Here are some suggestions for those searching for the best possible sound from their BL5s!

1. Is the room large enough? The BL5s "energize" a lot of air, and if the room is too small, that energy will be conflicting, cancelling out soundwaves, creating room nodes (interactions between sound waves and walls) and muddying up the sound. The room should be large enough to allow placement of the speakers at a distance from walls, with enough distance from the speakers to you, to let the first reflection from the disc drivers bounce off the side walls and reach you. Yes, you read that right - with the BL5s you want the room reflections that many audiophiles spend a fortune eliminating with conventional speakers. The BL5s are designed to avoid reflections from ceiling and floor, but to give you the side reflections.
Dave Moulton does not like giving the BL5s toe-in, that is when the speakers are turned to aim slightly towards the listening position. In order to engage the walls, Moulton recommends having the speakers point parallel to the room's listening axis. You can adjust this if, say, your speakers are far apart, then some toe-in can be justified, as long as you can have a listening position that is proper relative to the distance between the speakers. (In the listening room in Struer, they've given them toe-in because of this.)

2. This means that symmetrical placement is also a bonus, as you want similar reflections from the side walls. Symmetrical placement is otherwise also a must if you want true stereo perspective. And if one speaker reflects off a wall, and the other has empty space to its side, then that's not ideal, either.

3. Similarly, you should also have a little distance from the back of your head to the rear wall, in order to avoid listening inside the rear wall reflections.

4. Check the signal chain. Are the speakers getting a digital s/pdif feed, or Powerlink/line-in only? When the speakers detect an s/pdif signal, this gets priority over any other signal.

5. Check the tone settings in your source. Are they neutral? Mine are, as I want the character of each recording to come through as undistorted as possible, but for all you know, someone may have changed these settings.

6. If you have menu options for bass control in your source, go through these. Check to see where the cross-over is set for the bass. Usually from 80Hz-100Hz. Check to see that the LFE signal - the signal that goes to the subwoofer - is being sent to your front speakers. Usually you tick "NO SUB WOOFER" or something similar, and then this signal is sent to the L/R speakers, in this case the BL5s.

If you have a surround setup, set the rear/side speakers to SMALL, and the front speakers to LARGE.

7. Check your source player. Is it decoding the source properly? Some have a lot of options - such as Dynamic Range Control, Dynamic Range Suppression. These should be inactive when you use BL5s, you don't need it, they can take anything you send them.

Also check that you are not converting the original signal to a fake surround signal, or a stereo signal with Digital Signal Processing. If you have a digital connection from your source to the speakers, you want an untouched signal to reach your speakers. They are plenty advanced enough in their own processing of it.
If you are sending an analog signal to the speakers, from a surround processor for instance, then the setting is even more crucial, and needs to be checked. ProLogic, Neo6, etc., are all false surrounds. If you have DTS, Dolby 5.1 or the high-def audio formats in the source, then make sure that the processor is handling these natively and not translating them into another version. It really pays to read the processor's manual thoroughly on this particular point. (The digital input on the BL5s is not equipped to handle all kinds of surround signals, and you may have to opt for the analog signal from the processor if you get drop-outs, etc.)

8. If you're using a non-B&O source, get a synchronisation cable. If your BL5s don't respond properly to a Synch-cable (early versions), then do a volume STORE that you can reset to, if you suspect the speakers have drifted. Each blink of the green light, as you adjust the volume up or down, adjusts the speakers 1dB. If the speaker on the right hasn't received a volume instruction (your child was in the way), then the speakers are at least 1dB off in respect to one another. That's noticeable -- more than that is very noticeable.
Therefore, take the speakers all the way down, keep pressing DOWN volume until the light doesn't respond any more.
Then wait a little - before going back up tick-by-tick, while listening to a source.
For a while, you won't hear anything, but then you'll begin hearing the source. Press each tick-by-tick, slowly, while registering that both speakers are responding to the press of the UP button.
When you reach the volume level you like, store this using Audio SETUP in LIST.
Add RESET to your remote LIST, if it doesn't already have this.
You now have a simple way of resetting your speakers' levels, and being certain they're similar. It really matters to the bass reproduction, and you can now adjust up and down from the Reset Level, knowing you can easily restore this.

9. Is your listening environment absorbing too much of the sound energy, or reflecting too much of it? Worth taking a look at where you listen. Won't go into detail, but the ideal room has a little "echo" (room tone), without being dead or clangy. (Most B&O product photography takes place in rooms that are the last place in the world for good audio ... concrete walls and marble floors!)

10. Is your listening position dictated by the interior decorator or by the ideal listening spot?
I can't tell you how many times I've come to the house of a friend or acquaintance, and discovered that the sound merged much better in front of or behind the listening position they had arbitrarily chosen, before placing everything around it.
Begin with speaker placement negotiations with the interior decorator (your better half!). You do not want to put BL5s right smack up against a wall, it's not ideal, and speakers of this quality should have ideal working conditions. The air being shifted by the sub will reflect straight from the back wall and muddle up the next pulses.
Don't place the speakers too far apart. BL5s can be placed quite far apart, but speakers create and spread sound energy, and you want to focus this energy towards the ideal listening position. Too far apart, and you get reduced focus and an unnaturally extended soundstage - Joni Mitchell will have a very wide mouth. 2,5-4m should be your working range for spacing the speakers.

11. Where's the bass?
If you feel the bass is soft where you're seated but you find better bass spots elsewhere in your room, then you should reconsider the speaker placement or listening position.
People placing subwoofers use this trick: they place the subwoofer in the listening position, and start a source with good bass, then they move around hunting at floor level for the best sounding subwoofer pulse. When they find it, they place the subwoofer there, and check whether they get the same bass response in the listening position. Usually they do.
Complaints about the bass on the BL5s may just as much be a function of listening in the wrong place. The fact that you've placed a chair or couch there doesn't make it right.
The propagation of bass waves is quite a science - for instance, some of those waves are more than 27m long, clearly too long for 99.999% of listening rooms. Which is why you're dealing with reflections that could be pulse-cancelling and have to pay attention to optimum placement.
When I was deciding my ideal placement and listening position, I happened to place my outstretched hand on the back of my sofa, and noticed that it was vibrating to a bass pulse my head or chest weren't feeling. I went to sit there, and got a wonderful bass response (the chest cavity responds to the bass). So I redid the placement until I got that feeling in the listening position.

12. No - you can't place BL5s "anywhere you want" and expect a perfect result. But you will get good sound - however, they are much better than good sound. I agree with Dave Moulton, there's no way that the BL3s can create better sound than the BL5s, but if your listening environment isn't ideal, or if you have made mistakes in setup, then you may end up in the strange situation that you prefer your BL3s to the BL5s - but that would not be the fault of the speakers. It could simply be that BL3s or BL9s are better suited to the dimensions and characteristics of the room.

13. Does your source have poor, muddled bass while lacking dynamic range? Which, sadly, is true of most music produced today, unless it's classical or acoustic jazz from quality performers. Many sound systems do not go below 40Hz, and most stop at 65Hz. Your BL5s can dive to sub 20Hz - and need to be properly fed. Be critical of the music you buy, check reviews and references - and don't believe that expensive remasters are necessarily better than the original CDs!

Get a good reference CD, and use that. It's useful to get one with a variety of tracks on it. You can burn your own - try to include mostly acoustic music, that has not been generated or processed electronically.
My favourite test-CD is Burmester's CD3, which has tracks selected to test a range of variables.

link

When you have everything set up right, get this recording by Pierre Boulez and the Wiener Philharmoniker of Mahler's 3rd Symphony.
Sit back - and marvel at the miracles a pair of BeoLab 5s are capable of. You won't believe your ears - where most music today is mixed with a pitiful dynamic range and compressed to death, this recording has unsurpassed dynamic range. And the BeoLab 5s handle every single note beautifully.