I have recently (yesterday in fact) experimented with the suspension on my deck and feel it may be of interest to others to may be designing or building their own deck.
Perhaps I should describe my deck a little to aid my explanation of my trial. The main plinth consists of a 30mm slab of MDF which is machined to accommodate the stand which is bolted to it. Effectively the lower plinth and stand are one item. The stand is mass loaded and is spiked to the floor. The motor housing is attached to this lower plinth. A second (sub) plinth exists above the main plinth and the two are decoupled by four springs. A Nomex and carbon fibre laminated sub-chassis sits atop the sub plinth.
When I originally built this deck many years ago it did not have the sprung suspension element. Some years later I reengineered the plinth to incorporate the sprung element. This is at quite a low frequency and is also quite heavily damped.
I had been wondering if the relative lack of rigidity between the motor and the belt driven platter may be causing timing issues (though this is relative as timing is one of the decks strong points) and, given the current popularity for non-suspended designs, I wondered if it would sound better without the sprung element of the suspension (a later more rigid element of further suspension already exists between the sub-chassis and the sub-plinth). I therefore decided to short circuit the sprung element. This is very easy to do on my deck as I simply placed 4 (I also tried 3) small squares of thin Sorbothane sheet (I just happen to have some) between the upper and lower plinths. This effectively bypassed the springs and the plinth no longer bounced; time for a listen.
I played a couple of tracks and the sound was good but not obviously better and timing seemed to be no better or worse. I tried 3 squares of Sorbothane - no different. I then tried 2 squares of Sorbothane so the chassis was able to rock across the axis between the two support squares, but still be held by the springs, - no different. I experimented with changing the axis of 'rock' - no difference. I took the Sorbothane squares out and allowed the sub plinth to bounce freely again - I was genuinely surprised to find that this made a huge improvement with significantly more 'air' around instruments, much greater range of instrument placement, greater ambience retrieval and a generally more real and believable presentation. As a result I, obviously, intend to keep the sprung suspension and intend to pursue the design of a magnetic suspension which may (or may not) improve on what I have.
Perhaps I should describe my deck a little to aid my explanation of my trial. The main plinth consists of a 30mm slab of MDF which is machined to accommodate the stand which is bolted to it. Effectively the lower plinth and stand are one item. The stand is mass loaded and is spiked to the floor. The motor housing is attached to this lower plinth. A second (sub) plinth exists above the main plinth and the two are decoupled by four springs. A Nomex and carbon fibre laminated sub-chassis sits atop the sub plinth.
When I originally built this deck many years ago it did not have the sprung suspension element. Some years later I reengineered the plinth to incorporate the sprung element. This is at quite a low frequency and is also quite heavily damped.
I had been wondering if the relative lack of rigidity between the motor and the belt driven platter may be causing timing issues (though this is relative as timing is one of the decks strong points) and, given the current popularity for non-suspended designs, I wondered if it would sound better without the sprung element of the suspension (a later more rigid element of further suspension already exists between the sub-chassis and the sub-plinth). I therefore decided to short circuit the sprung element. This is very easy to do on my deck as I simply placed 4 (I also tried 3) small squares of thin Sorbothane sheet (I just happen to have some) between the upper and lower plinths. This effectively bypassed the springs and the plinth no longer bounced; time for a listen.
I played a couple of tracks and the sound was good but not obviously better and timing seemed to be no better or worse. I tried 3 squares of Sorbothane - no different. I then tried 2 squares of Sorbothane so the chassis was able to rock across the axis between the two support squares, but still be held by the springs, - no different. I experimented with changing the axis of 'rock' - no difference. I took the Sorbothane squares out and allowed the sub plinth to bounce freely again - I was genuinely surprised to find that this made a huge improvement with significantly more 'air' around instruments, much greater range of instrument placement, greater ambience retrieval and a generally more real and believable presentation. As a result I, obviously, intend to keep the sprung suspension and intend to pursue the design of a magnetic suspension which may (or may not) improve on what I have.