Sonus faber Cremona Auditor and Jeff Rowland??

Dear Brain74: About the best placement of your Auditor my advise is that you ask directly to Sumiko people, they can help you.

Now, you feel that have a bass booming sound, other than room placement, please analyse as follows: the Auditor is a medium efficiency speaker ( 88db ), it has a 4 Ohm nominal impedance ( low one ) that tell us that maybe it go down to near 2 Ohms in some frecuencies ( maybe in the bass ones ), its usuable bass frecuency is around 50 Hz.

All these specs tell us that the Auditors need a high current amplifier with very low output impedance that can put high current below 4 Ohms: your Concentra 1 can't do it, your Auditors needs a better match amplifier, maybe the Concentra 2 or other Rowland model. Again, ask to the Sumiko people: they have to help you.
Btw, don't wait to much in the low bass: 50 Hz are " only " 50 Hz, nothing more.

Regards and enjoy the music.
Raul.

I second Raul, above. I have enjoyed auditioning Mahler & blues on SF (Amati, Cremona & Strad) -- using hi-current design amps.
Unfortunately, I only listened to these speakers paired with European amps (i.e. expensive), and therefore can only recommend YBA Passion, Goldmund (the mid-level stereo, can't remember the number), and Symphonic Line RG4. The latter made the nicest music to my taste (I auditioned with Mahler & blues, cd source).
Again, this isn;t to say the Rowland is bad in any way...

I have been using the SF Auditors with the JRDG new Concerto int. amp. with great results. Placement is tricky however. I find even after months of use I still cannot find the optimal placement.

i have heard the Pass Labs X250.5 with great results too. No Bass Boom. just music!

Minimum Auditors impendance is around 3.1ohms( they were measured by german Stereoplay mag ) and any good amp should be able to drive it. I second Scottsman and Pingpong, both new Jeff Rowland Concerto Int. and Pass X250.5 are very good choices. Pass X150.5 also, specially with X2.5 preamp. If you like tubes ARC VT100MkIII/LS25MkII combo will also work nicelly. Interesting thing is that the most emotional sound I heard from Auditor was with Pathos Logos. Original stands for Auditor are very important to get the best sound out of them. They sounded horrible to me on non-original, too tall stands.