Femto 5, Shelf speaker   as in Hobby HiFi 6/2010

Technical data
- impedance: 6 Ohm
- sensivity (2,83V/1m): 80 dB
- size (HxWxD): 235 x 117 x 180 mm
- frequency range (-8dB): 49 - 36000 Hz
- crossover frequency(s): Hz
- speaker type: bass reflex

The Femto 5 is a miniature bass reflex loudspeaker designed by Bernd Timmermanns. The speaker is equipped with a Vifa 8 NE 125/4 full range driver.

Two versions are available: Femto in a normal bass reflex cabinet or Femto 5 with a high pass capacitor in series to the full range driver. The Femto 5 has roughly one liter more capacity and is capable of producing lower frequencies than the Femto.

The crossover consists of a wave trap in series while the Femto 5 contains a capacitor in series.

The Femto's frequency response is flat, and the decay within the medium frequency range is ideal and, therefore, excellent for a full range driver.

An excerpt from the Hobby HiFi review

"The Femto was not reviewed on the author's desk but in the listening room and connected to the reference system. With just below two meters the chosen listening position is in line with speakers of this size. Both Femto versions clearly show that they are way more than just nice sounding PC miniatures. These speakers reproduce music like grown-ups. Ok, you won't get a party going with them.

Certainly not. However, with restrained volume the sound from both version is so delicate, clear and detached from the physical speakers that it's a real joy. They succeed in reproducing a clean spatial sound with considerably more pinpoint placement of vocals and instruments than quite a few other full range speakers of top quality. The dynamics advantage of 6 dB predicted by computer simulation for the bass reflex Femto is in reality not that big; both reach their limitations quite soon when the volume is turned up carelessly. On the other hand, the low bass advantage of the 5th order bass reflex system is obvious. The Femto 5 also shows a little more clarity and definition in the mid frequencies. The tops show by all means a relatively brisk pace. The sound balance, however, always remains intact, well known vocals are natural and familiar. In general, the sound is simply a bit bright without being harsh. " ...

Our kit Femto 5 consists of

  • Vifa full range 8 NE 125/4
  • 2 pcs Bass reflex tube HP35, black
  • Polyester damping material
  • Binding Posts PK31 (red and black)
  • 1m Speaker cable 2x0.75 mm2, transparent
  • 4 pcs Pan screws 3.5x17 black
  • Plan for DIY kit

the crossover components (right),
to be mounted on a small wooden board.

  • electrolytic capacitor, unetched, 12uF (8.2 and 3.9 μF in parallel)
  • Electrolytic capacitor, etched 820 uF, 63Volt
  • 1mm air core coil, 0.47 mH/0.32 Ohm
  • MOX4 resistor 6.8 Ohm/4 Watt (blue-grey-gold)

Kit without cabinet, price per speaker EUR 92,00 excl. VAT: € 77.31 / $ 82.72


Kit with high-end crossover

In our high-end version only air core coils are used in the signal path to the woofer and in the signal path to the tweeter a Jantzen Z-CAP is employed

  • MKP CAP 12 μF / 400 Vdc (8.2 and 3.9 μF in parallel)
  • Electrolytic capacitor, etched 820 uF, 63Volt
  • 1.0 mm baked varnish air core coil, 0.47 mH/0.32 Ohm
  • MOX4 resistor 6.8 Ohm/4 Watt (blue-grey-gold)

Kit with high-end crossover without cabinet, price per speaker EUR 104,00 excl. VAT: € 87.39 / $ 93.51

universal PCB

 If you prefer to mount the crossover components on a 140 x 102 mm universal PCB instead on wood:
Universal PCB RA140, order no.. str-RA140, price per unit: EUR 4,20 excl. VAT: € 3.53 / $ 3.78
We recommend one board per kit (two boards for a speaker pair)

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