Raidho TD4.8 Floorstanding Speakers Black Pair

Introducing the Raidho TD4.8

Built-in a stunning Scandinavian design that will fit all rooms, this tall speaker is designed as a full-range speaker using in-house made Tantalum Diamond drivers with no less than 6 bass drivers and 2 midrange drivers.

Together with the upgraded TD-Series ribbon tweeter, this impressive speaker delivers world-class musical experiences that encaptivate the listener with a huge soundstage capturing the atmosphere and intimacy of your recordings. The TD4.8 speakers present a sound that is fast, coherent and authentic.

Placed on big, adjustable feet with built-in decoupling, the TD4.8 will make the best out of any room with its stunning looks. The TD4.8 was appointed the ”Cost-no-object speaker of the year 2018” in Hi-Fi+, and it is a testament to all music lovers.

At a glance

• Floorstanding speakers from Raidho's TD-Series
• Capable of extraordinary resolution, bandwidth, headroom and power handling
• Experience new levels of separation and dynamics in music
• Brand new, upgraded version of the world-famous Raidho sealed ribbon tweeter
• Newly-developed Tantalum/Diamond material drivers handle incredible levels of continuous, clean power
• Tantalum technology delivers lower levels of distortion than any other drive unit on the market
• Impulse-optimized crossover for optimal phase response
• Remarkably narrow footprint
• Adjustable feet with built-in decoupling
• Beautiful piano black finish
• Handmade in Denmark by world-renowned Danish loudspeaker designer, Raidho Acoustics

Newly-Developed TD-Series Technology

All the speakers in Raidho’s TD-Series have been upgraded and now use a new version of this Danish company’s ribbon tweeter, as well as cones made using the company’s newly-developed Tantalum/Diamond material, hence ‘TD’.

TD cones are of sandwich construction, with a central ceramic core contained within a one-micron-thick layer of Tantalum. Raidho designer Benno Baun Meldgaard says this modifies the characteristics of the ceramic to make it more suitable as a cone material. He says that, by then adding a layer of diamond to the Tantalum, the five-layer cone that results is even stiffer than Raidho’s own diamond cones, while at the same time being better damped. All drivers also have a new motor system for which Meldgaard says he has applied for a patent and is "the strongest underhung motor design on the market."

The ribbon tweeter now has a more powerful magnet system and a new acoustically optimised rear chamber. Meldgaard says the result is a reduction in distortion and an improvement in efficiency compared to the previous design.

Raidho TD "Turbine' Motor Architecture

For the new TD-series, we decided to raise the bar and we realized that we needed to push the boundaries further in our technology. An old idea about a different design was brought to life and from the minds of our design team, simulations and trials turned into our new, turbine-shaped motor system.

The goal was to create a driver with higher sensitivity, but also to eliminate all kinds of distortion. This was done with a design that more than anything is focused on aerodynamics. Looking at the driver it is very obvious that airflow was a priority, and the design is all about smoothening the edges, shaping the magnet system and adding as little as possible material to the design to allow the driver to move as much air as possible while at the same time having as little as possible influences that could cause distortion and break-ups.

The patent-pending driver design is built around an extremely powerful magnet system based on four neodymium magnets, our own proprietary edge wound voice coil and the Tantalum-Diamond cone. Compared to our OpenPlandriver, the TD-driver is more than twice as strong, and the driver is one of the strongest, underhung systems in the world with 1.1 teslas in the gap. In this small masterpiece, we have built-in a magnetic brake, preventing the driver to destroy itself in case of too much power handling.

The result is everything, we hoped for, and more. The drivers are extremely dynamic, and with remarkably higher sensitivity, they are easy to match in our speaker designs. The measurements are nothing less but extraordinary good with practically no distortion anywhere. This is also audible, and when you listen to a TD-series speaker, you will experience a sound that is extremely transparent and dynamic, revealing layers upon layers of music and taking you on a journey like no other speaker. The TD-drivers is not only about hi-fi, but also about music, and these new gems are the pinnacle of our musical testament.

Developing The New Raidho Tantalum-Diamond (TD) Cone

Even though our Diamond cone drivers are already groundbreaking in their technology and performance, we still don’t stop there – improving our technology is simply a part of the Raidho DNA.

With the new Tantalum technology, we have managed to better our already class-leading diamond cones. By adding Tantalum to our ceramic cones, before the diamond layer, we have created a 5 layer sandwich cone, which is even stiffer than our already extremely stiff diamond cones, while at the same time adding huge amounts of inner damping. This means that these cones move completely like a piston without any break-up nodes way above the human hearing limit. (Actually even higher than most high-quality tweeters)

What we gain from this is lower levels of distortion than any other drive unit on the market, lightning-fast transient response, matching our world-famous ribbon tweeters perfectly. The extremely low levels of distortion also ensure a very musical and organic reproduction – bringing you closer to the music than you thought possible.

As well as sounding incredible, this graphite content gives the diamond layer a beautiful charcoal grey finish.

How It's Done

Tantalum is an amazing metal. It conducts electricity and heat extremely well. It is extremely hard, but at the same time both dense and ductile, which is why it is also being used in special ammunition, able to penetrate 1m (3ft.) of solid concrete!

In case of our cones, we add a micron layer of Tantalum, on top of the ceramic layer making it even harder, while at the same time removing the brittle nature of ceramic. This also means that we can bombard the surface even harder with our Diamond layer, effectively adding more diamond and less carbon on the surface.

Besides resulting in the stiffest and best inner-damped cone in the world, the Tantalum layer also very efficiently helps to conduct the generated heat from the voice coil away from it, lowering any voice coil relayed distortion as well as raising the power handling capabilities of the speaker system.

About Tantalum

Tantalum is a strong, ductile metal discovered by the Swedish chemist Ekenberg in 1802. Atomic Nr. 73. This rare metal has a high melting point of more than 3000° Celsius, is immune to chemical attacks at room temp, and is an excellent heat conductor.

A composite consisting of Tantalum carbide and graphite is one of the hardest materials known and is used on the cutting edges of high-speed machine tools. For this reason, Tantalum is often used to make components for chemical plants, nuclear power plants, aeroplanes, missiles, and now these flagship Danish loudspeakers.

Natural Diamonds

Diamond is carbon in its most concentrated form. Natural diamonds are rare and formed under extreme pressure deep under the ground. Pure diamond is pure crystalline bonded in an sp3 triangular structure, and it has a clear and glass-like appearance. For our diamond membrane, we use cultivated diamond equal to 1.5 to 3 carat of pure diamond, depending on membrane size.

Diamond tops Mohs’ scale with a hardness rating of 10, whereas the aluminium oxide, used in our C-series, is a 9 on the same scale. Although one may think that there is not far between 9 and 10 on Mohs’ scale, we measured the surface hardness on our diamond membrane to be 140 times harder than the surface on our aluminium oxide membrane.

Raidho Ribbon Tweeter

The legendary Raidho Ribbon tweeter is a unique sealed ribbon tweeter. The tweeter employs an array of neodymium magnets to create an extremely powerful force field where an ultra-thin membrane is suspended. The membrane weighs less than 0.02g. Due to the extremely low mass, the tweeter stores no energy and has no resonances. The performance of this unique tweeter system is extraordinary and leaves absolutely no fingerprint on the speaker system.

The Raidho TD Series includes a brand new, upgraded version of the famous Raidho sealed ribbon tweeter, featuring a more powerful magnet system and a new acoustically optimised rear chamber. The result is increased sensitivity and resolution.

TD Series

The new TD-Series carries on the legacy of the highly acclaimed D-series, which has been well received all around the world by both reviewers and audiophile music lovers.

It was a big task to improve the series, but we took a serious approach and started from the beginning. We had an old idea about a new driver design, that would later prove to be superior to our previous design, so our design team came up with a completely new driver, based on an underhung system with a magnetic strength of 1.1 teslas, making it one of the most powerful in the world.

The new, patent-pending design, made in-house, is built around a new and improved motor system, shaped like a turbine and with great attention to aerodynamics to remove any unwanted reflections and give the cone optimal conditions. We use a new diaphragm with 5-layers, utilizing a combination of our Ceramix and Diamond cones, but with added layers of Tantalum to make the cones even harder and stiffer. The inner damping is higher as well, making the new drivers sound more natural. The new driver is extremely efficient, resulting in a sensitivity that is much higher than the previous drivers.

New drivers also meant that we had to look at our already really good ribbon tweeter, which is a Raidho-speciality. We managed to improve it as well by changing the rear chamber to remove unwanted reflections, and ended up with a tweeter with 3 dB higher sensitivity and no less than 35 dB lower distortion – and it was already very low. In combination with the new drivers, we achieved dramatic improvements in sensitivity in all the models.

With the changes made to the cabinets, to match the new drivers while still keeping the well-known design, careful attention to crossover design and careful matching of the new drivers, made it possible to launch a new series of speakers that all follow the same sonic qualities – massive dynamics, high resolution and musicality.

Great attention has been paid to timing, correct phase and coherency. All the TD models are optimal choices for any system, and they are extremely versatile. The high sensitivity makes them an ideal match to any amplifier, including tube amplifiers with low output, and the new design and technology delivers all the details, dynamics and slam without any colourations, staying true to the music.

The new TD-Series are advanced high-end speakers, but this is not only about technology. This is about music and feelings, and listening to a TD-series speaker, you will experience all of the emotions of the music, embracing you with an authentic and organic sound that, in our honest opinion, is among the best.

Raidho Open Plan Motor Architecture

Building a driver fast enough to blend seamlessly with the Raidho ribbon tweeter demands more than a light, stiff, low-colouration cone. That cone needs to have a powerful, responsive motor driving it. One look at the segmented motor structure of a Raidho drive unit makes it obvious just what a radical departure from convention it represents. Difficult and demanding to build, the use of a spaced, radial array of magnets, surrounding the open voice coil offers significant performance advantages. It allows us to employ spaced pairs of small but extremely strong neodymium magnets, creating an underhung, push-pull motor system with many times the power that can be produced with large, annular parts. But the open structure also improves venting and cooling of the motor assembly, reducing dynamic compression and back pressure, making for a more responsive, faster driver and one that can handle sustained musical peaks. So, when the musical signal says jump, a Raidho driver doesn’t just ask how high, it asks for how long, too. The result is unprecedented dynamic tracking, preserving the smallest musical nuances and widest orchestral climaxes, delivering recorded music with levels of intimacy and dynamic contrast that you’ll only previously have heard live.

Raidho Clamped Cabinet Construction

We use the term ‘loudspeaker system’ for a reason. The best drivers in the world are only as good as the cabinet they’re built into. At Raidho we go to extraordinary lengths to ensure that our enclosures contribute as little as possible to proceedings. The drive units are built directly onto the rear of the carefully profiled, machined aluminium baffles, eliminating the mechanical discontinuities introduced by a conventional driver basket at this critical junction. The braced, thin-wall enclosures are formed with curved walls to maximise stiffness and minimize stored energy. They are then securely clamped between the baffle and the substantial spine element, creating a constrained structure, constructed from differential materials to maximise damping, without using high-mass or absorbent materials that store energy and rob the system of life and resolution. By efficiently converting spurious energy to heat, the clamped cabinet minimizes intermodulation distortion and maximizes system clarity and articulation, goals that are reinforced by building the capacitors and inductors used in our crossovers in-house, with special emphasis on their mechanical stability. At Raidho, we go to great lengths to build cabinets and crossovers that you won’t hear, so that crystal clear music is what you will hear.

Raidho Acoustics

Evolutionary, Revolutionary and Unique. Raidho Acoustics develops and manufactures loudspeakers for people who appreciate both phenomenal audio and stylish aesthetics. Those who think sound should be remarkable, want their listening experience to be out of the ordinary and expect great looking equipment with an exceptional design and visual expression. Raidho Acoustics have become world-renowned as leaders in loudspeaker design, developing new technologies, creating musical masterpieces and recreating musical masterworks.

Handmade Speakers

“Good sound does not just blow in from nowhere. Reproducing good sound calls for expertise and hard work.”

At Raidho we say we have a special knack – so we do not let just anybody assemble a Raidho loudspeaker. What would be the point of innovative developers creating outstanding units, and skilled carpenters building beautiful cabinets in the best materials if the elements are not assembled with due respect for the ultimate product that a Raidho loudspeaker really is?

By checking and checking again, we make sure that we live up to our own ambitious goals for the products we want to supply to a quality-conscious and discerning audience.

All the components in a Raidho loudspeaker are designed, manufactured and assembled by Raidho Acoustics themselves. In the design process, they seek to create something unique, and the reward is a very special harmony in the interplay between the design of the cabinet and the design of the sound.