I used Science and Measurements to test is Vibration Control a Snakeoil - Stack Audio AUVA EQ review

https://www.youtube.com/watch?v=bs8EIxM636A

What is AUVA EQ Vibration Control

Same as you guys, I do watch and love a lot of reviewers here on YouTube. And one of the reviews that many reviewers made that always peaked my attention was Stack Audio Auva anti-vibration feet. It seemed like magic and snake oil, and I was shocked that so many people praise them.

And I said one day I am going to buy them and review them, as it really sounded like magic. I even started to make preparations for the review, like researching about Stack Audio, how they construct their speaker isolators, and about Particle Impact Damping (PID), the main technology of Auva isolators.

Particle Impact Damping is not audiophile pseudoscience — it has peer-reviewed literature in aerospace, civil engineering, and mechanical engineering going back to 1945. I am trying to sound as simple as possible, but it is not possible. The speaker's vibration energy shakes the particles inside the AUVA's cells. The particles smash into each other and into the walls of the cell, converting that kinetic energy into heat — tiny, imperceptible amounts of heat, but enough to "drain" the vibration before it can go anywhere harmful. Stack Audio describes this like throwing a ball into soft sand — the sand absorbs the energy from the ball, preventing it from bouncing.

It is a cool thing and great technology, which you can read more about on the Stack Audio website.

Particle Impact Damping and Custom Silicon Absorber Science behind this

But out of the blue, unexpectedly, Stack Audio sent me an email, and I was happy and surprised. Would I like to review Auva EQ isolators? And I was — hell yeah! Maybe it is not the speaker isolators I wanted to review, but this is meant as companion gear for your other HiFi products in your system — your amps, DACs, sources, etc.

I will try in this review to talk about the science behind this product, a subjective review of sonic quality, and objective measurements of improvements of the Auva EQ. So you will get the full picture of this product.

It works similarly to the original Auva isolators, but they add a bit more technology here. We now have a CSA — a Custom Silicon Absorber. So now we have Stage 1, which is PID, which takes vibration from your devices and converts it to heat, but is not able to convert all of it into heat.

Below the PID is therefore the CSA. The CSA operates on entirely different physical principles from the AUVA chamber above it, which is precisely why the two complement each other.

The CSA forms an inverted silicone cup that creates an air pocket once loaded, with four small holes that further damp the system — effectively creating an air-bag spring/damper suspension. The shape has been specifically modelled to absorb particular vibration frequency ranges which are harmful to audio signal purity.

Now, why two stages and not one? The critical insight of the AUVA EQ design is that no single mechanism covers the full vibration spectrum relevant to audio electronics.

PID excels at rapidly annihilating mid-to-high frequency vibration energy through collision — it is essentially non-resonant and broadband. However, very low frequency structural vibration (footsteps, room modes, building sway below ~10 Hz) involves large displacements that particles cannot fully respond to, because the collision rate at low frequencies is insufficient to extract energy quickly.

The CSA handles exactly this gap — its compliant air-spring suspension decouples the component from low-frequency structural input, lowering the system's natural resonant frequency below the excitation frequencies present in typical domestic environments.

The result is a device that converts incoming vibration energy into heat (PID), suspends the component away from remaining structural vibration (CSA air spring), and does so at low weight and without adding resonant mass to the system — addressing the fundamental engineering challenge of audio isolation without the compromises of traditional solutions.

As you can see, there is obvious science here, not magic. Technology that has been used for a long time in different applications. But someone thought about it — well, how about HiFi — and it happened.

How to use Auva EQ

I want to talk a little bit about the packaging and design quickly. You can choose to buy between 1, 3, and 4 in a box. The isolator pucks should be placed where the company naturally placed their product's feet. If your device has 3 or 4 feet, that is how many you need to put under your system. They need to be placed close to the feet of your product, or best of all, if you can remove the feet completely and put the Auva pucks in their place.

In my calculations you need 8 of them minimally, for your amp and source. Or if you have an all-in-one just 4, or if you have an external DAC then 12.

The price of a box of 4 is around 190 euros. So 2 boxes is around 380 euros. But you need to choose between CSA 1, 2, and 3 — and not to complicate things, it is about the weight of your gear. If it crosses 16kg you need CSA 2, if it crosses 40kg then you need CSA 3. So if your product crosses 60kg I guess you cannot use them? I don't know — I don't have a 60kg Class A monster power amp — so I don't know. But most of you will need CSA 1.

Otherwise they are super light and small in size. They do look like the feet you can find on more expensive turntables or equipment. They are easy to put under your system and they feel elegant and minimal. There is no complexity — even in the box you just get your pucks and that is it. You place them in the designated area and you are done. A very simple process and execution.

Let`s Talk about Value is it too much or not

I want to speak about value here quickly, as I think that feels like a major block for many people wanting to try this. And whether this is for you is more about a reality check rather than simply if it is or not. Do you have problems that this product can fix? You know, for a tool to help you there needs to be a problem for it to fix — it cannot be a magical tool that just improves your sound quality etc. And in the end, you must understand that this brings improvements, but they are not going to create a whole new sound signature or sound quality. You cannot expect drastic changes like buying a new amp or speakers. This does what it is supposed to do — makes your system a bit more clear, so you can hear more detail and transparency among the instrumentation.

Now in theory you can get improvements from just one box of 4, if you place it on your amp. You should feel improvements, but it would be great if it can cover your whole system. Now here is a small tip. If you have a whole chain of system from amp, source, and DAC, the best thing would be to cover all of them with 12 pucks, but I think 90% of that you can get if you cover the amp and DAC. Unless your source works independently from the DAC and goes right into the amp. As the internal clock of the DAC and its filters do help a lot with cleaning the signal path, just the DAC needs to have pucks beneath it.

And let's count together. So 1 pack is 190 euros, 2 is 380, and 3 is 560 euros.

It is not cheap, it truly is not — at the price of 3 you can seriously think about upgrading your amp and speakers with that money. But at the price of 2 or 1, that is where good value actually lies. Think about it — does adding an additional 380 euros or 190 euros to a new amp bring more quality than having these small boys clean your signal for you? I would always say the Stack Audio Auva is better value.

It improves your system, and is reusable when you buy your next gear, so it holds more value than investing the same money into new gear. In that sense, 1 and 2 boxes is great value, while 3 is okay. That is my thinking, and I do not think this is so much more expensive, especially if your products in the system cost 1000/2000+ euros. But even at 190 euros for one box there are tangible improvements. But all of this is very subjectively about what is a small or large amount of money for some people, so I will leave it there.

Subjective Sonic Improvements

And let's talk about the sonic improvements. I will try to explain it through both subjective and objective measurements.

The first time I heard tangible improvements in sound was not when I first put them on, but when I removed them. In general I have to say, with all my sonic padding of my room with acoustic reflectors and bass traps, plus Dirac Live, I am pretty happy with my sound.

When they arrived in the mail, I put the Auva EQ right away under my system and sat down to listen. I was like... well, I guess this is better. The bass is more defined, and... I guess maybe the system is more clear. So I listened for some time before even starting to think about the review.

When the time came for me to start writing notes and ideas for the review, I did my standard A/B with other devices, but this time I did not switch devices. I only switched the Auva EQ on and off — removing them and then returning them and listening to music.

And that is when it snapped for me. The sound that I thought was almost perfect was no longer so good. I was really missing those isolators. When I removed them, the sound was still good mind you, but it just lacked a bit of the openness and transparency that the isolators had provided.

First let's start with bass. To be honest, even before choosing the review, if what they told me on the website was true, the main improvements were going to be in the bass and mid-section. And they are. Let's talk about Nick Cave's song Jesus Alone. The opening minutes of Jesus Alone are built almost entirely on bass texture — a slow, layered low-frequency foundation beneath Cave's voice. Without the AUVA EQs, the bass was present and deep but somewhat indistinct, the individual layers bleeding into one another at the lower frequencies. With the EQs in place, the layers separated. The distinction between the synthesised sub-bass and the kick drum became tangible rather than implied.

Cohesion between instruments was more obvious, more separated — like the players and instruments had been moved slightly away from each other.

And therefore a body of bass, when listening to classical music with cello, was more apparent — like how it grows with textures and presence: the wooden body of the instrument became more audible as a separate acoustic element from the strings above it.

The music did not sound different. It sounded more itself — revealed, rather than changed.

Vocal intelligibility is one of the most sensitive indicators of midrange clarity in a hi-fi system. Listeners who have spent time with a system at its best will notice immediately when sibilance becomes edgy, when vowel shapes lose definition, or when consonants blur into one another. The AUVA EQ's effect on the midrange was most apparent on recordings where the human voice is the primary instrument.

Joni Mitchell's Both Sides Now from the 2000 orchestral recording provided a contrasting test. Here the voice is surrounded by a lush string arrangement, and the challenge is maintaining the delicacy of the vocal line against a dense orchestral backdrop. Through the isolated system, the vocal had a quality that was difficult to describe precisely but easy to perceive: it sat in front of the orchestra without apparent effort, each word fully formed, without the smearing of consonants that can occur when a midrange is not fully resolved.

Also, quiet moments in Mount Eerie's Crows Look at Me — a very minimal, sparse album with heavy atmosphere, and just acoustic guitar and vocals — sounded more clear, more present, more separated, and closer to you, even though it is an intimate album. The vocals now had complete control and space around them, more than usual.

I don't have much to say about treble. It seemed, at least to my subjective ears, that the treble did become a little more emphasised at the top — a little more clear and present. But no big dramatic changes here.

The improved timing and clarity does have a positive effect on soundstage, which is an obvious thing. Miles Davis's Kind of Blue — specifically Flamenco Sketches — is one of the definitive tests for soundstage and imaging. The five-instrument lineup should place each player in a distinct location in the stereo field, with the acoustic of the Columbia 30th Street Studio audible behind and around them. Without the AUVA EQs, the image was good but somewhat two-dimensional — the musicians were present but their spatial positions were approximate rather than precise. With the EQs in place, the image deepened considerably. Paul Chambers's bass moved to a specific position in space. Bill Evans's piano gained a rightward placement that the recording clearly intended but that had previously been somewhat vague. The studio acoustic — that distinctive slight reverb of the 30th Street Studio — became audible as a room rather than as a production effect.

I tried to explain the sound, and while there were improvements, a lot of these things are due to my own system. Everything just got more tight and clear, and that in turn brought some audible changes to the sound. But this is not miracles — this will not change your sound dramatically. It is still the strength and talent of your gear that tells the sonic stories here. The Auva EQ just helps a little bit to make it even better. For example, things like soundstage placement, imaging, and spatial information — all of that — maybe 85% or even higher you get without the EQ, but these small pucks do help truly to experience talent of your system.

Sonic Improvements via Objective Measurements

Frequency Response without Auva EQ

Frequency Response with Auva EQ

But in the end this is not magic — sound is easily quantifiable. If you hear something better or worse, it is because the sound waves reproduced by your speakers are in some way different and behave differently in the room they are in — reflecting, absorbing, etc.

I don't have the necessary tools to measure vibrations and how the Auva EQ removes them. I don't have the skill nor the tools. But I can certainly measure how my room sounds with and without, and that is what I did.

One thing to note — my room is under renovations. It is almost done. One bass trap is set and some room absorbers are in place. But most of the bass traps are missing, as I need to move those heavy things and drill holes in the walls to support them with restraining chains, so they would not kill my cat. With how busy I have been recently, that is going slowly. But maybe that is not such a bad thing, as it will sound imperfect like many, many rooms with HiFi in them.

Now I am going to show you two graphs — one with the EQ isolators and one without. And I am going to read them for you, explaining what they tell us and how they behave.

These are frequency response graphs. They show how loud each frequency is when your speakers play. The horizontal axis goes from low frequencies (bass) on the left to high frequencies (treble) on the right. The vertical axis shows volume in decibels (dB) — the centre line (0) is the reference point, above it is louder, below it is quieter.

The pink line and the teal/green line are your left and right speakers measured separately. In a perfect world, both lines would be completely flat and sitting right on 0 — meaning every frequency plays at exactly the same volume. In reality, rooms always mess this up.

Let's start with the bass region of 30Hz to 300Hz. This is where the biggest difference between the two graphs is visible.

Isolators OFF — the lines swing very wildly. You can see massive peaks going up to +8 or even higher, and deep valleys dropping down to -13 or -14 dB. That is a swing of over 20 dB in just the bass region alone. That is enormous. What this means in practice is that some bass notes will sound thunderously loud while notes just slightly higher or lower in pitch will almost disappear. Your bass is essentially a lottery — some notes boom, others vanish.

Isolators ON — the swings are still there (rooms always cause this) but they are visibly smaller and more gradual. The peaks don't go as high and the valleys don't go as deep. Your bass is more consistently present across different notes.

Now let's speak about the mid-section, 300Hz to 3kHz.

This range is the most important for music and voice. Guitars, vocals, pianos, snare drums — they all live here. This is also where your ears are most sensitive.

Isolators OFF — the two lines (left and right speaker) are diverging quite a bit from each other. There are spots where the pink line is notably higher than the teal line or vice versa. This means your left and right speakers are telling your ears slightly different stories about the same sound. Stereo imaging suffers — instruments don't sit as precisely in the stereo field.

Isolators ON — the two lines follow each other much more closely. They almost mirror each other through a lot of the midrange. This is much better for stereo perception. Instruments will feel more locked in place in the mix and vocals will sound more focused and centred.

And lastly, treble — 3kHz to 20kHz.

Both graphs look fairly similar here, which makes sense — high frequencies are less affected by furniture coupling because their wavelengths are too short to interact with surfaces the same way bass does.

However, Isolators OFF still shows slightly more erratic jumping between peaks and dips. With isolators on, the high frequency response is a tiny bit smoother and more consistent, which translates to cymbals, hi-hats, and vocal air sounding slightly more natural and less fatiguing over long listening sessions.

Think of it this way — your desk or shelf without isolators was basically acting as a third speaker that you never asked for. It was adding its own random resonances on top of what your speakers were actually trying to say. The isolators removed that unwanted "instrument" from the equation, and your frequency response got noticeably cleaner as a result. Not perfect — no room ever is — but meaningfully better, especially in the bass and mids where it matters most.

Conclusion

Objective analysis aside, what most people are going to experience is a subjective feeling, and that subjective opinion plays a big role here. Is it too expensive? Is it good? Is it good for my system? All of that is something a lot of people will have to experience on their own.

For me, this does make a change — it does make your system a little bit better. By removing unwanted micro-vibrations, the signal path to your speakers remains more clean, more organised, more correct. And that in turn makes the sound more clear and vivid. Very simple — you have my scientific, subjective, and objective thoughts. I hope this will help you a little bit to see whether these isolators are for you or not.

And hopefully you enjoyed this content as well, and if it is not too hard for you, please like and subscribe.

Keep daydreaming and see you in the next video.