Goldmund Tethys Passive Floorstanding Speakers

The Goldmund Tethys Passive is a high-end 3-way passive floorstanding loudspeaker that brings Goldmund’s Gaïa-inspired design language and digital loudspeaker development expertise to a traditional externally amplified system. Each speaker combines a soft-dome tweeter, 7-inch midrange driver and 9-inch woofer in a vented enclosure, with bass extension to 38Hz (-6dB) and a substantial 67 kg / 148 lb cabinet. Goldmund| The Art of Sound

Tethys is particularly interesting because Goldmund did not approach it as a conventional passive speaker. The company applied knowledge developed through its digital loudspeakers and precise digital filtering calculations to the design of the physical passive filters, with the goal of retaining Goldmund’s established sonic character while giving owners complete freedom over external amplification. Goldmund| The Art of Sound

3-Way Goldmund Architecture

Each Tethys Passive uses three dedicated drivers:

1 × soft-dome tweeter
1 × 7-inch midrange driver
1 × 9-inch woofer

The dedicated midrange allows the 9-inch driver to concentrate on low frequencies rather than asking one driver to reproduce both bass and the critical vocal range. Goldmund combines the three drivers through its passive crossover network to create a coherent full-range loudspeaker with a specified response extending to 25kHz. Goldmund| The Art of Sound

9-Inch Woofer

Low frequencies are handled by a dedicated 9-inch woofer operating in a vent-loaded enclosure. Goldmund| The Art of Sound

Goldmund specifies low-frequency extension to:

38Hz at -6dB

That gives Tethys meaningful standalone bass capability while keeping the enclosure considerably more manageable than the larger Rhea Passive and Theia Passive designs.

For a reference two-channel system, Tethys can therefore operate as a complete full-range loudspeaker without automatically requiring a subwoofer. A subwoofer can still be incorporated where deeper infrasonic extension or room-specific bass optimization is desired.

Dedicated 7-Inch Midrange Driver

The 7-inch midrange driver is significant to the Tethys architecture.

By separating the midrange from the woofer, Goldmund can optimize the driver specifically for the region containing much of the musical information responsible for vocal intelligibility, instrumental timbre and spatial detail. Goldmund| The Art of Sound

This dedicated three-way topology distinguishes Tethys from smaller passive designs that ask a single mid/bass driver to cover a much wider frequency range.

Soft-Dome Tweeter

High frequencies are reproduced by a dedicated soft-dome tweeter, extending the speaker's published response to 25kHz. Goldmund| The Art of Sound

Goldmund describes the drivers as custom-engineered for precision, wide frequency response and dynamic range, with the drivers, crossover and enclosure optimized as an integrated acoustic system rather than treated as independent components. Goldmund| The Art of Sound

Developed From Goldmund's Digital Speaker Expertise

One of the most important technical details of Tethys Passive is easily missed.

Goldmund describes the model as the culmination of extensive work on its digital loudspeakers. Rather than starting with a conventional analogue crossover methodology, Goldmund employed digital filtering techniques and precise calculations to develop the passive filters. Goldmund| The Art of Sound

The result is a passive loudspeaker intended to preserve the sonic signature developed through Goldmund's active and digitally processed speaker programs while allowing the customer to select external amplification.

That makes Tethys Passive particularly relevant to listeners who want Goldmund loudspeaker engineering but prefer a traditional separates-based system.

Advanced Passive Crossover

Because Tethys has no internal amplifier or DSP, frequency division is handled by a physical passive crossover network positioned between the external amplifier and the loudspeaker drivers.

Goldmund specifically highlights the model's advanced crossover engineering and its role in controlling frequency integration and dispersion. Goldmund| The Art of Sound

This is fundamentally different from Goldmund's digital active loudspeakers, where DSP performs filtering before dedicated amplification channels drive the individual transducers. Goldmund| The Art of Sound

Proteus LS Loudspeaker Modeling

Goldmund's current catalog identifies Proteus LS as part of the Tethys Passive engineering platform. Goldmund| The Art of Sound

Proteus is Goldmund's proprietary loudspeaker modeling technology. Within Goldmund's current passive-speaker development, the software is used to model parameters such as system impedance, driver membrane displacement, volume velocity and sound pressure. Goldmund| The Art of Sound

This modeling allows the drivers, cabinet and filtering architecture to be engineered as a complete system before final physical implementation.

Goldmund Mechanical Grounding

The Tethys Passive also incorporates Goldmund Mechanical Grounding, another technology specifically identified in the company's current catalog. Goldmund| The Art of Sound

Mechanical Grounding is fundamental to Goldmund's approach to loudspeaker construction: unwanted mechanical energy is given a controlled path away from the enclosure rather than being allowed to remain stored within the structure and contribute delayed resonances.

Combined with the Tethys' considerable 67 kg / 148 lb per-speaker mass, the design is intended to provide a mechanically stable foundation for the drivers.

6-Ohm Nominal Impedance

Goldmund specifies:

Nominal impedance: 6.0Ω
Minimum impedance: 4.7Ω. Goldmund| The Art of Sound

A 4.7-ohm minimum is relatively moderate for a reference floorstanding loudspeaker, but amplifier selection should not be based on impedance alone. Control, current delivery and transient capability remain important when extracting the performance available from a large three-way loudspeaker.

Tethys is an obvious system partner for Goldmund's own Telos amplification, while its passive architecture also leaves the customer free to use appropriately matched reference amplification from another manufacturer.

Mono-Amp or Bi-Amp System Configurations

Goldmund's current Ouranos configurator documentation identifies four dedicated Tethys Passive configurations supporting mono- and bi-amplification. Goldmund| The Art of Sound

That means Tethys can form the basis of either a conventional stereo system or a more ambitious multi-amplifier installation.

For a traditional system, one stereo amplifier or a pair of monoblocks can drive the speakers. A bi-amplified configuration allows additional amplifier channels to be incorporated as the system develops.

Unlike the larger Rhea Passive and Theia Passive—which Goldmund supports in mono-, bi- and tri-amplified arrangements—the current Goldmund documentation lists Tethys Passive for mono- or bi-amplification, not tri-amplification. Goldmund| The Art of Sound

Leonardo Time Correction With Ouranos

There is another important capability worth adding to the current Tethys listing.

When Tethys Passive is integrated with Goldmund's Ouranos audio processor, Goldmund provides dedicated Tethys configurations with Leonardo time correction. In passive-speaker systems, Leonardo processing is performed inside the Ouranos processor rather than inside the loudspeaker. Goldmund| The Art of Sound

This creates an unusual upgrade path: Tethys remains an externally amplified analogue passive loudspeaker, while a Goldmund processor can add the company's digital time-alignment and system-optimization technology upstream.

That gives Tethys considerably more system-development potential than a conventional passive speaker.

Gaïa-Inspired Industrial Design

Tethys was one of the models used to introduce Goldmund's newer Gaïa-inspired design language.

Goldmund moved away from the exposed structural aesthetic associated with the historic Apologue and toward the sculpted, architectural forms introduced with Gaïa. Tethys Passive, Pulp and Melos were among the products created around that newer visual language. Goldmund| The Art of Sound

The result is recognizably Goldmund without relying on a conventional rectangular wooden loudspeaker enclosure.

Handcrafted Construction

Goldmund describes every Tethys loudspeaker as meticulously handcrafted, with its drivers, cabinet construction and individual components selected and optimized around the complete loudspeaker design. Goldmund| The Art of Sound

At 148 pounds each, Tethys occupies an interesting position in the Goldmund passive range: physically substantial enough to provide the mechanical stability expected from a reference floorstander, yet considerably more compact than Rhea Passive.

38Hz–25kHz Frequency Response

The published frequency range is:

38Hz (-6dB) → 25kHz. Goldmund| The Art of Sound

Goldmund does not publish a ±3dB response window alongside that figure in the current Tethys specification sheet. I would therefore keep the Shopify listing exactly as Goldmund states it rather than converting the 38Hz figure into an assumed conventional frequency-response specification.

148 Pounds Per Speaker

Tethys measures:

11.4" W × 42.9" H × 14.6" D

or:

29 × 109 × 37 cm

and weighs:

67 kg / approximately 148 lb per speaker. Goldmund| The Art of Sound

A stereo pair therefore weighs approximately 134 kg / 295 lb before packaging.

Those dimensions make Tethys substantially easier to integrate into a listening room than Goldmund's larger statement loudspeakers while still providing the physical scale of a serious three-way floorstander.

Silver Grey & Black

Goldmund's dedicated specification sheet identifies the finish as:

Silver Grey enclosure with Black grilles. Goldmund| The Art of Sound

I would use that as the published finish on The Grid product page unless Goldmund provides a current dealer document confirming additional factory options for this specific model.

Technical Specifications

Goldmund does not publish sensitivity, recommended amplifier wattage, maximum power handling or crossover frequencies in the Tethys Passive specification sheet I found. Those should stay off the Shopify specifications rather than being estimated from third-party information. Goldmund| The Art of Sound

Tethys Passive in the Goldmund Range

Tethys fills an important position between Goldmund's compact Melos Passive and the much larger Rhea Passive.

The Tethys uses a 9-inch woofer and 7-inch midrange, reaches 38Hz at -6dB and weighs 67 kg per speaker. By comparison, Rhea Passive steps up to a 12-inch woofer, reaches 27Hz at -6dB and weighs 123 kg per speaker. Goldmund| The Art of Sound

That makes Tethys especially compelling for someone who wants a true three-way Goldmund floorstander and external amplification without moving into the size, weight and room requirements of the larger Rhea and Theia platforms.

Goldmund Tethys Passive at The Grid HiFi

The Goldmund Tethys Passive combines a 9-inch woofer, dedicated 7-inch midrange, soft-dome tweeter, 38Hz bass extension, Proteus LS modeling and Mechanical Grounding with the freedom of external amplification. Its crossover design also reflects Goldmund's extensive work in digital loudspeaker development, making Tethys much more than a conventional analogue floorstanding speaker. Goldmund| The Art of Sound

The Grid HiFi can design the complete Tethys system around Goldmund Telos amplification, Mimesis preamplification, Ouranos processing and Leonardo correction, reference digital or analog sources, cabling, power and equipment support, with amplifier and system matching based on the room and listening priorities.

Considering the Goldmund Tethys Passive? Call The Grid HiFi at (713) 218-8120 to arrange a private audition and build the complete system around it.