Question about sub woofer RCA input (Left/Right + LFE)

[radovantz]

Hi all,

I recently go to a home theatre shop and find some new powerred subwoofer models from Wharfedale and JBL equipped with 3 RCA connection which are dedicated for Left, Right and LFE. My question is, can all of them hooked up simultaneously from AVR's multichannel pre-output?

Previously I posted a thread "We may need a 5.1 subwoofer" where I highlighted my points that all speakers must be set al "Large" and subwoofer set as "LFE Only" to avoid frequency mixture. Since I found this new sub woofer with 3 RCA (Left, Right and LFE), I hope it can settle my problem if all 3 of them can be wired simultaneously. I post my question here because I can't find the answer from online Manual Instruction.

Here is an example: http://www.wharfedale.co.uk/Products/Product/tabid/78/PID/316/CID/318/language/en-GB/Default.aspx#detail

Thank you guys

 

[Hi-FiOutlaw]

Hi all,

I recently go to a home theatre shop and find some new powerred subwoofer models from Wharfedale and JBL equipped with 3 RCA connection which are dedicated for Left, Right and LFE. My question is, can all of them hooked up simultaneously from AVR's multichannel pre-output?

Previously I posted a thread "We may need a 5.1 subwoofer" where I highlighted my points that all speakers must be set al "Large" and subwoofer set as "LFE Only" to avoid frequency mixture. Since I found this new sub woofer with 3 RCA (Left, Right and LFE), I hope it can settle my problem if all 3 of them can be wired simultaneously. I post my question here because I can't find the answer from online Manual Instruction.

Here is an example: http://www.wharfedale.co.uk/Products/Product/tabid/78/PID/316/CID/318/language/en-GB/Default.aspx#detail

Thank you guys

I think that are just 2 RCAs inputs, it can work as mono with one RCA connected to the AV pre out or the two RCAs connected and work as stereo sub (Never done that though and don't know how it works)... Someone will jump in for sure!

My BK XLS200 mkII as 3 inputs, two RCAs (LFL)that can work as mono or stereo, in my case is connected mono to the pre out of my AV!

The second input is a neutrik input (HFL) that is connected to my Rega Brio R that has no pre outs for sub, and i connect the 3 wires that came out of the neurik cable and connect to speakers poles.

The BK has two independent level controles for this inputs, that way i can connect the AV and the Stereo amp at the same time with no problems!

 

[radovantz]

Thank you HifiOutlaw for your ideas. I believe most of subwoofers in the market have 2 high level input, 2 RCA input (L&R) and 2 RCA output (L&R). All the existing connection remains the same but some of new models just added extra RCA input for LFE only. Unlike we already knew the Left RCA usually used for LFE, but this one the manufacturer add extra RCA for LFE. Means there are 3 RCA input in total, ie. Left, Right and LFE. I believe they can be plugged to AVR's Pre-output for FL, FR & LFE respectively. However the salesman I met was unable to answer my question whether L&R can be connected simultaneously with LFE (2.1 channel to be driven by subwoofer).

If not, I need to go back to my previous idea of having 2 unit subwoofers with one of them to drive LFE while the other one to drive stereo, separately.

 

[Hi-FiOutlaw]

Thank you HifiOutlaw for your ideas. I believe most of subwoofers in the market have 2 high level input, 2 RCA input (L&R) and 2 RCA output (L&R). All the existing connection remains the same but some of new models just added extra RCA input for LFE only. Unlike we already knew the Left RCA usually used for LFE, but this one the manufacturer add extra RCA for LFE. Means there are 3 RCA input in total, ie. Left, Right and LFE. I believe they can be plugged to AVR's Pre-output for FL, FR & LFE respectively. However the salesman I met was unable to answer my question whether L&R can be connected simultaneously with LFE (2.1 channel to be driven by subwoofer).

If not, I need to go back to my previous idea of having 2 unit subwoofers with one of them to drive LFE while the other one to drive stereo, separately.

...or buying a sub with LF input and HF input like my BK, that way you don't need 2 subs.

 

[jonathanRD]

Why would you want to connect them all simultaneously? I'm trying to be logical here;

Using an AVR, for films using a 5.1 setup for example - you would connect the subwoofer pre-out to one of the low level inputs (on my BK XXLS400 I use a single RCA to RCA connection to one of the RCA inputs marked 'mono'). I then connect to the high level input on the sub from my separate hifi amp.

Using the AVR in one of the 5.1 modes it will play music through all the speakers including the sub connected via the low level input.

If you use a stereo or 'pure audio' or 'direct' mode, that only plays music through the front two speakers, I can then see why you would want to connect the sub via the high level connection. But in 5.1 mode, you are likley to get a signal from both the main front L & R speaker terminals to the high level input, and a signal from your subwoofer pre-out to your low level - I think?

But your question is - 'can all of them be hooked up simultaneously from the AVR's multichannel pre-out.

On my AVR I only have a subwoofer pre-out, but if I had full channel pre-outs, then my front speaker pre-outs would be connected to my hifi amp, and it would be from this amp that I would connect to the high level of the subwoofer - which I would use for stereo music - and therefore not at the same time as my AVR amp. But in 5.1 mode, using the pre-outs and both amps, you will get signals to the subwoofer from both amps again.

So - why would you want to connect them all simultaneously from the AVR's 'multichannel pre-out'?

 

[radovantz]

So - why would you want to connect them all simultaneously from the AVR's 'multichannel pre-out'?

According to some subwoofer manual instruction, I read the Mordaunt-Short and Wharfedale ones, they mentioned that RCA cannot be used with High Level simultaneously because they are conflicting in the subwoofer's amplifier system. If the BK subwoofer system allow us to use both input simultaneously, that's what I am looking for.

I want to connect 2.1 channel pre-out from AVR to subwoofers because I just realize my AVR-1909/1910 doesn't sound good when the subwoofer is set as "LFE+Main". It causes multichannel frequency mixed-up which in turn lack of detail and bad LFE performance. The best speakers configuration should be all channel set as "Large" (even for small speakers), and subwoofer set as "LFE only". However, when turn back to stereo, LFE output from AVR's pre-out won't channel bass signal to Subwoofer because it is set as "LFE only". That's why I need another unit of subwoofer to drive Left and Right channels only.

 

[jonathanRD]

I have both my hifi amp and AVR amp connected to my sub, but they are never used simultaneously as I suspect this would cause a conflict as the instruction manuals you have read suggest.

 

[AnotherJoe]

The left and right RCA's are for people who just have a 2-channel system, or want to setup their amp as not having a subwoofer -

I believe some of the REL subs let you have a LFE connection and then dial in the high level using a switch - though I've never really looked at this.