Luxury Brocade Combined with an Acoustic Solution
29. 4. 2023


Are you interested in modern trends in interior design? Do you prefer high quality to mediocrity? Then feel free to read on. In this article, we link the traditional role of fabrics in interiors, namely of luxury brocade, to its practical function: acoustic optimization of modern interiors. We will explain the basics of acoustics and show you how to add another very important yet invisible value to brocade fabric—acoustic absorption.

F4SX Audio Power Filter
30. 4. 2021

In this article, you will learn why a good audio power filter is essential these days, why we use latest nanocrystalline materials, how does a passive power filter help in audio and more.

Hybrid Diffuser – Mono&Stereo reference listening room
17. 1. 2021

“It took me a long time to finish my dream project, a dedicated reference listening room. Investing the time, money and painstaking efforts into the making of a personal ultimate man cave” …

“The main, back wall is covered with a large RDacoustics Hybrid circle pattern absorption Acoustic Diffuser (3 x 2 m). “

PrimaLuna EVO200 – Novo
12. 1. 2021

“Sounding consistently solid, firm and bigger than its power rating might suggest, the EVO 200 integrated amplifier from PrimaLuna offers tremendous value and I can see it being an end-game for many enthusiasts.”

PrimaLuna EVO200 – HI-FI CHOICE U.K.
12. 1. 2021

“This is an exceptional valve amplifier EVO200  that is consistently easy to live with, beautifully made and possessed of the power needed to make it practical with many modern loudspeaker designs”

PrimaLuna EVO200 – Hifi Pig
12. 1. 2021

“I had much enjoyment playing with the Evo200. This amplifier offers a detailed and fast sound with excellent mid-band and secure top with a beautiful patina that simply makes music human again . . . PL are renowned for value for money and this product carries this forward . . . this is a lot of tubes and music.”

RD EMI Neutralizer – HifiVoice test
8. 1. 2021

Basically, the first few tones were enough to make it clear that the isolating transformers work as they should and that the filter is not just an aesthetic matter. The bass is extremely firm and concrete.

RD power filter – A.J.
2. 1. 2021

These are hifi enthusiast feelings, nothing measurable or in any way quantifiable. The high end system sounds a bit different (although it wasn’t bad before) now. The sound became clearer, perhaps the vocal and individual instruments now stand out more with quality recordings.

RD Power Filter –
2. 1. 2021

For obvious reasons, rather than dealing with electromagnetic interference filtering and surge protection our filter is focused on, this review provides insight into the resulting sound our filter provides when used with different setups.

Euphoria speakers – Petr Chalupa
2. 1. 2021

In one word, your Euphoria speakers are perfect. They managed to enthuse our entire family. We even moved a dresser and a terrarium with our belowed lizards out of the living room to avoid sound disruption. Now we are finally enjoying quality listening of various music genres. The speakers can perfectly reproduce piano concertos by Chopin, opera, string quartet, but even Pink Floyd or Eric Clapton. Thank you.

Euphoria – L.N.
2. 1. 2021

The soundstage, width and depth, is among the best I ever experienced from a pair of speakers.

Euphoria speakers – Sound & Vision
2. 1. 2021

We found out how realistically the Euphoria can reproduce a guitar performance. The Euphoria speakers are fast enough to reveal even the smallest details.

Euphoria speakers – Hifi Pig Magazine
2. 1. 2021

These are a nicely balanced speaker that I think will appeal to many with a wide taste in music.

Euphoria speakers – Stereo & Video
2. 1. 2021

The speakers will gain your sympathies with transparent sound across the entire range transmitted, detailed presentation of midrange, depth of space and flawless instrument localization.

Evolution speakers –
29. 12. 2020

Instead of sounding tied down hard with comealong winches whilst sucking air through a narrow port tube (…), the Evolution with its large horn mouth and single driver behaved like an enormous heaving organism blessed with huge lungs.

Evolution speakers – HiFi Knights
29. 12. 2020

With wooden ears on [note: the Oris 500 front horn], the outcome is quite horn-alike, which for many enthusiasts is something to die for.
“David Brubeck’s “Take Five” (…) was a real eye-opener. All the instruments were sketched precisely, yet not clinical at all, and had a very vivid appearance in a remarkably convincing, big and open soundstage.”

Evolution speakers – Stereo & Video
29. 11. 2020

At the first catch, the Evolution speakers enthrall by detailed rendering of midrange and clean, open heights, balanced sound and excellent space reproduction with precise instrument localization. One, that is usually unheard of even in the world of high end.

Evolution speakers – HifiVoice
29. 11. 2020

You feel like sitting in the first row at a concert. (…) [The listening] gives you an amazing insight into the recording—you know exactly where each musician is standing, instruments have real size and most importantly, very accurate spatial anchoring including, for example, reverberation of the cymbal, realistically depicting the entire recording room.

Evolution speakers – Hifi Pig Magazine
29. 11. 2020

The more I listen to this recording the more enamoured I become of this speaker’s ability to make you feel you are listening to real musicians playing in real space before you… the vocal is truly stunning!

Background Noise in Audio
1. 8. 2020


Our new listening studio is not for listening experiences only. It provides us with a good enough space to carry out different experiments, measurements and tests. This article deals with background noise measurements of an audio system, in the hearable spectrum. Using a microphone, we measure the noise coming directly from the speaker. We are going to compare a real noise of an amplifier, once powered directly from the power grid, once using RD EMI Neutralizer power filter.

Building a High End Listening Room 4: Fine-tuning the Acoustics
15. 5. 2020

We bring you a comprehensive account of room acoustics tuning in our listening studio in Rožnov pod Radhoštěm. We have acquired a space in which we were able to realise our demanding requirements, ultimately leading to the best possible acoustic properties of the reference room.

Building a High End Listening Room 3: QRD67H – Hybrid Diffuser
2. 5. 2020

We finished a third step towards a perfect listening space. A hybrid acoustic diffuser now covers almost the entire ceiling. We tried to make a photo of it, but even a wide 10mm lens could not capture it in its entirety.

Building a High End Listening Room 2: Construction
21. 4. 2020

The second step towards our new high end listening space is behind us.

Building a High End Listening Room 1: Goals
17. 3. 2020

We are about to have a new listening room! On our hands, there is a space a construction of which we will be able to alter in order to reach ideal room proportions and gain the best possible listening space. The articles will be written continuously documenting the birth of the room. Ample acoustic and electrical measurements included.

Grounding Quality: Not Just for Audiophiles
18. 1. 2020

How and why does the grounding potential influence our audio system and how to improve it.

Measuring Power Grid Interference in Practice
23. 11. 2019

Would you like to know what interference occurs in the power grid? Why deal with filtration? To illustrate the issue, I made measurements at four different places. For comparison, I used a common EURO cable and RD Power Filter.

We shall Plant a Tree for every Product Sold
2. 11. 2019

Enjoying rock climbing as a free time activity, I feel close to nature and its sustainability. As a company, we do not wish to simply slide on the ecological wave, we want to actually act.

Acoustics Theory – Sound Behaviour in Closed Space
30. 3. 2019

To understand sound behaviour in closed space better, we have to get into a bit of theory.

Room Acoustics: Not just for Audiophiles
30. 3. 2019

The most perfect speaker systems will not deliver great results in lousy acoustic conditions. Are you interested in improving your room acoustics? Read on.

Perception of Music: People Are Not Machines
14. 5. 2018

Why do our ears dislike the clean curve produced by an electronic tone generator?

What Is an Audio Power Filter For?
23. 1. 2018

Are external power filters useful in any way? Why are high quality EMI (electromagnetic interference) filters not a part of most consumer electronics devices? Should we care about high frequency interference, considering we cannot hear it or see it?

Audio and ElectroMagnetic Compatibily
22. 1. 2018

What is “electromagnetic compatibility”? Does it serve any purpose nowadays, or is it an anachronism? Why most consumer electronics cannot withstand a lightning strike

The Skin Effect Exists
19. 1. 2018

Is the term “skin effect” often arising in the audiophile world only a “voodoo fallacy”, or does this phenomenon, as described by J. C. Maxwell in 1892, really influence music reproduction?

The War of Dynamic Range
22. 12. 2017

Soon it will have been nine years since Ian Shepherd declared the Dynamic Range Day. Has something changed?

Modern Renaissance of the Horn Cabinet
20. 12. 2017

The principle of a horn cabinet (also known as horn baffle or transline) has been known for a long time. The Maya, the Celts and Egyptians (even in the predynastic period) were able to use the physical properties of a hollow animal horn

Musica Nuda
7. 12. 2017

The unconvential Italian duet—Petra Magoni and Ferruccio Spinetti—released great audiophile album Complici in 2011.

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