Beolab20 Bass issues

Viewing 12 posts - 1 through 12 (of 12 total)
  • Author
  • #3787
    BRONZE Member


      Does anybody know how I can disable ABL on my BL20s?  As far as I know ABL is adaptive bass linearization. I still can’t digest the fact that on loud volumes the speakers bass doesn’t even disturb the next room.

      Some Rap/R&B tracks are mostly deep bass and believe me this doesn’t sound great on my speakers.

      SILVER Member
        • The Netherlands

        As far as I know, ABL was mainly developed to lift the ‘presence’ of bass in the lower volumes.
        So I think that relatively seen, it does not boost bass in the higher volumes.


        Probably there are other forum members who know more about ABL. Please comment.

        BRONZE Member

          I’ve doubt that it can be disabled.  ABL attenuates the bass at high volumes to protect the speakers so, if there were a way to turn it off, you’d risk damaging your drivers.  Hence, many B&O speakers are known for being “screechy” at high volumes.  The screech is an indication that you should probably lower the volume.  Do you have a very large room or do you just enjoy music at “club” levels?

          BRONZE Member

            When I say high volumes I mean 55-60 max because I have neighbors but the speakers are 30 cm from the wall as seen in the pic. It’s an open space that I have around 80m2 but nevertheless and from my experience low frequency bass should be heard specifically if you stand in the corner which is not happening.

            The speakers are capable of going as low as 19 Hz ( yeah +-3 dB ) but the point is that this bass is being somehow cancelled and you can feel that the speakers are intentionally cutting deep bass for some reason. I tried playing with the Avant settings and trying different settings but they all are the same.

            One thing I would like to mention is that the dealer visited me couple of months ago and updated the firmware of the speakers and I feel that ever since, the issue was amplified. Could be my imagination but certainly not what I’m expecting.

            I have a pair of old stand floor bipolar mirage speakers each with 2 x 6″ bass drivers each and believe me the bass extension can be heard in the entire building. Certainly not possible with the BL20’s which is very very odd.

            I’m honestly out of ideas and the speakers are set to freestanding mode which is the highest bass you can get.


            SILVER Member
              • The Netherlands

              If you like to read into this topic, here’s an article about B&O’s ABL. It describes that ABL is not just one system, it has evolved with new speaker systems. But there’s hopefully something you will learn form it:

              B&O Tech: What is “ABL”?

              BRONZE Member

                Thanks. It looks like I did a mistake and picked up a $15k pair of speakers that have a very aggressive ABL and that was the difference between the BL5 and the BL20s.

                I also believe that the latest firmware update had changed the characteristics of the ABL because even the dealer admitted that the MK1 version had a lot of circuit board replacement and  power supply failures so that’s my only explanation.

                Will call the dealer and see if I can downgrade the firmware and report from there.

                GOLD Member

                  It is not possible to disable the ABL algorithm, however:

                  Disabling the ABL will not increase the level of bass (relative to the other frequency bands) in any Beolab loudspeaker.

                  If you were able to disable the ABL, you would merely get distortion caused by clipping of the signal – either caused by

                  • excessive excursion of the loudspeaker drivers
                  • reaching the limits of the amplifiers, or
                  • reaching the limits of the power supply.

                  ABL is there to prevent this clipping (and therefore a short time with distortion, followed by destruction of the loudspeaker).

                  There are some people who confuse ABL with a “loudness” function (which boosts the bass and sometimes treble frequency ranges at lower listening levels) – however, these should not be conflated. Beolab loudspeakers (Beolab 28 excepted) do not have a loudness function, since this would be a feature of the source (e.g. a Beovision television) instead.

                  BRONZE Member

                    Hi Geoff, I was commenting on your blog but looks like you were faster.

                    I do realize that the Avant has in Sound settings an option to enable/disable loudness as well as clipping protection but lack of bass extension in the 40Hz down to whatever the Bl20 can play is surprising.

                    Do you believe changing the source would change the speakers behavior? I don’t wanna waste my money if the speakers are designed to play the way they are.

                    BRONZE Member


                      Maybe it so simple (and difficult) as speaker placement? The BL20 is a full range speaker, but the lowest frequency may not be possible to hear in your listening position.. Thats the great thing with subwoofers, they can be placed where the bass fills the room (or your listening position) the best. While the speakers is placed for best imaging and stereo seperation.
                      Just for a test – try to use the subwoofer-trick to place one of your BL20. Place it your listening position and walk around the room and find where the bass is best – then put the speaker at that spot.



                      BRONZE Member

                        Have you ever tried connecting the Beolab 20’s to a different source/using different cables?
                        Looking at your photo (nice room!), the 20’s should absolutely deliver enough ‘bass’  in this setup.

                        GOLD Member

                          > I do realize that the Avant has in Sound settings an option to enable/disable loudness

                          This will “only” increase the levels of the low and high frequency bands at lower volume settings, as is described in the Beovision Technical Sound Guide.

                          > as well as clipping protection

                          This will “only” prevent the analog and wireless power link levels from clipping due to a combination of high signal levels, increases in the tone controls, and playing at maximum volume.

                          It’s difficult for me to diagnose whether or not there is actually a technical problem, or whether this thread is a discussion of a mismatch between your preferences / expectations and the sound design & capabilities of the loudspeakers. Changing the source will not increase the maximum possible amount of bass that the Beolab 20s can produce – but it’s possible that the settings in your current source (which I assume is a Beovision Avant, based on your comment) are reducing the bass level. However, if this is true, then the Avant is configured to reduce the bass at all volume settings.

                          In order to make sure that you’re not dealing with incorrect settings in the Avant, create a new Speaker Group with only two loudspeakers (the BL20s) set to Left Front & Right Front – and then choose the Music Sound Mode (and reset it to the default settings).

                          Also, check your global Bass and Treble settings on the Beovision Avant to make sure those are set to the default values.

                          From there, you can tweak the settings to your preferences. However, if this does not give you the desired amount of bass at extreme volume settings, it’s because you’re hitting the physical limits of the loudspeakers.

                          Of course, the placement of the loudspeakers in your room will result in changes in the overall spectrum – but there’s no way to diagnose this or make any recommendations remotely. Generally, the old rule of putting loudspeakers in corners will give you more bass – but it’s typically a very “boomy” and uncontrolled bass due to the coupling to room modes.



                          PS. I’ve (hopefully) disabled the comments on my website – but I might have missed a page or two here or there by accident.

                          BRONZE Member

                            Thanks everyone for the suggestion. I paired the speakers to a beosound moment and guess what? the BL20’s sound awesome.

                            It’s not my imagination or a placebo effect because I can hear stuff rattling and shaking in the room. I immediately reset the Avant NG ( reinstall TV) but unfortunately that didn’t help.

                            For here I think it’s either the TV is doing something really nasty or I just need to live with it and use the internal speakers. I’ll keep the BL20’s for music only on BS moment.

                          Viewing 12 posts - 1 through 12 (of 12 total)
                          • You must be logged in to reply to this topic.