[James Romeyn]

Disclaimer: reader acknowledges full responsibility for any damage or injury resutling from this post.

OEM RM40 woofer siting is MW at bottom, midbass up top.  Upon inverting them (MW to top, midbass to bottom) the sound quality improved.  I did not percieve the minimized lowbass output Brian predicts.  PR mass adjustments were minor (removed three-four thumbnail slivers).  It might have corrected a room defect (a couple of major modes below 100Hz), but I have reason to believe it is an overall improvement regardless.  

The reason I tried it is my wife's ubiquitous complaint: when the output emphasized the midbass driver's range (extending into the low mids), the imaging & staging was irregularly & unnaturally elevated.  While I listened with my eyes closed she alternately blocked the upper 10s output with a pillow.  It sounded better blocked.  Try it yourself.  

After the screws are removed the woofer will remain locked into place, resulting from suction caused by the gasket tape applied to the woofer seal.  Lay the cabinet on its back.  Remove six screws (of the eight) from each woofer.  Loosen up the remaining two screws (from each woofer) so the woofers will not fall out altogether after the seal breaks.  Now turn the cabinet onto its face & let gravity break the gasket seal over time.  If the gasket tape breaks unevenly, you may need to remove it from the cabinet to reuse, or you may need to buy some (hard to find at the 5/16ths" width).

If the quick-disconnets are too loose, increase tension by tightening with wire snips, slightly compressing the tunnel on each side at top & bottom.  If too tight, the tension can be minimized by spreading open the slot between the tunnels with a flat scredriver.  Use the woofer terminals facing side to side rather than the vertical.  Clean all contacts with Caig Pro Gold contact cleaner, using a rag behind the woofer terminals to protect the cone.

VMPS Sales & Service, Jim Romeyn, Petaluma CA, 707 765 1992, RibbonSpeakers@cs.com

[JoshK]

this is as opposed to just inverting one speaker as you had proposed to me?  Did it make a difference?

[James Romeyn]

Invert the woofers on both channels.  As many as feel up to it should try it.  The chances of Brian changing production are increased if the response is overwhelmingly positive.  If two persons are available, alternately have them block the output of the top woofers with pillows & compare for yourself (have them stand to the outside, inside will screw up imaging).  Don't contact the woofers with the pillows.  Has anyone noticed the anomaly, or I am I nutz?  Scratch that.  I wonder if dual MWs are indicated?  The 10" MWs must go high enough, as the RM2 uses only the 12" MW, which rolls off sooner on top.

Tip: wood blocks necessary under cabinet to make space for the woofers to drop down.

Jim Romeyn, VMPS Sales/Service

[Xi-Trum]

Instead of inverting the speakers, wouldn't it be easier to listen while standing up-side-down (like a bat)?  

[James Romeyn]

Don't know.  Will return woofers to OEM postions, bolt chair to ceiling & report back to class.
Jim R.

[doug s.]

xi-trum,

try one of these:



doug s.