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 high-end kit comes with high-value ClarityCap 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 want to use a valve amplifier with this speaker an impedance correction should be employed. In this case the component quality is less important; therefore, we offer only one kit (upon request higher quality components are available).
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 / $ 6.00
We recommend one board per kit (two boards for a speaker pair)