BeoLab 8000: woofer drivers & disturbing vibration ?

3 replies
KolfMAKER
KolfMAKER
Bronze
569 posts
Posted July 31, 2024 at 16:00 GMT ? Edited August 1, 2024 at 14:03 GMT
#689166
Issue When playing music there seems something wrong with the representation of bass by the two drivers for mid and bass. When it happens, the vibration sounds like there is something loose or damaged in the driver (foam ring, cone, dust cap). The vibration does not occur at low(est) volumes, but it starts to be hearable at medium volumes (and gets awful at higher volumes). These BeoLab 8000's have serial numbers in the 1072 xxxx.   Music (with bass) tested:
  1. Vail Johnson – Bass solo (): Immediately from the beginning of the song, the vibration can clearly be heard. The vibration follows the kick drum instrument. NOT OK
  2. Bass test 20 Hz (Result: no damage or loose parts found.   Comparison test: How
    • I played Coldplay Magic on 3 different sets of BeoLab 8000.
    • I changed the two speaker drivers between the sets used in the test. BeoLab Set 1Set is the set where the issue started. I used BeoLab Set 2 as a reference, because I did not have the vibration issue on this set.
    • Source: iPhone 12 with Spotify, connected via Lightning to RCA cable, to the RCA input of the BeoLab.
    • Measuring: Spotify has 16 volume steps. I measured 4 points: a) at what highest volume step level there was no vibration, b) at what volume step level the vibration starts, c) at what level it gets clearly hearable, d) at what level it mis absolutely bad.
      Comparison test: Results Please, have a look at the table attached with the test measuring results. The woofer drivers clearly had issues in the BeoLab set 1 (as I noticed the issue with this set). But when I put these woofer drivers in BeoLab set 2, I also heard & measured the vibration issue. In fact the measurement with these drivers in set 1 and set 2 are almost the same. I also wanted to know what would happen when I would put the woofer drivers of set 2 (the no-issue set) into set 1 (the set with issues). Result: the 'good' woofer drivers, performed bad in set 1. Actually the measurement is about the same as with the 'bad' woofer drivers that are originally with set 1. As a reference, I also measured in Set 2, with its own woofer drivers. Result: far better than any other combination tested. (Confirming this is a good set, without the vibration issues)       Question First I thought it's the woofer drivers of BeoLab set 1 that caused the problem. Cause if they perform bad in a 'bad' BeoLab 1 set, but also in a 'good' BeoLab 2 set, it could be damage somewhere to the driver. But I was surprised to find that the 'good' woofer drivers from the 'good' BeoLab 2 set, performed bad in the 'bad' BeoLab set 1.
    1. A bit confusing now, because is this problem a combination of bad woofer drivers with a problem on the amplifier/cross-over filter side?
    2. So, what could be wrong here and what should I check?
      Any advice is welcome!   Attached:
    • Pictures of the 'bad' drivers from BeoLab set 1, after I removed them from the panel to have a visual check.
     
Attachments (2)

Location: The Netherlands

My B&O Icons:

Beoremote-Beo4.png Beoremote-Beo4.png
Beovox.png Beovox.png
Beosound.png Beosound.png
Beosound-9000.png Beosound-9000.png
Beolab-18.png Beolab-18.png
KolfMAKER
KolfMAKER
Bronze
569 posts
Posted August 8, 2024 at 14:58 GMT
#710907
With help of @spassmaker I focused on possible air ventilation/gaps. So I now changed two things since last time:
  • I cleaned away every tiny bit of the left glue of the old gasket. To make sure the whole surface is smooth and straight.
  • I placed brand new foam (original B&O, placement according to B&O instruction).
Also, I checked the bad woofers by gently pushing them down in the middel, and feel if there was any scratchy feeling? > There is no scratchy feeling or noise. Result: Happy that I can say that the bad vibrations are gone. Just one remark about that. I have played a list of songs with a bit more heavy and low bass tones. All play well, but only one song keeps disturbing me a bit: Coldplay with Magic. Still, in the first part of the song, the vibration can be heard when the kick drum comes in. But the effect is much less than before, and only at high volume (75% or up). Maybe it is in the song.  

Location: The Netherlands

My B&O Icons:

Beoremote-Beo4.png Beoremote-Beo4.png
Beovox.png Beovox.png
Beosound.png Beosound.png
Beosound-9000.png Beosound-9000.png
Beolab-18.png Beolab-18.png
KolfMAKER
KolfMAKER
Bronze
569 posts
Posted August 9, 2024 at 10:37 GMT ? Edited August 16, 2024 at 15:58 GMT
#710913
XX

Location: The Netherlands

My B&O Icons:

Beoremote-Beo4.png Beoremote-Beo4.png
Beovox.png Beovox.png
Beosound.png Beosound.png
Beosound-9000.png Beosound-9000.png
Beolab-18.png Beolab-18.png
or
BeoWorld Gold Membership card
Join BeoWorld

Register to access the forums, reference material, and exclusive member benefits — including our monthly prize draw.

Become a Member

December 2026 Prize Draw

Gold Members Only

As a Gold member you're automatically entered into our exclusive prize draw — your chance to win iconic Bang & Olufsen products. A unique benefit of BeoWorld Gold membership, every draw brings a new opportunity to win something special.

View Prize Go For Gold
BeoSound Level

1st Prize

BeoConnect Core

2nd Prize

BeoRemote Halo

3rd Prize