[Tweaker]

Is there any reason(s) why the midrange ribbons aren't being built in longer sizes? It seems it would be preferable to have, for example, one 14" long ribbon over two 7" long drivers.

[Mathew_M]

I've heard actually that the mid-range ribbons used are surplus from some manufacturer, designed for use in automobiles.  I could be wrong and there is probably more to the story than that.  I'm sure either Brian or John will chime in.

[Tweaker]

Mathew_M,
I just checked the VMPS website and it appears you're right. I thought I remembered reading on the old site, or somewhere, that the ribbons were handmade by some guy in Canada, or something like that. There was talk about how hard they are to assemble because of the strong magnetic fields. So I assumed they were custom made for VMPS.

[john1970]

To whom it may concern,

From what I've read the VMPS midrange ribbons are highly modified from a Level 9 ribbon which was originally designed in Canada.  I would not worry too mcuh about the origin.  I have a pair of RM40 speakers (4 mid-range drivers / speaker) and the midrange is first rate.  From what I have read their reliability is excellent.  If you are concerned about long-term relaibility you can purchase spare drivers directly from VMPS.

Hope this helps,

John

[gitarretyp]

They were at least made by level 9 in the past (not sure if it's still true), but the level 9 speakers are licensed from eminent technology

http://www.eminent-tech.com/SensibleSoundReview.html

[Tweaker]

I'm not concerned about reliability. My original question was about the size and would it not be better to have one long ribbon rather than two short ones. (I own a pair of RM2s, by the way).   I guess it's now a hypothetical question.

[ka7niq]

I've heard actually that the mid-range ribbons used are surplus from some manufacturer, designed for use in automobiles.  I could be wrong and there is probably more to the story than that.  I'm sure either Brian or John will chime in.

Here is what I was told.
Bruce Thigpen of Eminent Technology developed these drivers, and then licensed them to a Company in Vancouver, Canada.
The company made Computer speakers, but also made some speakers aimed at the High End market.
These speakers were called Monsoon.
I owned the Monsoon 1000, the middle of the line.
My friend here in Tampa owned RM 40's at the same time.
He still does.

He listened to them briefly, and thought he heard a small "family resemblance to his 40's.
I did not agree, and they got out of my house, quick.

But back to what I know about the ribbons.
A man named Dragoslav takes the old Monsoon ribbon driver, and modifies it by replacing the cheap ceramic bar magnets with expensive, and much more powerful Neo ones.
Now, rumor has it that because the Neo magnets are much more powerful then the cheap ceramic ones, the weight of the diaphragm can be increased.
This would allow frequency response to be extended downward from stock, allowing a lower crossover point.
Transient response wouldn't suffer because of the powerful push pull Neo magnets.
I am pretty sure the diapraghms in the VMPS ribbons are different then the Monsoon's were.
Perhaps the stock diapraghms wouldn't stand up to the powerful magnetic field of the Neo magnets ?
Or perhaps there were other reasons for the change ?

Whatever the reason, it works.
Like I said, I owned the Monsoon 1000's, and I also owned the Eminent Technology LFT 8A's too.
The LFT 8a uses a new design ribbon.
I didnt care for either speaker.
The LFT 8 was very inefficient, like 83 db 1 watt  1 meter, and very dynamically limited by it's single 8 inch woofer.
The Monsoon 1000 would play louder, but was midrangey to the point of screechiness.
In my opinion, neither one could touch an RM 40 in performance.

[Skynyrd]

Thanks for your synopsis of your Eminent Technology  LFT and Monsoon speaker experience, KA7niQ (sorry I can't remember your moniker);

The dream of a fullrange push-pull planar line source is yet unrealized in my experience.  The best sound I've heard from these technologies has been the Carver AL-3's.  They at least have some warmth and sound nice with most recordings.
Reading your posts on more overly-midrangey dynamically compressed planar magnetics is another disappointment and, yes, another nail in the coffin for this technology.  Overall, these "ribbon" speakers sound  anemic!  Where's the lush and the warm?  Of course, it is because the speakers are too good.  Ugh.
 And I own VMPS RM40's, MagnepanMMG's mounted atop NHT woofers, and Martin Logan Quests and they all suffer from lower midrange-upper bass anemia.   I think it is the weakness/implementatin of the planar technologies.
These planars just don't go low enough.

I heare the Legacy Focus a couple of years ago.  Nice presentation--and they sounded great whether driven with all AVA equipment or a cheap Yamaha receiver.  Maybe a little thick in the lower midrange/upper bass. Just what may fit the bill!  A little pricey, even used, though.

 I also really liked the Magnepan 20.1's I auditioned a few years back.  They're like $15 grand, push pull planar magnetic and ribbon tweets and sounded lush. Fodder for others at that price point.  

Back to standard-driver two-way with subs!!!

I'll be keeping the planar stuff for a few years yet, anemia and all,
Skynyrd

[warnerwh]

Skynyrd: This upper bass lower midrange anemia you refer to is not an issue with my RM 40's.  I like it heavy here for vocals and dynamics as it sounds more real to me.  If you have the latest incarnation of the RM 40's it's your room, speaker position or other equipment.

I do have my Behringer adjusted for a "room curve" which calls for a boost in frequencies below 400hz or so. If you do research on what sounds natural in a room you'll find a flat response is NOT what you want and is why a room correction device can be very desireable.

My room is a completely treated LEDE room with 4 large bass traps.  Without any correction the amplitude variation is still plus or minus a full 10db.  IF you haven't measured your room you should.

The first RM 40's I heard suffered from this weakness but my system with the latest version that crosses over at 280hz does not. This did require room correction though as I also think that this is an area that can seem too weak especially since the upper woofer is much above ear height. With a high ceiling (mine is a low 7'2") you get no augmentation there either. If you sit nearfield this will also limit this upper woofer's response.

[John Casler]

Skynyrd: This upper bass lower midrange anemia you refer to is not an issue with my RM 40's.  I like it heavy here for vocals and dynamics as it sounds more real to me.  If you have the latest incarnation of the RM 40's it's your room, speaker position or other equipment.
...

Warner makes an excellent point here.

Just what does a VMPS speaker "sound like"??

In fact what does "any" speaker sound like?

The RM40, for example, comes with "many" options, and over the years since its introduction, it has improved steadily.

So when someone comments on the speaker, just what is being said.

Then to further Warner's point, the ultimate sound of any "incarnation" of a speaker is totally at the mercy, of the room, the system, and the software.

A lot of variables there.

So what does that mean?

It means everytime I see comments on speakers (not just VMPS) I take them within the context that I either know, or don't know, all the details of the listening experience.

It is many times too mind boggling to accept that anyone, except your can really hear something the same way you do.

Case in point.  I have one of the cleanest rooms ans systems I have ever heard.  That is, no noise, extremely low distortion, nearfeild listneing and almost no room reflections (in the listening chamber).

I had a very knowledgable freind stop in and listen a few weeks ago and he was suitably impressed, and his only comment was "I don't hear the "decay" I hear in my system".

Well what he didn't realize is that the "decay" he was hearing in his system was "room echo" (reflective distortion).

He had grown to "expect" that as "part of the recording" when in fact it was "part of his room sound".

So, it is important to remember, that we all listen to our (and others) system(s) based on a sonic we are familiar with as "preferable".

Me, I like accuracy, and sonic realism (soundstage, imaging, hearing the venue, etc).

Others might like something else.

So when you read about speakers, rooms and systems, remember, that it is important to find a sonic that "YOU" like, and for whatever reason.

No one should buy a product because Bill, Fred, George or Frank, said it is the best.  They don't have your ears, and in fact they are only authorities, on what "THEY" like. (this includes me )

I do like VMPS.  I like to hear as much of what was recorded as I can.

But, unless you want to pursue the same sonic goals, you might find something else as appealing.

But like Chris here who now has a pair of RM40s (without all the latest of upgrades, I might add) is finding out, these speakers can be magical if you are open to their potential, and have the room and system to discover it.

[Brian Cheney]

There seems to be confusion about the provenance of our mid panels, so here's a brief summary:

Technology is licensed from Bruce Thigpen.  His ET panels use ferrite motors, however, instead of Neodymium.

Both David Graebener and Dragoslav Colich collaborated on the design of the "Monsoon" panel which originally was intended for use in an add-on, high end audio system for Kia automobiles.  "Monsoon" also marketed home speakers with this panel and a 3" ferrite-motor planar tweeter.  A cheaper and smaller panel was developed for the computer speaker market (I have no experience with that one).  All the panels were made in "Monsoon's" (Sonigistix') Canadian factory.  About 300,000 mid panels were produced, the last in 2003.  An Asian conglomerate called Eastech purchased Monsoon/Sonigistix and changed the company name to "Level 9".  This company produced the final version of the panel with a "doublehigh" stator to prevent buzzing on loud LF passages.  This panel had an F3 around 166Hz, and originally I was determined to wring the last possible low note out of it.  For reliability's sake the crossover was later changed to 280Hz.  

Dragoslav told me he once made an array of over 200 Level 9 mid panels which he operated down to 80Hz at high levels (110dB/1m).  This means the panel is useful into the third octave, but such large arrays are not commercially viable.  Currently VMPS makes arrays of 1,2,3,4,6, and 9 panels, all crossed over around 280Hz.

All Sonigistix/Level 9 panels have both virtues and drawbacks.  The virtues include ruggedness, LF extension, linearity,  wide bandwidth, low THD, and a steady resistive load to the amplifier.

The big drawback of the design was a mechanical flaw.  An aluminum rivet pressured-fitted to the input ciruit board carried the signal to the diaphragm, and with time, the rivet loosened and the panels became intermittent.  Virtually all of them failed in the field.  Although we had many meetings and exchanges of correspondence with the Level 9 people, they were unwilling to acknowlege the problem, or fix it.  Eastech pulled the plug on Level 9 after about a year of ownership, likely because of the failures.

John Chapman and another RM40 owner (both engineers) came up with a fix which replaced the rivet with a different mechanical assembly that has proven reliable over the past 3 1/2 years.  Failure modes we still see are buzzing and open diaphragm traces, caused by dislodged magnets.  Freight damage has been identified as the source of most of these problems which, of course, do not show up in the course of our extensive QC.  We have experienced about 80 failures of this sort out of 7000 panels in use.  The only "fix" is to replace the panel. To cut down on such failures we have bulked up the packaging and now use airfreight (BAX) almost exclusively to ship our speakers.

As for size, 4x8" was selected for ease of tensioning and good directivity.
Large, long panels have more excursion in their centers, which means higher stators, lower field strength, more frequent buzzing, plus travelling waves which cause IM distortion.  Of course now with the CDWG, panel width is effectively .675", which only works because most of the panel output (about 75%) comes from the long travel in the middle.  Remember there is no suspension on the diaphragm so its motion is not pistonic.  Tests designed around pistonic motion show poor results on planars.

[Tweaker]

And I own VMPS RM40's, MagnepanMMG's mounted atop NHT woofers, and Martin Logan Quests and they all suffer from lower midrange-upper bass anemia. I think it is the weakness/implementatin of the planar technologies.

 I sure have not had this experience with my RM2s! (Or my Maggies or Acoustats).  Perhaps there is a room induced suckout in that region you are experiencing or perhaps you are used to speakers that produce excessive lower midrange/upper bass (you know, where all male vocalists sound like James Earl Jones), and have come ot regard that as normal or desireable. The comment about "wheres the lush and warm" would also lead me to believe that that is probably the case. John makes a good point, I think, in that when exaggerations in certain frequencies or, as in his case, with a friend feeling somehting was wrong by not hearing the room induced effect that he was used to are removed things can sound wrong. I remember long ago when I had a Sansui integrated with a loudness contour switch how hard it was to get used to listening to music without it engaged.

Back to standard-driver two-way with subs!!!

 I can never go back to a conventional moving coil speaker design again. They all sound lifeless by comparison. Personal taste, though as always.

[Jose R.]

.Failure modes we still see are buzzing and open diaphragm traces, caused by dislodged magnets. Freight damage has been identified as the source of most of these problems which, of course, do not show up in the course of our extensive QC. We have experienced about 80 failures of this sort out of 7000 panels in use. The only "fix" is to replace the panel..

My personal experience bears this out.  I have had problems with two panels in my Rm30C's - one intermittently "cut out" affecting all the panels on that speaker.  The green PC board was a bit loose.  Brian kindly sent out a replacement panel.
The other panel also cuts out and also buzzes at around 600-700Hz - when it becomes silent, I have found that pushing on the exposed terminals switches it back on again.  The DC resistance is also higher (about 3.8 ohm vs 2.9-3.0 for the other panels).  Brian has sent another replacement panel but it seems to have got lost.
Unfortunately, living in South Africa, I am at the mercy of shipping trauma but there is not much one can do about this...
I had been worried that somehow the digital crossovers I am using was responsible but Brian's explanantion makes more sense.  I seem to have had a run of bad luck with the panels I have but hopefully things will improve.

Regards

Jose

[ka7niq]

Hey, this is "off topic' but I need to ask you a question ?
I love Dogs!
I have been curious about wild African Dogs all my life.
I have taken wild kittens and made loving pets out of them.
I have bottle fed countless litters of abandoned wild feral kittens, and with plenty of Love and socialization, they make excellent, devoted pets.
I always wondered if someone could take a wild dog litter, and do the same ?
Is there any instances of say breeding a wild dog to a domestic one, and what were the results ?
I think it would be way cool to have a wild dog for a pet.
I owned a Wolf/Hybrid once.
he was part McKenzie valley timberwolf, and 1/2 German Shepard.
He was OK with me, but real "spooky" around others.
Please tell me about African Wild Dogs ??

[Jose R.]

..Please tell me about African Wild Dogs ??
.

Hi
Sorry but I cannot tell you anything about domesticating them as I am not aware of this being tried.  They are a highly protected species here and a lot of effort has gone into breeding them in the wild.  They have not been able to compete with or protect themselves from the larger predators in the game reserves.  They are fascinating animals with a highly developed social structure and not often seen in the usual game parks.

Regards

Jose

[ka7niq]

Thanks for the reply!
My cousin has an African Dog, it;s called a Rhodesian Ridgeback.
"Sally" as she is affectionatelly called, is a loveable Dog that has an insatiable need to lick those she loves.
She is a determined guard dog to those she does not know.

Yes, the wild dogs of Africa are beautiful creatures, and display much affection to their fellow pack members.
Perhaps someday they can be trained to guard Elephants from those who would kill them for their Ivory ?

[eekrat]

what does increasing the number of panels do for the quality of sound? Power handling, clarity, or something else? I would think it would be more difficult to get multiple panels covering the same frequency range to behave exactly the same...right? I own RM2's and a LRC just to give a basis for comparison. Also, if I understand correctly the panels are no longer being produced, so there is now a limited supply, is there a new driver being developed for future speakers?

[Brian Cheney]

Power handling and output levels improve, distortion goes down as you add panels.

We have a good supply of our current panel, when it runs low we will look at building something custom.

[davidc1]

I know this thread is literally over 14 yrs old, but, I just couldn't pass this up!

What's up with the wild dog posts  3-5 posts above? (I did have a Basenji though...)