Sonus faber Cremona Auditor and Jeff Rowland??

I wouldn't rule out the possibility of the Rowland and the SF being a mismatch, both are reported to be on the laid back side of the spectrum.

I am quite fond of the Concentra II, having owned one; here is what Rich Maez (of JRDG) responded to me when I asked about the Concentra and the Concentra II:

The CN I and CN II differ completely by power supply. The CN II has a much more powerful (50% more power) supply and therefore has much better control and power into low frequencies. It also has a separate front end supply that allows the unit to dedicate more power to large transients and make the CN II much more dynamic. High frequency distortion was reduced quite a bit with the second generation unit as well, so it has a much more open and extended high frequency response.

That said, it will cost you nothing to give your current setup more time, so I would suggest you do that first; it could take several months for them to settle in.

>I placed my auditor more than 3.5 ft away from the wall and 4ft from the side wall.

Conventional wisdom seems to be that these two distances should not be as similar as you have them (3.5 and 4 feet). Try moving the speakers around.

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.