I always used to go for spiked feet into carpet for floor standing speakers and spikes top and bottom of the stands for stand mount speakers. I mean, that’s the first thing you do to improve your Hi-Fi. The speaker manufacturers supply spikes and the aftermarket suppliers supply them. It must be right? Stop the speaker cabinet moving, allow the drivers to do their job, improve imaging.
Indeed, imaging improves and bass extension gets better, however, at realistic levels (90+dB), a wide bandwidth speaker with spiked feet starts driving the floor. Walk around barefoot whilst playing music with bass and percussion, you will feel it through your feet.
I realised it was happening when certain bass notes in my listening room (with a suspended timber floor) were significantly louder than others and that low frequency decay was excessive – Percussion was not as tight as through headphones. The room itself had fairly extensive bass trapping and diffusion – the problem was that the floor was being driven by the loudspeakers.
The perceived wisdom is to mass-damp the system by putting the spiked footed, floor standing speakers on top of heavy, inert blocks e.g. paving slabs, granite blocks etc. This improved the situation but still there were problem frequencies and the decay time was still too high.
I realised that the suspended floor was acting like a soundboard with the speakers driving it. The cavity under the floor didn’t help.
Adding mass under the speaker had reduced the problems but ultimately, hadn’t worked (I had an 80kg granite block under each speaker). I needed to stop the floor resonating. The answer – replace the floor with a solid concrete floor!
So, 6 months and 10 tonnes of concrete later with new decorations and fitted carpet, the room treatment and Hi-Fi was setup back in the room. The spike footed speakers this time directly onto the carpet. After listening for some time, with a wide range of music, there was a marked improvement compared to the old room setup, however… at certain frequencies the floor was still being driven by the speakers and there was still decay time issues – nowhere as bad as with the wooden suspended floor, but still noticeable and annoying.
After fairly extensive research, I realised that as long as the speakers had spiked feet the speakers would continue to push energy into the floor and cause the floor to resonate at certain frequencies. The solution was remove the spiked feet and replace them with some form of controlled isolation. This had to achieve both the isolation of the vibrations from the speaker to the floor AND maintain the position of the speaker so that imaging and dynamics are retained.
I eventually went for Track Audio speaker stands (
www.trackaudio.co.uk). Not cheap, nor silly money, and beautifully engineered. The local Hi-Fi store got me a pair to audition. Amazing. All the floor issues were gone. Imaging, outstanding. Percussion now has no overhang. The speakers and room now disappear and there is now just music. From small simple productions to huge works, I am now listening to the music, not the room or the equipment – bliss.
Needless to say, the local Hi-Fi store only got the audition stands back when they delivered my own pair
Equipment:
TAD D1000 Cd/SACD/DAC
Bryston BDP-2
Bryston BP26
Bryston 4BSST²
PMC PB1 signature
Analysis-Plus cables
Track Audio speaker stands
GiK Acoustics room treatment
