[Jack D.]

Is there still a choice between waveguides and non-waveguides when ordering new speakers?

If I remember correctly, there was a crossover change to adapt to the waveguide, so it's

just not a matter of removing the waveguides if you don't like them.

[BobRex]

There is no crossover change, the change is to the FST tweeter.  Originally the tweeter came with a built in "waveguide/horn" which was fine before Brian came up with the CDWG.  B "de-horns" the tweeter, which increases its output a little.  The output is then adjusted via the Lpads to compensate.  As far as running the speaker with the "de-horned" tweeter and no CDWG, I doubt you would notice any difference between the original "horny" tweeter and the "de-horned" version.  The crossover is too high for the original horn to matter. 

Be aware that using the CDWG will reduce the output of the panels by a couple of dB, enough to be noticable.  Since I run a SET amp on my panels I need the additional output, and therefore run without the guides.

[Zheeeem]

Sometimes I listen with the waveguides on.  Sometimes I listen with the waveguides off.  Without the waveguides they are ever so slightly brighter and with slightly better dimensionality at "the" listening spot.  With the guides on, they look better, the drivers are more protected, and the imaging is pretty good over a much wider area.  I do not adjust the L-pads when shifting between the two, although there is, of course, a slight attenuation when the guides are on.

[Scottdazzle]

Sometimes I listen with the waveguides on.  Sometimes I listen with the waveguides off.  Without the waveguides they are ever so slightly brighter and with slightly better dimensionality at "the" listening spot.  With the guides on, they look better, the drivers are more protected, and the imaging is pretty good over a much wider area.  I do not adjust the L-pads when shifting between the two, although there is, of course, a slight attenuation when the guides are on.

My experience is exactly as Zheeem has described.

[John Casler]

Is there still a choice between waveguides and non-waveguides when ordering new speakers?

If I remember correctly, there was a crossover change to adapt to the waveguide, so it's

just not a matter of removing the waveguides if you don't like them.

Hi Jack,

You certainly can order the speaker to function "best" with either the WC on or off.

In the beginning B, "DID" perform a X-over adjustment until he found that "dehorning" the tweeter would get most of the job done.

If you are a solo, sweet seat, serious audiophile, type listener, then you can order the speaker fully horned and perform your serious listening with the WG off.

Or vice versa.

Optimally each version (on and off) has a precise cross-over equalization, but they are very close.  Some will make them closer by "boosting" the tweeter and panels when the the CDWG is on, and backing them down when the CDWGs are off.

While in a lively room the differences will be less, you will find a significant change in a highly treated room.

But the point is if you listen seriously solo, then go fully "horned and CDWG off", if you are more of a social listener then CDWG on and "dehorned" will likely work the best.

Additionally the SDE of the RM30 can be loaded with dual equlizations for either to get you "perfect" everytime.

[Jack D.]

Thanks everyone,

For the responses.

John, I'll talk to you later!

Good luck in Vegas!

                          Jack D.

[tbrooke]

I actually also listen with and without waveguides but I did some measuring and with the waveguides on my RM30s there is a serious off axis drop in response as opposed to without the waveguides. This is the opposite from what people have reported.

Has anybody else done any measuring to confirm wider dispersion with the waveguides?

Does anybody think they sound better with the waveguides?

They definitely look better with the wave guides

Tom

[John Casler]

I actually also listen with and without waveguides but I did some measuring and with the waveguides on my RM30s there is a serious off axis drop in response as opposed to without the waveguides. This is the opposite from what people have reported.

Hi Tom,

Actually that is to be expected since the Wave Guide does two things.

1) It covers a good portion of the NeoPanel and this "reduces" SPL by a few DB

2) It then "distributes/directs/disperses" the remaining sonic energy over a greater area further reducing the SPLs to any particular area.

While I am not a speaker designer (obviously  ) the physics is pretty simple.  When you take an "energy" and distribute it over a larger area it reduces the energy by the size of the area of distribution.

That is why directivity and beaming are trade offs.  One will allow you to experience a greater distribution of sound over a broader area, and the other will focus that energy at the cost of a loss of that distribution.

If you think of a WAVE GUIDE as and sonic energy distribution and control device it becomes more clear.

A simple HORN is a directivity device and it (like a megaphone) directs and controls the directivity (directions that the sound will be controlled to).

There are many types of wave guides, and all direct the sound to do what the guide is shaped to do.

Many like horns and parabolic shaped guides simply "guide" the sound to the desired degree of dispersion.

Funny enough, when I was a kid, we had this 100' garden hose.  My sisters, brother and I used to take my mother's funnels and run that hose through the hay and straw caves and forts we used to build in the hay stacks.

We could whisper into to the funnel at one end, and hear the words of the other person 100' away quite clearly since the sound waves (energy) were guided from point A to point B, with low dispersion and loss of energy.  This is the opposite Wave Guide function of controlling the directivity and energy.

As you can see the VMPS wave guide is not a horn nor is is a circular parabolic guide.  It is a conrolled and specifically shaped "acoustic lens" through which the sound passes.  The size and shape is specific to the range of frequencies it is to affect.  The frequencies are then shot through the aperture, much like a stream of water shoots through a "nozzle" on a garden hose.

Just like on that "nozzle" and that stream from the hose, if you control the stream by changing the aperture the stream changes from a solid directivity stream, to a "dispersed" (and lower pressure) spray.

While my example is a simple one, the PHYSICS, have a degree of comparison for illustration purposes.

[DFaulds]

A simple HORN is a directivity device and it (like a megaphone) directs and controls the directivity (directions that the sound will be controlled to).

A horn amplifies a signal and controls dispersion.

[John Casler]

A horn amplifies a signal and controls dispersion.

That is correct that it controls dispersion.  That is, it controls the directivity (dispersion and direction) of the sound energy.  However in the case of a horn, it "reduces" the dispersion of the energy being produced and "funnels/directs" it by controlling the directivity.

Some may find controlled directivity useful when trying to get somone's attention who is far away, or in a noisy environment.  We cup our hands and yell. This keeps the sound from dispersing hemispherically, and pushes a higher energy forward to the target.

However the VMPS CDWG has just the opposite effect, and it is designed to "increase" dispersion and directivity to a wider area, by forcing the sound through an acoustic lens. (the slot in the CDWG)

Anyone interested in directivity can look here:
http://www.mcsquared.com/directvt.htm

I'd be interested in the physics of it causing amplification.

[DFaulds]

I'd be interested in the physics of it causing amplification.

There are quite a few papers on the net, but you could start here.

http://en.wikipedia.org/wiki/Horn_loudspeaker

I think the Klipsch site, or the Lansing Heritage site should have some decent discusion of the affects of horns on a driver.

[Jack D.]

The new SOTA RM 50 does not have front radiating waveguides.

How will that effect other speakers in the VMPS line?

[John Casler]

The new SOTA RM 50 does not have front radiating waveguides.

How will that effect other speakers in the VMPS line?

It won't affect the other speakers as they all have their own design goals.

The RM60, RM40, RM30 and 626 can all be ordered with or without CDWG.

The RM2 does not have the CDWG as an option.

The RM50 has A CDWG on the REAR DRIVER ARRAY. 

The tweeter array on the front of the RM50 has a VERY large horizontal dispersion.  I was amazed

The design (Dual Line Array) of the RM50 does not allow the implementation of the CDWG, nor is it needed for most listening purposes.