[7x57]

I was over at hometheatershack.com and this outfit called GR Research run by a guy out of Texas did an "upgrade" for a customer on a VMPS 626R speaker. The article is highly suspect as he measured a sensitivity of 80 dB with huge swings of 18 dB peak-to-peak in the output response. He measured the speaker on the tweeter axis at 1 meter, which is wrong in the first place. You would think a guy in the upgrade business would know better. However, he has to convince people there has to be an upgrade. Miraculously, his crossover design got back the efficiency to 88 dB. Yeah, right! I smell somebody searching for some upgrade business. I posted my thoughts and experience and let it be known I smelled BS.

Possibly, the speakers in question had the midrange panels charged in reverse polarity. I built my RM1 speakers from a kit and both my panels were charged in reverse polarity, which is easily corrected by switching the leads around. The kit instructions give instruction for testing Neopanel polarity. A call to Brian revealed that he was aware of some panel magnets being charged in reverse polarity. Anyway, this article got me to thinking about my RM1 crossover design.

In searching around the web for what Brian might have said about this "upgrade" by GR Research, Brian admits that the Neopanel has a 3 dB peak between 1 kHz and 3 Khz. After some time, the crossover had an inductor and possibly a resistor installed to tame that peak. I have the very earliest model of the RM1 with nothing but a 3.6 mH inductor and a 62 uF capacitor in the Neopanel crossover circuit. I have a 3 dB peak centered at 2.5 kHz, but it hasn't really bothered me. Also, for these early models, the Neopanel was said to crossover to the Tweeter at 10 kHz. I have only a 1.6 uF or thereabouts series capacitor on the EMIT-R tweeter and a small value air core inductor, so the crossover is very high. The Neopanel runs free on its top end. The tweeter could almost be considered a super tweeter. Measurement suggests that it really does cross over at 10 kHz as I read back in 2001 when I bought the kit. My math suggests the same thing.

I read somewhere about a series connected 0.13 mH air core inductor on the Neopanel on later models. This would result in the later claimed 7 kHz crossover frequency to the tweeter. I have considered changing over to the later crossover design, but adding a series inductor would blunt the transient response of the Neopanel, which I might not like. If the peak at 2.5 kHz is not bothering me, it might be a waste of time and money to change anything.

Changing the midrange crossover circuit would also result in changing the tweeter crossover circuit. The 626R and RM1 should have the same midrange and tweeter crossover circuit as long as a single Neopanel and single EMIT-R tweeter are in use. The RM2 and higher models should be different.

Has anybody heard the early vs. later crossover designs in these two speakers using the EMIT-R tweeter? I would suspect the FST upgrade would result in a different crossover circuit to at least the tweeter. As far as I know and my hearing goes, my early crossover design "ain't broke yet", and maybe ultimate transient response beats killing the 3 dB presence peak. It would seem like a "six of one, half dozen of the other" upgrade to me and would come down to listening preferences. Anybody out there have experience with both crossover designs and who knows the values of the components involved???

Phil

[Danny Richie]

There seems to be some misunderstandings here so please allow me to clarify some things.

First of all the speaker tested (that you were referring to) was one of the last 626R's that VMPS produced. And it was tested as it left the factory. It was not altered in any way prior to testing. I have also tested, measured, and designed upgrades for earlier models as well. And the test results of another earlier model was also well documented and available.

There may have been some polarity issues with some mid units at some time. It was not the case with this model. And again, these speakers were measured just as they left the factory.

Measuring on tweeter axis is also an industry standard. However, they were also measured at various other heights with no real improvement to the measured response. In the thread you mentioned there is also a measurement taken in the vertical off axis at four different heights showing the cancellation effect that the design suffered from as slight time delays caused deep cancellations in the response.

The reason that this model showed an unusually low sensitivity is because the mid panel was allowed to roll off very low, and it was out of phase from the woofer with an overlapping response. This caused the cancellation that resulted in the low sensitivity. Also the customer had turned down the levels on the mid and tweeter to attempt to match the lower SPL levels in the area where the mid and woofer overlapped.

And by the way, the measurements taken used a gated time window that allowed only the speakers true response to be seen without room reflections. It yields the same results that I would get if I measured them in our anechoic chamber that I owed at our previous facility. Taking "in room" measurements is more of a measurement to show room interactions and not speaker responses. It is not the way we as professional designers measure speakers.

And while I don't work in a repair shop for medical equipment, I have worked as a designer in the audio industry for the last 21 years. I have upgraded hundreds of speakers and have been brought in for design work by many companies. And my design work has won pretty much every industry award in every magazine online and in print. So I think I know what I am doing by now. And despite your earlier assumptions I would still be glad to help you if you were to decide that you'd like to do something with them.   

[7x57]

Danny,

Dick Olsher was the last person to review the 626R in an online magazine in 2008, I believe. He got a vastly different measurement and opinion of the speaker than you got. The review is still online.

Since you got what you got on your test equipment, I would suspect something wrong in one of the crossover components, either the L-Pad or TRT cap being the most likely. And since Brian instructs builders to test Neopanel polarity, that is the first thing to check when doing any work on a Neopanel speaker. They need to be tested under dynamic conditions at working voltages with a differential o-scope looking for noise or other issues. Brian said elsewhere that some of the TRT caps can fail as they are a rather fragile design that has some problems with the leads not being well enough supported. I would also not use the CDWG, as it cuts at least 3 dB off the sensitivity and Dick Olsher said he liked the speakers better without that "upgrade".

Getting rid of a L-Pad is good after you determine the internal values at your best setting, then constructing a substitute using fixed resistors. My L-Pads do not sound bad, and I routinely give them 10 full rotations like I did on my 2Ci speakers.

Where I need help is in getting the Neopanel and EMIT-R inductor and capacitor values as used in the later model RM1 and 626R that used those drivers.

I talked on the phone with Brian about his crossover design. It separates the phase shifting points of the inductor and capacitor and spreads the total phase shift of a two-pole design over a wider frequency range so that the phase shift with frequency change is at a rate similar to a single pole design. Of course, the total phase shift is the same as if you put the two points at the same frequency, but it is spread out over twice as much territory meaning it is at a lower rate as the frequency sweeps up and down. It also protects the drivers much better than a single pole filter, and a bit better than a standard two-pole design. That is why his drivers are less stressed and sound more dynamic than if he used standard crossover practice.

The capacitor value will seem to be about half as big as needed for the stated crossover frequency, because he purposely chooses a driver that is about +6 db loud at the lower crossover point, allowing a smaller capacitor set about an octave above acoustic crossover, better protecting the driver, and setting its major phase shifting range away from the inductor's major phase shifting range. The phase shifting rate relative to frequency change thus mimics a single pole design, with two-pole protection from lower frequencies.

Brian readily admits his design will not be the flattest measured at crossover frequency, but my measurements say they are not bad at all. Like I said, I am about + or - 4dB across the range from 32Hz to 20kHz measured at my listening position, where a speaker should be measured if used for listening rather than testing purposes.

I like Brian's crossover design sonic values, but not everybody agrees. I would like to reiterate that the only "defect" I can see in the Neopanel is slightly boosted output above 1 kHz with a peak centered at 2.5kHz. That is my computed frequency for the side panel resonance in the midrange box. Brian suggested stuffing the midrange cavity with lambswool. I also know that a 0.13 mH coil was added in series with the Neopanel in later models.

My question was, will I get an improvement or just a change for another defect? That defect would be blunted transient response if adding a series coil. VMPS owners usually do not worship at the altar of absolute flattest frequency response, and Brian stated numerous times that flattest frequency response was not his primary design goals. Phase shifting and compressed dynamic range are of more importance and to be avoided after getting a reasonably flat response.

Also, the FST tweet upgrade does not mean much to me as my panels run to 10kHz as it is now and I can't hear above that frequency anyway. It would matter if I added the series coil to the Neopanel as I would have to lower the tweeter crossover frequency.

The best way to get flat frequency response would be to do some equalization in the digital domain, but when I checked the prices of a professional grade equalizer, I said "no way". Maybe things have changed since then. Right now, I need to buy some pro grade detection and analysis gear that works from Hz to Gigahertz range, since I am biomedical oriented and I need to detect and analyze electromagnetic fields as it affects the human body. This is for very serious purposes as we are drowning in electromagnetic noise, to the point I had to take an old Hafler tuner out of my system as it would not work in the intense cellphone noise field that existed.  I have to study ways of shielding and very high speed grounding for entire rooms and buildings. There really is no big money now for audio gear upgrades.

For what its worth, a German scientist proved that the "human spirit" resonates at a frequency range that is in the middle of the cellphone transmission range. It takes only a tiny fraction of a watt of cellphone frequency to open the blood-brain barrier and massive amounts of toxins in the blood can come flooding in. Some toxins, once in, will not be coming back out. This is serious stuff, way more serious than most audio gear. Audio gear that uses WiFi for connection is a very serious health threat as well. For those who have not studied Psychotronic Mind Control, I suggest they do so. Also, look into the work of John Christian Lily, inventor of the Lily Wave, who invented a waveform that opens the human mind to wireless programming. He quit his work when he saw how it could be misused, but the cat was already out of the bag.

So you see, I can't get too much into audio nervosa right now. I can tell you for certain that last summer during Jade Helm exercises, I noticed a strange reoccuring effect during the period of testing that is much less prevalent for now. It was a test of Artificial Intelligence, and the computer in use was said to process in a 24-hour period all the human brain thought processing that all humans had ever processed in the entire existence of the human race. Yeah, I have a whole new field to mess around in.

[7x57]

I am going to add this part for those who may be reading this thread but do not own VMPS speakers. As Danny said in his article on the upgrade to a 626R, he got rid of the L-Pad. The L-pads on mine are 8 ohm units and the Neopanel measures 4.4 ohms DCR and the tweeter measures 3.5 ohms DCR. The L-pads tend to function somewhat as current sources as their impedance is higher than the drivers. These drivers have almost no resonance effects so they do not need a low source impedance to make them behave. Also, they are much more efficient than the woofers at around 95 dB at one watt. My woofers are 89 dB units, which is common for low frequency drivers that operate into the first octave of music. That means you have to throw away 3/4 of the energy going to the Neopanel and tweeter to get that 6 dB reduction. In a tiny room you might get to turn the mid and tweeter full on to balance the sound, but I doubt it.

However, you COULD turn your 626R or RM1 into a 95 dB efficient unit if you replaced the low frequency drivers with high efficiency midwoofers such as those sold by Eminence and others for the pro market sound reinforcement systems. You could then turn your L-pads fully on which is the simple way. To get rid of the L-pad, you would have to redesign the mid and tweeter crossovers to handle the lower impedances, or add sufficient series resistance to equal 8 ohms which kills a bit of the signal. High efficiency midwoofers might need a capacitor added for increased high frequency rolloff as they do not roll of by themselves at midrange frequencies as the low frequency woofer supplied by VMPS does. I would only recommend going this route for those with low powered SET amps and such. Those amps do not have good low frequency response anyway, so a high efficiency midwoofer would go low enough, after which you add a powered subwoofer if you have to go real low.

VMPS never really sold to the SET crowd with low powered amps, but the Neopanel and tweeters are efficient enough if you put in high efficiency midwoofers and forget about the low bass that VMPS floorstanders are famous for. The Neopanels really are magical in their retrieval of inner details and the ribbon drivers have flat impedance response that would work well with SET amps that have high output impedance. SET amps don't do the low bass thing anyway, unless they are some kind of large and exotic unit with radio transmitter tubes or such. I heard such a unit once, that ran at such high voltage that I made sure I stayed well clear, and it put out over 30 watts RMS.

The 626R and RM1 had the lowest efficiency because of their smaller cabinets and smaller woofers. The bigger speakers could run in the mid-90's sensitivity range, and you can get the 626R and RM1 there by getting rid of some of the low bass. The magic is in the Neopanels, and you need a subwoofer with the 626R anyway, so I think a low frequency woofer in it is a waste anyway. You can only tolerate 3mm of movement in a low frequency driver before doppler distortion becomes an issue, so that is why I had no interest in the 626R. The RM1 is basically a 626R that does not need a stand and subwoofer. You could wire an RM1 woofer to a solid state amp and run the Neopanel and tweeter with the L-Pads turned full on through a SET amp. Lots of possibilities with an RM1 or RM2.

[Danny Richie]

I don't think I can help you with your spirit resonances, psychotropic mind control, lily waves, Jade Helm conspiracies, blood-brain barrier, or artificial intelligence pursuits. But I can try to clear up a few misconceptions about the speakers that you have asked me about.

I can assure you that nothing was wrong with the crossover components. The measurements are typical of this speaker.

Also, only a few of the earlier Neo panels may have had polarity issues. Later units came from other manufacturers and did not. I even used them in hundreds of other speakers that I designed for another company with zero issues.

And these were not a kit. These were production models built at VMPS. So I tested them just as they were sent out.

Also, knowing what values were used in various crossovers between the Neo panel and EMIT-R tweeters aren't going to help you like you think they might. There wasn't even consistency in the parts values used within the same models from one run to the next. And low order crossovers like those used cannot be implemented in high frequency ranges like that without adverse effects. That is one of the reasons for the re-design. For those of us in the industry, that design loudspeakers, we typically try to make sure that at any crossover point the drivers acoustic centers are closer together than the wavelength of the crossover. Otherwise the drivers sound like two different speakers with separation between the two rather than a single speaker. So if I were to cross two drivers at 10kHz then the acoustic centers of the drivers would have to be less than 1.3" apart from each other. That is not possible with too many drivers. Also, using low order slopes means that if they are made to be in phase at the crossover point then they will be out of phase above and or below the crossover point where the wavelengths are no longer in phase. And then if the measuring or listening height were to change even a few inches up or down, then the slight delay in driver offset will again cause them to be out of phase. This is why those speakers have various cancellation effects up top. Even if you don't hear above 10kHz the cancellation effects will be heard even down into the 3kHz and 4kHz range because of the low order slopes.

For these reasons the upgrade we offered shifted the crossover point between the mid and tweeter much lower into the 3.7kHz range. This improved the phase relationship of the drivers, and improved both vertical and horizontal off axis responses responses. And this lower crossover point has no effect on compressing the dynamic range, stressing the drivers, or power handling. In fact I have used the same tweeters in other models crossed in the 2.5kHz range with zero issues, and there are hundreds of them out there still in use with no failures.

And you might want to review what the owner posted about these speakers before and after the upgrade. It might give you further insight as to the improvements.

Thanks....

[7x57]

S. Clark,

I worked in the biomedical equipment field for many years. I also know and went to and was treated by the world's best environmental health doctor. He treats people at his clinic in Dallas, TX, all the time for exposure to strong radio frequency electromagnetic fields, and many other environmental issues. The military has known for decades that radar negatively affects humans, which is microwave energy. Nazi scientists were experimenting with microwave effects on humans as far back as 1938. In 1959, using old tubed electronics, it was demonstrated that by using microwaves you could transmit a message into the head on one person in the room while nobody else got the message. The technology is so advanced now that you can transmit images into the head of a person. Russian scientists discovered back in the 1970's that by using phased array antenna systems, they could construct a 3D electromagnetic field that imitated the electromagnetic field of chemical substances. Thus, they could imitate the electromagnetic signature of nerve gas and get the same effect of nerve without unleashing nerve gas, which can come back on the person that sets it loose, and have major collateral damage unintended. Scientists were killing animals in lab tests with their electromagnetic field "nerve gas" in as little as 1/6 second. Also, there is this thing called a gamma ray burst, which can be unleashed by lightning. Certain substances in the air will unleash gamma rays when in the near vicinity of a lightning strike. It will immediately destroy the nervous system causing instant death with no physical damage evident. Probably what happened to those 300 reindeer mysteriously killed in the Hardangervidda area of Norway earlier this year. Some people died in Australia a few weeks away during a lightning storm from "asthma". Evidently they were having trouble breathing. I could go on and on about what is being unleashed in the environment.

By the way, most of the doctors out there do not believe what Dr. Rea would tell them.....until they get sick and are forced to go see him after all their pharmaceutical BS fails. Tesla and Einstein disagreed on many things. Tesla was and is right. Energy, frequencies and vibrations is all there is and what everything we call "matter" comes from. I refer you to The Double Slit Experiment, and you can get a video on Youtube. Even the comedian Bill Hicks spoke of this back in the 1980's. It should be embarassing to many scientists and physicists that a comedian knew what they still don't several decades ago. But hey, Einstein was wrong while Tesla got it right. Lots of info about Einstein and his plagiarisms on the internet these days.

Back during WWII, Col. Philip Corso worked in Army Intelligence and befriended a top Italian scientist. He informed Col. Corso that the human body was electromagnetic in nature and that physical science as being taught was wrong. Just like Tesla had already said. You can get a copy of Col. Corso's book, The Day After Roswell for free on the internet over at Bibliotecapleyades website. While in Army intelligence, he was secretly releashing captured technology from the 1947 Roswell UFO crash directly to private corporations for their development without Congressional knowledge or approval, since it had to remain secret. It resulted in lasers, night vision, integrated circuits, fiber optics, control by direct thought and other stuff. He said that he felt Naval Intelligence had captured similar stuff and were keeping it secret as well. Story goes the Navy got their first UFO back in 1942. Gordon Cooper said in an interview that he chased numerous UFO's while a fighter pilot in Germany. What is interesting is that people have been skillfully misled away from the real origins of most UFO's or to think it's all a bunch of bunk. I grew up near SAC bases and know its not a bunch of bunk. Seen them here in Montana too, as I live near a Minuteman III missile base. They get buzzed on a regular basis, it seems. The reports are true.

[7x57]

Danny,

What I have been asking for all along, and never seem to get, is the actual values of those crossover components in the 626R speaker you modified. We got vastly different measurements in the midrange and tweeter frequency range. I do NOT want anything that would measure as bad as what you presented at my listening position. If the owner is happy with them, then that is fine with me. If you could give me those values, that would be fine, and if not that is fine too.

peace,

Phil

[7x57]

Early B.,

The information I am requesting does not belong to Danny but belongs to VMPS and its heirs. I am NOT asking for Danny's crossover design. I am a VMPS owner, and Brian would not have held back information and he left all component values on his supplied crossover components.

Since when did VMPS component values become proprietary to Danny, and Danny never said he had propriety over them, but you say that he does??? You are making an assumption.

Danny assumes the component values will not be beneficial. I can assume some things as well.

Do you think Danny sells VMPS crossover information for a living? That is what I am asking for. I never asked for anything that was proprietary to Danny. I am asking for the VMPS factory specs to see what might have changed between his Neopanel crossover and mine. Whether or not he supplies them does not matter much to me as my VMPS speakers sound fine and measure much better than what he posted. People in other websites were wondering why the speakers measured so badly as well.

The lack of acoustic stuffing in the speakers has me wondering. Do others who own this speaker have the same unstuffed cabinets?

Also, Danny talks about the problems of low order crossovers, but failed to mention the ringing that high order crossovers exhibit, and the way they destroy musical timbre. The fact is that some prefer low order designs and some prefer high order designs. Do you want cherry pie or apple pie? It is a preference and not proof of absolute superiority of one over the other.

Also, a low order design can reproduce a square wave, such as the Vandersteen 2Ci did back when John Atkinson tested it for Stereophile magazine. Can your crossover design do that, Danny? If it cannot do that, then it is tearing apart the signal and reassembling it the way it wants. A square wave can be created from numerous sine waves of various frequencies added together. If a loudspeaker cannot reproduce a square wave at the listening position, then it cannot have correct timbre, and if it cannot, then it is a colored reproducer. Let's see a square wave, Danny! You have a real winner of a crossover design if it can do that. Also, did you supply an impulse response curve with your upgrade? I will have to go back and review the article in question.

A good test of a loudspeaker is to listen to it and then listen to the same thing from a single driver headphone of high quality such as an AKG K601 or Beyerdynamic DT880 or AKG HEARO 999 Audiosphere (it cost $1100 retail in its day, and designed as a pro use headphone in demanding applications), all 3 models that I happen to personally own. These are all highly rated models, so I know what something resembling natural sound happens to be.

I just want to know why that 626R could be so far off from what myself and others have experienced. You do not expect a German Shepherd to act like a Chihuahua. Did Brian Cheney send some really strange dogs out of the VMPS factory?

As for upgrades, the best crossover is no crossover, at least as far as passive components are concerned. Hook each driver directly to its own amplifier and do the crossover ahead of the amps in the digital domain. Forget the fancy capacitors and inductors and resistors. If you want coherence, go buy some new Ohm Walsh loudspeakers as almost everything runs through a single driver, except for a super tweeter. I can see why they sell direct. Audio dealers want people trading equipment, and Ohm loudspeakers are not a tweako thing. I would probably use an Ohm if I did not have my VMPS. You can even trade in your old speakers in  working condition on new models. 120 days to see if you like them. Stays in business with almost zero advertising. Owners that are probably more fanatical than VMPS owners. Easy to repair. Just take off the head and ship just the head back to the factory. The industry doesn't talk about them much, and I can see why. Modifiers have no use for them as well. Tend to be owned by people who listen to music more than listening to audio gear. Go figure. If the VMPS gives up the ghost........................

[Early B.]

Early B.,

The information I am requesting does not belong to Danny but belongs to VMPS and its heirs. I am NOT asking for Danny's crossover design. I am a VMPS owner, and Brian would not have held back information and he left all component values on his supplied crossover components.

Since when did VMPS component values become proprietary to Danny, and Danny never said he had propriety over them, but you say that he does??? You are making an assumption.

Relax, dude. I said the information was proprietary. I didn't say it was Danny's information.

[Danny Richie]

Okay Phil, the way you worded the question lead everyone to think you were asking for the values used in the speaker that I modified.

...is the actual values of those crossover components in the 626R speaker you modified.

So you are wanting the values of the stock crossover and not the modified one. 

I have been into several 626R's, and of the pairs I have been in, I did note that the crossovers were different from pair to pair. One pair used an iron core inductor on the mid and the other pair used an air core inductor on the mid. And in one case the crossovers in one pair of them didn't even match each other. Different capacitors and a different number of capacitors were used to make one value. I didn't write down the values as it was of no value. I have pictures of them though. And it really doesn't matter. It does not work. You can throw any values that were even close to the original values for either of the two pairs that I have been in, and it really won't matter.

And for whatever it is worth, the first pair that I measured (an earlier produced pair) measured better than this later model.

And the reason your measurements do not match mine is that you are taking a room response from the listening position. And it could even be both speakers playing at the same time for all I know. My measurements were taken of the speaker only with no room reflections. And if I measured your pair in the same manor then the measurements of yours would also look very much like that of the other two pairs that I measured.

And higher order crossovers do not exhibit ringing or destroy musical timbre. I am a fan of less is more and try to minimize crossover parts totals as much as possible. I even use first order crossovers on occasions but rarely in crossover ranges above 200Hz. They certainly can't be used in higher ranges like 10kHz. The out of phase cancellations are just too great. You'll get 6db peaks and 15db dips every time. And that has a far greater adverse effect than just about any other problem that you can come up with.  You'd be better off running the mid to 10kHz with no tweeter at all. At least then it would play to 8 or 10kHz (depending on listening height) with no other problems other than a sharp fall after 10kHz. With the tweeter added, and only a first order slope used, there are cancellation effects at all frequency ranges above 3kHz with peaks and dips varying with height.

Also, a low order design can reproduce a square wave, such as the Vandersteen 2Ci did back when John Atkinson tested it for Stereophile magazine. Can your crossover design do that, Danny?

Unlike the Vandersteen speakers (that also uses first order crossovers) the VMPS drivers are not physically aligned. So the actual time alignment is all over the place. And any single driver can be used to produce a square wave. The problem is that when the wave from one that is out of phase from the wave of another then you have no wave at all.

[7x57]

Thanks for the reply, Danny. My pair is extremely early, ordered only 4 months after the Neopanel models were released.

I have the iron core inductor on the mid, air core on the tweeter. Some people think VMPS use first order crossovers, but they are second order. First order on the woofer, but the woofer also has acoustic rolloff added. Vertical position is not as critical as Vandersteen 2Ci.

I am not seeing the cancellation effect you are talking about. I do have a floor dip around 300Hz, but that is normal and unavoidable. I have the normal floor/ceiling boost around 70 Hz and a sidewall boost around 55Hz, which are the calculated half wave values. There is a dip between these peaks, of course. Nothing I can do about that, and these are the biggest discrepancies in frequency response. I used the Stereophile test CD, second version.

I did many measurements with each speaker only and both speakers together. I also did 1-meter on axis measurements and the slot loaded radiator measurement, which is why I decided to vitrify the passive radiator as I had some midrange noise coming through.

Even the tweeters were usually less than 1 dB variation when I miked them closely. As I said, all I had was woofer foam rot problems, and the foam was thin is spots and probably why it failed so soon. All my crossover components were "spot on" in tolerance.

In the last couple of years, Brian Cheney was sick and often did not answer the phone. I called for a new tweeter diaphragm a few months before he died and it took several calls over a period of days to get through. I would not be surprised if things were falling apart a bit at VMPS during those last couple of years. He had the RMV60 in development and I suspect too much was going on in his life with the deteriotating health and all to keep up with things the way they should be. I ordered some of those panels that stick on to the neopanels and basically do the same as the CDWG, but I never got them. That was shortly before he died. I read the obituary just before I was going to call and see where my panels were at.

Brian said his speakers would not measure as well as others. You have proved that point. About the 626R bass. You might as well seal the box because that little 6.5" woofer cannot make real VMPS bass. You need a subwoofer if you get a speaker that small unless you live in a closet.

The most important thing is that you find something you really like listening to. The VMPS owners circle is one of the biggest owner circles in this website. In spite of the fact that VMPS was always a small company. That says a lot right there. VMPS no doubt built some stinkers, and that is probably what you mainly see a modifier working on. I have listened to Thiel and Magneplanar and JM Lab (owned a pair) and even a Soundlab electrostat, but they don't move me like the RM1. It is something that measurements do not explain. Test instruments do not have emotions. Stuffed animals do not make good pets, and most loudspeakers remind me of stuffed animals compared to my real dog......that craps on the floor sometimes. I guess he just measures a bit bad.

Phil

[Danny Richie]

I am not seeing the cancellation effect you are talking about. I do have a floor dip around 300Hz, but that is normal and unavoidable. I have the normal floor/ceiling boost around 70 Hz and a sidewall boost around 55Hz, which are the calculated half wave values. There is a dip between these peaks, of course. Nothing I can do about that, and these are the biggest discrepancies in frequency response. I used the Stereophile test CD, second version.

You are not going to see the speakers actual response using test tones and an un-gated time window. You are sending a continuous tone with late arriving reflections that get summed in with the on axis response that can be in phase or out of phase depending on the frequency and time delay.

You will only see the actual response of the speaker if you measure it using a gated time window that will allow you to see the response of the speaker without room reflections.

I can easily explain this further for you so that it will make sense if you like. Just give me a call at GR Research. Our number is at the bottom of every page on our website. It will me much easier to explain that to type a long drawn out explanation. And I can easily answer any other questions.

[7x57]

Thanks for the interest, Danny.

You are correct about many things. The two of us use different test instruments, and get different results. My best test instrument is an AKG HEARO 999 Audiosphere II headphone system. It is a complete system intended for pro audio engineers. I was turned on to it by a German engineer who uses it in his mastering studio and had something to do with the dersign, as he knows the AKG folks. It was the first wireless headphone that gave nothing away to wired headphones. It is a single transducer unit and has no crossovers or phasing problems. It has many features no other unit has. It has seven positions to compensate for the audio canals of different people. It has two digital inputs and can be used as the system DAC. It has an analog input with variable out, so it can be used as a preamp. It can synthesis surround sound from a two-speaker audio system. It can synthesize different environments such as club, auditorium, stadium for checking against sound systems in those environments. It has settings for voice, music, movie and normal situations. The wired headphone amp is made for pro AKG headphones such as my K601. This is the only setup that sounds better than the wireless headset. The reason is simple: The K601 is slightly midrange forward (typical AKG) and the amp is slightly midrange scooped. Inserting a DT880 in the amp increases the scooped character of the DT880. Some people in the know preferred the K601 to the K701 or K801, but the audiophile magazines shy away from the pro AKG products. The HEARO 999 Audiosphere II bombed in the audiophile market which is why I got as new $1100 unit for $450 on closeout. The whole kit came in a carrying case, and you even get to choose between leather ear pads or velour ear pads as both are included. A real Rolls-Royce type of audio gear. To a professional, it was well worth the $1100. Since you get a preamp, DAC, headphone amp, wireless transmitter, and some tweako features found nowhere else in a single unit, it was a windfall for me.

When Leo Fender thought he was going to die, he sold his company and CBS engineers took over. They were aghast as to how poorly the guitar amps measured. They turned them into something more high fidelity with flatter response that measured better. They forgot to measure the Fender guitar pickups. The pickups are humped, so the guitar amp tone controls had to be scooped. Musicians refused to buy the new amps, so CBS went back to Leo's original circuits (which had a lot of RCA design in them) and musicians were once again happy.

The moral is that the final arbiter is the ears of the listener. The HEARO 999 can be tuned to the ears of the listener. I am going to take your previous advice and turn off the tweeters in my RM1 and listen with only the Neopanels running free on the top end. I will then do some more listening to the same music through the K601 and wireless headsets. I will get back with my results after extended listening. The fact of the matter is that much of our music these days is mixed through high quality headphones, with Quincy Jones be a really avid promoter of AKG headphones, saying they are the best he ever used.

The fact of the matter is that sound from the speakers and the room is bouncing all around anyway, and it would be rare for a truly linear loudspeaker to sound linear in most rooms to most people. Also, it  was a requirement in my previous job to have my hearing tested every year. My ears are linear up to 8 kHz, after which the sound falls away.

Don't you wish more audio engineers had their hearing tested, and then used the results to equalize the sound so that they were hearing in a linear manner? At least I have some proof that I hear in a linear manner up to 8 kHz. Beside testing just the gear, I have tested myself.

Why would an audio engineer measure only equipment without measuring his own hearing as well? I wish audio testing was required of every audio reviewer I ever read, and the results published along with their reviews. Just my 2 cents. Since they do not do this, my ears are the final arbiter of sound quality for myself.

[7x57]

I listened to music late at night when the electricity here is the cleanest. Turning the tweeters off did not make much difference. I slightly prefer the tweeters at my normal setting. The rise in output in the Neopanels around the presence region is the biggest defect, but not really aggravating. The sound is a bit scooped out between the floor dip at 300Hz and the rise in output beginning around 1 kHz. However it is only around 1 to 2 dB low between floor dip and 1 kHz and very flat by my measurement. If bringing up this region to match bass output, the presence peak is much more noticeable. It sort of has that old DT880 scooped midrange effect. Brian Cheney likes large scale orchestral music and people who like this kind of music think that a slightly elevated bass and treble gives a more spacious and open sound. The Beyerdynamic DT880 cans work well on that music as well, but the high end AKG cans definitely sound better on vocals and guitar driven rock and pop music. It's the best midrange of any set of cans I ever heard. Having owned pro level Grado, Sennheiser, Beyerdynamic and AKG cans, I can definitely agree with Quincy Jones that AKG pro level cans are the most natural and engaging to listen to (not the broadcast headset cans, which by design are not linear). From the K601 and on up the line. The Neopanels sound a lot like the AKG cans except for that peak in the presence region.

When I was building the kit, I had misgivings due to the broad flat sidewalls of the Neopanel box and the cheap fiberglass stuffing. I only had enough Acousta-Stuf to properly pack the woofer cavity. My math said there would be a resonant peak around 2.5 kHz, and that is what I have. Brian admitted that he later used long fiber lambswool in the midrange cavities and he recommends that upgrade. I just don't have any and will have to get some. I might just order a pound of Acousta-Stuf since it will be easier to get than long fiber lambswool.

The best crossover upgrade is no passive crossover. Pro installations were abandoning passive crossovers a long time ago and it's time for audiophiles to come out of the crossover stone age. I have a spare B&K ST-202+ amp that can power the bass section. That could get rid of the inductor on the woofers and an inductor and capacitor on the Neopanel. What I need is a digital electronic crossover that I can place between my preamp and the power amps. It also needs to be combined with equalizer functions. Then I can dump the L-pads as well. I will probably have to go looking in the pro audio market to find what I need.

In a recent email, a guy who was asking me about my C-J amp said that the Crown pro amps were now getting good reviews by audiophiles. I said give it a try because they are mass produced, widely distributed, and have repair centers all around the country. My AKG HEARO 999 purchase showed me that pro gear can rock with the best audiophile snob stuff. It's the cheap pro stuff you have to avoid. I should be looking in the pro audio market for a nice electronic crossover/equalizer so I can dump passive crossover components altogether.

Phil

[Danny Richie]

The fact of the matter is that sound from the speakers and the room is bouncing all around anyway, and it would be rare for a truly linear loudspeaker to sound linear in most rooms to most people.

Actually it is very critical that a speaker has a linear response in the off axis. The reflections that you get in the room are based on those off axis responses.

And they do not get averaged together like some might think. And what you get with a continuous test tone is not what you get with music playback. What you get with music playback is an arrival and then a delayed arrival (reflection). So the signals do not line up and sum like a continuous sine wave signal.

The best crossover upgrade is no passive crossover. Pro installations were abandoning passive crossovers a long time ago and it's time for audiophiles to come out of the crossover stone age. I have a spare B&K ST-202+ amp that can power the bass section. That could get rid of the inductor on the woofers and an inductor and capacitor on the Neopanel. What I need is a digital electronic crossover that I can place between my preamp and the power amps. It also needs to be combined with equalizer functions. Then I can dump the L-pads as well. I will probably have to go looking in the pro audio market to find what I need.

Actually, the opposite is true. When using high quality components the difference between having the high quality passive parts in there and not having them in there is very minimal. But the difference in the quality of various digital crossovers or digital filters is very significant. I have worked with the best digital crossovers available and can put you in touch with someone that can provide you with a much higher quality digital system than anything else you can buy. But it still does not beat out passive crossovers and the top level DAC and digital system that I use. It is pretty close though. Most of the rest of them are a long way behind.

And what the pro market uses won't beat out a budget CD player for audio playback quality. We audiophiles are a lot further from those stone ages than you think. If only there were a bleed over from our market into the pro market....