Anthem MRX-700 setup for full range front speakers with built in powered subs

[melvin long]

Woot - first post! You guys are awesome, great info!

Long story short, I have a set of Def Tech Mythos ST-L arriving next week, swapping out my Mythos One's and pair of Paradigm PW2100's. When we built the home theatre, we foolishly didn't put in conduit (more a time constraint than anything) so the pre-wiring has only one set of wires going to the front speakers and the LFE channel has a y-splitter in the wall with the sub cable going to two spots in the back of the room. Now with the ST-L's coming, we're faced with the powered subwoofers being in the front of the room - doh! Here are the questions:

1. If we just set the anthem mrx-700 to have full range front speakers and no subwoofer, will that suck a bunch of power unnecessarily to attempt to drive the woofers on the ST-L's? And does the usual LFE get piped back to the front speakers? Should I call Anthem and get some input?
2. Is there any advantage to setting up the ST-L's as small (or large) and the sub section as LFE? Factor in using ARC for room correction.
3. Anyone know of a flat subwoofer cable? I'm willing to run new wire but too many joists in the way to fish a new cable through. I know there are flat paintable speaker cables. Also brings up - is there actually any difference between speaker cable and a subwoofer cable? Always wondered that, haven't googled it.
4. ARC and REW room EQ software - can one use these together? Does ARC eliminate the usefulness of REW? Any guides out there for using REW with built in room correction?
5. Aside from adding some db's, any good reason to keep the pw2100's? Reports on the ST-L's are showing plenty of bass (plenty usable at 20Hz and lower), deeper than the pw2100's (rolls off steeply about 22 Hz). I'll of course play with them and report back.
6. Last question! On our pw2100's, I installed SVS soundpath isolation feet. I was honestly shocked by the difference - room rattling gone, bass felt tighter, volume increased, impact increased. Would it be advisable to install these on the ST-L's since they also have a subwoofer? Or would the increased movement be detrimental to imaging or something? I tried googling this but don't see any comments.

Thanks all for helping with my newbie questions!

 

[lovinthehd]

Well, just my .02:
The "subs" in the STLs have their own amp so won't use any power from your avr. Your LFE goes to whatever subs you hook up to the sub pre-out on your receiver; if you set speakers to small then you get redirected bass to your subs on top of the LFE channel content (assuming your content has a .1 channel). Personally I wouldn't rely on the speakers for sub duty, they don't dig that deep.

Subwoofer cable is coaxial so flat probably not much of an option; haven't seen one at least but google should find one if its out there. Not the same as speaker wire.

You can use REW to measure but don't think ARC has a feature to import any suggested EQ but I'm not very familiar with ARC. This might be a good question for Anthem.

The STL's look to roll off steeply below 30hz, check out these test results http://www.soundandvision.com/content/definitive-technology-mythos-st-l-loudspeaker-test-bench#O47S6c6ygmts3O82.97 so it looks like your subs do dig deeper (even DT subs generally don't dig deep either, they're small and cute but not very good subs). I'd keep your subs, and subs can be positioned for optimum bass whereas a L/R speaker pair is limited as to where they will work correctly.

Never had reason to buy something to put under a sub; on the ones I build I just put rubber feet on them. If I needed to I would find something around the house (hockey pucks or pieces of carpet/foam come to mind) rather than those SVS things. Personally I think that tightening of bass is pretty much in your head rather than reality; I've heard some say they can resolve rattles but I usually chase down the actual rattle and fix it anyways so never an issue for me.

Good luck!