isoacoustics isolators

[John Phillips]

Only one microphone required even an inexpensive USB model will be more than adequate, two measurements at the same output level without moving the microphone position, REW software, if the floor is audibly resonating it can be measured.

I don't think so.

The BBC research from circa 1977 on audible levels of cabinet resonance had audible thresholds between -20 dB and -30 dB compared to the excitation.

Even if you assume the same for the floor without any proof, and assume that this is additional energy rather than substitution of cabinet resonance for floor resonance, you would have to repeatably detect differences in the range 0.3 dB to 0.8 dB. That's a very tall order from using REW in an uncontrolled home environment. IMHO impossible. The likely error bars look to me to be much higher than that, so drawing conclusions from differences at that level would be highly unreliable at best.

And the floor is a bigger radiating surface so the BBC's audible levels may be much lower from the floor.

And then if there's no more audio energy in total (rather likely) then the floor resonance is substituting for cabinet resonance rather than adding to it. So interpreting a difference is not going to address "the null hypothesis" of the experiment.

The design of this experiment does not seem to me to be good enough to reliably show what is intended (EDIT: unless the magnitude of the effect is rather large).

 

[Purité Audio]

You have to distinguish between cabinet resonance, which should be controlled by the designer of the loudspeaker, and the structural transmission of that vibration of a magnitude capable of creating audible resonance in the floor.
A few years ago an engineer from Spiers&Robertson measured the transmission of vibration into the floor here with a three plane accelerometer, speakers were huge horns with 2x12” bass drivers, playing bass heavy music loudly, there was surprisingly little transmission.
Keith

 

[Sue Pertwee-Tyr]

You have to distinguish between cabinet resonance, which should be controlled by the designer of the loudspeaker, and the structural transmission of that vibration of a magnitude capable of creating audible resonance in the floor.
A few years ago an engineer from Spiers&Robertson measured the transmission of vibration into the floor here with a three plane accelerometer, speakers were huge horns with 2x12” bass drivers, playing bass heavy music loudly, there was surprisingly little transmission.
Keith

Which tells us nothing. What sort of floor? How were the speakers coupled to the floor?

For starters.

 

[Purité Audio]

Engineered suspended flooring, directly coupled loudspeakers,
Keith

 

[Sue Pertwee-Tyr]

How ‘engineered’? Different to regular domestic joists and boards? Carpet? Rugs?

 

[Rug Doc]

On a suspended floor with hollow space underneath I can totally see the need for GAIAs, but on a solid ground floor concrete floor with a bitumen laid parquet floor over surely spikes would be better to connect to directly to the floor? Anyone with experience of using both most appreciated.

Heavy 63kg Impulse speakers currently on Superspikes.

 

[albany]

I used GAIA under my 57kg speakers on a concrete/parquet solid floor. I did not like that they took some of the life out of the music, mostly classical. I sold them on and now use castors so I can move the heavy speakers easily.
Life restored to the music and the castors remain.

 

[ToTo Man]

Heavy 63kg Impulse speakers currently on Superspikes.

No longer have Yamaha NS's?

 

[Rug Doc]

No longer have Yamaha NS's?

Yes have those as well as the Impulse. Both have their strengths, but atm the Ta’us are winning for realism and delivery.

 

[Amber Audio]

On a suspended floor with hollow space underneath I can totally see the need for GAIAs, but on a solid ground floor concrete floor with a bitumen laid parquet floor over surely spikes would be better to connect to directly to the floor? Anyone with experience of using both most appreciated.

Heavy 63kg Impulse speakers currently on Superspikes.

Not using GAIA, but my Logans sound quite a bit better on Townshends than they did on their supplied feet/spikes.

Solid cement floor with Karndean.

​

 

[Patu]

Only one microphone required even an inexpensive USB model will be more than adequate, two measurements at the same output level without moving the microphone position, REW software, if the floor is audibly resonating it can be measured.
Keith

The difference is easily measurable. Please check this article by Bob Katz:

https://www.stereophile.com/content/bob-katz-loudspeaker-isolation

Katz also reports, without providing details, that "some critical listeners have observed" a "subtle increase in clarity . . . when a loudspeaker is isolated from its supporting surface." Katz concludes that "In the main, isolators placed under floor-standing loudspeakers over a wood floor produce a measurable and often strong improvement in performance." The exceptions, he writes, "seem to be related to the unique and non-symmetrical shell construction in this room."

 

[Rug Doc]

Not using GAIA, but my Logans sound quite a bit better on Townshends than they did on their supplied feet/spikes.

Solid cement floor with Karndean.

​

interesting. I wish that there was a set of Gaia1s available for trial.. I’d pay the money if they made a difference, but don’t want to get into a situation where they make zero difference but are non-returnable because the threads are non virgin.

 

[Amber Audio]

I went with the podiums cos I’ve heard them in action, read many positive comments and not seen an owner post they have gone over to GAIA, I have seen a couple of posts where someone has gone from GAIA to podiums. They also look more of a hassle to fit under heavy speakers on your own, manoeuvring the MLs onto the podiums myself was remarkably easy.

 

[John Phillips]

The difference is easily measurable. Please check this article by Bob Katz:

https://www.stereophile.com/content/bob-katz-loudspeaker-isolation

Katz also reports, without providing details, that "some critical listeners have observed" a "subtle increase in clarity . . . when a loudspeaker is isolated from its supporting surface." Katz concludes that "In the main, isolators placed under floor-standing loudspeakers over a wood floor produce a measurable and often strong improvement in performance." The exceptions, he writes, "seem to be related to the unique and non-symmetrical shell construction in this room."

That's very interesting. His "up to a dB in distortion in some ranges; up to a dB in frequency response" in his studio is about what I expect to be audible from reading the BBC research. But from my experience of using REW it's still not likely to be something a home measurement will reliably reveal.

However I hadn't thought about his reverberation time and low-level waterfall differences, and I haven't used REW enough for these tests to understand their repeatability.

 

[Patu]

On a suspended floor with hollow space underneath I can totally see the need for GAIAs, but on a solid ground floor concrete floor with a bitumen laid parquet floor over surely spikes would be better to connect to directly to the floor? Anyone with experience of using both most appreciated.

Heavy 63kg Impulse speakers currently on Superspikes.

I use GAIA's on regular apartment building living room under ATC SCM40A. All surfaces are solid concrete and there's parquet floor on top of it. Under the parquet there's usually a layer of "insulation" or some kind of absorber which makes foot steps less audible to people living in the apartment(s) below.

Anyway the difference was very clear in my setup. In the end I had to completely readjust my Linn Space Optimisation to fit the new sound profile after adding the GAIA's. I'm currently waiting for my new speakers to arrive and I was planning to compare spikes + spike feet against GAIAs again with them. After installing, it's just pain in the ass to remove them.

 

[Heckyman]

interesting. I wish that there was a set of Gaia1s available for trial.. I’d pay the money if they made a difference, but don’t want to get into a situation where they make zero difference but are non-returnable because the threads are non virgin.

The difference should be easy to hear. What's more difficult to say is if it's an improvement or not, or whether Townshends would be better.

 

[hifinutt]

Yes have those as well as the Impulse. Both have their strengths, but atm the Ta’us are winning for realism and delivery.

fab , I use track audio under taus

I went with the podiums cos I’ve heard them in action, read many positive comments and not seen an owner post they have gone over to GAIA, I have seen a couple of posts where someone has gone from GAIA to podiums. They also look more of a hassle to fit under heavy speakers on your own, manoeuvring the MLs onto the podiums myself was remarkably easy.

had specially designed townshend Stella under my summits and made a huge difference with tighter bass

 

[Amber Audio]

fab , I use track audio under taus

had specially designed townshend Stella under my summits and made a huge difference with tighter bass

They aren’t cheap but make a significant difference and are worth it, dealing direct with Townsend does get you a very good discount.

 

[hifinutt]

Yes mine came from a well known audiophile who had them in a flat and the big hole in them fired sound through the floor so he got rid of them ( they were specially made for summit x)

 

[Purité Audio]

The difference is easily measurable. Please check this article by Bob Katz:

https://www.stereophile.com/content/bob-katz-loudspeaker-isolation

Katz also reports, without providing details, that "some critical listeners have observed" a "subtle increase in clarity . . . when a loudspeaker is isolated from its supporting surface." Katz concludes that "In the main, isolators placed under floor-standing loudspeakers over a wood floor produce a measurable and often strong improvement in performance." The exceptions, he writes, "seem to be related to the unique and non-symmetrical shell construction in this room."

Thanks for that link Patu, I have read the original AES paper that Katz submitted, he used a compressed fibre glass ‘isolator’ didn’t experiment with other more effective types, visco-elastic, rolling air diaphragm or spring/gasket.
Check out the paper for yourself but there is very little difference directly coupling or using the fibre islolators, a quote from the paper on the REW amplitude responses.
Quote,

‘In the amplitude measurements of the left and right speakers (Fig 11, 12), for the most part, isolators and wood blocks perform identically, with some small exceptions and no clear indication which performs better overall.’

Keith