Product name: Acorn Equipment Support Feet.
Manufacturer: Sound & Design - Italy
Cost: 52€. (YMMV)

Reviewer: Mike Cox - TNT UK
Reviewed: February, 2012

Introduction

These little acorns arrived just before Christmas 2011 from the manufacturer Sound & Design, a small company based in Bari in the south east of Italy. Sound & Design also produce some interesting and rather different looking speakers so please do take a look at their web site.

Design & Philosophy

The team at Sound and Design explained the design a philosophy as follows;

"We designed Acorn because we wanted to overcome some limitations of the two main support approaches.

1. Spikes.

2. Damped feet.

We tested both in depth and found they have some main behaviours. Spikes generally control (and sometimes over-control) the deeper bass but can colour the higher frequency range. Damped feet are more variable, the overall result depends on mass load and also if mass load is equal distributed between feet. We tried different products and also we built some feet using different damping compounds but the result was practically unpredictable. It can be good or poor and sometimes very poor, anyway we never found an excellent result.

We found graphite or carbon block works better than damped feet, and completely by chance we tried wood. As you will see the real illumination came when we first tried a two compound wood feet set. Wood acts absolutely different than steel or a damping material, the mechanical characteristic is different: tension modulus is different to compression modulus. Theoretically wood acts like a non linear spring.

A non linear spring can be heaven or hell, it can distribute vibration more uniformly but it can also have some peaks or dips. Measurement showed us that two glued woods with similar mechanical characteristics but different textures, amplify the non linear effect reducing peaks and dips. We tested some geometry and the "acorn shape" was one of the best to get a good non linear spring effect and a good mechanical stability ... when one put a device on it!"

In Practice

The Acorns come in two sizes, the standard that are designed to support equipment that weighs no more than 15Kg per Acorn. This means if you are using four Acorns the equipment must not exceed 60Kg. The larger Acorn called the "Acorn_HL" is capable of supporting 25Kg each so a total of 100Kg. Sound and design recommend using four Acorns for each piece of equipment. Three Acorns are fine if the user finds it difficult to place all four without one feeling loose. The Acorns have no height adjustment so if the bottom face of the equipment or mounting surface are not completely flat four Acorns will allow the equipment to rock. If there is a problem with rocking when using 4 Acorns the recommendation is to add a shim made from aluminium foil between the flat top side of the Acorn and the equipment.

As you can see from the pictures I used the Acorns to support my turntable and pre-amp. The turntable is a Garrard 401 in a custom plinth that is designed to be supported on 3 hardened steel dome headed bolts. The Acorns are a considerable cosmetic improvement and 4 fitted without any problems. The plinth is in two sections with the arm attached to the lower section with the Acorns fitting between this section and the shelf. The upper section of the plinth is is separated from the lower by a damping material so as to reduce any mechanical vibrations from the turntable reaching the arm and cartridge. With the Acorns in place the sound seemed to have a quieter background with more relaxed presentation. The sound was smoother flowing, perhaps musical is the term that best describes the Acorns affect. The bass was not changed by the Acorns which remained tight with good rhythm and timing, an area the Garrard excels at in my opinion. In this setup the Acorns tidied up the mid-band and high frequencies.

Sound & Design suggest you can fit the Acorns under existing equipment feet, this only works if the existing feet have flat surface, as my pre-amp has small domed rubber feet I fitted Acorns directly against the bottom of the case. As the pre-amp is passive, just a couple of transformers, a couple of switches and some wire I was not expecting much change. In practice the Acorns were effective in a similar way to the turntable, the music seemed more relaxed and refined in the mid-band and high frequencies. There is not a massive change, it is positive and every bit helps.

I next tried the Acorns under my phono stage, the Whest PS.30R. The Whest already has damped feet with a flat surface so I was able to fit the Acorns between the existing feet and the glass shelf. This raised the Whest up rather high and make it look rather ridiculous. I could hear no significant change to the sound in this setup. The Whest has been designed to filter out any vibrations from the sensitive high gain circuits so the Acorns really did nothing to help what is already a well designed product.

I have also experimented with fitting the Acorns under the Helder Class D amp I reviewed recently. The case is not suitable for fitting the Acorns as prescribed so I placed the Acorns between two pieces of MFD with another set of the Acorns under the amp but flat face at the bottom and the pointed ends in touch with the plastic case. I then had to add some weight to the top of the amp to hold it in place as it is so light, the speaker cables tended to make the assembly unstable. It was experimental and did not look great but it has proved to me the Acorns again helped to damp any vibrations and make a small sound improvement. As with the other setups the Acorns help to refine the mid-band and high frequencies. The system sounds more relaxed and open, again a small change. If you make a number of small changes to a system it can add up to a very beneficial improvement.

There is nothing to attach the Acorns to the equipment, gravity keeps everything in place and for me that is the downside of these feet. As the Acorns are design to be fitted point side down it turns into a balancing act getting all four in place and if the equipment is heavy this can be challenging. I have wondered about using double sided tape to attach them and make the task easier. This problem is not unique to the Acorns so I persevered so they were used as intended.

Conclusions

I have to admit I like the look of the Acorns and fitted under my turntable they really look as though they are part of the original design. Fitted between the pre-amp and the glass shelf the Acorns do look a little out of place against all that glass, brushed aluminium and painted steel.

Whatever the look the sound of my system has changed for the better with a more refined and musical sound. I have not mentioned any particular music used for this review as I used many albums from all my sources. The small improvements were consistent across all the sources and genres of music. As I write this review I am listening to Eva Cassidy, the vinyl version of Songbird, the beautiful voice projecting from the speakers is so clear and realistic. It is such a shame Eva is no longer with us, I hope Eva is out there wowing the souls of the world with that voice.

Review system

• Speakers - Amphion Krypton Mk1
• Pre-Amp - Music First Audio passive magnetic
• Power amp - NET Audio NA200, Leak ST50 or ST20
• DAC - Aqua Acoustic La Voce
• Transport - Meridian CD200 or streamed from ITunes via USB or Toslink
• Phono stage - Whest PS.30R
• Turntable/arm - Garrard 401 in custom plinth and Rega arm
• Cartridge - Denon DL103

Review Track Examples