Use subwoofer LFE connection simultaneously with integrated pre-amp dual pre-out RCA connections (using Y-splitter and single RCA)

[JorisCeoen]

Hello all, I’ve got a mindwrenching situation which I cannot seem to find the answer to.

I’ve got a Yamaha A-S1100 integrated amp, and a Yamaha RX-A4A receiver. I’ve got a BK PB12 subwoofer that has SpeakOn and L/R RCA-jacks. One is for LFE the other in case you use a pre-amp with L/R pre-out.

Of course, and as always, my amp is a floating balanced type which means high-level input isn’t possible, or at least unwieldy. Using it causes hum in my sub (it’s not humming if nothing is connected so the sub is fine).

For my amp, Yamaha suggests not using high-level but instead using the pre-out to an active sub. Doing so, I have almost no hum (only if I turn the gain 100% which I’ll never do).

So, now I’m wondering. Is there a way to connect the pre-amp’s pre-out (dual RCA) to the left RCA of the sub, and the LFE to the right (meant for LFE to begin with)? I’m thinking a Y-splitter from the pre-amp and a single RCA from the receiver, as it should.

Is this a good idea since a (single) sub is mono anyways, or is this bad practice?

I can’t figure out any single way to get rid of the hum due to grounding, so I gotta have a solution this way somehow.

 

[Devnull]

Rane note on why not wye

Why Not Wye?

Wye-connectors (or "Y"-connectors) should never connect two outputs together, but Rane tells you how to use them correctly.

www.ranecommercial.com

 

[JorisCeoen]

Rane note on why not wye

Why Not Wye?

Wye-connectors (or "Y"-connectors) should never connect two outputs together, but Rane tells you how to use them correctly.

www.ranecommercial.com

Ok. I translate this as ‘aka not possible no solution’? I think I’m about to toss this sub back to where it came from and just call it a day honestly.

 

[JorisCeoen]

I’ve been trying to find a different solution to my problem, and as far as I’ve been able to understand I would have to go for a signal switcher (so 1xRCA for the LFE and also 2xRCA for the pre-out of the integrated amp) and have that device automatically switch between both signals.

My problem with this is, if the receiver sends a signal to both the sub and also the integrated, that integrated will then send the signal as well to the switching device… aka how does any device know which signal to pass?

Ideally I’d like to have the LFE-channel take over priority when watching TV/Movies. If I then simply listen to music or a CD it will be the only signal so I assume no problem there.

I’d love to hear people who are in such a situation or have similar switching devices and hear their opinions, as I’m not going out to buy before knowing the ins-and-outs.

 

[Devnull]

Just hook up the LFE. Set the speakers to small and set the crossover frequency. The AVR will route the low frequencies for the speakers and the LFE out through the LFE out.

 

[JorisCeoen]

Just hook up the LFE. Set the speakers to small and set the crossover frequency. The AVR will route the low frequencies for the speakers and the LFE out through the LFE out.

I read a bit more into the manual of my amp. When it’s on ‘Main Direct’ it disables the pre-out (main direct is connected via the receiver).

Does this mean that I can use a Y-splitter, since in each case it’ll only receive one signal everytime, or would that still not be a good idea? The way I understand it is that if it’s on Main Direct the receiver only sends its own signal and the Y-connector only receives that signal, since the other side pre-out is disabled by the integrated. If I then put any other input (CD/Phono/Line In/Tuner) it only receives the pre-out right side signal (left side goes into left of the subwoofer). Never will there be two signals going into the Y-splitter.

 

[Devnull]

I read a bit more into the manual of my amp. When it’s on ‘Main Direct’ it disables the pre-out (main direct is connected via the receiver).

Does this mean that I can use a Y-splitter, since in each case it’ll only receive one signal everytime, or would that still not be a good idea? The way I understand it is that if it’s on Main Direct the receiver only sends its own signal and the Y-connector only receives that signal, since the other side pre-out is disabled by the integrated. If I then put any other input (CD/Phono/Line In/Tuner) it only receives the pre-out right side signal (left side goes into left of the subwoofer). Never will there be two signals going into the Y-splitter.

I have no idea. I don't understand how you want the rcvr and amp to work. What's going to do the bass management and the LFE? You need to do a drawing of how you want to hook things up and post it. Maybe someone that's familiar with Yamaha equipment can help.

Typically bass management and LFE is done in the AVR. Then if you want to use an external amp for the front speakers you hook the pre outs up to the amp inputs. The AVR should still do the bass management correctly and route it to the LFE channel.

 

[JorisCeoen]

I have no idea. I don't understand how you want the rcvr and amp to work. What's going to do the bass management and the LFE? You need to do a drawing of how you want to hook things up and post it. Maybe someone that's familiar with Yamaha equipment can help.

Typically bass management and LFE is done in the AVR. Then if you want to use an external amp for the front speakers you hook the pre outs up to the amp inputs. The AVR should still do the bass management correctly and route it to the LFE channel.

Hey, I've made an illustration (to the best of my abilities) to explain what I'm trying to achieve, or want to seek advice on based on the article mentioned above:

So as I said earlier, the Y-splitter would be to 'guide' two seperate possible signals to the same Right-channel on the subwoofer, without ever sending two signals into one at the same time. I'm not sure if this is allowed with the Y-splitter, since the article is too technical for me to understand. The only thing I understand from it is that it's OK to use a Y-splitter from one signal to two, but not from two to one. Except, in my case it would always be 1-1, except that the first '1' comes from either the receiver OR the integrated, but never both. Yamaha has a system that disabled the pre-out from the integrated if a receiver is attached to it and sends a signal (through Main In).

Hopefully this illustrates my point better. If it's too much of a risk, I will likely just deviate to an A/B-switcher, but I've come to realise that in my area/country they don't really have such a device that does it automatically.

 

[Theta]

Hello all, I’ve got a mindwrenching situation which I cannot seem to find the answer to.

I’ve got a Yamaha A-S1100 integrated amp, and a Yamaha RX-A4A receiver. I’ve got a BK PB12 subwoofer that has SpeakOn and L/R RCA-jacks. One is for LFE the other in case you use a pre-amp with L/R pre-out.

Of course, and as always, my amp is a floating balanced type which means high-level input isn’t possible, or at least unwieldy. Using it causes hum in my sub (it’s not humming if nothing is connected so the sub is fine).

For my amp, Yamaha suggests not using high-level but instead using the pre-out to an active sub. Doing so, I have almost no hum (only if I turn the gain 100% which I’ll never do).

So, now I’m wondering. Is there a way to connect the pre-amp’s pre-out (dual RCA) to the left RCA of the sub, and the LFE to the right (meant for LFE to begin with)? I’m thinking a Y-splitter from the pre-amp and a single RCA from the receiver, as it should.

Is this a good idea since a (single) sub is mono anyways, or is this bad practice?

I can’t figure out any single way to get rid of the hum due to grounding, so I gotta have a solution this way somehow.

I would add never use a high pass filter with a sub-.woofer