Yes. With the older systems with a built in power amplifier, you may use any passive speaker from any manufacturer.
The newer systems, however, have no power amplifier fitted as the power amplifier is now found in the B&O speaker, as this allows the speaker and amplifier combination to be optimised. Therefore you will need to provide a power amplifier for any passive speakers you wish to attach. There are a number of ways of doing this but the simplest is to buy a B&O external amplifier that will make your passive speakers react in the same way as B&O speakers.
You would normally use a Powerlink to Amplifier cable to connect from one of the Powerlink outputs on your B&O audio system or TV to the stereo RCA inputs of the amplifier, then use normal passive speaker cables between the amplifier and the speakers.
A proper active speaker is one that is fed non amplified sound, the sound is then split into the various frequencies required by the drive units and is then amplified by a power amplifier dedicated to that particular drive unit.
This allows very close matching of drive unit and amplifier and allows the cabinet to be much smaller as the amplifier response can be tailored to match the cabinet frequency response. The frequency response can also be made to match that of the drive unit so the final sound should be more linear than with a passive speaker which has to cope with any amplifier attached to it.
The earliest Beolab speakers are not actually active. The Beolab Penta is better described as a powered speaker as it has a power amplifier built into the base which produces a flat frequency response and then this is fed to a passive crossover before passing to the drive units.
The Beolab 3000, Beolab 4500 and Beolab 5000 were also powered speakers but interestingly, the power amplifier produced an output with a non linear output designed to compensate for the reduced bass response of such a narrow speaker.
These are the adjustment screws that are used by the factory to fine tune the speakers to ensure a flat frequency response. they are also used if you are unlucky enough to require a new drive unit to match the amplifier to the new unit.
Some customers like to alter these themselves and they are your speakers to do with as you wish. However remember that B&O have spent a fair amount of resources delivering your speakers to you in what they regard as perfect balance. The advice is to twiddle at your own risk!
Entire books have been written about this topic, so the following advice should just be considered as a starting point; exact positions will vary depending on your room acoustics and choice of loudspeakers. The following advice is suitable for either stereo speakers (ie. 2 channel) or the two main front speakers in a 5.1 or 7.1 channel surround sound system. Good speaker positioning improves the sound quality and stereo image, so that instruments sound more lifelike and appear to come from different parts of the stage (as they would sound at a live concert).
As a starting point, locate the “tweeter” or small high-pitched driver in the speakers (Just play some music with plenty of rythym and listen for where the cymbals appear to come from!) These drivers should normally be positioned at about ear level when you are sitting in your usual seat (or standing up dancing!)
Measure from your usual listening position to the front wall of the room where the speakers are placed (ensure that they are in front of you, not to the side or behind you) This distance should be roughly the same as the distance between the speakers.
Now look at the back panel of the speakers. If there is a hole in the back (known as a bass port) or a grille cloth on the back (covering a bass driver), then the speakers should normally be placed away from the front wall of the room. If neither holes nor grilles are present, then the distance from the front wall is less important. The distance the speakers should be placed from the wall for best effect will vary, but 50cm (0.5m) is usually a good starting point for most speakers. Listen to some music you know well with a clear bassline and try various positions to see which gives clear, realistic bass notes that fit in well with the rest of the music.
Finally, ensure that the speakers are solidly mounted on suitable brackets or stands (for smaller speakers) or securely placed on the floor (for taller speakers). Try pointing the speakers directly at your listening position, straight at the back wall and then try them angled inwards to point at a position about 50cm in front of your listening position. This will alter the positioning of instruments “on stage” and you should be looking to hear the lead singer clearly in the centre, with backing vocals and instruments spread evenly between the speakers.
Above all, there is no “right” or “wrong” way to position your speakers, so feel free to experiment and find out what works best for you.
First, find or buy a cable to connect your audio system to a device with YouTube!
Second, run the following bass test video on YouTube and listen. The frequency of each successive note is announced, so you can work out the limit of your audio system from the point where the tones disappear – the results may surprise you!
For reference, the lowest note on a Tuba, Bosendorfer Imperial Grand Piano and most cathedral pipe organs (C0) is 16.35 Hz, although few modern pianos go lower than 27.5Hz and a four string double bass “only” reaches down to around 41Hz.
