that your receiver/pre/pro has a setting that will accomplish the same thing while only requiring a single mono LFE cable connecting the subwoofer to the receiver/pre/pro. It's probably called something like "LFE+Main" or "SUB PLUS" setting in the subwoofer setup menus and what it does, when the front speakers are set to LARGE, is sends duplicate bass info from the front R+L channels that's below your receiver/pre/pro's crossover setting to the subwoofer.

And no, the RSW15 does NOT have an LFE input AND R+L inputs that can be used simultanously.

[DrWho]

And no, the RSW15 does NOT have an LFE input AND R+L inputs that can be used simultanously.

Well it is toggled with a switch...you would never want to use all three simultaneously.

[sivadselim]

Well it is toggled with a switch...you would never want to use all three simultaneously.

Unlike his ML, there aren't 3 holes there to use simultaneously. There are only 2; a R and L input. For a single LFE input only one is used. The toggle simply controls whether the sub's crossover is applied or bypassed.

BUT apparently he does have all three holes (LFE and R+L inputs), there on his ML and they're connected simultaneously. And he "may" actually use them simultaneously. We need some clarification from him as to how it is all connected and implemented.

The answer to your original question, wstrickland1, is NO, you can't connect the RSW15 to both an LFE and R+L source simultaneously. But could you explain exactly why you'd want to connect a sub this way?

[DrWho]

Oh wow, guess you'd have to own one to know that. It was kinda hard to tell from the 360 degree view thing they have on the website. Yet one more reason klipsch needs to have better pics of their products...

Btw, I would not recommend using the adapters to make it work...you never want two outputs driving the same input (but you can have a single output driving multiple inputs...like what I was describing with the LFE output of the reciever).

[sivadselim]

Oh wow, guess you'd have to own one to know that. It was kinda hard to tell from the 360 degree view thing they have on the website. Yet one more reason klipsch needs to have better pics of their products...

Btw, I would not recommend using the adapters to make it work...you never want two outputs driving the same input (but you can have a single output driving multiple inputs...like what I was describing with the LFE output of the reciever).

Yeah those other 2 RCAs on the RSW15 are pre-outs, actually.

I'm still very interested to hear wstrickland1's scheme for the ML with all 3 inputs connected. I think it must have a toggle switch that controls which input is being used, LFE or 2-channel.

[wstrickland1]

Here's the thing, and maybe I don't fully understand what the Ref 50 will do. As it is now, when listening to music in Stereo 2, 3, 4, 5 or 6 mode, I get no subwoofer help at all through the LFE output. I did get sub help when it was wired to both LFE and main channel pre-out (as the ML instructions said to do) before, just now I am short the dedicated dual inputs. Incidentally, my old KSW 150 has the same dual inputs and works the same way as the ML. I do have the RSW wyed into the R L inputs from the LFE now. It just simply doesn't give me squat unless there is program material from the .1 channel. MAybe I have to do something with the pre-amp setting. SO:

Does anyone know how to get the LFE to output when in 2 channel mode and listening to 2 channel music from a B & K Reference 50?

Thanks in advance.

Billy

[DrWho]

Ok, if you read page 46 of your manual you will find your answer.

Basically, if your mains are set to large, then you need to set the

subwoofer to "plus" in order for the sub to come on in the other modes.

Or you could simply set your mains to small and subwoofer to yes.

And then you'll only need one cable going between your reciever and subwoofer.

[sivadselim]

Yeah, wstrickland1, connecting a sub by both it's LFE input and one or both of it's R+L inputs with the intention of feeding both sets of inputs simultaneously is not at all proper.

If what you want to do is send a full-range signal to your speakers that are set to LARGE and also send redundant bass info to the subwoofer from the front channels, then what Dr. Who suggests is absolutely correct.

You need only connect your RSW15 via a single mono cable to your B&K's LFE output, though. You do not need a splitter. You'll set the B&K's crossover setting to an appropriate one below which it will send duplicate bass info from the front channels to the subwoofer. Bypass the sub's crossover altogether by setting the "low pass enable/disable" toggle to Disabled (LFE Mode).

Let your B&K do the bass managing, not your (incorrect) subwoofer wiring.

[wstrickland1]

Yeah, wstrickland1, connecting a sub by both it's LFE input and one or both of it's R+L inputs with the intention of feeding both sets of inputs simultaneously is not at all proper.

If what you want to do is send a full-range signal to your speakers that are set to LARGE and also send redundant bass info to the subwoofer from the front channels, then what Dr. Who suggests is absolutely correct.

You need only connect your RSW15 via a single mono cable to your B&K's LFE output, though. You do not need a splitter. You'll set the B&K's crossover setting to an appropriate one below which it will send duplicate bass info from the front channels to the subwoofer. Bypass the sub's crossover altogether by setting the "low pass enable/disable" toggle to Disabled (LFE Mode).

Let your B&K do the bass managing, not your (incorrect) subwoofer wiring.

OK, cool. Last night I actually read the manual carefully and found when the processor is set to Ultra in the SW set up I get sub action. I do have the single LFE output split into both inputs on the sub though. Are you suggesting I do not do this? I actually think that splitting that is ok and even desired. I don't know if that's right but I do know this.........the RSW 15 is one mean sub. I mean, the Martin Logan is a fine sub, excellent even but this monster is nasty.

[sivadselim]

No need to use the splitter. It does nothing for you. Unless perhaps you use the Auto-On function and your sub has trouble waking up with only one input connected.

[DrWho]

No need to use the splitter. It does nothing for you. Unless perhaps you use the Auto-On function and your sub has trouble waking up with only one input connected.

Well...it actually results in a 6dB gain from the input signal. Is this needed? Probably not because you should have no problems saturating the sub input without the boost. However, you do ideally get a lower noise floor....but since it's a subwoofer it's not reproducing amp hiss anyway []

Anyways, the adapter isn't going to hurt or make anything better...just realize that there is a 6dB difference if you switch back and forth. In other words, if you get rid of the adapter, you will find that you need to bump the subwoofer volume a few notches in the reciever.

I try to leave everything at "0" on the reciever and then I would try to put the volume on the subwoofer amp to about 50%. If you find that you have the gain cranked all the way without the adapter, then add the adapter and you can turn the volume down. If you find that you have the gain cranked all the way down with the adapter, then remove the adapter and turn the volume up.

We call this "gain structure" in the pro audio world...I guess it applies to home audio as well.

[sivadselim]

Anyways, the adapter isn't going to hurt or make anything better....

I agree.

Point being, it doesn't, as you say, really increase your headroom.

(BTW, ~3db is the increase in SPL you get when you double output.)