Line level sub connection - mono?

[rcchap]

Looking to hook my sub up via the line level pre outs (front speaker) of my reveiver. I've got a typical sub wire that has a t-type splitter on one end. Would it work connecting the front L and R speaker preouts to a single line in on the sub or should it be reversed. My inclination is the first choice. I think I remember reading that the sub processes everthing to mono internally anyway.

Chris

[theMaximus]

I'm curious as to why you are having to do this. Does your receiver not have a subwoofer output? Connecting the sub as you described would work only if your subwoofer has a active crossover that cuts out the high frequency signals (typically over 80~100 Hz). Also, make sure to cut out the low frequency signals going to the front channels using the receiver settings.

[Lex]

Though I have never tried this, I don't believe the signal can be blended from 2 to 1 without electronics designed to combine the signal.

Lex

[rcchap]

My sub does have a variable active crossover.
I cannot adjust crossover settings with my receiver.
My receiver does have a sub out but I am afraid that there might be some issues with the two low pass filters (receiver and sub) working together.

[hidefdvd]

My sub does have a variable active crossover.
I cannot adjust crossover settings with my receiver.
My receiver does have a sub out but I am afraid that there might be some issues with the two low pass filters (receiver and sub) working together.

What sub are you using? You should run your sub coax cable from the receiver to the subs LFE input. If you have a L/R LFE input then use the splitter to run into both. This gives you either a 3db or 6db gain. On the back of your sub set the crossover to its highest reading and set your speakers in your sub to small. Your receiver? may have a fixed crossover when the speakers are set too small(100 or 80hz) So by setting your subs crossover to the highest setting you won't get any issues.

[rcchap]

I would rather bypass the LPF in my receiver and use the one in sub. Why use a pre filtered signal? I cannot defeat the LPF in the receivers sub out so I was wanting to use the Speaker line out with the front speakers set to large and all others set to small with sub set to OFF. I like the sound of my front speakers as large. Just seems to be fuller, more even stage. I believe that this setup will help but I am wondering if I can get away with using one cable from the receiver's R/L speaker preouts (line level) to the subs line level in or should I use two cables (R/L)?
Or am I just crazy :roll:

[junior77blue]

Use 2 cables...otherwise you will only be sending the sub a R or L channel signal which isn't the FULL MONO signal.

So, from the reciever R/L preout have a 1Male=>2Female RCA one going to your stereo amplifier the other going to the input of the subwoofer.

I don't think you will notice a difference in sound if you were to use the reciever crossover and the subwoofer crossover simultaneously, assuming one was much higher than the other....but who knows.

[rcchap]

Thanks Junior, I have the tweaking bug. I just recently moved my system to a new room and the sound is a little off. It probably has more to do with the room and my speaker placement but I can't help trying any little thing that I can think of without spending any more $$.

I don't think you will notice a difference in sound if you were to use the reciever crossover and the subwoofer crossover simultaneously, assuming one was much higher than the other....but who knows.

I have read that when both LP filters are combined, whatever their settings might be, that the interaction can cause irregularities in the frequency response.

So, from the reciever R/L preout have a 1Male=>2Female RCA one going to your stereo amplifier the other going to the input of the subwoofer.

I don't have a separate amp so my preouts on my receiver are all open.
Do I need one cable coming from my receiver front L line level out to the subs L line in and another cable conecting the R line out from the receiver to the R line in on the sub or can I connect the R and L outs on the receiver into one of the line ins on the sub, either right or left.

Sorry for making a mountain out of a mole hill. I should just use two cables and forget all of this silliness. I was just thinking that the sub mixes everything to mono internally so would it matter much if I combined the R and L signal from my receiver before it got to my sub? Maybe I should just try it but I figured I would try to tap into the wealth of knowledge here in the forum first.

Thanks everyone.

[junior77blue]

Im the same way...

I'm willing to bet you need to send it both R/L signals. That or use a jumper at the reciever end to send both r/l channels.

Either way would work.

From what a sales guy told me, using both the L/R inputs to the sub will only effect the output level by 3db. You will just have to tweak the knob a bit. But I'm not so certain how or why...figure i'd pass along his comments, very knowlegeable guy.