[jeff442]

I just picked up a pair of used RM30's and the previous owner recommends not using the grilles.  I was curious as to what other VMPS owners have experienced.

[Wayne1]

While the CDWG expands the listening area, covering 2/3 of the mid panels does reduce the dynamics of the speakers.

They do look better with the CDWG on.

[John Casler]

I just picked up a pair of used RM30's and the previous owner recommends not using the grilles.  I was curious as to what other VMPS owners have experienced.

Hi Jeff,

Not sure if you'll get an accurate polling since the choice was "with grills" or "without grills" and the CDWG is not a grill.

I never listen with the "grills on" but might listen with the CDWG's on for some applications.

[PLMONROE]

And if that isn't confusing enough, there are those of us who prefer to listen with one CDWG on and one off.   

Paul 

[Pez]

One cdwg? Wow that is very odd.

Let me put it this way. Cdwg limits dynamics, f$&ks up the frequency response limiting certain frequencies more than others, colors the sound, and muffles the presence region in vocals. Couple that with the fact that I'm using 5 watt SET amps and No I absolutely do not use those damn things and think they are a terrible idea. not to mention getting a set that actually fits your speakers properly after market from VMPS is pretty much impossible.

[jeff442]

Hi Jeff,

Not sure if you'll get an accurate polling since the choice was "with grills" or "without grills" and the CDWG is not a grill.

I never listen with the "grills on" but might listen with the CDWG's on for some applications.

I revised my options to reflect your suggestion. 

I'm surprised by the feedback thus far.  I thought there was a lot of excitement about these when the first came out and many were looking to retrofit their speakers with the CDWG.

Can you give me an example of an application where you would use them?

[mjosef]

Mhnnn...so why was it even invented/introduced?
I never heard any of the speakers with the CDWG, but I did express interest in acquiring a set for my RM1s some time back...never heard anything further about it after the official, " ...will be available for all ribbon speakers" inc. my model. 

[Pez]

Mhnnn...so why was it even invented/introduced?

I don't know, why was crystal Pepsi invented?

[fredgarvin]

As I understand it, retrofitting with waveguides demands a crossover change to perk up  some upper freq areas. New models with the guides have hotted up responses so, theoretically, won't sound tonally correct without the guides.  Using a set amp with 5 watts is seriously underpowering them as it is, no wonder they lose dynamics with retrofit guides.  Me, I like th immediacy of the pre waveguide models.

[Hipper]

I listen in a nearfield arrangement so I can use a tight sweetspot.

I understood the Wave Guides were to create a wider listening position but need some adjustments of the tweeter.

Check out post #2 item 16, and post #3 of the sticky 'Set Up Guides...'

[woodsyi]

I listen with the guides on.  I don't want to be a pig that hogs the oh-so-narrow sweet spot.  I removed the horns on the tweeter.  I also bi-amp with ribbons driven by 85 triode tube Watts per speaker.  Actually tri-amp if you count the subs.  I don't lose anything in the vocal presence region.  The woofs are on their own with 1000W per channel.   I tried running just the ribbons with an 8 Watt 300B SET.  It just wasn't enough juice to run the Neos at full throttle even without the wave guides.  You are under-cooking your 40s, Jason.  You are eating rare meat when you want medium rare.    I would consider the Neos the heart and soul of the speakers as they cover the whole Soprano vocal spectrum.  The reason I added subs is the relieve the woofers from any lifting below 80 Hz which is the lower limit of bass voice.  I didn't want the big drum rumbles to tax the woofers (and amps) from doing "delicate" work.  I would probably be better off with smaller woofers in the 30s but they weren't around when I got the 40s.

[Pez]

Fred, I use a DCX which allows instant dialing of any crossover changes needed. IMO nothing made the CDWGs sound decent.

Woodsyi,  If I were Bi-amping I would agree with you, I know from 1st hand experience that 5-8 watts is not enough to power the 40s biamped. But I am tri-amping and believe it or not it makes a gigantic enormous cosmic difference despite what anyone tells you. More dynamic headroom, way better clarity, deeper soundfield. 2 five watt SET amps and a beefy 600 watt amp for the woofers is enough to drive the 40s to absurd, piss off the neighbors 2 houses over SPLs.

Plus, not sure what you were using that drove your 300Bs, but if it's like most mid level tube amps it probably was built with cheap iron, and was just barely able to push its rated 8 watts. My amps are rated 5 watts and push 8 watts no problem.

Oh and FYI to carry your steak analogy further using the CDWGs is like putting ketchup on filet mignon. 

one last thing, what amp are you currently using?

[woodsyi]

Plus, not sure what you were using that drove your 300Bs, but if it's like most mid level tube amps it probably was built with cheap iron, and was just barely able to push its rated 8 watts. My amps are rated 5 watts and push 8 watts no problem.

I thought MagneQuest made good irons.  It is a stereo amp and not a pair of mono blocks.  I am still debating to pull the trigger on tri-amping the twitters and drive them with the 8 Watter.  I have all the fancy WBT binding posts and all and have a three way crossover.  I just haven't pull the trigger as I am pretty happy with the sound. 

one last thing, what amp are you currently using?

The ribbons on my 40s are driven by a pair of ASL Hurricanes modded by Bill Baker.

[Pez]

I just haven't pull the trigger as I am pretty happy with the sound. 

Do it DO IT for the lOve of all things holy and hellbound!!!!! DOOOOOO IIIIIIITTTTTT!!!!! Nothing on earth is more wondrous than the 40s pushed with a pair of awesome SET amps.

[turkey]

Mhnnn...so why was it even invented/introduced?

It was buzzword compliant.

Brian seems to be a really nice guy and I don't want to trash his speakers, so I'll just say that these "CDWG" things did not appear to be his best work.

[satfrat]

.

Oh and FYI to carry your steak analogy further using the CDWGs is like putting ketchup on filet mignon. 

Whew, I'm glad you didn't say A1 Steak Sauce.     
 
Cheers,
Robin

[woodsyi]

It was buzzword compliant.

Brian seems to be a really nice guy and I don't want to trash his speakers, so I'll just say that these "CDWG" things did not appear to be his best work.

It works as advertised if you bi-amp.  There is a woofer/ribbon imbalance after the ribbon output is curtailed by the CDWG.  You can side step that if you actively (or passively, I think) bi-amp.

[John Casler]

Lots of interesting comments here and good questions.

First the "WHY" of the CDWG.

In the history of Loudspeaker Design one of the Holy Grail goals has been to provide a full frequency directivity of the sonic information to any spot within the listening environment.

With current technology this is an IMPOSSIBLE GOAL.  It is impossible, because there are NO MECHANICAL drivers made that can cause this to occur.  All drivers have radiation patterns that have differing on axis and off axis responses, and most full range speakers use multiple drivers just to cover all the frequencies.

Cones, domes, ribbons, planars, etc all radiate differently.  And if that weren't enough of a problem, radiation patterns also change with wave length (frequency).  Low frequencies, tend to radiate the best, and as the frequency rises the radiation "tightens" into more of a beam.

Even this beaming differs between different drivers with cone drivers differing from planars and ribbons.  Planars and ribbons are even more precise in their Mid and High Frequency radiation.  However planar and ribbon drivers offer other sought after advantages due to their design. So you had trade offs.

In a hobby such as High End Audio, each user has his own set of listening preferences.  Quite often you hear the complaint of a small sweet spot, or the fact that you need to employ a "head in a vice" listening position.  This coupled with the fact that some like to listen with others, or while relaxing in more than one position means the radiation pattern would need to be increased.

Increasing the radiation also comes with its own set of problems called reflections.  Increasing the radiation pattern also increases the amount of reflected to direct energies one hears.

However, using constant directivity of a broader band will also reduce the perception of certain frequencies being a problem depending on the reflective surfaces of the listening environment.

Couple that with one of the traditional goals of loudspeaker design (constant directivity of frequencies to ALL seats in the house) and you have the motivation for the development of the CDWG.  The CDWG allows one to still use the desired qualities of the Planar and Ribbon Drivers, while increasing the DIRECTIVITY to a broader listening area.

Of course this too comes with its own set of compromises and one of those is, that as you disperse the sonic energy over a larger area, it is reduced in SPL.  This then requires a change in the XO to compensate to a degree to that change.  Even then a direct comparison of "off and on" will simply demonstrate that one has the ability to play louder than the other, which is simple physics.  But while playing louder, the "OFF" sonic will then again be restrictive to the listening position.

I often compare it to an Formula ONE race car and an M3 BMW.

The Formula ONE has Torque, Power, Braking and Handling that simply could not be approached by the M3.  However, you can easily get 4 passengers in the M3 and you can drive it in the city as well as the freeway and even the track.

Once you have driven a formula car, the sports sedan seems absolutely sedate and somewhat useless to achieve that same RUSH.  This is HIGH PERFORMANCE DRIVING.

In Audio, if your Primary Goal is what I call "High Performance Listening" which is that head in the vice, unbelievable imaging and perfect soundstage enjoyment that can ONLY be achieved by REDUCTION of highly reflective sounds and the only concern is what reaches your ears in THAT position only.  THEN the "no CDWG" is going to provide the most satisfaction.

If your goal is to have the best M3 type of performance with friends co-listening in a larger sweet spot (which can be as large as good images virtually any place in the room) then the CDWG on, is for you.

While one can argue which is better, it is simply a matter of preference, and once again, VMPS is the only speaker that I know of, that offers either option for most of the present line, IF the technology will work with that particular model's design (for example it will not work with the RM50)

So the listener can decide how they want to listen, and purchase their speakers with that in mind.  As well, with the D-OXO you can save TWO different equalization XO curves and use either "on" or "off" as fits your  mood.

[Pez]

This myth of a sweetspot that 4 people can sit in baffles me. I don't care what crazy engineering you put into a speaker there is one sweetspot and it is approximately as wide as a human head. You can put a CDWG or have an omnipole speaker like the German physics and still, you have a sweetspot as wide as a human head. That isn't to say that outside of the sweetspot the sound isn't more "even" with the CDWG or an omnipole, or that the speaker won't image in some way even if it is inaccurate to the recording, but nothing you do to a speaker will make it sound as good outside of the human head sized sweetspot period, so IMO something like the CDWG is nothing but a compromise regardless of whether you're in the sweetspot or not. It will sound more even outside of the sweetspot, but at the cost of everything else I wrote above.

[wywires]

I have a pair of RM30-C's with the CDWG coming next week and I'll be driving them with a 50WPC EAR 534 push pull EL34 amp. Although I enjoy pinpoint imaging, the notion of having a soundstage that is discernable from different off axis locations is compelling. I heard this effect at the california Audio Show in the Acapella room and it was impressive. I'll listen both ways and report back.