Beolab 9 frequency response

The B&O service manual quotes 30-20.000Hz on the Beolab 9. However I can´t seem to find a reliable source for the regarding "method" they use to get this data. Is this +/-3db ? 

I have a Bowers&Wilkins ASW610 Subwoofer which goes down to 27Hz at +/-3db and 20Hz at +/-6db

If the 9 go down to 30 at +/-3db anyway the benefit from the sub is not really present and using "higher" volume on the sub just to make the sound boomy is the opposite of what i want. 

 

B&O often fools around with the product specifications considering that they seriously quote the Beolab 3 with an "effective frequency range" of 50-23000Hz.

well.... at +/-10db and having 200-2000Hz as reference

The sub is fun and all for movies etc. but i´ll just repeat my question here: Do the BL9 go to 30Hz at +/-3db ?

I tend to believe both those frequency ranges, i haven’t owened either, but my previous bl1’s and bl2 and my current bl50’s do exactly what they say and do it either quietly and at very uncomfortable listening levels

Producing a valid, accurate frequency response measurement is a difficult thing to do right. And it's an area that is rife with abuse by different manufacturers and has been since the beginning of audio gear. Even a reputable company like B&W, their measurements mean almost nothing in a real world room. If you're lucky, they will tell you that it's measured in accordance with some standard and identify the standard. That, however, to the average person, means effectively nothing since you aren't familiar with the standard, and since all competing claims are probably not the same standard. This is also an area where the most honest companies can come off at a loss against inflated claims from other companies. And if a speaker is x to y freq plus or minus whatever, in a standard sized semi-anechoic chamber driven at a certain signal level, it's about impossible to take that and predict what it does in your particular room, especially in the bass.

If you close mic the speaker, and use a fairly low level, you can get appreciable bass measurements out of small drivers. In the real world, at volumes loud enough to actually hear, getting deep bass out of small drivers is not going to happen, as an example. Also, differences between bass reflex and sealed speakers rear their heads too. If you have two speakers, spec'd to be say -6 dB at 50 hz, one a bass reflex and the other a sealed, note that below system resonance, the bass reflex speaker falls off at 24 dB/octave while the sealed falls off at 12 dB/octave. You could have a bass reflex speaker that claimed 45 Hz instead of 50 Hz have less deep bass in a real world environment due to this.

For what it's worth B&O has generally not played this game, they give figures that, in most real world environments, accurately describe the results you can probably expect, and have at times suffered for it because they are on the conservative side. For example, the BL8000s I have were rated at something like 50 Hz, but I got appreciable output down to the lower 40 Hz range in my last houses oddball and hard to live with acoustics. The acoustics in that room made even the tiny Magnapan speakers sound like disco monitors, I had quite a bass boom issue.

B&O specs are misleading without a range or methodology. Freq response from any make are basically guesses and assumptions anyway.

Again B&O are about simplicity and not getting into such details.

I forgot to say that i tested all my speaker and so far the range had been accurate. Did some frequency sweeps and tone testing at several volume levels, i have yet to find any inaccuracies.

I doubt you need more bass than two bl9’s, those will shake your room, but i guess if you want to shake your house you can add more

PPS,

You’ll effectively have two 10” subwoofers in your room. For most rooms that’ll be quite alot. So how big is the room? and secondly where are you placing them? And lastly, what are you going to use them for(movies/music)?

davidr:

B&O specs are misleading without a range or methodology. Freq response from any make are basically guesses and assumptions anyway.

Again B&O are about simplicity and not getting into such details.

http://www.tonmeister.ca/wordpress/2014/10/15/bo-tech-reading-specifications-part-1/

MM

I went with the ASW610 and am quite happy with the outcome. 

Usually when listening to classical music or Jazz I have the sub turned off to keep the "acoustic balance"

. For movies i turn it on with 1/2 Volume and the crossover set to 45-50Hz - the effect on the reproduction of LFE effects in movies like Avatar or Interstellar are very noticable and are just what i missed with the 9s.

Simply adding it to the powerlink chain with a Din-Cinch adapter at the end was very easy to set up and gives me no buzzing sound etc.

Millemissen:

http://www.tonmeister.ca/wordpress/2014/10/15/bo-tech-reading-specifications-part-1/

MM

There is a tv - and there is a BV.

At the end of the article, it says;

“3. Subwoofers are different – since it doesn’t make sense to try and find the average magnitude response of a subwoofer between 200 Hz and 2 kHz”

It was a great write up on how B&O measure frequency response and allocate specifications, so what/how are the Beolab 2 or Beolab 19 specifications arrived at?