B&O Tech

These are links to the various postings I’ve written about the technology behind and inside Bang & Olufsen loudspeakers. Most of these are answers to questions that I get asked either indirectly through our customer service representatives, or directly, when we host visits to the company headquarters in Struer, Denmark.


#93: Internal vs. External Volume Control
#92: Volume controls vs. Output levels
#91: What is a Virtual loudspeaker?
#90: Beosound Theatre: Virtual loudspeakers
#89: Beosound Theatre: Spatial control
#88: Beosound Theatre and Dolby Atmos
#87: Beosound Theatre: A very short history lesson
#86: Beosound Theatre: Outputs
#85: Beograms side-by-side
#84: Bass Management in Beosound Theatre
#83: What Use are Watts?
#82: What’s a woofer?
#81: Volume control
#80: High-level sources and Beolab loudspeakers
#79: Closed headphone magnitude response
#78: A brief introduction to parametric equalisation
#77: Beolab loudspeakers and Third-party systems
#76: “Auto” loudness
#75: Distance Tweaking
#74: It’s not just a Soundbar
#73: Directivity and Reflections
#72: Signal Mixing and Decomposition
#71: Introduction to Acoustic Interference and Loudspeaker Directivity
#70: The basics of sound
#69: Beolab 50 Set-up procedures
#68: Beolab 50 – Introduction to Features
#67: Beolab 50 Design
#66: Beolab 50 Production
#65: Beolab 50’s Beam Width Control
#64: Beolab 90 – How to set up Active Room Calibration
#63: Introducing the Beolab 90 Concept
#62: Native vs Fixed Sampling Rates
#61: The Beolab 90 Story
#60: SoundStage! InSight interview about Beolab 90
#59: Twenty Years of Stylus Development
#58: The Beocord 8000 Design Story
#56: 100 Years of Danish Loudspeakers
#55: A quick primer on distortion
#54: Headphone Signal Flows
#53: The Beogram 4002 Design Story
#52: Location, Location, Location
#51: The Cube
#50: Active Room Compensation – Some More Details, Part 2
#49: Why select one loudspeaker driver instead of another? (Part 1)
#48: Intuitive Directivity Plots v.2
#47: Product playlists
#46: Intuitive directivity plots
#45: Uni-Phase Loudspeakers
#44: Beolab 90: Production
#43: Beolab 90: Measurements
#42: Beolab 90: The top three features -Live!
#41: Beolab 90: Behind the scenes
#40: Active Room Compensation – Some Details, Part 1
#39: Heat of the Moment
#38: Beam Width Control – A Primer
#37: Shark Fins and the birth of Beam Width Control
#36: It’s Lonely at the Top…
#35: Active Room Compensation
#34: What is “Beam Width Control”?
#33: Video Engine Customisation Part 1: Bass Management
#32: The Naked Truth V (Beolab 14 Sub, Beolab 3500)
#31: Video: How B&O Develops a Loudspeaker – Part 2
#30: Video: How B&O Develops a Loudspeaker – Part 1
#29: The Naked Truth IV (Beolab 17, Beolab 20)
#28: Reading Specifications, Part 1 (Frequency Range)
#27: Near… Far…: Depth perception in stereo recordings
#26: Combinatorics: BeoVision 11/Avant parameter settings
#25: Where great sound starts
#24: How loud are my headphones?
#23: Visual Analogies to Problems in Audio
#22: Listening Tips and Tricks
#21: What is Loudness
#20: Beovision Avant Audio
#19: Free / Wall / Corner: Compensating for loudspeaker placement
#18: The Naked Truth III (Beolab 2, 19, 14 Satellite, 18)
#17: A day in the life: Listening to recordings
#16: Ribs and Dogbones: Loudspeaker Cabinet Stiffness
#15: Curves are Better than Corners: Diffraction and Loudspeaker Design
#14: Multichannel setup: Tips and Tricks
#13: But what if my room is Scandinavian?: Room acoustics and sound reproduction
#12: The Naked Truth II (Beolab 18 prototypes, Beolab 14 subwoofer)
#11: How to Make a Loudspeaker Driver (A primer)
#10: Where Should I Decode?
#9: Thermal Compression Compensation
#8: Subwoofer Tweaking for Beginners
#7: What is Sound Design?
#6: What are Subwoofers REALLY For?
#5: TrueImage Upmixing
#4: Loudspeaker Development Process
#3: The Naked Truth (Beolab 3, BeoLab 11)
#2: What’s So Great About Active Loudspeakers?
#1: What is “ABL”?


BeoLab 14
BeoLab 17
BeoLab 18
BeoLab 50
BeoLab 90
BeoVision 11
BeoVision Avant
BeoPlay A9
BeoPlay H2 headphones
BeoPlay H6 headphones
BeoPlay H8 headphones
BeoPlay H9 headphones

  1. Bart De Bie says:

    Hi Geoff,
    I have a couple of questions about the Beolab Transmitter 1.
    Is there a DAC inside?
    If so, will one get better sound from using the Toslink digital connection vs RCA stereo analogue connection?
    I’ve heard somewhere that the analoge section of cd players can differ in quality but that a digital conection (coax or toslink), since it’s digital transmission, doesn’t vary all that much in quality thereby meaning that hooking up a cdplayer digitaly to your audio system results in the most transparent sound, is this true or not?
    If this is true would this mean that there is no difference between the digital output of (let’s say for comparison) an expensive emm labs or dCS sacd/cd player, a mid priced oppo blu-ray sacd/cd player or parasound cd player or a cheap sony or pioneer sacd player?
    Thanks in advance for answering all my questions.
    As being a big fan of your research i say keep up the good work and to seal it of with a quote of ken kreisel: good sound to you ALWAYS!

  2. Hi,
    There is no DAC – but there is an ADC for the analogue input.

    Generally speaking, it’s always better to have as few conversion stages as possible in your signal chain. So, if you can connect your CD player digitally instead of via analogue, it’s probably a better choice.

    As for the difference between the digital outputs of two different devices – there can, indeed be differences (for example, in jitter). However, whether the differences are relevant is dependent on what you’re connecting to. For example, if you have a receiver with a good PLL that can reject jitter, then the jitter of your source isn’t as worrisome…

    So, as usual, the answer is “it depends”… there’s no simple answer, since the specific behaviours of the devices you are connecting define their interaction.

    – geoff

  3. Fotis Gimian says:

    Hello there Geoff, really hope you’re doing well :)

    I had a little question regarding the H6 if that’s OK. A few folks on the head-fi community and I have noticed a difference in sound between older H6 models as compared to the current revision and limited edition versions (such as the graphite version). We noticed that bass presence has been increased in the newer models.

    Has the driver technology or porting changed over the lifespan of the H6s to improve their bass response? If so, is there any way to determine which ones have the revised drivers and/or design based on a serial number or similar?

    Thank you so much! :)

  4. Hi Fotis,

    To my knowledge, there has been no change in tuning of the H6 headphones.

    However, you should be aware that the bass response of any closed headphone is heavily dependent on the sealing around the ear. For the H6 (and many other headphones), a common location for leakage is just below the pinnae, at the jawline. As the foam and earpad material softens over time, the amount of this leak will change. In addition, different softnesses of earpad material from product to product and batch to batch will change the way the headphone leaks (the softer the material, the more easily it conforms to your head shape, and the less leakage).


  5. Hello Geoff,

    Very interesting site! I recently had the pleasure of auditioning the B&O sound system in an Audi Q5. After setting the focus to “driver” I had very nice imaging, although I had to set the balance to the right a little to get the singer to the center of the hood, where it should be. No problem.

    However, I then auditioned the B&O system in an Audi S3. I was disappointed to find out that there is no “driver” setting, just “front”. The front setting, which I assume is a compromise between driver and passenger seats, had the imaging too far to the left of me, and I felt the soundstage was skewed and compressed towards my left. I have had similar experiences with the Logic 7 “front” setting, which has the same problems.

    My question is why do you only offer a “driver” setting in some models, mainly the A5 and Q5 model lines, and not in the other cars? I find that the “front” setting really handicaps the system and does not allow it to sound as good as it could. In fact, for me it is a deal-breaker on the S3 and I am now looking at S5 models.

    Can you please elaborate on the decision not to include a driver focus setting on most Audi systems, when most of the time it is the driver who has the highest expectations/standards and why would the driver need to accept a “compromise” setting when he is alone in the car most of the time? Thanks in advance for clearing this up for me, because I am very confused…thanks!

  6. Hi,

    Sorry – but I can’t answer your questions. The automotive sound systems are outside my “jurisdiction” so to speak…

    I will forward your comments to the appropriate persons, though.


  7. Hello Geoff
    My name is Paul and I live in Holland. I am very much interested in buying the Beolab 18 and also the beolab 19. In your articles i can’t find much informations about these speakers. Why is that?
    I do have a number of questions. I hope you can answer them..
    Is there a difference in the performance of the speakers between wireless and wired; what is the max sample rate of the transmitter; what is the frequency range of the speakers (18 and 19)
    I also ask myself if it’s better to have two subwoofers instead od one; i can only put my subwoofers in a corner. Will that cause a problem? I know that you can adjust the speaker for the placement in the room, but I don’t know what this actally does; is it simply a change in gain?
    Can you reccommend the speakers?


  8. Hi Paul,

    My articles are intended to be more about the technology behind B&O products and not the products themselves. Beolab 90 is somewhat of an exception, since it is the only loudspeaker in our portfolio that contains some features such as Beam Width Control or Active Room Compensation.

    To answer some of your questions: there is no difference in the frequency range or frequency response of a Beolab loudspeaker when switching from Power Link to Wireless Power Link. There is a change in the signal to noise ratio, since the wired connection has a slightly higher noise floor. On the other hand, in the case of some installations, there may be some errors in the wireless signal – but in all our testing, the error concealment algorithm built into the system makes these errors inaudible.

    The theoretical maximum sampling rate of WiSA is 96 kHz. However, when you are using a B&O transmitter (named “Wireless Power Link”, since it is a WiSA signal and a proprietary communication channel, similar to Power Link Data) we limit the sampling rate to 48 kHz to improve the overall performance of the system.

    I do not have the Frequency Range spec’s for the 18 and I’m currently travelling. I will try to get these when I return to work. If you’d like to know more about Frequency Range in general (and why it’s not a terribly meaningful indicator of anything), this article might be of interest.

    A Frequency Range for a subwoofer doesn’t make much sense due to its limited bandwidth – so I doubt that this will be a specification that we would release, but I can check on this for you when I return as well.

    It is certainly better to have two subwoofers instead of one. There has been much research done on this topic back about 15-20 years ago. The bulk of the reason has to do with the coupling of the loudspeakers to the room. This is why it is better in almost all cases to have full-range loudspeakers rather than an x.1 system.

    If you put your subwoofer in a corner, you will have a case where you are maximising the coupling of the loudspeakers to the room modes. If you like bass, this means you’ll get more of it – but at the resonant frequencies of your room… Almost all B&O loudspeakers have a built-in filter that can do some general compensation for corner placement. This issue is discussed here. In addition to this, the BeoLab 19 has extra controls for alignment with your main loudspeakers. These are discussed here – although not all of the things mentioned in this article will be directly applicable to you, depending on how you connect your loudspeakers to your source.

    To answer your last question – I never recommend any loudspeakers, since the choice of loudspeaker is a very personal one, depending on usage, taste, and preference. The only recommendation that I have is that no one should ever buy a loudspeaker without having heard it with their own music, preferably in their own listening room.

    I hope that this adequately answers at least some of your questions.


  9. Hi geoff,

    I’ve been reading lots of “audiophile” articles lately saying that cables do affect, a lot, the final sound quality of any music system. I was amazed when I found out that simple RCA cables and even AC plugs can be found in the market costing thousands!!! Some like to use lots of fancy words to describe how transparent a cable is, but, if it is trully transparent, how can one know it? ;-)

    Anyway, I’ve never seen a B&O speaker equipped from factory with a fancy power cord or a 24k golden PL plug. Could you be so kind to shed some light on this obscure matter and enlight us with real knowledge?

    Best regards, Dante.

  10. Hi Dante,

    This is a very big / dangerous question due to the fact that the answer may offend the religious…

    As I wrote in the Technical Sound Guide for the BeoLab 90, we recommend that you do NOT buy expensive AC Mains cables or “power conditioners” for the BeoLab 90, since this will potentially introduce an increase in impedance between the loudspeakers’ mains input and the circuit breakers in your house. In addition, the BeoLab 90’s have power filtering built into their power supplies, so additional filtering is redundant.

    As to spending a fortune on cables:
    – If the cable is for an S/P-DIF input, then it is wise to ensure that you are using a cable with the correct impedance to reduce the possibility and influence of reflections on long cable runs. This does not necessarily mean that you need to spend a lot of money. Of course, this is dependent on the jitter attenuation capabilities of your digital input.
    – If the cable is for an analogue input, I, for one, don’t have a religious belief in expensive cables. I believe in good grounding, good shielding, correct balancing (if you’re using a balanced cable), good (very low impedance) connections, and the low-pass filtering effects caused by the RC network created in the wire itself. Again, a well-designed interconnect need not require re-mortgaging your house. And, as I tried to imply (actually, I was too explicit to pretend that I was implying anything…) in this posting, moving 10 cm in the room will have a larger effect than changing your wires…

    I once heard a wise man say at an AES conference that people have to believe that expensive cables sound better – if they didn’t, then this means that they wasted their money, which is not an option…


  11. Which is more relavent : an amplifier that can exploit the limitations of your loudspeakers or a loudspeaker that can expose the flaws of your equipment ?

  12. Hi Jeff,

    There’s no way to reliably answer this question without more information. The problem is that the question is heavily dependent on the specific characteristics of the “limitations” and “flaws”. In a perfect world, all pieces of the chain reach their limits simultaneously… If they don’t, then you have to choose, for example, between a loudspeaker that reveals the clipping of your amplifier, or an amplifier that can drive your woofer to bottom out on the magnet (to pick just two examples of system limits).


  13. Hi Geoff,
    I have read many articles on your sites and although I am not an acoustics engineer or anything similar I feel that if I had encountered such literature when I was eighteen I might have followed a different path in my career… Next month I will be sixty and have been a fan of B&O since 1979 when I bought my first receiver/cassette recorder called beocenter 2600. I still have it and it’s operational.
    The Beomaster 8000 with its siblings followed in the late eighties and now my 60th birthday present to me will be the final edition of the Beolabs 5 for which I have already placed an order. I have eyed these early from their beginning in 2003, however, the 8000 system with the beovox ms150 with which I lived proved to be a very lovable and reliable stereo system to depart from it.
    Now I am going for the actives and I hope that my old ears will allow me to hear every possible bit of sound or may be some of it. You see these speakers were a dream to be achieved.
    I will be using non B&O equipment with the Beolab 5s. Unfortunately no CD player nor any record player from B&O. I wonder why they do not treat their old loyal friends with some retro editions!
    So, Geoff, I would need your help in choosing a preamp which would do the job.
    I have thought of a tube preamp but I am not sure if it would live well with the fives.
    I have also thought of a Quad pre or even a Rotel. I suppose that the last Beomasters from the past were not any better from these preamps.
    As I am very anxious about matching the equipment could you please give me a hint about it?
    Thank you for reading this.

  14. Hi Nicholas,

    Thanks for your kind words!

    If you’re buying a non-B&O device, then I would suggest that you find a stereo preamp with RCA/cinch line outputs that best suits the requirements imposed by your devices “upstream”. If the output can deliver (A) adequate output levels (2 V RMS minimum as a maximum output level) (B) a good signal-to-noise ratio and (C) reasonably flat frequency response, then you’re “safe”. It is unnecessary to buy a dream with built-in room compensation, since the BeoLab 5’s have ABC. I hope, however, that it’s understandable that I cannot recommend a specific brand or device…

    Once everything is installed, I would suggest that you spend some time adjusting levels on your preamp and loudspeakers to ensure that you maintain the best signal-to-noise ratio. This is a balancing act between the startup volume of the BeoLab 5’s, the setting of their line input with respect to expected voltage, and the output level of the preamp – so there is no out-of-the-box answer for this – it will have to be calibrated by your installer.

    I hope that you’re happy with your birthday gift!

    – geoff

  15. Hello Geoff,

    i get your contact from B&O who recommend you…
    we´ve a industrial installation with a combination of BL18/19,
    feeded by a Mediacontrol operated DSP-mixer (Extron DMP128).

    Did you have any recommendations for setup up the DSP
    (leveling, filter curves, cut off freq.) for us ?

    Please contact me by PM for further details.

    Thanks in advance,
    Best regards,

  16. Hi Manuel,

    Without knowing the levels that you’ll be playing at, or anything else about the system, I would recommend that you use a 4th-order (24 dB / octave) Linkwitz-Riley crossover with a centre frequency of 120 Hz for your bass mangement system.

    However, if you’re typically playing at lower levels, then you can drop the frequency to 80 Hz or so.

    Also, if the loudspeaker placement and / or acoustical behaviour of the room dictate, it may be necessary to include additional EQ, phase, delay, or gain adjustment to align the speakers in the room.

    Hope this helps.