Speaker Isolation - Stack Audio AUVA, Townshend, Audite, Iso

Photos not showing, sadly

Pete should be testing on a suspended wooden floor imminently too....

Thanks so much for taking the time to do all the testing and comparisons. Different systems and different rooms is great for getting a wide range of test results!

It seems that quite a few people are reporting better results with the AUVAs in direct contact with the cabinets - really useful information.

Loudspeaker isolation
Spoiler alert- The Stack Auva 100 have improved the sq of my system to such a degree that I have purchased a set. Not cheap, but paradoxically offer superb value for money. They are quite simply outstanding.
Didn’t want to come across as a rabid fanboy, but it just can’t be helped.
Not only that but the change in performance in my system was greater than the uplift I heard at Jason’s day of trials with Stack Auva vs Isoacoustic Gaia’s vs Townsend bars.

It’s been a long journey to get to this stage, not without frustration. The combination of Arke Ektas and a Neurochrome 686 should have brought audio nirvana, and whilst good... there was always that sense of something lacking.
Many cable changes and tweaks (equipment isolation) have provided improvements.
The Auva 100’s have finally produced that level of performance that defies any expectation that an isolation foot should be able to deliver.

When Jason first built my Ekta’s he offered to install outriggers, which I declined. My plan was to use Townshend bars which unfortunately were of a lower weight rating and unable to support the 34kg Troels Gravesen design speakers. I did try Townshend bars at a later date (thanks Oli) which were the correct rating and certainly offered a better sound.
Then followed a succession of trials of sorbothane feet, discs, ice hockey practice pucks and cheap Chinese isolation products. They all worked to some degree often improving one part of the audio spectrum at the expense of another.
I made some real progress after installing some plastic outriggers from eBay.



I replaced the spikes with Isoacoustic Gaias I had from my sitting room system, which also utilised the M8 threads in the outriggers.
The result was a significant step forward in instrument separation and hence better soundstage. The best I had achieved to date.
Mind you, it did give the appearance of a Gerry Anderson model from Fireball XL5 or Thunderbirds (for the younger members)



It wetted my appetite for what alternative isolation products might offer, as I still had this hollow feeling that my system wasn’t delivering the feelings I was experiencing with other systems. As it happens I was right.

Then Jason invited me over to his place following explorations of offerings with some isolation products currently available.

A heroic effort to bring in as many choices as possible, which mainly through availability limitations boiled down to Isoacoustic Gaia, Townshend bars and Stack Auva.

Kudos must be given to Stack Audio for supplying demo sets of 100’s, 70’s as well as EQ feet.
Little point in me repeating Jason’s detailed review of the day. I totally agree with his reflections on the day with the Stack Auva 100’s providing the biggest improvement in resolution and sound staging.
The one aspect I will remember from the day is how different the reproduction was of Dave Brubeck’s Take Five.
When you listen to it, the piano part is actually the rhythm foundation. The Auva rendered this with dynamics and power. The Gaia’s were good but not as resolving. However the Townshend almost lost the piano part which just seemed to get absorbed into the rest of the mix. Most strange, and didn’t reflect how I recall Townshend clearing up musical presentation when in other systems. Odd.

So.. I was able to return home clutching a demo set of 100’s, 70’s and EQ’s.
Jason’s system in his room and with the Vaders give you a proper taste of high end audio, which the Stack products had just elevated yet further in my mind.
However it was in my system that I was keen to see if the same degree of improvement could be achieved. Laminate flooring over concrete looks good, but also gives a highly reflective acoustic surface to contend with. Hey ho.



Jason had also manufactured a set of aluminium outriggers custom built to fit the Ektas, and a fairly easy job to replace the plastic outriggers with these.
I removed the Gaia’s and decided to go for broke by putting in the 100’s.
Boom (well, no not literally).
The lift in resolution felt even greater in my system than we experienced at Jason’s.
Expectation bias ? Maybe.
But even now after a couple of weeks, I’m still caught out with surprises at what I’m hearing.

Controlled but deeper bass, delicate touches from percussion that I’ve never experienced before and an absorbing insight into whatever I played.
I swapped out the 100’s for the 70’s and whilst very very good, and certainly improved soundstage and presentation over the Gaias there was a magic sparkle that had disappeared and that occurswith the 100’s.

So.. not quite the whole story.
The 100’s are big. In fact 100mm big.
On the Aluminium outriggers they destroyed the clean lines and aesthetic visuals of Jason’s speakers.

So I decided to re-install the plastic outriggers, but reverse them so the Auva’s could sit underneath the speaker.



The surprising outcome was not only an improved visual, but to me the sound also improved by calming the hi-end frequencies a tad. Might be the plastic bodied out-rigger (in rigger/ foot mounting now). Might also be that the speaker benefits from further damping due to position.
Jason has offered to re-work the Aluminium outriggers so that I can refit but keep the Stack Auva’s in the same position.
It’s been a long old journey for me, and the damping speaker isolation solution allows me to benefit even more from the changes I’ve made installing triple c cabling and equipment support.

Be interesting to hear other reflections.
I understand a number of demo sets of Stack Auva’s have been floating around.

@arke "I have been sourcing replacements from Stack Audio."

The devil's work is never done.

Jason, are your Auva's still on outriggers or have you tried placing them directly under your Vaders?

I’ve just added some threaded inserts to my 851s, thanks for the advice Arke. AUVAs now screwed into the speakers and spiked through the carpet. Speakers are pretty rock solid. Another great improvement in separation of instruments, lowering of sound floor. Definitely worth doing, improved the sound quality no end.

It really is a straightforward job if you have a measure and some drill bits, I needed 5mm, 8mm and 11mm, also need a 6mm Allen key. Plus a £3.79 pack of inserts from screwfix. Oh, and a drill of course😁

He has got some then? 🤣

We’ve been here before, haven't we? The latest new kid on the block blowing minds and wallets seemingly at will. Brand new devices that make systems unlistenable once they have been in situ. The few shout: “Foolish are those who try such devices without scientific evidence and proof of performance!”

Well, call me a fool, because after my exposure to the Stack AUVA100 at Arke Audio's speaker isolation group test and their performance Vs Townshend Seismic Bars, I knew I had to try them at home.

Seeing as Jason (Arke Audio) was already in firm contact with the guys at Stack, he arranged the loan on my behalf, but this didn’t stop Josh (of Stack Audio) from reaching out directly and starting a very welcome and informative dialogue. I love proactive HiFi people, and this interaction was not sales driven, but just a little get to know you…it was greatly appreciated. Josh was also kind enough to offer me a set of EQ isolation feet to try under the DAC. I accepted, but that review will follow separately.

The day new hifi parts arrive is always a little bit exciting, isn't it? Well, I wasn't excited. I was dreading it as I knew that previous adopters of the AUVA had unanimously reported the feet being most effective directly coupled to the cab of the speaker. This meant that I had to shift my 40kg (each) speakers and fit threaded inserts into the bottom. A Job that I never had to do with my Townshends!

Whilst the fitting of threaded inserts is hardly bothersome, the moving of the speakers was highly bothersome. Having lived with Spondylitis and two herniated discs for the last few years I know my limitations, and this was not my idea of fun.

All actually went really well, until I had to get the speakers back into position. Once the feet were on, I installed the three (per foot) spikes. Once upright, I realised a fairly significant issue. The three spikes per foot meant that I couldn't “walk” the speakers into position. I had to lift them, and I really wasn’t happy about that. I had a quick scan of the supplied instructions and spoke to Jason, who suggested adding books under each side of the speaker to raise them high enough to fit the feet after moving the speaker into position.

Back down went the speakers, out came the feet, books were fetched and off I went. This wasn’t as painful as I thought it would be. I wonder if this process could be easier though?

Anyway, With the speakers now in position with the AUVA on, I decided to start easy. Like the legendary Bill Shankley said, “If you can’t pass the ball whilst standing still, you've got no chance while running!”

The first album i tried was Doc Watson - Southbound (CD)

It’s not unfair to say that I have listened to this CD so much since i bought it, that i am surprised the laser hasn’t melted it lol. From the very first vocal in “Walk on Boy” I was aware that this was a more powerful delivery. It was so clean and precise I was floored, then something had changed, and not for the better. The double bass hits and this was WAY too overblown in my room. This is a 1950’s recorded album and it has, what i call, soggy bass. It's a feature of a lot of old recordings due to the recording methods of the time, but here we are in 2024 and it was suddenly a soggy mess. I leaned across the back of the system and changed the Hypex setting on the speakers to the flatter response Jason did for me, and it got a little better, but it was still too much. I ended up having to adjust the Hypex attenuator by 1-2db to try and pull the energy out of the room.

Most of you will recall that the reason I got the Townshends initially was to remove my floor's acoustic influence from the sound, a job they did really well. The listening space here is small, probably 4x3m and with a tongue and groove floor with cavity below. The biggest issues I faced in this room HiFi wise have always been speakers due to the 40hz room modes and floor excitement. They were back, and it wasn’t fun.

I swapped to Tears for Fears - Alice in chains

This was MUCH better, but it still wasn't right. The low frequencies were stuck in standing waves at levels of volume that had been a doddle for the Townshends.

I decided to call Jason and explain what was going on.

After some head scratching, he suggested putting two books under the speakers where the ports fire downward. His theory being that due to the AUVA being taller than the townshend bars, the distance between the floor and the downward firing port had increased and was now changing the port tuning

The filter settings at 70hz and 40hz that had been set while the Nextel-2F (with 2x10” subs ) on the Townshends were now potentially wrong, so he asked me to download Spectroid and see if I could identify the booming frequencies. I played the same tracks again, and sure enough, Spectroid was peaking at 64hz and 39hz when the boom was taking over the room.

I reset the potentiometer to 0 on the hypex, pulled out two books approximately 25mm thick and put them under the speakers. I played the same tracks again, and it made a significant difference to the room modes. Although 70hz still needs a little tweak in the software IMO, on almost all tracks it’s no longer creating a standing wave or booming at my normal listening levels. Result!

With things now better controlled, I listened to a fair few albums in the course of the first two days, and even though it had been reported that the feet improved over time, I didn't hear that. Most likely due to spending some time tweaking my semi-active speakers!

So, with things now fairly settled down and in place, I decided to crack on and give this new setup a good thrashing!

First up, the oldest thrasher in my collection of CDs…Mozart

Clarinet Concerto in A, K.622 - Sabine Mayer.

I am totally addicted to this CD. I heard a snippet of this piece on Classic FM about eight months ago, and to my joy the CD was in my wifes late uncle's collection that I had inherited. Since then I have been listening to it almost daily. To say I am familiar with this piece is not unfair lol.

As I listened to the clarinet, a noticeable change to what I had been accustomed to hearing was staring me right in the face. The clarinet is an instrument in which sound is produced when the player breathes into the mouthpiece, causing the single reed that is fitted to the mouthpiece to vibrate. These vibrations are then “tuned” by pressing down the metal valves and closing off the escape holes for the air. This momentary press causes a pinching like effect on the note, kind of like a link of sausages, for a visual representation.

Why I mention this is that I had never been aware that this was audible in my system. Maybe for multitudes of reasons, but I definitely was not aware. In fact, I had forgotten all about it from my days as a young Cellist, but here we are with significantly older hearing holes and a recording on CD hearing this with real clarity. I made a note to myself…”listen for this when you put the Townsends back in”

As it went on and into the second passage, the notes from the clarinet were delivering left and right channel interplay. Notes bouncing from left to right and back again. The system was creating a mental image of a “Tinkerbell” type figure jumping between the speakers and climbing stairs between the speakers as the notes increased in pitch. It was a delight to listen to, but a new experience of what's contained within the CD. Then, just as I was thinking to myself “this is great” we landed at 6.36 minutes into track 3, and the orchestral interplay started to gain gravitas….wow. The separation and individualism of each section was definitely clearer and more defined. The fourth track started and it is the best I have ever heard it here. The control, the grip and the way each section now felt as though it was audibly separate from the others created a mental image of having a sort of birdseye view of the musicians playing in their own sections. The lower notes rumbled and grumbled with grip and menacing clarity, the horn section was dramatic and brassy, the wind section fast and nimble. What a joy. Wonderful stuff indeed.

The funny thing is, after all this time of listening to this CD almost religiously, there were now new artefacts that I had been blissfully unaware of. Strings playing really quickly and very quietly in quiet passages of music…. Where did they come from? Yes, I had heard the music, but not with the definition I have now. That speed of bowing the strings was not audible to this degree, according to my memory.

Changing pace, i decided to play “Talk Talk - The Colour of Spring”

For those who are unfamiliar with this album, go and have a listen. It’s a great recording and it’s full of tracks to test kit with. I chose “Happiness Is Easy”

I like this track because of the spontaneous instrument bursts. For instance, there is the odd guitar twang out of the blue, seemingly random in nature. Drum strikes, synths, double bass….it’s eclectic.

The reason I pick this track so often is that it hits hard in places, has some fairly deep LF, and can get a little too hot in a poorly assembled system, which incidentally was when I first heard it lol. I am not exaggerating when I say it scared the life out of me. I had the volume up a little too high from the CD before, and the drum machine created beat was bloody impactful lol. I leapt out of the chair and turned it down a notch. My heart still pounding, I started the track again, and even though I had lowered the volume, that bass note was still slamming hard. Hard enough to prompt the gaffer to pop in and tell me she can’t hear The Crown over the bass lol. In truth, it was still a little loud, so knocking it back a little further, I was delighted to find that the resolution didn’t fade. The spaciality of the soundstage was still very much audible. The sporadic outburst of the instruments were sharp and tight, seeming to appear from a vacuum, only to return to the vacuum with the same speed at which they arrived. It was also in this track that piano is played. The harmonic layering of the combined notes lingered in the decay well beyond the point my mind said “they don’t normally hang around this long”

Along with synths and pianos are real guitars. I was impressed with how totally obvious real instruments were vs the synthesised versions, the human aspect to vocals was tangible and oddly comfortable and familiar to listen to.

A common theme that was now occurring was the layering in the music was considerably more obvious than I recall with the Townshends in situ. Every little thing was easier to identify and place in the soundstage.

Another change of pace and in went “The Popular Duke Ellington”

This is one of my prized CD possessions. I love this album. The version I have is a West Germany made one and the numbers of these are pretty low. Its sound quality is superb, and before I start breaking it down, let me just say that it sounded utterly glorious.

There is a lot of trumpet in this album, and man alive, it sounded so raw and unfiltered. It wasn’t hard, etched or fatiguing, just really live and direct. It was incredibly good. Again, my mental familiarity and aural memory were saying “this is new” at an almost mentally overloading frequency. Drums were so vividly tight and taut. The skin tension was audible somehow…wowsers…what voodoo is this?

Again, spending a lot of time in my younger years participating in live musical environments, there are things you forget about how things sound “live” after 10 years out of it. The drums were a real memory jogger, a memory jogger that hadn’t been activated by the system before.

You see, the more I listened to my system with the AUVA 100 in place, the more I realised how much more alive, vivid and energetic the system sounded. It didn’t seem to matter which instrument played, who was singing, how many musicians were in the track…..the system resolved all of these things at a higher level. The impact of drums playing was considerably higher, like the speakers were energised and more powerful. Even at lower levels of volume, the resolution didn’t dip. Bass is tight, deep and now highly resolving in even lower frequencies. I was thoroughly enjoying what I was hearing, and there was renewed captivation as a result of what I deemed to be new artefacts in the recordings. Whether that be improved space in the soundstage, higher level of clarity and resolution or simple things like being exhilarated by someone whacking a snare….I was loving it.

Whilst my intention was to put the Townshends back in, I kind of don’t want to. I don’t want to suggest that I have put the AUVA in and suddenly my system is unlistenable without them, or that it sounds dire with the Townshends, because that isn’t true. The Townshends fixed a multitude of issues for me. They were a system saver at a time where I couldn't find a way through the room issues I was having, and still do have with passive speakers. My reluctance to put them back in is borne from the fact I can continue to tweak and tune the speakers I now have, which means I can move to Stacks and continue to work with the software to negate the remaining room issues in the LF. Doc Watson still isn’t quite right, but in fairness the tuning I had for the Townshends isn’t what's required for the Stacks. Jason at Arke Audio has offered to help me redo the filters, which is greatly appreciated.

Believe me, I wouldn't be willing to go and learn about DSP and the like if I didn't think there was a big gain to be had with a move to AUVA’s under my speakers. That in itself says a great deal about what's happened here. My feeling is that the AUVA have cleaned up the sound the speakers produce, and in turn have revealed opportunities for further refinement in the speaker filter. This is a great result for a tweaker like me. I am after every inch of improvement, and the AUVA seem to be opening the door to more.

Congratulations to the guys at Stack. They have made a superb product, and huge thanks for the loaner set. Thanks to Jason for the help with the speakers and arranging the loan. As always, I have not received or been offered any incentive to write this review, and have only shared my experience of using the AUVA in my system.

Thanks Mark.  Oli is certainly second to none with his eloquent reviews!

An update on the results:  So far, everybody has been impressed, and everybody has bought a set!  Sounds far fetched, but so far it's a 100% hit rate!   

This is starting to get a bit evangelical now . With so many using the Auva,s and not only being convinced of the improvements but also impressed enough to buy them as well . I will soon have two sets on loan 50,s and 100,s and starting to get very nervous about it . Firstly I need to make sure that I try the smaller version first and listen to what that offers . Then move to the 100,s and see if I can both hear the difference and then if I can live without them . These items are not cheap and I may have to wait to buy as next month is going to be costly . Thanks to all that have shared there thoughts . Now I have to listen for myself .

Thanks Mark. The differences were not AS pronounced as i experienced at Jasons, but then i have had to do a fair bit of tweaking with my speakers due to the room. Now dialed in a little better, the increments of improvement keep being revealed.