Rogue Audio Sphynx and Martin Logan Odysseys

I was awe struck by this amp when I auditioned it 2 weeks ago and bought it while at was at the dealer's shop. I hooked it up at home to Martin Logan Odysseys and was completely satisfied except for a somewhat muddy sounding bass when listening to low passages of Michael Hedges' guitar music and other similar music. I was told by someone quite knowledgeable that the best way to tighten up the bass is to bi-amp using at least 200watt amplifiers. The preamp of this integrated unit is one of the best I've owned and I don't want to change the amp but it does not have pre out capability. It may be time to change speakers, and I would like to trade them anyway, unless there is another approach that will get me where i want to be without losing this wonerful amp. Any suggestions will be appreciated.
Rogue's website shows the Sphinx with a variable output, and states it is for subwoofer or biamping. Just add a Medusa power amp @ 200 WPC.
I am a speakers-first kind of fella. Settle on speakers, and then look for the best amp pairing for those specific speakers.

It also occurs to me that you may want to let the Sphinx settle in a bit, and see if the bass tightens up.

I am also a bit surprised you are hearing muddy bass. Those Class D amp modules have pretty high damping factors which tend to do a pretty good job controlling the bass.

What were your dealer's thoughts on the match of the Sphinx and the Martin Logans?
Thanks for your responses and I guess I exposed my ignorance of both biamping in general and the capability of my own amp. I'm in the process of learning terms such as active, passive, horizontal, vertical, etc., and I think what I needed to ask has to do with using pre outs from the Sphinx to a more powerful stereo amp supplying the speakers. I'm not totally convinced that my bass needs more damping or even if simply adding more power would accomplish this. I spoke with a Martin Logan tech who didn't disagree with the logic of this proposed solution, but my very expert audiophile Rogue dealer believes that the Sphinx should keep the bass pretty "tight" by itself. I'm just starting my learning curve and have a relatively limited budget as regards equipment purchases so any and all advice will be appreciated.
I would not assume that the bass issues you are experiencing are necessarily due to not having enough power. There is much more to amplification and speaker-amp interactions than power.

You bought your amp at a dealer. So have you inquired with this dealer about this issue? Dealer support is one of the main advantages of buying from a dealer as opposed to used from a private seller here or elsewhere.
There is no doubt that opinions about damping factor will vary. In the past, I did believe that a very high damping factor would be beneficial to control the bass, however, now I think these high specifications will have very little, if anything, of an effect on the bass for most systems. Take a look at this link,

I agree that you can’t assume the amp is the problem, but you can’t rule it out based on damping factor. Trying a different amp may be the only way to determine if the Sphinx is a good match for your speakers. Will your dealer let you try one of his demo units? Also, what is the rest of your system, source, cables, etc.?
Yes, damping factor is one potential consideration among many others. Though I have had instances where damping factor was clearly the problem in the bass of the speakers I was running (over-damping the bass in my case, though under-damping may be a more common problem in more conventional set-ups).

My main point is that it is important not to leap to the conclusion that more power will solve this problem. There are a number of potential contributors to this problem you describe.

Sent from my iPad

I appreciate these responses mostly because of your sharing knowledge but partly because it confirms the fact that it wasn't just my limited experience keeping me from making what I thought was going to be a simple and straightforward fix. It might help if, as suggested, I provide some detail describing my equipment and listening area.

My listening area is my living room which restricts my latitude in several ways including the inability to use spikes on our wooden floors, placement of speakers relative to furniture, etc. I have done some experimenting with placement using the Jim Powers flashlight method of adjusting toe in of curved ESLs, and moving them further away from the front wall (this actually seemed to help a little). My equipment is not top shelf audiophile grade but I think it is pretty good relative to what I've heard described as more common consumer based products. This is what I have:

1. Martin Logan Odysseys which I've had for around 13 years, with the original panels. They still perform beautifully at least in the mid to high frequency range.

2. Rogue Audio Sphinx hybrid amplifier (100 wpc) which I've had for 2 weeks.

3. Shanling solid state CD player which I've been very happy with.

4. Sony multi-disk " jukebox" with a California Audio Labs DAC. Before installing the DAC listening from this source was not good at all, but convenient.

All of my equipment was purchased used except for the amplifier and I have used other amps with more power with these speakers including Yamaha and Pioneer surround receivers, and Arcam, and McCormack amps. I'm not a bass loving listener and my previous appreciation of bass was based on how low and loud it was, especially when I was setup for surround sound movie listening. I've now become more aware of bass in terms of how well it represents musical instruments. The example that I've heard expressed in regard to bass tightness or damping is the reproduction of "kick" drums.

When I auditioned the amp, the dealer was using a very high end tube based Shanling CD player and a $3300 pair of bookshelf sized speakers and the sound was the best I've ever heard on any combination of components. That's when I became aware of bass tightness and the fact that this amp was capable of controlling bass, at least with these smaller and lighter speakers. I don't expect to duplicate what I heard there and I'm almost sorry I heard it, but I do want to improve bass control because I'm otherwise very satisfied with my setup as it is. If I don't have to add addition power but, if I have to, I will.

I hope I haven't stepped over the line in terms of thread length but hope this detail will help with a solution.
Jimbreit, thanks for sharing the additional info for your system setup. One problem you have is not using the spikes on the speakers. Using the spikes will definitely tighten the bass. Read the section, “Solid Footing” in your speakers manual here,

Also, this would solve the problem with your wooden floors,
What are your dealer's thoughts on this? And have your contacted Rogue to get their impressions? As much as I like A'gon, I'd start with those first.

Rogue has always been particularly helpful when I have had questions or problems.
In all my years of audio interest I've never used spikes so I have a drawer full of them. I guess I just didn't understand, and am still a little fuzzy, how this seemingly simple application could accomplish much. Anyway, I appreciate your knowledge and experience so will continue to try understanding the rationale. I'm trying not to sound hard headed about spikes and I do like the idea of using "pucks" of some sort under the spikes but wonder what would be accomplished by moving the interface between the speaker and floor to between the puck and the floor. As a matter of fact, it creates 4 extra points of contact using this method. BTW, I do have the owners manual but didn't, obviously, heed ML's instructions. I'm going to try soft feet because I do believe that it will result in more solid contact than the flat floor to flat speaker box, because neither are truly flat.

BTW, both Rogue Audio and my dealer agree that this amp with a damping factor of 1000, should easily keep the bass tight, everything else being equal.
You have spikes and choose not to try them? As for an uneven floor, spikes can be adjusted (how far in you screw them) so the unevenness can be corrected for.

Spikes are the recommendation of your speaker manufacturer. Take em out of the drawer and try 'em. Doesn't cost you a thing.
If I decide to use spikes it won't be until after everything else is tried and adjusted and, even then, it will not be directly into/onto the floor. I had spikes on a Vandersteen sub a few years ago and it did cause damage when I tried moving moving it to accommodate new furniture. I'm 71 years old and have some significant difficulty lifting these things straight up to minimize damage to the floor so some compromise is necessary. After all, my whole listening area is already a compromise. Btw, I'm starting a new thread because I just discovered that one of my speakers needs a new transducer I think. Talk about a pain in the neck.
This is jimbreit but I had to do some changes to my ID and password to gain access again to the forum. Anyway, it looks like I'll logging is as "broadstone" which was my iD in 2005.
I reconsidered my decision about the spikes and realize that I have been ignoring an important part of setting up. This morning I grabbed a speaker at its top and moved it back and forth and am amazed at how easily they rocked and how pronounced the movement is. That HAS to be a problem. I am going to try soft feet first and make them adjustable to compensate for any floor irregularities. I know it's probably not the best way to go about this but these are new floors and I don't want to do to this one what I got in trouble for with the old floor. BTW, we didn't replace the floors because of the spike damage; we had a minor flood in another part of the house which required replacing flooring in 3 rooms.