[James Romeyn]

What do you smarty pants think about my proposal?  The sum total mod from OEM is the inputs wired as follows:

Wire the M as if it was only a C version, ignoring the 10MW.  Only one input binding post is utilized for all C drivers, meaning C drivers are single amp/single wire only.

The 10MW is direct-coupled (no passive XO whatsover) to the second set of input binding posts.  Both L & R channel 10MWs will be powered by one outboard active XO/1000W amp/parametric EQ.  Assumed LP XO point around 45Hz.  The parametric EQ may provide deeper bass cutoff vs. the OEM specified "32Hz".  

Per above, the active dual 6.5s & the ribbon array are driven by the main amp, while the 10MW is driven by a seperate subwoofer amp.  All 3 active woofers are within the same cavity & reflex loaded by the same dual 6.5 passive radiators.    

The goal is RM30C performance & obvious cosmetic appeal (my old RM40 spiral's only clear advantage is in the bass range), with more/deeper/room-equalized bass w/o external subs.    

Am I barking up the wrong tree?  Will it be impossibly difficult to tune?  Will it sink or swim?  If this works, & Brian agrees, & offers it as a wiring option, I demand it be christened with the suffix "JR".  If it doesn't, then, as Rosanna Rosannadanna used to say, "Never mind".........

[Redbone]

Yeah, I think that you are barking up the wrong tree.  What I have found with the 40s is that the whole cabinet combined with the two woofers and the passive sub react to form the bass and mid bass output.  The 30s just don't have the cabinet capacity nor the driver compliment to reproduce the 40's sound.  Don't underestimate the cabinet's role in producing the bass.

On a separate note, we finally had some spring weather here in MD with temps in the low 70s.  My basement warmed up and boy did that affect the 40s !  Much better bass response at 70 degrees than at 55.  Part of this is the sealed cabinet design.  The pressure will equalize inside the cabinet as the temperatures warm up, otherwise the damn things would explode !  The cabinets are not completely sealed, at the very least the woofers are semi-permiable to air.  But the temperature of the air inside the speakers affects its density and the speed at which it carries sound.  Apparently 15 or 20 degrees makes a big difference.  So putty tuning must be done for a specific temperature.  I wonder what would happen if you filled one with Helium, would it sound like a chipmunk ?

[James Romeyn]

Yeah, I think that you are barking up the wrong tree.  ...The 30s just don't have the cabinet capacity nor the driver compliment to reproduce the 40's sound.
...

All only my opinions, YMMV.  I am clear the RM30s will never do 24-32Hz like the 40s.  The cosmetic differences are self evident.  Didja hear the RM30s yet (I only heard them at Bs)?  The RM30s XO between the 6.5s & mids is, if memory serves, between 280-320Hz.  The ribbons are transformed vs. your RM40s 166Hz.  The RM40s 10s probably have HF limitations prohibiting their reproducing 166-300Hz like the RM30s 6.5s.  The linsource beats the symmetrical array, subtle but easily heard, only my opinion.  Others have stated similar reaction, but both have exclusive  advantages.  I previously thought baffle width was way overstated in importance (the RM2s can sing).  But dynamics jump out of that RM30 like nothing I've heard (except possibly the RMX).  The presentation is such that my personal weighting of the overall pros & cons is: the 30s improved look & reproduction everywhere except the lowest bass favors the 30s.  If my room was dedicated or much larger, the results would be inverted, favoring the RM40.  My 2c.  B will kill me.

[Redbone]

One issue at a time.  For low bass the 40s will smoke the 30s for the reasons already stated.  My opinion is that modding the 30s to improve the low bass will not overcome the cabinet limitation and driver compliment.

As far as mid bass the 40s have a definate limitation that has been discussed on many thrreads.  I believe that it has to do with the drivers themselves, not the cabinet.  The 30s have the smaller 6.5" mid bass drivers and although I have never heard them it sounds quite reasonable that because of these drivers the 30s have better mid bass than the 40s.

I don't think that the crossover has a great effect on the NEOs, they seem to be able to handle a very wide frequency range.  The 30s and 40s have a very similiar NEO and FST compliment, and are probably about equal in this area. Perhaps the 30s have a little better midrange, I would have to hear them to decide.

Because the mids/highs are the strong point of the VMPS line, and it appears that the 30s sound as good/better than the 40s in this range, it would be reasonable to say that they are in most ways a better speaker than the 40s.  A lot, if not all of this is due to the 6.5" mid bass drivers, IMO.