Bi-wire implementation of Luxman 590AXii and Luxman M10X

Experts.  I currently have a L590AXii powering Sonus Faber Sonetto 5s.  I like the SF sound and intend staying with this brand and moving up the line.  My concern is that the L590AXii, while being a very nice class A integrated, does not have enough power to bring out the best of the SF speakers.  SF speakers have a impedance rating of 4 ohms and rated sensitivity of 90db, and the manual suggests amp power output of 50-300 watts per channel.  The L590AXii has a rated power output of 30 Class A watts per channel into 8 ohms and 60 Class A watts per channel into 4 ohms.  Beyond Class A, the L590AXii is said to produce higher power in A/B output mode.  But it still seems to be on the lower side for SF speakers.   My system sounds good but I'm looking to optimize and improve the sound.  On other Audiogon discussions it has been suggested that SF speakers do best with more power.

So consequently I have ordered a Luxman M10X- yay!!.  The question is how best to implement the preamp/control function.

Option 1.  I could get a separate preamp/control amp (e.g. Luxman C900u) to drive the M10X.  This option requires me to buy another unit and sell my L590axii. or ...

Option 2.  use my L590 AXii as the preamp/control amp using the pre-outs provided.  

Option 3. (Suggested by the audio shop salesperson), is to bi-wire the L590AXii and M10X amps.  The idea is to run the higher frequencies with the L590AXii and run the low frequencies with the M10X.  He says this will give me the best of both worlds:  Big power where it is needed for the base, and sweet class A sound in the higher frequencies.  He indicated that, in this configuration, the L590AXii pre-out would be connected to the M10X input so that the L590AXii volume knob will control both amps.  He said this setup introduces a bit of distortion but that didn't seem concerned about that.

So what do you think about these three options?  Is Option 3 viable?   

Obviously, I can try options 2 and 3 with what I have, whereas option 1 requires another sizeable investment.

I appreciate your thoughts and advice.


My experience with the 509ux is that the preamp section is absolutely superb, and a real challenger to the separate preamp. Your third option is, in my mind, the best.

erik_squires. Just to make sure I understand you, you are saying that using the 590axii as the pre-amp is the best option.  That was my option 2. But then you say option 3 is the best, which is the fancy option of using the 590 as both preamp and amp for highs and using M10x as amp for lows.  Please clarify, is it option 2 or 3 that you recommend?  Thanks!

Hey OP,

I was saying the preamp section is very very good, so using it to bi-amp your speakers sounds like a really good idea to me, since you already have a separate amp on order.



thanks.  if I can ask you a follow up question:  the upper speaker posts of the SF speakers are labeled "mid-hi" and the lower speaker posts are labeled "low". 


So when bi-amping, does this mean one amp feeds the tweeter and mid speaker drivers and one amp feeds the woofer(s) or...


does it mean one amp feeds the upper frequencies as governed by the cross-over electronics to all drivers and the other amp feeds the lower frequencies as governed by the cross-over to all drivers? 


I guess i don't understand how the cross-over is working when bi-amping.  Is it bypassed?  Any light you or other can shed is appreciated.

Hi OP,

With most multi-way speaker designs and their crossovers each driver and it’s filters are wired in parallel to the input. So in the simplest case case, with a tweeter and woofer, the tweeter would be in series with a capacitor and the woofer with a coil.

When you remove the straps on the speaker terminals the filter components (cap and coil) remain in place.

Using two stereo amplifiers this is actually technically not bi-wiring but "passive bi-amping."

Each amp section must reproduce 100% of the voltage that was needed before, but only the current for their component, and that does have the effect of making the smaller amp perform more stiffly and with less sag on the amp rails.

With the Luxman integrateds you can also do something cool. You can put a capacitor between the pre and amplifier sections letting you reduce the bass the integrated amp must produce, and increasing the available dynamic range. You use the "Separate" feature to accomplish this, along with a Y splitter on the pre-outs. One for the integrated, another for your external amp.

PS, this blog post I wrote may help you better understand what happens when you separate a speaker’s inputs. Look down at the section on High Pass and Low Pass Impedance.



You could sell your integrated and buy a nice tube pre and a some cash left 😜