Posted on 7th August, 2018


While Alto-Extremo may sound more like a spell from Harry Potter or the name of a way-out jazz saxophonist, it's neither. It is, in fact, an engineering company based in Germany that produces a range of isolation products. StereoNET has opted to start at their entry-level offering from their Prestige line, the Exact.


Prestige Exact Isolation Feet

£195 (Set of 3) £245 (Set of 4)

Alto-Extremo was founded in 2014 in Germany and focuses on the development of audio related products. The team consists of highly qualified engineers with all production taking place exclusively in Germany. This allows the company to have complete control over their products, from the design, to testing and of course the manufacturing processes.

The Alto-Extremo Prestige range consists of two dedicated devices that are designed for different applications, but the company does recommend them to be used with CD Players, preamplifiers and smaller speakers. The Classic can be especially beneficial to tube amplifiers, (both pre and power), according to Alto-Extremo.

The Exact is made up of a stainless steel body with a bronze ball that sits between the steel inner and Delrin outer. Delrin is a thermoplastic material which is well documented as having excellent resonance control capabilities.

The Exact's M4 thread means that it can be directly mounted to a variety of components and compatible speakers.

Alto-Extremo Exact Specifications:

  • Weight capacity: 50kg per puck
  • Diameter: 43mm
  • Puck height: 30mm
  • Thread size 4mm

Setting up

Prior to installing the Exact isolators I played three tracks that I'm very familiar with and took listening notes. Next, I installed the Alto-Extremos and immediately replayed the same tracks, comparing what I heard with the Exact installed in turn underneath my turntable, CD player and amplifier.

With the turntable (Pro-Ject 1Xpression with Cartridge Man Music Maker) I tested the Exacts placed directly under the turntable as well as underneath the marble platform that the turntable sits on. The CD player being used is an Oppo UDP-205 and the amplifier is a Musical Fidelity M6si.


Without exception, every track produced tighter bass, more refined mids and greater focus and depth.

With the Exacts directly supporting the turntable, there was little improvement. However, with the Alto-Extremos placed underneath the marble plinth and then the turntable on top of that, the results were much more pronounced. I suspect that this has something to do with the weight loading on the isolation feet.

Having upgraded to the UDP-205 from the 203 a few months ago, you could say I'm still in a bit of a honeymoon period with it. However, the Exacts seemed to squeeze even more detail from the player with more impactful bass being a highlight.

I have owned the Musical Fidelity M6si for many years now, and it's fair to say I know exactly how it sounds. Slipping the German pucks underneath the MF resulted in improved vocal imaging and a broader and deeper presentation; the music had a more three-dimensional, natural sound.


Overall, the improvements brought by the Alto-Extremo Prestige Exact isolation feet were neither subtle nor slight. With the isolators in place, especially underneath the CD player and amp, listening was a more emotional experience.

In fact, I found myself discovering micro-details in the music that I hadn't heard before, no matter the genre being played.

The “Made in Germany” label is proudly displayed, and rightfully so as Alto-Extremo's engineering is direct and effective. I'd suggest that you'd have to spend substantially more on component upgrades to achieve similar performance improvements.

For more information visit Alto-Extremo.


      Jay Garrett's avatar

      Jay Garrett

      StereoNET UK’s Editor, bass player, and resident rock star! Jay’s passion for gadgets and Hi-Fi is second only to being a touring musician.

      Posted in:Accessories Isolation
      Tags: alto extremo  nunu distribution 


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