Thiel Drivers

Cumulus, taken from Hobby HiFi 5/2004 - the most favourable review ever in Hobby HiFi.

Technical data:
- Impedance: 4 Ohm
- SPL at rated input(2,83V/1m): 87 dB
- Dimensions (HxWxD): 115 x 26 x 40 cm
- Frequency response(-8dB): 29-33 000 Hz
- Crossover frequency: 160 Hz, 1,7 kHz

Review in Hobby 5/2004

"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. This speaker has certainly the quality to redefine this term. The Cumulus' ability to project three-dimensional and spacious sound with absolutely precise placement of instruments matches even the best full range loudspeakers on the market, while tonality is on the par with the most exquisite multiple driver speakers. The transparent, detailed and airy high frequencies are difficult to top: the first dome tweeter that matches ribbon tweeters and magnetostats in brilliance and ultra high frequencies while volume and warmth of vocals remind us of top dome tweeters. At Hobby HiFi we have never experienced all these qualities at once."

Verdict in Hobby HiFi 5/2004

"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."..."All members of the panel, listening closely to the cumulus were convinced that this speaker belongs into the elite group of international top class speakers and doesn't need to worry about the competition asking more than 10,000EUR per speaker. Therefore, the Cumulus has an excellent price performance ratio."
Thiel Koinzidenzwandler

Description

Jim Thiel / USA - not to be mixed up with Bernhard Thiel/Accuton whose products we sell as well - developed a wonderful coincidentally mounted driver (coincident source array) who encouraged 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. For bass the Visaton AL 200 was added, mounted in the right position in relation to a point source with 160 Hz crossover frequency (i.e. approx. 2 metre wavelength).

The kit consists of (high-end version):
- 1x Thiel coincidentally mounted driver, shielded
- 1x Visaton AL 200 bass driver
- 1x polyester fleece (mid range section)
- 1/2x polyester fleece (at the bottom)
- 14x Bawotumex
- 0,5x foam sealing tape MDM-5
- 2x bass reflex tubes HP 100
- 1x 106 mm drain pipe as Helmholtz resonator (from hardware store or included upon request)
- 2x terminals
- 10x PAN 10 Allen screws
- 3,5 m cable, Spirit of HighSilver 2x2,5 mm²
- building instruction

For the crossover:
- 5x universal PCB LP 06, not tin plated
- 1x Carbasse core coil 10 mH (or T130-transformer)
- 1x powder core coil 18 mH/3,7 Ohm (I-982)
- 1x Mundorf cfc16 copper foil coil 0,56 mH
- 1x Mundorf cfc16 copper foil coil 0,47 mH
- 1x Mundorf baked varnish air coil 6,8 mH / 1,4 mm
- 1x powder core coil 6,8 mH/2 Ohm (I-972)
- 1x 0,27 mH baked varnish air coil
- 1x 0,33 mH baked varnish air coil
- 1x 0,022 mH baked varnish air coil (coiled by us)
- 1x 2,7 mH baked varnish air coil, 0,7 mm

- 1x elco unetched foil 100+47 uF
- 1x elco etched foil 330 uF
- 1x Mundorf MKP 100 uF + 47 uF/400V
- 1x 100 uF Mundorf MKP/400V audiophile capacitor
- 1x 800+680 uF etched foil
- 1x 22 uF Mundorf MKP
- 1x 4,7 uF Mundorf MKP
- 1x 6,8 uF Mundorf MCAP-Supreme
- 1x 2,2 uF Mundorf MCAP-Supreme
- 1x 22 uF Mundorf MKP
- 1x resistor 3,9 Ohm / 20 Watt
- 1x MOX10 resistor 6,8 Ohm (blue-grey-gold)
- 1x resistor 2,7 Ohm / 20 Watt
- 1x MOX10 resistor 3,3 Ohm (orange-orange-gold)
- 1x MOX4 resistor 1,0 Ohm (brown-black-gold)
- 1x MOX4 resistor 0,39 Ohm (orange-white-silver)
- 1x MOX10 resistor 10 Ohm (brown-black-black)
- 1x MOX4 resistor 33 Ohm (orange-orange-black)
- 1x MOX10 resistor 6,8 Ohm (blue-grey-gold)

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

Price of Cumulus kit, high-end version, without impedance correction (for valve amplifiers)
without cabinet, per unit: - not available

Price of Cumulus kit, high-end version, with impedance correction (for valve amplifiers)
without cabinet, per unit: - not available

Simplified Cumulus kit:
- like our high-end suggestion above, with the following changes, however:
- without impedance correction for valve amplifiers
- with 10 mH Monacor transformer core coil, instead of Carbasse core coil
- with 11 boards Bitumex 4mm instead of Bawotumex for side and rear panels
without cabinet, per unit: - not available

Cumulus Standard according to Hobby-HiFi description:
Upon request we supply the much cheaper standard crossover suggested by Hobby HiFi. Further cost reduction can be achieved by replacing Bitumex with roofing felt (available in hardware stores).
without cabinet, per unit: - not available

Cumulus Frequenzweichen aus Hobby Hifi 5/2004 The Cumulus crossover components should be distributed over the 5 PCB's and then wired up.

In case of problems - we're just a phone call (E-mail) away.

Important: The PCB's sides should be shortened by 1 cm. Alternatively, the cabinet's height should be increased by 1 cm ensuring that the lower crossover compartment is 2 cm higher. Upon request (no additional charge) the correctly sized PCB's can be supplied.

The finished crossover is available as well

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