BPPR Three (standing for Best Price Performance Ratio) is a floorstander. It is developed by Dennis Frank and Daniel Gattig as a mixed system.
The upper woofer is in a closed volume the lower woofer in a bass reflex system. BPPR 3 contains a 30 mm Wavecor dome tweeter and two Wavecor woofers.
Its crossover consists of a low-pass and a high-pass branch each of second order, i.e. with a slope of 12 dB per octave. A resistor is in series to the tweeter as a voltage divider. To give a slight lifting to the highest treble, a capacitor is wired parallel to that resistor. No components are needed for eliminating any resonances or bulges in the frequency response.
We see a very even on-axis frequency response from 70 Hz to 30,000 Hz. The decay spectrum shows small resonances at 4000 Hz and below 500 Hz; apart from that it is nearly without fault. At 85 dB and 1 m, non-linear distortions remain below 0.3 % almost everywhere above 300 Hz.
the crossover components (right),
to be mounted on a small wooden board.
The high-end kit comes with high-value Clarity Cap MKP foil capacitors, type ESA in series to the tweeter. The inductances are baked varnished coils for minimizing microphonic effects. - The current flow through the coil creates a magnetic field which sets the reel of wire in motion. This motion induces a voltage in the coil which adds itself to the signal. The stiffer the reel of wire is, the less the signal will be altered.
If you prefer to mount the crossover components on a 159 x 127 mm universal PCB instead on wood:
Universal PCB RA160, order no.. str-RA160, price per unit: EUR 5,90 excl. VAT: € 4.96 / $ 5.35
We recommend one board per kit (two boards for a speaker pair)