|Product :||BeoLab 2500||
|Produced from :||1999 - 2004|
|Designed by :||David Lewis|
|Finish :||See description|
Designed especially for the Beocenter 2300 and Beocenter 2500, Beolab 2500 was a small, slender-looking active loudspeaker which employed separate bass and treble amplifiers, an electronic crossover filter and ABL (Adaptive Bass Linearisation) to increase bass reproduction automatically.
Attached by way of a specially designed bracket for mounting the whole ensemble on the wall, the speakers could nevertheless be used separately on a shelving unit, for example. Sound quality was excellent from such small speakers.
A wide variety of cloth covers (on the earlier models - Type 6036) was available. The cloth speaker fronts were eventually replaced in 2001 with more rugged aluminium fronts (Type 6039), again in a choice of colours, similar to the metallic cabinet cover on the BeoSound 1.
- Cloth finish (Type 6036): Black, Blue, Green, Silver, Red, Yellow
- Metallic finish (Type 6039): Light Blue, Silver, Black, Russet, Violet
Advanced technology has contributed a great deal to the new Beosystem 2500, and no more so than in the incredibly slim-line active loudspeakers. The actual enclosure has an internal volume of only 2.8 litres. Frontal dimensions are 260mm wide by 360mm high and the depth starts at only 28mm, increasing to 160mm at the base where the built-in power amplifiers and their cooling vanes are located. The seeming impossibility of producing adequate bass from such a tiny enclosure has been tackled in two ways. First, the 115mm diameter bass drive unit has been specially developed, with a heavier and stiffer diaphragm than usual and with a coil/ magnet system of the long-throw type able to handle large amplitudes without running into non-linear distortion. Second, the built-in amplifiers have been designed not only to make good the low sensitivity implied by that massive, but small diameter, diaphragm and tiny enclosed volume; they also have a response tailored to match the driver properties and boost the bass as necessary. There are separate 70W amplifiers for the woofer and the 25mm tweeter, with active IC-based crossovers prior to the output stages. The filter slopes are a steep 24dB/octave on either side of the 2,500Hz crossover frequency and there is a 30dB/octave roll-off below the bass resonance, which is in effect equalised to +11dB. The result is an effectively flat response from 80-20,000Hz and a maximum output level rated at 103dB SPL at 1-metre in room conditions. A protection circuit is activated to cut the bass in case of malfunction. The treble amplifier has ‘dynamic adaptation’ to check and control strong signals. The amplifiers are switched off when the system is in standby mode.
The enclosure is bass reflex loaded, the spiral shaped port emerging near the top of the back moulding. The enclosure shape practically eliminates parallel surfaces, avoiding standing waves, and a metal plate reinforces the front baffle and adds to the considerable non-resonant mass.
The two drive units are offset towards the outer edge and the left/right speakers are mirrored. A Lycra grille cloth is stretched over a thin plastics frame and is held in place with a simple clip fixing. Six different cloth colours are available, to match different room decors. Any colour can be chosen within the basic price and further grilles can be added for about £10 per pair extra.
In the simplest stand-alone arrangement, the loudspeakers are bolted on either side of the central unit at each end of a substantial bracket which conceals the interconnecting cables. The bracket has carrying handles so that the whole assembly (weighing about 20kg) can be moved around. There is a separate mounting plate which allows the system to be wall-hung on two or more screws.
This sets the loudspeakers only about 70cm apart and naturally limits the stereo spread. This accords with B&O’s idea that the 2500 is an “alternative music system”, typically placed within reach of the listener. However, some users will prefer, at some loss of mobility and convenience, to unbolt one or both loudspeakers to provide the more conventional 2-3 metres spacing. As I have said, both the loudspeakers and the central unit are tilted back at 13 degrees, and ideally a position below eye level will be chosen to put the listener’s ears on axis.
How it performed
The B&O design and engineering team have reason to be proud of the Beosystem 2500. Its simple yet stylish appearance and remarkable compactness give few hints of the sonic pleasures in store. After a short learning curve with the magic doors, the control panel and the Beolink remote control, I came to appreciate the pleasing qualities of the radio, CD and cassette performance. The actual music-centre is perhaps only a slight advance on previous integrated systems from this design-conscious manufacturer, with further miniaturisation made possible through the use of new surface-mount component techniques and the removal of the power amplifiers, transformers and other bulky components to the loudspeakers.
No, the single most spectacular feature is the new Beolab 2500 loudspeaker. Thanks no doubt to scrupulous tailoring of the amplifier response to match the known behaviour of the two drive units, the whole middle and treble registers have been given an incredibly ‘integrated’ smoothness. Running an in-room response curve showed a ±3dB consistency all the way from about 90Hz to 20kHz and beyond. In addition, the robust slimline enclosure revealed no trace of cabinet resonance and the dispersion was wide enough to produce an airy spread of sound, though sometimes at the expense of bass definition. Presence and attack were fine, with voices in particular sounding true to life. It was also possible to increase the volume to well above normal levels and enjoy distortion-free results.
Keeping the loudspeakers bolted alongside the centre unit inevitably restricted the stereo width but the imaginary sound-stage did give a feeling of extending beyond, and even above, the physical dimensions. I made the system nicely mobile by standing it on a wheeled table (actually the stand from a long-deceased TV receiver) and this allowed me to position it a couple of metres from my desk or armchair and produce a near-optimum stereo arc. Alternatively I could place it across a room corner, which paid dividends in terms of simulated spread, reinforcement of the steeply rolled-off extreme bass and amelioration of a certain congestion otherwise heard in ‘busy’ music. In a word this is a fun system rather than something for the dyed-in-the-wool audiophile.
Technical tests on the individual sections showed that they met their respectable specifications. CD frequency response was ruler-flat, with a wide dynamic range and good low-level linearity. Resistance to vibration or feedback was remarkably good. The cassette deck response was within 15dB of the IEC standard overall when replaying calibration tapes. The record/replay response, particularly on chrome tape, was good enough to make input and output signals barely distinguishable except for minimal wow and the very faint tape hiss.
Whether this innovative, compact, and relatively expensive, system is right for you will depend less on technicalities than your attitude to styling and your listening room topography. However, if the whole concept seems to fit, you should be happy in the knowledge that the actual musical performance is of a high order. I have enjoyed seeing and hearing the Beosystem 2500 around the place and, now that it is on its way back to Gloucester, I know I shall miss it as an attractive back-up for my much larger main system.
Taken from ‘Gramophone’ magazine - April 1991 (page 168)
BeoLab 2500 types: