B&O Beolab 9 measurements

[solderdude]

Because I had everything already connected and cleaned up, I used the Topping Dx7Pro instead of the NAD C510 dac/pre.
I measured 1 speaker with the umik1 from 1 meter distance.

I noticed something interesting: the distortion is almost exactly at 50Hz, the frequency of AC in my country.
Is this noise induced due to mains leakage into the signal chain?

Possibly but not necessarily. You could very well have a room resonance there.

 

[HarmonicTHD]

Thank you, that confirms the quite dark tuning, except the dip around 6 kHz which is probably is a interfernce pattern result of measuring both with not 100% centered mic, maybe you could repeat that for each loudspeaker.

Mhhh. The 6k dip didn’t show in his initial measurement although at different scale. Is that because of mic placement in the second attempt ?

 

[thewas]

Mhhh. The 6k dip didn’t show in his initial measurement although at different scale. Is that because of mic placement in the second attempt ?

Yes, that's what I guess, in his first measurement the dip was around 10 kHz.

 

[HarmonicTHD]

Yes, that's what I guess, in his first measurement the dip was around 10 kHz.

Got it.

 

[Marc v E]

Yes, that's what I guess, in his first measurement the dip was around 10 kHz.

I noticed that too. It appeared after the 1 meter measurement áfter I turned on the Frequency dependent window (with the default 15 cycles) in IR Window button.

One possibility is the position of measurement mic and the tweeter configuration.

 

[thewas]

I noticed that too. It appeared after the 1 meter measurement áfter I turned on the Frequency dependent window (with the default 15 cycles) in IR Window button.

One possibility is the position of measurement mic and the tweeter configuration.

Best is to measure the left and right loudspeaker separately.

 

[HarmonicTHD]

Best is to measure the left and right loudspeaker separately.

I noticed that too. It appeared after the 1 meter measurement áfter I turned on the Frequency dependent window (with the default 15 cycles) in IR Window button.

One possibility is the position of measurement mic and the tweeter configuration.

Yes please measure it separately at your listing position and then together without moving the mic in between. If you can be very accurate with the mic setup eg use a laser distance meter. And the topping would be if you could share the REW file directly so everyone can apply their preferred smoothing and scale Pretty please.

 

[Marc v E]

Yes please measure it separately at your listing position and then together without moving the mic in between. If you can be very accurate with the mic setup eg use a laser distance meter. And the topping would be if you could share the REW file directly so everyone can apply their preferred smoothing and scale Pretty please.

Will do in a few days

 

[Timcognito]

Thanks for this always wondered how their speakers tested. Glad to see that B&O is not just a lifestyle brand. Their used TT's go for a pittance eBay because the cartridges are rare and no longer available.

 

[amj101]

I was looking around and found an interesting looking link to a document regarding the Beolab 9 that was formerly on the B&O website. Unfortunately, the link was long dead when I tried to download it, but somehow, B&O customer support managed to locate a copy, which they sent to me. Perhaps it may be of use to this thread.

 

[Hyponx]

I own a pair of these myself. I have never measured them but it may be worth investigating if the slope of the response isn't caused by the built-in ABL system (which cannot be turned off). This Adaptive Bass Linearization system is basically a loudness system combined with a driver protection system at higher levels. The higher bass distortion may be indicative of this feature still being active at the measurement level. Here is the blog of the B&O tonmeister regarding this feature. https://www.tonmeister.ca/wordpress/2013/11/07/bo-tech-what-is-abl/

B&O Tech: “Auto” loudness

#76 in a series of articles about the technology behind Bang & Olufsen loudspeakers If you look at the comments section to a posting I wrote about ABL, you’ll see a short conversation the…

www.tonmeister.ca

 

[Hyponx]

Oh! one other neat oddity, there is a research paper on this speakers cabinet. There was a discovery late in the design stage (tooling was already manufactured) that the cabinet exhibited unacceptable resonance at ~140hz. The results of this paper led to the installation of an additional internal brace.

Cheers all.

https://www.loudsoft.com/wp-content/uploads/2019/07/MasterThesis.pdf

 

[Marc v E]

I own a pair of these myself. I have never measured them but it may be worth investigating if the slope of the response isn't caused by the built-in ABL system (which cannot be turned off). This Adaptive Bass Linearization system is basically a loudness system combined with a driver protection system at higher levels. The higher bass distortion may be indicative of this feature still being active at the measurement level. Here is the blog of the B&O tonmeister regarding this feature. https://www.tonmeister.ca/wordpress/2013/11/07/bo-tech-what-is-abl/

B&O Tech: “Auto” loudness

#76 in a series of articles about the technology behind Bang & Olufsen loudspeakers If you look at the comments section to a posting I wrote about ABL, you’ll see a short conversation the…

www.tonmeister.ca

Thank you for your input!
I will measure them again when I get the opportunity. One other thing to rule out is the microphone with usb connection to the laptop. Finally, it could also be due a measurement error on my part. This was my 2nd time measuring.

In due time I plan to buy the flex eight. Would be nice to see if I can get an improvement in room compensation.

 

[poxymoron]

So, how do the Beolab 9s sound?
This is an interesting thread, I'll continue to watch it.

 

[Marc v E]

So, how do the Beolab 9s sound?
This is an interesting thread, I'll continue to watch it.

I would describe them as having an effortless sound, with every listener being able to pick out all elements of a music piece. They sound good with all quality of music recordings, because the treble never gets piercing or tiring. And they have a very wide sweet spot. One final benefit is that they sound good at very low volume due to ABL (bass boost at low levels) and neutral at medium to high levels. They can play loud without breaking a sweat.

Only negatives are that to sound good with all quality of recordings you might miss the utmost 5% detail/neutrality of sound compared to speakers that are brutally honest. You can definately hear differences in quality of recordings though. OTOH I've heard other speakers which made clean recordings sound beautiful and compressed recordings absolutely unlistenable. That is not the case with the Beolabs.
The other is that connections are unbalanced rca or a propriatary B&O plug. The B&O connection sends an on/off signal, while via the rca they turn on when receiving a signal, which can be a few seconds into the first thing that's playing.

 

[Hyponx]

My experience is similar to Marc's. They have an easy-going full-range sound. The active-amplification setup is also advantageous as these speakers are very small compared to a conventional passive tower but each conceals the amplification and basically a 10" sealed subwoofer in the chassis. Very high spouse approval and can be run on a tiny DAC/preamp so no big amplifier/receiver to worry about either potentially. Can have a very minimalist system and still have great sound quality.

Regarding the Line-in auto detect delay if ones source has a 12v trigger-out it is possible to use an adapter to supply the 5V on/off trigger. Like this one:
https://www.av-connection.com/?PGr=1760.

I seem to recall some enterprising folks have made USB triggers as well.