Magnepan 3.7i with two (2) DWMs with Pass Labs XA100.5

I recently upgraded by speaker cables between my Pass Labs XA100.5 and Magnepan 3.7i and a pair of DWMs. I've tried connecting the DWMs both in parallel and in series (using the DWMs crossovers).  I moved from Kimber 12TC to Audience Au24 SE.  This change added more detail and transparency.

Interesting when running in parallel (i.e., the 3.7i and DWM each connected directly to one of the XA100.5's two connections), the XA100.5 quickly left A-class.

Having the each cable around and given the nature of the DWM, I tried running the system both parallel and in series on the same system.  In other words, I was using all four sides of the two DWMs.  I wouldn't say that the XA100.5 couldn't handle it (opinion welcome, read on), but it was quickly out of A-class.  The meter would swing back and forth.  The interesting thing, is that I lost the Pass Labs sparkle.  Bass was very powerful and could be felt.  Yet it was almost muddy for the loss of a better word. Was the loss of mid-range magic, the XA100.5 running out of steam?
Hi tgonzales,

I too have 3.7i's and DWM's. Some questions, as I got confused on the details.

By parallel, I think you are stating that you run one set of wires to the main speakers out of one set of taps and you run a second set of wires out of the second set of terminals.  That is how I have always run my DWM's. 

When you say "series and parallel" in the same system are you saying you ran a set of jumpers from one half of the DWM to the other half? Wouldn't that imply a 1 ohm load? Or have I Misunderstood?

the only time I have used both sides of the DWM at the same time is when I run a single one, in which case I connect the right channel to half and the left to the other half. (For those not owning DWMs this gives the volume of two DWMs with a single unit, but restricts placement options). 

I will say that even driving half the DWM out of the second speaker taps can result in muddy sound in my system. It is easy to get too much lower midrange and too much upper bass (I have never heard ANY benefit below 63 hz of using DWMs). They recommend placing the DWM 10 inches loser than the mains, and this does help, but I suspect it also messes up the coherence of the back waves, which are now clearly lagging (by my thinking if the front wave is lined up ten inches closer then the back wave is off by twenty inches?).

two things which I have found help. First is I use resistors to lower the output of the DWM, and second I find that I can get less bloat in the bass by running them exactly parallel and on the outside of my mains. Since my mains are pointing directly at my ears, the DWMs are effecyively the same distance. This tightens the bass up, but does not always work, as I can sometimes get peaks (depending on where my main speakers are in the room). 

How do you have yours placed in comparison to the mains? Are you using resistors or attenuators? 

Thanks for your response.  Yes, you are interpreting my set-up correctly.  By parallel I meant one tab of each mono-block to the main speaker and the other tab of the same mono-block to the DWM.  By in series, I meant one tab of each mono-block to the DWM and then via the cross-over out to the main speaker.

I have tried the resisters (attenuators) recommended (sold by) Magnepan when I ran the speakers in parallel.  I felt the bass was a bit rolled off for my room.  On the other hand, when I didn't use the attenuator, I felt that the sound staging was a bit confused.  I think the DWM were voicing a bit too high.

The best set up for me so far has been running them in series without attenuators.  (I'm sure that the DWM's cross-over its up to snuff but it still sounds better.)  I have tried the DWMs in between the 3.7i's, about 12 inches in front of and 12 inches behind the 3.7i's.  Currently, I have them behind the main speakers because it makes it easier to both assess my turntable (which is against the back wall) and the LP rack (which is against the side wall). 

As mentioned in the original post, I changed the Kimber Kables 12TC for the Audience AU24se.  This really helped.

Thanks again for your post and thoughts.
P.S. you are completely right about the 1 ohms.  It probably too much even for the mighty Pass Labs.