Well I guess the consensus is NO regarding silver. Thanks you all for saving me some cash on this.
Regarding Bill's comments on definition. I guess the aim of this sub build was to have the good attributes of my two other subs. One being a DIY 5 cu/ft sealed Tempest I built 7 years ago and a smaller factory built Rythmik Audio sub I also have.
The Rythmik has a hard time below 20hz and can't play super loud like my Tempest but it does have what I call definition or maybe the term would be pitch where when a kick drum hits it is more like a knock (both subs are low passed at 40hz).
Can anyone explain what contributes to this. Is it the QTS of the driver, the fact it is a servo sub, maybe the smaller size of the Ryhmik enclosure,or...?