Stack Audio isolation products

[parrasaw]

As part of the setting up of new speakers and components in our living/listening room, I used Stack Audio (UK) AUVA 70 Speaker Isolators, and a variety of Stack Audio AUVA EQ System Isolators under all of the other components (with the exception of the two amplifiers at this point).

Stack Audio website:  stackaudio.co.uk 

 

After reading many reviews about the products and speaking with @AN AUSSIE AUDIOPHILE (Shane Stephenson), who has placed Stack Audio products under just about everything in his system, I went ahead and purchased the products.

Shane  has reviewed the products on his YouTube channel. He was super impressed (to say the least). Interested members can view his thoughts on the videos on his channel.

 

After installing the products in our system, I am happy to say that I am a big fan too.

The speaker isolators noticeably improved the sound in the room - especially in the bass frequencies. We may have lost a couple of Hz, but the bass is much "cleaner", and the considerable level of excitement in the floor which was quite noticeable prior to installation of the speaker isolators is no longer an issue.

 

So, I think that the products are terrific (reflecting the views of many reviewers and other end users, and the people at Stack Audio are great to deal with.

 

Some news: I was so impressed with the products that I asked Josh at Stack Audio if they could spare a set or two of the Component Isolators for me to be able to lend to other members to "try out" in their systems.

Yesterday I received a box of CSA -2s and a box of CSA-1s for interested members to audition.

 

If you are a SN member who lives in driving distance from Sawtell NSW, and you have been interested in trying these products, PM me and we can organised a short term audition (of say 1 week).

Later on, if it is feasible , I would be prepared to organise auditions for other SN members who live a bit further away.

 

Before contacting me, please go to the Stack Audio website, read up on the products, check out what @AN AUSSIE AUDIOPHILE and others are saying about the products, and then get in touch with me if you wish.

 

Two photos:

1. The speaker isolators under our Linkwitz LX521.4 speakers.

2. Component isolators under the other components in our system.

 

 

     

Edited April 18, 2024 by parrasaw

[playdough]

Nice, lovely system.

Used Sorbathane bumpers myself and they made measureable results in REW Measurements. -5dB less reverberation from 14Hz up the range. Also suspended hardwood floor boards. Monumental in fact the improvement.

[parrasaw]

44 minutes ago, playdough said:

Nice, lovely system.

Used Sorbathane bumpers myself and they made measureable results in REW Measurements. -5dB less reverberation from 14Hz up the range. Also suspended hardwood floor boards. Monumental in fact the improvement.

Thanks @playdough.

We are having a great time enjoying music which we know well, but which now sounds better than we have heard it before in our room. Plus lots of music which is new to us (via the Lumin streamer).

 

Our room has many similarities to your situation I think.

 

Our living/listening room is on the second storey of the house. Particle board floor on large Oregon joists. Good thick underlay, good wool carpet etc. 

The speaker isolation had a noticeable, beneficial impact on the sound - Shane ( @AN AUSSIE AUDIOPHILE) and I did a before and after listening comparison. No measurements in our room, but he had already done a before and after comparison (with some measurements I believe) in his own room, so he had a good understanding of the likely benefits of installing the AUVA 70 speaker isolators ...... and he wasn't disappointed with what he heard in our room post installation. 

In the next few days I might post a few more photos of the system in the "My system today" thread here on SN.

 

Both Shane and I are also big fans of the AUVA EQ component isolators. In his system, Shane was blown away by the gains which he heard in his Playback Design components when he installed the Stack Audio products - videos of his thoughts are on his YouTube channel entitled "An Aussie Audiophile". 

[playdough]

On 19/04/2024 at 6:13 PM, parrasaw said:

Our room has many similarities to your situation I think.

 

Our living/listening room is on the second storey of the house. Particle board floor on large Oregon joists. Good thick underlay, good wool carpet etc. 

Yes, very much so.

Suspended floor is not an easy thing to deal with and isolation holds the keys to less interaction or coupling, of the bass system to the floor.

Both products I would guess, do the same thing "isolate" and both cause measurable effect.

Love it, everyone wins. 

Have not tried isolating the equipment however it is never wise to subject any of the front end, or speaker to speaker cabinet vibration in any way.

 

 

 

[almikel]

On 18/04/2024 at 4:30 PM, parrasaw said:

2. Component isolators under the other components in our system.

what effect is expected under a component like an amplifier that has no moving parts?

On 19/04/2024 at 6:13 PM, parrasaw said:

Both Shane and I are also big fans of the AUVA EQ component isolators. In his system, Shane was blown away by the gains which he heard in his Playback Design components when he installed the Stack Audio products - videos of his thoughts are on his YouTube channel entitled "An Aussie Audiophile". 

I'll have a look...

[parrasaw]

2 minutes ago, almikel said:

what effect is expected under a component like an amplifier that has no moving parts?

I can't answer this question, because I haven't put the Stacks under my amps at this stage.

Shane is planning to do that soon in his system, so it might be worth you sending him a PM?

[almikel]

On 12/05/2024 at 5:14 PM, parrasaw said:

I can't answer this question, because I haven't put the Stacks under my amps at this stage.

I expect no difference.

Possibly a difference if you have valve amps experiencing microphonic input through vibrations, but no effect on typical solid state gear with no moving parts.

 

There's good science involved in isolating components with moving parts, and likely snake oil in the improvements isolating components that don't have moving parts can make.

 

Mike

[parrasaw]

On 14/05/2024 at 9:14 PM, almikel said:

I expect no difference.

Possibly a difference if you have valve amps experiencing microphonic input through vibrations, but no effect on typical solid state gear with no moving parts.

 

There's good science involved in isolating components with moving parts, and likely snake oil in the improvements isolating components that don't have moving parts can make.

 

Mike

Hello Mike.

I might have had similar thoughts to you, until I watched @AN AUSSIE AUDIOPHILE (Shane Stephenson) latest two videos, after he placed the AUVA EQs under his Vitus mono-blocs.

I think he was surprised at the level of difference which he observed, and an hour or so ago he posted an extra comment about the reason(s) which he suspects are behind the improvements which he observed.

 

I would think that the "benefits" which might be gained, would likely be greater still when using the EQs with tube amps?

 

Worth a look I think - the videos gave me plenty to think about.

Edited May 30, 2024 by parrasaw

[almikel]

On 30/05/2024 at 10:56 AM, parrasaw said:

I might have had similar thoughts to you, until I watched @AN AUSSIE AUDIOPHILE (Shane Stephenson) latest two videos, after he placed the AUVA EQs under his Vitus mono-blocs.

I think he was surprised at the level of difference which he observed, and an hour or so ago he posted an extra comment about the reason(s) which he suspects are behind the improvements which he observed.

I watched the video.

Cognitive bias ?

His reasons weren't a good explanation of the "next step up" difference he supposedly heard.

Audio memory is very short (ie multiple seconds) - if you can't instantly switch between scenarios, you can't effectively evaluate the difference.

 

On 30/05/2024 at 10:56 AM, parrasaw said:

I would think that the "benefits" which might be gained, would likely be greater still when using the EQs with tube amps?

If the valve amps suffer from microphonic effects, then isolation would help.

 

I've done many sighted changes to my setup where I was sure the difference was chalk and cheese, but doing the same change unsighted I couldn't tell the difference - that's cognitive bias.

 

Mike

[parrasaw]

On 16/06/2024 at 3:52 PM, almikel said:

I watched the video.

Cognitive bias ?

"Cognitive bias" . One of the "buzz words/expressions" in discussions on some audio forums for some time.

 

At last count (several years ago) there were nearly 190 types of cognitive bias which had been identified and described, any one (or more) of which may (or may not) affect any of us at different times in different situations, from day to day.

I have a fair idea about some of the biases which you may suspect might have been at play when Shane installed some AUVA EQs under his amps, however, given that so far I suspect you have probably only seen his initial reaction video, perhaps you don't have the "full picture" at this point?

 

It is my understanding that Shane has spent considerably more time evaluating the EQs under his amps since he posted his initial thoughts some weeks ago.

Perhaps he will soon be ready to post his more detailed thoughts on his channel.

 

As to your other comments, Shane may have some thoughts of his own which he is happy to post here

 

 

Edited June 18, 2024 by parrasaw

[AN AUSSIE AUDIOPHILE]

On 16/06/2024 at 3:52 PM, almikel said:

I watched the video.

Cognitive bias ?

His reasons weren't a good explanation of the "next step up" difference he supposedly heard.

Audio memory is very short (ie multiple seconds) - if you can't instantly switch between scenarios, you can't effectively evaluate the difference.

 

If the valve amps suffer from microphonic effects, then isolation would help.

 

I've done many sighted changes to my setup where I was sure the difference was chalk and cheese, but doing the same change unsighted I couldn't tell the difference - that's cognitive bias.

 

Mike

Hi there , Mike. I guess my question is the same as Paul's above comment. What sort of cognitive bias are you talking about I might be suffering from here?

 

I take my job as a reviewer very seriously and I take my time constantly writing notes about my observations.

 

I have posted a "genuine" first impressions video and I am about to present my final thoughts on the Stack Audio EQs underneath my monoblock amplifiers and preamp. This review is taken me over 3 weeks to compile the information that I have and the observations I've made. I have had theEQs in and out from underneath my 85 kilo amplifiers three times now. I've had a couple of my very good friends  who's ears I trust very much give me their thoughts. I'm certainly not going to preview the video but it will be posted in the next few days.

 

I must say I disagree with you about the time frame around comparisons. That may be the case for people who have not had the training and experience that I have had.

Let me tell you a little bit about my experience. I have worked extensively as a sound engineer in my early years as a tracking, mastering, and live engineer.

I've also worked in high-end audio retail and have been dabbling in high-end audio for over 35 years now.

 

Now let me explain why I believe decoupling and isolation are equally important for both tube equipment and solid state. Everything with a power supply in it will be resonating. These resonances often affect a piece of equipment's performance to be at it's best. Digital equipment for instance, like a Dac that has an oven baked oscillating crystal clock in its topology, and other very sensitive digital circuitry are affected by these resonances coming from their power supplies. There is often further problems that occur when you have another frequency oscillating from something else that combines with a piece of equipment's resonating frequency, this creates a veil a lack of coherency. Too often this is confused with being jitter, which is quite possible depending on the quality of the equipment. But by decoupling and isolating, most people find a general improvement in that piece of equipment  due to it being  decoupled or isolated.

 

The Stack Audio isolation as far as I'm concerned, is quite revolutionary in relation to its particle dampening technology, and it's ability to decouple and kill resonance in the equipment sitting on top of it.

 

I have a very resolving Hi-Fi system, and I have noticed definite substantial audible improvements in each component that I have put this isolation decoupling underneath.

I've done it bit by bit and have continued to notice more clarity, more detail, and more tonal accuracy in the lower octave. If you like a real sense of the music being alive, and a convincing presentation that my system sounds like the artists are in the room performing to me more than I've ever observed in my system before.

If your ever down this way you're welcome to come and have a listen. In fact you can even help me lift each of my 85 kilo amps up and we'll do an A/B test so that you can hear the difference for yourself.

 

Edited June 20, 2024 by AN AUSSIE AUDIOPHILE

[almikel]

Hi Shane,

 

Thanks for your detailed response.

 

On 18/06/2024 at 8:39 PM, AN AUSSIE AUDIOPHILE said:

I must say I disagree with you about the time frame around comparisons.

 

I'm happy to accept that your training/experience may increase the length of time between tests that you're still accurately able to determine a difference when a change is made to your system, compared to other listeners.

Floyd and Olive wrote some papers on this, which found that "trained" listeners were much more consistent than "untrained" listeners in picking "better sounding" speakers from "not as good sounding" speakers on blind tests, but interestingly/encouragingly, both groups still chose speakers with a flat frequency response and a smooth gently falling "off axis" response as "better sounding speakers".

 

IMHO the time frame to add these Stack devices under your kit is still way too long to do an accurate A/B comparison between "no Stack decoupling" and "with Stack decoupling"...I'm guessing at least few minutes?

 

On 18/06/2024 at 8:39 PM, AN AUSSIE AUDIOPHILE said:

What sort of cognitive bias are you talking about I might be suffering from here?

You know the Stack devices have been installed, ie a sighted test - that's cognitive bias.

Combine a sighted test with multiple minutes between tests and IMVHO that's no longer an accurate A/B test.

 

Obviously "instant switching" between "no Stack decoupling" and "with Stack decoupling" is not practical.

"Single blind" testing would get closer to an accurate A/B test:

• you not in the room
• friends apply "no Stack decoupling" or "with Stack decoupling" randomly (eg coin toss)
• you come into the room blind folded, not knowing which - listen/assess/note whether there is "no Stack decoupling" or "with Stack decoupling"
• you leave the room, and friends re-configure (or not) the Stacks based on the coin toss
• repeat at least 10 times

If you get it correct at least 90% (based on your review it should be an easy 100%), then IMHO that would indicate the Stack devices under your SS amps are improving the sound.

The gold standard for A/B testing is double blind, or A/B/X (ie the friends running the test don't know which either) - but also just as impractical as instant switching in our home stereo context.

 

On 18/06/2024 at 8:39 PM, AN AUSSIE AUDIOPHILE said:

Everything with a power supply in it will be resonating. These resonances often affect a piece of equipment's performance to be at it's best.

Do you mean actually physically resonating/vibrating?

We've all heard street transformers humming due to the laminations in the transformer core vibrating, but this is not an issue with well designed audio gear - particularly the toroidal transformers found in most decent power amps, which have a lower magnetic field, hence lower forces causing transformer lamination vibrations.

More important is the equipment Power Supply Rejection Ratio (PSRR) - the ability for the power supply to stop mains borne noise from getting into the audio circuitry.

All well designed amps have excellent PSRR, but it won't be improved by mechanical isolation devices under the amp.

 

On 18/06/2024 at 8:39 PM, AN AUSSIE AUDIOPHILE said:

Digital equipment for instance, like a Dac that has an oven baked oscillating crystal clock in its topology, and other very sensitive digital circuitry are affected by these resonances coming from their power supplies.

I get that noisy power supplies can inject noise into audio circuitry - but this is dealt with by improving the PSRR of the power supply, keeping power supplies separate for digital and analog stages, good shielding, circuit layout etc etc - ie good design - mechanical isolation of the device will have zero impact on the amount of noise getting to the audio circuitry from the power supply.

 

On 18/06/2024 at 8:39 PM, AN AUSSIE AUDIOPHILE said:

 But by decoupling and isolating, most people find a general improvement in that piece of equipment  due to it being  decoupled or isolated.

OK - but that statement is about as subjective as it gets - "most people find a general improvement"...

 

Looping back to an earlier point I made in this post, Floyd and Olive were able to demonstrate that both trained and untrained listeners chose a speaker with a flat FR and smooth off axis response as a "better sounding" speaker than speakers with a lumpy FR and poor off axis response based on good science/analysis - that's data that can objectively define a "good sounding" speaker as one that has a flat FR and smooth off axis response.

 

The Stack isolation devices just have marketing speak on their website with no good science backing up their marketing spiel.

 

On 18/06/2024 at 8:39 PM, AN AUSSIE AUDIOPHILE said:

I have a very resolving Hi-Fi system, and I have noticed definite substantial audible improvements in each component that I have put this isolation decoupling underneath.

I've done it bit by bit and have continued to notice more clarity, more detail, and more tonal accuracy in the lower octave.

And every change included cognitive bias...you knew a change happened...

...do the test...have a friend remove (or not) any of the Stack isolation without you knowing or seeing - can you tell the difference?

Repeat it 10 times

On 18/06/2024 at 8:39 PM, AN AUSSIE AUDIOPHILE said:

I have noticed definite substantial audible improvements in each component that I have put this isolation decoupling underneath.

You should easily nail it 10 out of 10...

 

...You'll get my point when you're sure there's a difference, but nothing was changed!

 

Mike

[Gryffles]

@almikel sounding rather messiah like their fella. 
How about showing a bit of respect for other people and their views instead of attempting to impose yours 

[frednork]

On 16/06/2024 at 3:52 PM, almikel said:

I've done many sighted changes to my setup where I was sure the difference was chalk and cheese, but doing the same change unsighted I couldn't tell the difference - that's cognitive bias.

It could be cognitive bias but it also could be your inability to hear the difference, your setups inability to resolve the difference in a way that can be heard, or it could be your lack of understanding of the test you are trying to perform.  It is likely that you have performed a very low quality blind test which is in fact no less suspect to bias than a sighted one. I dont have an issue with any of that. If it satisfies you than that is fine.

 

The issue occurs when you use this (likely) poorly conducted test as some sort of higher quality evidence that proves something more than someone using a sighted test. This is just not true.  Blind (sensory) testing is a science in of itself and cannot be half done.  If I am mistaken and you have indeed performed a high quality test then please list the details of it as you would no doubt have recorded all the details of it as that is an important part of a correctly conducted test. 

 

Even though you have proven whatever it was to yourself (if you have not performed a high quality test) you have no solid basis to criticize how others may  conduct their listening tests as yours are just as poor. You have likely  shown nothing with your blind test.and just as you accuse others of confusing themselves with a sighted test you may have done the very same thing with the false confidence of conducting yours blind.  Blinding is not enough to show there is no difference.

 

[AN AUSSIE AUDIOPHILE]

The only thing I thing I need to add here is that I concur with the above statement in relation to blind testing, and @almikel putting up your methodology around that testing for all of us to see. 

I have no problem with people questioning the way I go about my process, and in this instance with the Stack Audio isolation the differences were significant to me, in my system. And giving the splash these things are making on the world market currently I'm confident I'm not the only one. 

[Be Quiet...Listen]

On 16/6/2024 at 3:52 PM, almikel said:

 

I've done many sighted changes to my setup where I was sure the difference was chalk and cheese, but doing the same change unsighted I couldn't tell the difference - that's cognitive bias.

Cognitive bias…

I guess we’ll see everyone at the SNA show this year blind folded…

Get your helmets ready gentleman. 

[sir sanders zingmore]

8 hours ago, Be Quiet...Listen said:

Cognitive bias…

I guess we’ll see everyone at the SNA show this year blind folded…

Get your helmets ready gentleman. 

No need for helmets, audiophiles can navigate via ultrasonic echolocation

 

[Pim]

On 22/6/2024 at 11:16 AM, AN AUSSIE AUDIOPHILE said:

The only thing I thing I need to add here is that I concur with the above statement in relation to blind testing, and @almikel putting up your methodology around that testing for all of us to see. 

I have no problem with people questioning the way I go about my process, and in this instance with the Stack Audio isolation the differences were significant to me, in my system. And giving the splash these things are making on the world market currently I'm confident I'm not the only one. 

Shane, with the Auva 100's you did a video with them under your speakers and the IsoAcoustics as a comparison. That comparison video made is very easy to hear improvements on some songs. From what I remember, the improvements were mostly in the mid bass so with songs without mid bass I couldn't hear a difference, let alone an improvement. Still, the improvement in the mid bass was remarkable.

 

I know it's a bastard of a job with the weight of your amps, but I'd love to watch another comparison video with the Stacks under your equipment. 

[Pim]

On 16/6/2024 at 3:52 PM, almikel said:

 

Audio memory is very short (ie multiple seconds) - if you can't instantly switch between scenarios, you can't effectively evaluate the difference.

I don't understand how that myth of short term audio memory got into the conversation in this hobby but in my experience that's just a myth, nothing more.

 

I'm an immigrant and I don't speak with my friends and family from back home very often. Some of them I might speak with once a year or less. Every single time I instantly recognise their voices. If their spouse happens to answer, I recognise them too.

 

When I'm home, I listen to my stereo for hours almost every day. It has a voice. When I'm at my mate's place and listen to his stereo, I sit there thinking how I prefer some attributes of the voice of his system over mine and like mine in other ways over his. When I installed a bunch of power conditioning gear my mate was coming over to evaluate. A couple of hours before he came he sent me a message telling me he wanted to hear my system with and without the gear to hear the difference. When he sat down and listened with the gear installed for a few songs he told me it wasn't necessary to swap the gear out because the improvement was so obvious. He's my best mate and he knows my system well but he hadn't heard it for at least a few weeks. 

 

We are both Dutch. We're well known to tell it like it is without pulling punches. If he hadn't heard any difference or he thought it sounded worse, he would have told me. After all, I had it on loan and hadn't paid for it yet, nor was it actually in the planning to buy it. If he hadn't heard the improvement he would have told me not to bother spending all that cash.

 

As for isolation under gear. I have Devialet Expert amplification and due to some slight bends in my home made shelves I decided to get some isoAcoustics pucks, otherwise the amps would wobble. To my ears, there was no change in sound at all. Shane has very different amps to mine with very different power supplies that sit right next to his speakers. I can only imagine that his components will rattle loose over time. That would surely have a negative impact on the sound of his amps.

 

BTW, Shane, is your floor concrete or timber frame?

[sir sanders zingmore]

1 hour ago, Pim said:

I don't understand how that myth of short term audio memory got into the conversation in this hobby but in my experience that's just a myth, nothing more.

 

I'm an immigrant and I don't speak with my friends and family from back home very often. Some of them I might speak with once a year or less. Every single time I instantly recognise their voices. If their spouse happens to answer, I recognise them too.

 

I think most people misunderstand the intent of fast switching. It's recommend because it makes it easier to hear differences when those differences are very small. It's there to help. 

 

For large differences - like the sound of your friends' voices - you don't need fast switching because the differences are significant.

[almikel]

My point is that knowing a change was made will change your perception of what you hear (this is the cognitive bias I'm referring to).

 

There's good science on this.

If you happen to be an Audio Engineering Society member (I'm not) you can access Toole and Olive's paper titled "Hearing is Believing vs. Believing is Hearing: Blind vs. Sighted Listening Tests, and Other Interesting Things" here:

https://aes2.org/publications/elibrary-page/?id=6338

Unfortunately it's behind a paywall

 

There's a short summary from the paper on Olive's blog:

https://seanolive.blogspot.com/2009/04/dishonesty-of-sighted-audio-product.html

 

And there's a thread on AVS which includes some screenshots of the paper:

https://www.avsforum.com/threads/sighted-versus-blind-listening-tests-30-years-later.3277811/

 

Extracts of the paper are also in Toole's "Sound Reproduction - Loudspeakers and Rooms" - in my edition it's chapter 17.5 "Bias from Non-Auditory Sources".

 

Some nuggets:

From Olive's blog post:

" The psychological biases in the sighted tests were sufficiently strong that listeners were largely unresponsive to real changes in sound quality caused by acoustical interactions between the loudspeaker, its position in the room, and the program material. In other words, if you want to obtain an accurate and reliable measure of how the audio product truly sounds, the listening test must be done blind."

 

Also from Olive's blog post is a quote from Gordon Holt, the founder of Stereophile magazine:

“Audio as a hobby is dying, largely by its own hand. As far as the real world is concerned, high-end audio lost its credibility during the 1980s, when it flatly refused to submit to the kind of basic honesty controls (double-blind testing, for example) that had legitimized every other serious scientific endeavor since Pascal. [This refusal] is a source of endless derisive amusement among rational people and of perpetual embarrassment for me..”

(45th Anniversary edition of Stereophile Magazine - Interview of Gordon Holt conducted by John Atkinson)

 

From Toole's "Sound Reproduction - Loudspeakers and Rooms", 17.5 Bias from non-auditory factors:

"A widespread belief among audio professionals is that they are immune to the
influences of brand, price, appearance, and so on. They persist in conducting
listening evaluations with the contending products in full view. This applies
to persons in the recording industry, audio journalists/reviewers, and loudspeaker
engineers"...

..."In general, though, what listeners saw changed what (they thought) they heard."

 

My own testing that made me realise sighted testing could introduce cognitive bias includes a hardware change and numerous MP3 vs FLAC tests:

 

Years ago, I installed an Isotek power board - which is still in my system. 

I thought the difference was significant - tighter bass, better imaging.

A colleague called BS to the difference - so we did a blind test.

He swapped out the Isotek power board with the previous power board numerous times without me knowing which...

...when I first installed the Isotek, I could hear a clear improvement...

...when my colleague "maybe changed/maybe didn't" change the power board, the differences I'd heard previously weren't clear anymore, and I guessed correctly around 50% of the time

 

Most of my music is ripped from Redbook CD to FLAC.

I've done a bunch of tests comparing FLAC to MP3 conversions of the same FLAC file.

Volume matched with instant switching back and forth.

The person that has the remote control in their hand (me included) swears they can hear a "significant" difference between a 256K MP3 and the FLAC file (with of course the FLAC file sounding more detailed etc), but others in the room can't pick the difference.

Hand the remote to another person and it's the same...

...a recurring comment from the one that holds the remote is, "surely you can hear that difference?"

 

Mike

[frednork]

3 hours ago, almikel said:

My point is that knowing a change was made will change your perception of what you hear (this is the cognitive bias I'm referring to).

 

There's good science on this.

If you happen to be an Audio Engineering Society member (I'm not) you can access Toole and Olive's paper titled "Hearing is Believing vs. Believing is Hearing: Blind vs. Sighted Listening Tests, and Other Interesting Things" here:

https://aes2.org/publications/elibrary-page/?id=6338

Unfortunately it's behind a paywall

 

There's a short summary from the paper on Olive's blog:

https://seanolive.blogspot.com/2009/04/dishonesty-of-sighted-audio-product.html

 

And there's a thread on AVS which includes some screenshots of the paper:

https://www.avsforum.com/threads/sighted-versus-blind-listening-tests-30-years-later.3277811/

 

Extracts of the paper are also in Toole's "Sound Reproduction - Loudspeakers and Rooms" - in my edition it's chapter 17.5 "Bias from Non-Auditory Sources".

 

Some nuggets:

From Olive's blog post:

" The psychological biases in the sighted tests were sufficiently strong that listeners were largely unresponsive to real changes in sound quality caused by acoustical interactions between the loudspeaker, its position in the room, and the program material. In other words, if you want to obtain an accurate and reliable measure of how the audio product truly sounds, the listening test must be done blind."

 

Also from Olive's blog post is a quote from Gordon Holt, the founder of Stereophile magazine:

“Audio as a hobby is dying, largely by its own hand. As far as the real world is concerned, high-end audio lost its credibility during the 1980s, when it flatly refused to submit to the kind of basic honesty controls (double-blind testing, for example) that had legitimized every other serious scientific endeavor since Pascal. [This refusal] is a source of endless derisive amusement among rational people and of perpetual embarrassment for me..”

(45th Anniversary edition of Stereophile Magazine - Interview of Gordon Holt conducted by John Atkinson)

 

From Toole's "Sound Reproduction - Loudspeakers and Rooms", 17.5 Bias from non-auditory factors:

"A widespread belief among audio professionals is that they are immune to the
influences of brand, price, appearance, and so on. They persist in conducting
listening evaluations with the contending products in full view. This applies
to persons in the recording industry, audio journalists/reviewers, and loudspeaker
engineers"...

..."In general, though, what listeners saw changed what (they thought) they heard."

 

My own testing that made me realise sighted testing could introduce cognitive bias includes a hardware change and numerous MP3 vs FLAC tests:

 

Years ago, I installed an Isotek power board - which is still in my system. 

I thought the difference was significant - tighter bass, better imaging.

A colleague called BS to the difference - so we did a blind test.

He swapped out the Isotek power board with the previous power board numerous times without me knowing which...

...when I first installed the Isotek, I could hear a clear improvement...

...when my colleague "maybe changed/maybe didn't" change the power board, the differences I'd heard previously weren't clear anymore, and I guessed correctly around 50% of the time

 

Most of my music is ripped from Redbook CD to FLAC.

I've done a bunch of tests comparing FLAC to MP3 conversions of the same FLAC file.

Volume matched with instant switching back and forth.

The person that has the remote control in their hand (me included) swears they can hear a "significant" difference between a 256K MP3 and the FLAC file (with of course the FLAC file sounding more detailed etc), but others in the room can't pick the difference.

Hand the remote to another person and it's the same...

...a recurring comment from the one that holds the remote is, "surely you can hear that difference?"

 

Mike

Mike , I dont really disagree with much you say until you start talking about how your test shows something that should be taken any more notice of than sighted testing.  Indeed Toole and Olive know how to run a blind test. I have no issue with that. However your test only could convince you and anyone else who doesnt understand sensory testing. 

 

If you take a step back and consider your criticism of sighted testing (which is not entirely unjustified) we dont really know if the listener is able to hear a difference or is just cheating by using his eyes (despite any intent they may have not to do that). 

 

Similarly in your example we dont know if there is a difference, whether you are highly suggestible (which is why your sighted listening showed a difference, whether you are capable of hearing the difference, whether your system is capable of showing a difference, and of course whether you understand how to perform the test you are attempting to do which I would have to assume is a big no in this case.

 

I also dont understand why you would essentially just repeat your previous post with no improvement in the quality of information whatsoever and sadly compel me to reluctantly do the same. 

 

To add some extra value to this post I would say please do some real research on how these kind of tests are performed. It is possible to do them at home but you do need put a lot more effort in than you have done so thus far.

 

I would suggest reading this as a start. https://www.itu.int/dms_pubrec/itu-r/rec/bs/R-REC-BS.1116-3-201502-I!!PDF-E.pdf The methodology is not over the top for your situation as if you are finding it difficult to detect a difference then it is this type of approach that is required and similar to what Toole and Olive did. It is the suggested science on how to do a successful test of this kind  where detection is not easy.  

[Guest]

Good morning all. Interesting thread. There were a number of posts being reported late last night and given the time of the evening and that no mods would be around, I placed the thread on Post Approval. Some of those posts overnight will not be approved.

 

As I see, it two things are being discussed here, and it would be nice to allow the thread to continue.

 

To summarise where are are at, from what I can tell:

 

1. A trial of Stack Audio products generously organised by @parrasaw at no cost or obligation for StereoNET members to experience for themselves, and for what I assume is for no personal benefit to himself. Get involved in that, or don't - again, there's no obligation.
2. @parrasaw strongly refers to @AN AUSSIE AUDIOPHILE's findings and encourages people to read/view that content.
3. The testing parameters and/or claims have been questioned of said content and the processes are now being discussed. I don't see why that cannot continue in a civil and respectful manner, particularly if @AN AUSSIE AUDIOPHILE is willing to engage in that discussion, while it is respectful. I wouldn't blame him for bowing out if that does not happen.
4. I would like to remind all of the Website Guidelines that we all agree to abide by and would like to highlight one point as a reminder for people contributing to the discussion:

• Respect other viewpoints, and avoid circular and repetitive arguments.
  Discussion, by its very nature, consists of varying viewpoints. It's OK to disagree, but be constructive with your arguments. 
• Know when to move on and ensure your participation is for enjoyment.
  Avoid repeating the same arguments, no matter how valid you might think your point is - it is divisive and will attract potential sanctions. Disengage and move on.

 

It would be beneficial to read all the points in the General Guidelines, however.

 

We do not like closing any discussion here on StereoNET, but once a thread has ran it's natural life, and/or we have exhausted the tools we have available to us for moderation we are generally left no choice. 

[AN AUSSIE AUDIOPHILE]

On 27/06/2024 at 8:04 PM, Pim said:

I don't understand how that myth of short term audio memory got into the conversation in this hobby but in my experience that's just a myth, nothing more.

 

I'm an immigrant and I don't speak with my friends and family from back home very often. Some of them I might speak with once a year or less. Every single time I instantly recognise their voices. If their spouse happens to answer, I recognise them too.

 

When I'm home, I listen to my stereo for hours almost every day. It has a voice. When I'm at my mate's place and listen to his stereo, I sit there thinking how I prefer some attributes of the voice of his system over mine and like mine in other ways over his. When I installed a bunch of power conditioning gear my mate was coming over to evaluate. A couple of hours before he came he sent me a message telling me he wanted to hear my system with and without the gear to hear the difference. When he sat down and listened with the gear installed for a few songs he told me it wasn't necessary to swap the gear out because the improvement was so obvious. He's my best mate and he knows my system well but he hadn't heard it for at least a few weeks. 

 

We are both Dutch. We're well known to tell it like it is without pulling punches. If he hadn't heard any difference or he thought it sounded worse, he would have told me. After all, I had it on loan and hadn't paid for it yet, nor was it actually in the planning to buy it. If he hadn't heard the improvement he would have told me not to bother spending all that cash.

 

As for isolation under gear. I have Devialet Expert amplification and due to some slight bends in my home made shelves I decided to get some isoAcoustics pucks, otherwise the amps would wobble. To my ears, there was no change in sound at all. Shane has very different amps to mine with very different power supplies that sit right next to his speakers. I can only imagine that his components will rattle loose over time. That would surely have a negative impact on the sound of his amps.

 

BTW, Shane, is your floor concrete or timber frame?

Hi there I agree with all of the above hence why I've given it a thumbs up. And to answer your question my floor's are suspended hardwood timber.

[MTL]

How many of us have drawers full of products that were great at first blush? 
These do seem well reviewed however, but will they still provide smiles in 6 months.

Who knows?