FAQ

The big speakers travel strapped to a pallet, the grills facing inward. Inside the carton are sheets of 1.5″ solid styrofoam full width and length protecting sides and back. You can load pallets on top, drop them, or otherwise abuse without damage.

The only assault not prevented is the old forklift-tyne thru the carton. Even wooden crates don’t stop that. Hasn’t happened in a long, long time.

We use a function generator for at least 24 hrs (48 hrs on large systems) that sweeps 20Hz to 2500Hz every two seconds at the 2W level, a very strenuous breakin. It’s the equivalent of 10 times that time with music. But I agree all parts breakin: caps form, wire sets up a conductive path, and there is the loosening of suspensions from motion and excursion.

Did I mention the damping adjustment is VERY IMPORTANT?? I thought so.

Do you also burn them in after assembly (floorstanding loudspeakers)? For how long?

They get a minimum of 48 hours on the function generator which includes a 20Hz to 2500Hz sweep repeated every 3 seconds. Plus they are then listened to for several hours and a preliminary tuning of the PR and setting of the level controls is done. The rest is up to you.

“Q” stands for “quality factor” and is a measure of the system bass characteristic. Generally a “Q” of .7 is considered ideal if the entire system (woofer plus enclosure plus vent if any) can achieve it. Ported systems have high Q (above .7), sealed systems have low (Q) (below .7). A tunable passive radiator system like ours is the best of both worlds, since it adjusts to various Q’s and even compensates for the series resistance of your speaker wire.

In the past attempts have been made to produce enclosureless bass systems with very high Q’s designed to overcome the severe rolloff caused by the dipole effect. Carver’s ribbon speakers used an array of open-baffle 10″ woofers with extremely high Q’s (around 10). It didn’t have good extension. Some people prefer overdamped bass (Q of .5 and below for the system). I believe in the middle road, system Q of 0.7.

The ribbons don’t sag. They are clamped at the edges all around, and the diaphragms weigh about 1.5g. No mass to speak of, so no weight to pull them down. They should last basically forever. The tweeters have a moving mass of 0.1g, same thing. Longevity should be excellent.

If the foam appears intact leave it alone. If you can poke your finger through it you’ll need to replace the woofer. We have a new 38cm driver with a double thick surround guaranteed 20 years not to rot. The 30cm is rubber.

Spikes both couple and decouple the cabinet/speaker output from the floor.

Bass wavelengths are quite long and, below about 200Hz, boundary dependent. Without a surface to travel along they dissipate somewhat rapidly. A woofer would ideally be as close to a boundary (floor) or multiple boundaries (side and back walls, and even ceiling) as possible, or at least a constant distance from them. By elevating a cabinet from the floor with spikes, you reduce the propagation efficiency of bass wavelengths. So, you decouple bass from the room, even if ever so slightly. The effect is quite audible.

Spikes couple cabinet output to the floor, turning it into a transmission medium. Soundwaves travel through many solids much more rapidly than through the air. Instead of “moving the floor”, cabinet output is transmitted to the listener ahead of the music, through the floor (made usually a good carrier of sound like wood or stone). This is why I’m no fan of spikes, and the Sunfire people aren’t either.

Try some damping compound between the spikes and the cabinet (not between the spikes and the floor) and let me know if you hear a difference. I’ve seen composite spikes that were metal only on the tips, otherwise rubber. Should work better.

Since spikes do two things I don’t like–diminish bass propagation, and transmit or even amplify spurious cabinet talk–I never recommend their use.

As Sunfire recommends, rubber or other absorbent materials can be used as feet for speakers or subs.

Since a lot depends on the height of the stand and the materials from which your floor is made, why not experiment? Personally I like Dynamat.

This calls for a booklength response. I’ll give you a few short pointers: 1. Use push-pull ribbons. Single ended waveform fidelity is terrible. You only build a ribbon single-ended to save money. 2. Use low crossover freq. Right now no ribbon mid we have crosses over higher than 166 Hz. 3. Have the ability to adjust levels with great precision. Our electronic crossover permits 0.01dB increments per channel. 4. Build passive crossovers to very tight tolerances. For us that means four decimal places, or 1/2000th of 1%. We laugh at the tolerances (5%, 1%) even the best competitors use.

We have two setups to voice crossovers/speakers and a system must sound good on both. First is Krell MD10 CD transport, Wadia 27ix DAC, SST Son of Ampzilla amplifiers and Kimber Select IC’s in a completely treated LEDE 14×31′ room. Second system is a $99 Philips CD changer, Parasound 2200, Ratshack IC’s and Belden 16 gauge speaker wire in a completely untreated, very large room. Between the two it’s very easy to hear flaws and problems. We optimize xovers to 1/2000th of 1% tolerance, which makes the 1% and 5% parts found in commercial designs look pretty silly. It’s important to us however.

Yes, and I do it myself. Have a B&K Precision cap meter accurate to four decimal places. Each xover is trimmed to exact value, no tolerances. This means, for example, 1.600uF, not 1.6uF. We laugh at 5% and 1% parts. You only get repeatability with high levels of precision.

Inverted polarity means the leading edge of the music waveform is ongoing negative. Trumpeters suck their instruments, singers inhale their notes. It’s an amusical, dull sound. Try both polarities to discover the correct one. Requires you reversing the speaker leads at both speakers. Don’t bother if your speakers are the ordinary kind with inverted polarity drivers. It’s wrong both ways.

You can easily hear polarity on all our speakers. The “MP” in “VMPS” means “minimum phase”. All drivers are electrically in phase, and first order networks perserve the phase coherency of the envelope. Common practice is to wire the drivers in a multiway system alternatively out of phase, to maintain good amplitude linearity through the crossover region. Unfortunately in the passband the midrange (of a 3way) is out of phase with the woofer and tweeter. Most manufacturers do it this way because it measures better. The practice destroys the integrity of the music signal and I hate it. You can cover the “in phase notches” in a crossover network by various means. Although the in-phase speaker will measure less flat (particularly in the crossover region) than the non-minimum phase design, its sound is superior. Some designs in addition are completely phase random, with slopes claimed to be approaching 100dB/oct. You can’t tell whether the music is coming or going with such speakers, which I also dislike.

The best known “ribbons” weren’t ribbons at all, but single-ended planar dynamic. They only reproduced half the waveform, THD averaged 30% below 5 kHz, where a push-pull tweeter came in. To add to the problems, the tweeters and midwoofers were wired in opposite polarities. There were huge differences between the Apogee sound and convential cone dynamic speakers because the Apogee’s errors were so huge. Not to say they didn’t sound good, they just had serious design flaws.

Todays push-pull midrange and treble ribbons are a completely different animal. They sound a lot like conventional speakers (if you can find such with all drivers wired in phase, still a great rarity). Properly executed modern ribbons just sound more like live sound.

With the right amplification VMPS ribbons sound extraordinarily lifelike, even the smallest model. Normally I am not great enthusiast for my own stuff (all I ever hear was the problems) but two nites ago, listening to the RM 2 Neo’s through a pair of CJ Premier 12 tube monoblocks, the sound was sublime, without defect. The music (Beethoven Pastorale, B. Walter on CD from 1958) haunts me as I write.

I always thought a speaker must be flexible in placement and setup. It should adapt to its environment and associated equipment, not the other way round. After all, your chances of finding the exact right sources, IC’s, and speakerwire by trial and error are about zero, which leads to the frustrated audiophile who owns good equipment and is getting bad sound, wanting to chuck the hobby completely.

The RM 2 Neo may be placed as close as 4″ to a back wall, tho I use about 2.5′. Ditto the side wall. It can go in the middle of the room. It can be adjusted for rooms as small as 8×10′ or as large as 20×50′. Level controls and the bass damping adjustment of the passive radiator permit all these things.

Too many owners ignore the setup instructions and get less than optimum results. A VMPS floorstander sets up like no other speaker and you have to train your ear to what is better and what is just different. It’s worth the effort.

A very good compromise would be to get an SS amp that has good current and biamp your speakers. You can use the tube amps for the mids and up and the SS for the bass. I think you might really like the results. Of course you need a good electronic crossover.

Actually passive biamping with the builtin crossover works very well and no electronic crossover is necessary (though you can use one once the woofer coil is bypassed provided the xover offers 6 dB or 24dB slopes, don’t use 12 or 18 dB).

You don’t have to worry about the power mismatch, it is input sensitivity you worry about. Typically tube amps have higher input sensitivity than solid state. If the level difference is small you can compensate with the speaker level controls. Otherwise you’ll need a volume pot on the tube amp, or use a tube amp that has level controls, or an integrated tube amp.

If your pre has one set of outputs get a Y connector/splitter to turn one output into two. Run fullrange signals into each amp, the speaker does the crossovers. Once you have adjusted relative levels you’re ready to biamp.

If you don’t do the level matching all you’ll hear is the mid/treble amp, with very faint bass.

Level controls can’t increase output, only cut it. Therefore you need an adjustment on the louder (more sensitive) of the two amps, unless you’re using identical amps. Tube amps are invariably more sensitive than SS.

You can sit fairly close to the RM 2 and get a wide soundstage. Simply toe in the speakers more severely towards the center the closer you sit so that they crossfire a few feet in front of you.

My room is 31′ long and I sit about 25′ back. I toe the speakers in so I can see the front and back outside edge of each speaker cabinet, and a good expanse of the outside baffle. I toe the speakers in until the center image is very firm. More toe in makes the image bloat, less toe in makes it diffuse. If I move say, to 10′ away I make a sharper angle towards the center of the room, always so I can see the front and rear outside cabinet edges. Try it and see.

The idea is simple and necessary. The bass loading affects the entire spectrum right up to the treble. I adjust my speakers all the time, like when trying out new equipment. Especially with the Analysis Plus wire (which required considerable undamping) I’m glad the adjustment is there.

Most adjustments have been taken out of speakers since some manufacturers concluded customers are too stupid to follow directions.

I just did an installation with the RM 40 where the owner, for reasons of his own, had a 5m run of M350 interconnect to a subwoofer and another 5m run back to the power amp from the woofer line level out. In the bypass mode that meant 10m of interconnect between preamp and amp. The signal loss was amazing, including virtually the entire bass range. The level was down about 2dB according to the preamp volume control which had 1dB increments. Restoring the system to a 2m pair of IC’s also restored all the music.

I am firmly in the short interconnect, long speaker wire camp.

As a professional speaker designer I will comment briefly on this subject.

Very few designers use anechoic chambers for speaker measurements any more. Most such chambers are not large enough for accurate measurements below 200Hz (the so-called “boundary dependent” region). Many engineers utilize gated computer-processed measurement systems, such as the one I use, Sysid. Sysid generates phase, distortion, transient and amplitude response measurements simultaneously. Most people who refer to “anechoic frequency response” measurements are referring to amplitude alone, which is indeed an inadequate spec that hides more than it reveals. I make my measurements in the near field (about 1/4″ (6 mm) away) with a 1″ B&K mic and a John Curl custom mic preamp.

I find such measurements most useful in transducer design, rather than system design, since the problems you can measure in a driver can be fixed either by driver parameter adjustment or with crossover filters. System measurement is limited by where you place the microphone. If people listened to their speakers at 1m on axis, such a measurement might be helpful. They don’t, and it isn’t. Still, this is the most common “anechoic frequency response” measurement.

On the whole I would say it is impossible to design good speakers without accurate measurements. I would also say it is impossible to design good speakers with accurate measurements alone.

The mics in any SPL meter I have used (including B&K) are not flat enough, particularly in the bass, to give an accurate reading, and most signal generators aren’t either. It takes very sophisticated equipment to make accurate measurements on speakers. If you really want an indication of how good the speaker is you wish to measure, listen to it full range on familiar music. Better drivers sound cleaner, clearer, faster. Train your ears and leave the test gear to the guys with big bucks and experience. And even they are pretty clueless, most of the time.

Ribbons function in the same environments and follow the same rules as other transducers. If you want a ribbon to extend into the bass range its suspension must be compliant enough and the moving mass high enough to permit accurate reaponse in that area. This necessarily limits its usefulness in the trebles. The Raven 2 tweeter, which we use crossed over at 6.5 kHz, is an excellent example. Its resonance is much lower but it is comfortable as a tweeter with flat response from 5 khz to about 30 kHz. R3 attempts to responddown to 500Hz but is still a monopole with a chamber behind the diaphragm which is not capacious enough to absorb an energetic 500 Hz backwave. So, the R3 is really a tweeter with a fairly low (500Hz) resonance. Lots of softdome tweeters, for example, have resonances in the 700Hz to 800Hz ranges. Like the R3, their power handling is poor in that range. If you were to apply a 30W sine wave at 500Hz to the Raven R3 the diaphragm would vaporize. Power handling is a real problem with the R3.

So, there are many reasons why there is no such thing as a fullrange speaker. Our panels with 166Hz to 6.9 kHz come pretty close. In the bass, nothing beats dynamic woofers in a very stable columnar array. Which is what we use.

The production budget for a system retailing at $2,000 in the US will run about $200 (US) for the pair. This explains the small woofers and the $4 tweeter on most products. There is no excuse for the electrolytic tweeter cap; a polypropylene of the same value might have cost $3 instead of 80 cents.

My experience is that the High End exists primarily as expression of company owners’ vanity. These outfits never make a profit, go through huge sums of Other Peoples’ Money, fail and reform only to repeat the process. In other words a large, costly ego trip readily supported by the audio press, some of which is performing the exact journalistic equivalent for the very same selfish reasons. Or perhaps you think “The Audio Critic” (one example) exists to sell ad space?

Mid fi and consumer audio corporations are out to make a buck; I never met anyone from those quarters who cared much about sound quality or even music. That area is dominated by offshore mass marketeers with all the heart of a large granite slab.

So just what am I doing here? Hopefully advancing the art, taking chances, indulging a taste for high quality and low prices and, I might add, making a living. And there is always the music. I make sure my rig gets the music to me intact; it’s my job and my reason for existing. My first setup was a Garrard Lab 80 and a Grundig table radio, which did just fine for the first year or two in this hobby. I built my first speakers at 15 and have done little else ever since. I’ve gotten better at it. If you find reproduced music lacks soul, maybe the lack is in the listener, not the equipment. Hear some live music and see what effect it has on you, if any. You might study music like I did, or pursue musical genres with which you have no familiarity. The unadventureous never develop the depth to receive the true message of op 131 or early Elvis or Fisher-Dieskau or Louis Armstrong.