Good video on isolation feet vs spikes under a speaker, with measurements.
RMAF 2018 and isolation demo | PS Audio
RMAF 2018 and isolation demo | PS Audio
Woah. How could anyone properly compare any possible audible difference due to mechanical isolation with the difference in speaker heights colouring the results?
It isn't your listening height I am concerned about. The concern is the change in distance of the drivers relative to room boundaries in the video demo.
Assuming the room is symmetrical, there shouldn't be any major issue with the speakers placement relative to the walls since they have used a staggered arrangement - for each configuration one speaker is in the inner position and one is in the outer. As long as the audio track used doesn't have a left or right bias, and the listener sits perfectly centred (which would make them horizontally off-axis to the stereo centre - another issue), they should sound the same just with room effects mirrored. What they haven't controlled well as rscamp has pointed out is that the height of the speaker has changed. This will cause an audible change.
In the video I do hear an increase in volume somewhere around 1-5kHz when the speakers with the aftermarket feet are used. I suspect this is entirely down to the difference in height since the camera/mic is relatively close there is a significant difference in angle between the mic and tweeter/mid for each feet configuration. The camera appears vertically more off axis to the speakers with the standard feet. That speaker crossed from the mid to tweeter at 2.7kHz, so perhaps it is no surprise to hear a significant change around there when the height of the speaker is altered.
The measurements show that the most significant cabinet vibrations are in the upper bass and lower midrange (200-600Hz). I don't hear any significant change at those frequencies.
In the video I do hear an increase in volume somewhere around 1-5kHz when the speakers with the aftermarket feet are used. I suspect this is entirely down to the difference in height since the camera/mic is relatively close there is a significant difference in angle between the mic and tweeter/mid for each feet configuration. The camera appears vertically more off axis to the speakers with the standard feet. That speaker crossed from the mid to tweeter at 2.7kHz, so perhaps it is no surprise to hear a significant change around there when the height of the speaker is altered.
The measurements show that the most significant cabinet vibrations are in the upper bass and lower midrange (200-600Hz). I don't hear any significant change at those frequencies.
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Just found this page that shows tests where the height was controlled to 1/4". Measured data is included. Looks good.
IsoAcoustics Technology | IsoAcoustics
IsoAcoustics Technology | IsoAcoustics
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