I use the 3 Ultras under my Raven one and found a marginal improvement over the Stillpoints with Risers.
On a different tack, I just got 2 sets of 4 Track Audio Isolation feet, to replace the Edensound Brass feet under my Daedalus DA-RMa speakers. They made more difference than any footer I have ever used before, deeper tighter base, better imaging. Like the Ultras, they are not cheap, but I highly recommend them for speakers. They are from the UK, but available in the US, through music direct I believe.
On a different tack, I just got 2 sets of 4 Track Audio Isolation feet, to replace the Edensound Brass feet under my Daedalus DA-RMa speakers. They made more difference than any footer I have ever used before, deeper tighter base, better imaging. Like the Ultras, they are not cheap, but I highly recommend them for speakers. They are from the UK, but available in the US, through music direct I believe.