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
Can anyone explain exactly how the 3.5 mm jack works on a BL4 (PL version).
There is no real schematic available and the input jack in the blocked schematic is shown as a stereo jack.
The switch PC/LINE is definitely doing more than just changing sensitivity when feeding the speaker with a stereo signal... I am guessing the speaker is supposed to be fed with a mono signal (mono jack) but why is a stereo input shown... ?
Dom
2x BeoSystem 3, BeoSystem 5000, BeoSystem 6500, 2x BeoMaster 7000, 2 pair of BeoLab Penta mk2, AV 7000, Beolab 4000, BeoSound 4000, Playmaker, BeoLab 2500, S-45, S-45.2, RL-140, CX-50, C-75, 3x CX-100, 3x MCL2 link rooms, 3x Beolab 2000, M3, P2, Earset, A8 earphones, A3, 2x 4001 relay, H3, H3 ANC, H6, 2014 Audi S5 with B&O sound, and ambio
The diagram is a simplified version.
Normally/mostly the DIN connector (powerlink) is mounted and also stereo. In the middle diagram you can see that at the switch the choice is made for left or right.
Beobuddy: The diagram is a simplified version. Normally/mostly the DIN connector (powerlink) is mounted and also stereo. In the middle diagram you can see that at the switch the choice is made for left or right.
Except that the L/R ONLY works with the PL connector,- feeding the BL4 with a stereo signal on the 3.5mm jack in the Line setting simply doesn't work correctly...
@ beovox 141. You can solder one R and one L mono cable.
https://soundsheavenly.com/beolab-4-and-4pc/79-335-beolab-4-4pc-input-cable-minijack-connection.html
Hi Beovox141,
The line input is similar to that on Beolab 6000/8000, as you mentioned already the Left/Right switch only applies to the Powerlink input. When in Line mode, the speaker takes the mono audio input fed to it via the 3.5mm jack and auto-senses, so the speaker turns on when the audio starts and it then turns off three minutes after the audio has stopped.
I keep a wide range of cables for Beolab 4 (Powerlink and PC versions), please ask if you need any further help: https://soundsheavenly.com/40-beolab-4-and-4pc
Kind regards, Steve.
Steve.
www.soundsheavenly.com
Founder of Sounds Heavenly Cables and Brand Ambassador for Bang & Olufsen
Sounds Heavenly are proud to sponsor BeoWorld!
Please check out my YouTube channel at https://youtube.com/soundsheavenlycables
Hi Steve
The picture of the cable on you website threw me off a bit.....
It shows stereo Jacks in both ends, but in the text you actually describe two different connectors, so I am assuming the ones plugging into the BL4 are mono, because if they're not,- it wont work. You will get sound but its kind of a pseudo mono.
THAT IS UNLESS yous are as clever as I think you are
Its a very strange implementation of an input, but I guess if its B&O it has to be...
I compiled pictures of all the BL4 parts from EBAY here:
https://forum.recordere.dk/forum_posts.asp?TID=4389&PID=1594467&title=bang-olufsen-fortid-nutid-lg-tv#1594467
Pretty compact little thing (IMHO Highly over engineered though)
Please don't worry, although I use stereo jacks, they are each wired as mono - this gives me the option to use higher quality jacks that aren't produced in mono versions. All my cables are tested and working perfectly prior to shipping - I use Beolab 4s at home, so I know them well!
Hi Steve.
You can buy higher quality 3.5 mm. Mini Jack Mono Male Connector, metal.
Here - https://www.av-connection.com/?PGr=2812
Hi,
Thanks for that, but I now use a higher quality Neutrik plug than that one, which isn't shown on my website photo (I will get the pictures updated very soon).
Steve at Sounds Heavenly: Hi, Thanks for that, but I now use a higher quality Neutrik plug than that one, which isn't shown on my website photo (I will get the pictures updated very soon). Kind regards, Steve.
Okay I cant help myself... I have to ask the million dollar question
What did you do with the ring that does NOT carry a signal ?
For Beolab 4 speakers, the ring connection can be left disconnected or wired to signal ground, as it isn't used.
Steve at Sounds Heavenly: Hi Beovox141, For Beolab 4 speakers, the ring connection can be left disconnected or wired to signal ground, as it isn't used. Kind regards, Steve.
Here is what I found: I left unconnected (remember its actually a STEREO receptacle) you will get a buzzing sound when the Laptop goes to sleep (tested on two Lenovos), when grounded it stays quiet. These are both laptops.
One of these day I will take it completely apart, just to see how that input is done, unless you already did?
Thanks,
That is interesting, I will try that.
Apart from awaiting the results of the testing, that BEOVOX141’ post probably leads to.....when these two jack connections each are mono, you will have to know which one is RIGHT and which one is LEFT, right?
On the picture you posted I see no marking.
MM
There is a tv - and there is a BV
Hi MM,
I now put a red tag on the plug that goes to the right speaker, this plug contains the right audio signal
Hi DMacri,
The Beolab 4PC version doesn't have a Left/Right switch, only a Line/Auto switch. There is no Powerlink socket on this version of the speaker, just the 3.5mm Line input.
My gut feeling is that there aren't many of the PC versions out there - I think most of the Beolab 4s were the Powerlink versions, initially sold with Beosound 4, or as rear surrounds on a Beovision 7 system. Now that these are changing hands on the pre-owned market, I see both versions being used in any situation, ie. PC speakers, as part of a surround sound setup with either B&O or an AV receiver, or as stereo speakers on a B&O system.
Although B&O intended the PC versions to only work as stand-alone computer speakers, they can just as easily work on a B&O TV or music system by adding the right cables!
@ Dmacri
Somewhere its mentioned that it needs to be a "special cable", and you are right the stereo to 2*mono is a difficult one to come by!
@Steve
A am actually fiddling with the PC/PL version,- thus my initial question. I kind of like them, and as written elsewhere I sometime use a single one on the coffee table as center speaker when the dialog is tough to distinguish. And i am still baffled about the amount of filtering the deployed in such a small speaker..
Millemissen: Apart from awaiting the results of the testing, that BEOVOX141’ post probably leads to.....when these two jack connections each are mono, you will have to know which one is RIGHT and which one is LEFT, right? On the picture you posted I see no marking
On the picture you posted I see no marking
Yes! And that is the strange thing. The PC/PL version already has a three way switch for placement, whereas the PC/LINE input is only two way.
When used in PL mode you can use this switch to select Right or Left, but in PC mode that option is not there since you only have two positions an they are already taken up by the PC/LINE functionality... Had this switch been three way as well,there would have been more options, and one less part number.
What makes this even more convoluted is the fact that this set up requires the 3.5mm input jack to be STEREO, since a MONO would short Left and Right on the PL input,- A truly strange way of doing thing especially when you consider how much effort (cost!) they put into everything else in this tiny gem.
Best part is,- my daughter is happy now, although it took "slightly" longer than anticipated to get the hooked up correctly...
DMacri:Hi Steve, I see that, I guess I don’t recall seeing pc speaker cables with stereo to dual mono outputs. Was this cable typically shipped with the Beolab 4 PC version? Just curious now more than anything.
I see that, I guess I don’t recall seeing pc speaker cables with stereo to dual mono outputs. Was this cable typically shipped with the Beolab 4 PC version? Just curious now more than anything.
Yes, they were shipped with the right cables.
In the manual for the ‘full version BL4’is written, that you - for use with a PC (soundcard) can buy the right cables from the B&O dealers.
The problem nowadays - when buying these speakers second/third hand - however, is that they don’t excist anymore and probably can not be bought from B&O anymore.
MM —— click the pic,
I am also a fan of these speakers - in the right application.....
This review of Beolab 4 may interest you (entitled "Is this the worst speaker that B&O ever made?"):
https://youtu.be/cOXKT9GvSgE
Steve at Sounds Heavenly: Hi Beovox141, I am also a fan of these speakers - in the right application..... This review of Beolab 4 may interest you (entitled "Is this the worst speaker that B&O ever made?"): https://youtu.be/cOXKT9GvSgE Kind regards, Steve.
I saw that one already,
I actually enjoy all your videos, so keep them coming
Thanks!
Videos coming in the next couple of weeks should include a tour of a vintage B&O collection, a review of the Beovision Harmony and comparison of Beolab 3 vs. 8000......