Purus   in Klang+Ton 6/2008

Purus aus Klang+Ton 6/2008
Technical data:
- impedance: 4 Ohm
- rated SPL (2.83V/1m): 90 dB
- size (HxWxD): 110 x 23 x 28 cm
- frequency range (-8dB): 35 - 30000 Hz
- crossover frequency: 2800 Hz
- speaker type: bass reflex
The objective: a loudspeaker with pure sound quality and low distortion, providing listening fun independent of the music style.

After many listening test we decided to go for the relatively expensive Newtronics HT-1 tweeter (since 9/2016 we deliver Scan Speak D2604-833000) since this driver possesses an excellent omni-directional ability, a linear frequency response and low harmonic distortion.

A matching partner seemed to be the Audaphon MB 18-8 with die cast basket, ventilated magnet system and dried paper cone.

Our goal to get away with a simple crossover, without sacrificing a linear frequency response was no problem with these drivers.

Lab results by Klang+Ton:

"Impeccable: the Purus enjoys a well balanced frequency response that rises slightly towards the tops and without any nasty surprises. The same can be said about the waterfall spectrum. The omni-directional directional properties are flawless; even at an angle of 30 degrees this magnificent dome tweeter achieves 20 kHz. Distortion is a foreign word for the Purus at any volume – the distortion level at 85 dB and 95 dB is almost identical."

Review in Klang+Ton:

"Don't let the unassuming looks of this speaker fool you - in our listening room the Purus put on quite a show. Not that this speaker is a show-off, but certainly possesses authority. The bass shows tremendous tightness, dynamics and pace, without going overboard. Even the nastiest peaks are mastered without a drop of sweat. To a degree the tops may be adjusted in certain rooms by angling the speakers towards the listener; keeping them straight, however, seems to me the most accurate solution. The midrange, where usually most of the action is, shows such a pinpoint accuracy that the listener won't notice the equipment; that's how the Purus stands back behind the music. Three-dimensionality maybe perceived as a homogenous experience of huge depth and width or the listener may concentrate on individual instruments or vocals that are projected with absolute precision. - This is first-class and even after long listening session also at higher levels this appeal is maintained."

Verdict by Klang+Ton:

"Purus – the pure. A more descriptive name could not be found for a speaker that performs at such a high level and with such neutrality. The designers at Lautsprechershop Strassacker show once again that a top notch speaker can be produced with a relatively low investment, but with the right know-how. Absolutely convincing!"

Our standard kit consists of

- tweeter Scan Speak D2604-833000
- 2 x Audaphon MB 18-8 bass driver
- 2 packs (4 mats) polyester fleece, white
- one bass reflex tube HP70
- self-adhesive sealing tape
- 20 screws for the drivers
- 4 m loudspeaker cable 2x1,5 mm2
- a bi-wiring terminal with gold plated brass binding posts
- building instruction
the crossover components to mounted on wood
- 1.2 mH air core coil with 1.4 mm wire
- 0.33 mH air core coil with 0.7 mm wire
- 2 x 10 uF Mundorf MKP capacitors/400V
- 1.0 Ohm MOX10 resistor (brown-black-gold)
- 3.3 Ohm MOX10 resistor (orange-orange-gold)
- 8.2 Ohm MOX10 resistor (grey-red-gold)

Purus kit without cabinet
Price per unit EUR 216,00

If you prefer to mount the components on a PCB instead of a wooden board we recommend to use one PCB per speaker.
PCB, Order No. I-8805017,     Price   EUR 4,70

Our Purus with high-end crossover

The standard kit already contains high quality components that can only be found in handful other speakers (no ageing and brittle ELCO's, and no high-distortion core coils). Those of you who prefer even higher quality components should go for our high-end version. This kit contains only cfc coils in the signal path and the lowest loss capacitor known to us: the Mundorf MACP Supreme.
The crossover components to be mounted on a wooden board:
- 1.2 mH cfc14 Mundorf foil coil
- 0.33 mH Mundorf backed varnish air core coil with 0.7 mm wire
- 10 uF Mundorf MCAP Supreme/800V
- 10 uF Mundorf MKP capacitor/400V
- 1.0 Ohm MOX10 resistor (brown-black-gold)
- 3.3 Ohm MOX10 resistor (orange-orange-gold)
- 8.2 Ohm MOX10 resistor (grey-red-gold)

Purus kit with high-end crossover without cabinet
Price per unit EUR 275,00

If you prefer to mount the components on a PCB instead of a wooden board we recommend to use one PCB per speaker.
PCB, Order No. I-8805017,     Price   EUR 4,70

Impedance correction

If you want to connect a valve amp the following impedance correction should be used, for the standard as well as for the high-end version:
Order No. str-purus-ik,     price per speaker EUR 7,45

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