Thiel driver

Cumulus, taken from Hobby HiFi Spezial 1: Heimkino+Surround - the most favourable review ever by Hobby HiFi.

technical data:
- Impedance: 4 Ohm
- SPL (2,83V/1m): 86 dB
- dimensions (HxWxD): 34 x 21 x 30 cm
- frequency range (-8dB): 60-33 000 Hz
- cut-off frequency: 1,7 kHz

Review in Hobby HiFi Spezial 1: Heimkino+Surround

Cumulus Satellit aus Hobby HiFi Spezial 1

"The Cumulus' acoustic performance is quite an experience. Everyone who has the pleasure to listen to these speakers discovers - possibly for the first time - how far homogeneity of sound reproduction can go. Five sound channels harmonising as a uniform and integrated whole, a three-dimensional display setting standards in spaciousness and simultaneous pinpoint accuracy. Excellent voice clarity, silky tops without any edginess. At the same time breath-taking dynamics, not excessive, produced in a rather relaxed way and just like that. Incredible attention to detail already at the lowest level, but also a distinctive confidence when it gets a bit livelier.

The bass is an experience on its on. Very rarely did we encounter a bass so tight and dry. It seems totally impossible that small 2bass drivers are on duty here. Glass fibre cones deliver an enormous, incredibly low and tight bass. The Sitronik amplifier has no problem in keeping the four bass drivers under strict control. That's how low bass should sound.

Cumulus gives surround sound an audiophile character. It seems almost too mundane to play the usual action movies using these speakers - although it's still a lot of fun. The Cumulus is capable of a lot more: some music DVD's will really give the listener goose flesh - e.g. "Bella Fleck and the Fleckstones". As Jack-of-all-trades the Cumulus is a delight playing both, music and movies - it doesn't matter whether soft or loud, and always in superlative style."

Verdict by Hobby HiFi Spezial 1

"The Hobby HiFi editors believe that in search for perfection, this project helped us to gain momentum. Everyone who wants to build an uncompromisingly good loudspeaker needs to seriously consider the Cumulus. Considering it's a DIY speaker project, even the cost involved are extraordinary: only for the material needed to build the five Cumulus satellites and the subwoofer, substantially more than EUR5.000 has to spent." - "Compared to similar finished products, however, Thiel Koinzidenzwandler

this expenditure becomes irrelevant: a five digit EURO amount - and not necessarily with a "1" at the front - is due to acquire a finished product in this performance segment. All this considered the DIY Cumulus is more than affordable."

Description

Jim Thiel / USA - not to be mixed up with Bernhard Thiel/Accuton, whose products we sell as well - developed a wonderful Koinzidenz-Wandler, (coincident source array) encouraging us to offer top quality drivers coming from the finished loudspeaker market. The inherent problem of multiple drivers mounted side by side or one behind the other (coax drivers) is the lack of precise imaging. This kit suggests a coincident source driver that is time and phase coherent regarding low and high frequencies.

The kit consists of (high-end version):
- 1x Thiel coincidentally mounted driver, unshielded
- 1x Polyesterwatte
- 4x Bawotumex für sides, top+bottom
- 0.5x foam sealing tape MDM-5
- 2x terminals
- 6 Allen screws 4x25
- 1.5 m cable Spirit of HighSilver 2x2,5 mm²
- building instruction

For the crossover:
- 1x universal PCB LP 06, not tin plated
- 1x Mundorf cfc12 Kupferfolienspule 0.68 mH
- 1x Mundorf cfc12 copper foil coil 0.33 mH
- 1x 0.15 mH baked varnish coil 0.7 mm
- 1x 0.33 mH baked varnish coil 0.7 mm

- 1x 0.022 mH baked varnish air coil (coiled by us)
- 1x 2.7 mH baked varnish air coil, 0.7 mm
- 1x Elko unetched 82 uF
(100 uF for shielded Thiel)
- 1x 33 uF Mundorf MKP / 400V
- 1x 4.7 uF Mundorf MKP / 400V
- 1x 6.8 uF Mundorf MCAP Supreme
- 1x 2.2 uF Mundorf MCAP Supreme
- 1x 22 uF Mundorf MKP / 400V
- 1x MOX10 resistor 6.8 Ohm (blue-grey-gold)
- 1x MOX10 resistor 4.7 Ohm (yellow-purple-gold)
- 1x MOX4 resistor 1.0 Ohm (brown-black-gold)
- 1x MOX4 resistor 0.68 Ohm (blue-grey-silver)
- 1x MOX10 resistor 10 Ohm (brown-black-black)
- 1x MOX4 resistor 22 Ohm (red-red-black)
- 1x MOX10 resistor 6.8 Ohm (blue-grey-gold)

Price of loudspeaker kit Cumulus Satellite, high-end:
without cabinet, per unit: EUR 925,00

Cumulus Standard according to Hobby-HiFi description
Upon request we supply the much cheaper standard crossover suggested by Hobby HiFi with 10 mH Monacor transformer coil. Further cost reduction can be achieved by replacing Bawotumex with roofing felt (available in hardware stores).
without cabinet, per unit: EUR 796,00

In case you run into problems in building the crossover, we are pleased to give you a hand.
Or you may choose one of our finished crossovers, additional charge per unit: EUR 45,00

Impedance correction for valve amplifiers:
- 1x 4.7 mH baked varnish air coil, 0.7 mm
- 1x 0.33 mH baked varnish air coil
- 1x 15 uF Mundorf MKP
- 1x 10 uF Mundorf MKP
- 1x resistor 8.2 Ohm / 20 Watt
- 1x resistor 6.8 Ohm / 20 Watt

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