ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
Hi
My speaker groups indicate I have two subwoofers, but I only have one. How come?
A bit more imformation would be helpfull.
Which subwoofer?
Picture of the menu, where the subs are listed etc?
MM
There is a tv - and there is a BV
Its a Beolab 2, and the TV is an Eclipse 65. It is listed twice in all the sound settings - speaker groups, speaker distance, calibration etc. I can set each mention independently
Hi,
One small piece of information to start:
A BeoSound 2 has uses both audio channels (Left and Right) from the Powerlink input. This is because it can do the bass management processing for an additional pair of "main" loudspeakers - so it removes the bass from the Left and Right. (independently) and then sends those two signals further on to the other loudspeakers (if you've connected them). The bass that has been removed from the two channels is then summed together and sent into the sub's output.
This means that, when you connect a Powerlink cable from your Eclipse to the BeoLab 2, and you send signal on either the PL Left or the PL Right, you will hear something from your subwoofer.
When you go to the Speaker Connnections menu, you have two choices:
1. Set EITHER PLx Left OR PLx Right to BeoLab 2 - and set the other to "none". This means that you are only using one of the two potential connections to the subwoofer.
2. Set BOTH PLx Left AND PLx Right to be BeoLab 2 (which is what you have done, I guess...).
The main disadvantage of doing #2 is that you have to ensure that your Speaker Distances for "both" BeoLab 2's are the same - otherwise you may get undesirable results due to phase mismatches in the two audio channels that are summed inside the subwoofer. The second disadvantage is that it's a bit of a pain to do the setup generally, since you have to do things twice.
So, the better solution is to do #1. You can do this retroactively by going to your Speaker Connections menu, go to one of your "two" BeoLab 2s and select the "Disconnect" option. This will shut down one of the two Powerlink channels once you leave the menus - and you will find only one BeoLab 2 in your Speaker Groups menus.
Hope this helps.
-g
@Lawrence:
FYI, the BeoSystem 3 menu logic behaves differently. So, everything I said above doesn't apply to you. :-)
Cheers-g
Thank you so. much, Geoff, for explaining that so succinctly. All is clear now
Geoff Martin:@ Lawrence: FYI, the BeoSystem 3 menu logic behaves differently. So, everything I said above doesn't apply to you. :-) Cheers -g
Geoff:
How do the menu settings work with the BeoSystem 4? I've always been frustrated that the subwoofer and also the center channel each use 2 channels -- using up available BeoLab connections when it would be nice for them to each use just one connection.
beojeff: Geoff: How do the menu settings work with the BeoSystem 4? I've always been frustrated that the subwoofer and also the center channel each use 2 channels -- using up available BeoLab connections when it would be nice for them to each use just one connection.
Hi Beojeff,
The short answer is that this is a hardware issue - not a software problem.
We have to distinguish between the menus / BeoSystem 4 behaviour and the loudspeakers to which it's connected.
WRT the Software
There's nothing in the logic controlling the menus that stops you from having (for example) a BeoLab 2 and a BeoLab 17 on the same Powerlink cable. (I was a little in doubt - so I just set up my BeoVision 11 (which is the same as a BS4) to do exactly this... in the menus...) Similarly, I could have two BeoLab 2's connected via a single Powerlink cable, if I split the signals correctly... (read on!)
WRT the Hardware
If you have a BeoLab2, BeoLab 7-4, or BeoLab 10 connected via Powerlink, then all three of these loudspeakers will sum both incoming audio channels on the Powerlink. This is where the "problem" starts.
If (for example) you want two subwoofers connected to the same Powerlink output on the BS4, and you use a "normal" Powerlink splitter, then you will be sending both Left and Right channels to both subwoofers. This is because the "normal" Powerlink splitter sends both channels to both Powerlink terminations (because normally, you can use the L/R switch on the loudspeaker to "tell" it which channel to play.
HOWEVER, the was a "special" Powerlink splitter that was available in the DIN days for splitting to two subwoofers. It split the audio channels so that the left channel went to one termination and the right channel went to the other. I believe that the other channels were unconnected - so if you connected (for example) a BeoLab 8000 to the Left side of the splitter and set the 8000's switch to Right, you would get no sound...
The problem was that the "normal" splitter and the "special" splitter look identical from the outside. So, if you weren't paying close attention to the part number (say, if you were stocking them at a dealer, for example), you might just throw them all together into the same box on the shelf... This didn't happen often - probably because the "special" splitters were a bit rare...
So, if you use a "special" splitter - or if you manually cut one of the two audio channels on a Powerlink cable to make it either a Left-only or a Right-only cable, then you could connect (for example) a BeoLab 2 and a BeoLab 17 via a splitter on the same Powerlink - and the menus will allow this. (Admittedly, this is not easy to do with the RJ45 cables - but BeoLab 2, 7-4, and 10 are all DIN inputs, so it's easier to get inside the DIN connector and cut the connections to the pins in there.)
Note that a BeoLab 19 has the "L / R / L+R" switch, so you don't need the "special" Powerlink splitter for this.
Hope this answers your questions-g
And what does this little guy do?
Thank you for that nice explanation! I'm seeing in the BeoSsytem 4 menu that it IS possible to assign different speakers for L and R channel connections when subwoofers and center channel are assigned.
I would suspect that Steve at Sounds Heavenly could craft cables to isolate the L or R channels (unless you happen to have the part number for the B&O special cable and if it is still available).
My question now to you is whether there is any loss in sound in doing this channel isolation for subwoofers and center channel speakers. Do they really NEED for the left and right channels to be summed?
@beojeff
When I set up my S8 sub for my V1, it also ‘used’ both channels.
I simply set one of these to ‘nothing’ in the menu - works fine.
Only question, how can I use the second, now free channel (e.g. for a second sub).
Must do some experimenting with the little guy in the pic above, when I have some spare time.......and the house is empty ;-)