[SoundStage!]Max dB with Doug Blackburn
Back Issue Article
July 1999

Let's Get Right to the Point - Nordost Pulsar Points

Feet for your audio components are over-hyped and potentially over-priced accessories. Let’s blow up some myths right here and now and discuss one of the best-sounding feet I have ever encountered at any price.

Cones are mechanical diodes…BUZZZZ, wrong!

For years cone makers have claimed that cones are "mechanical diodes" passing vibrations only in one direction. This is baloney, and here is how you know. Vibrations are three-dimensional things. A table or rack shelf vibrates in three directions: up and down, left and right, and front and back. Hold a board in your hands, a board large enough to support an audio component. Put an audio component on the board on some cones. Now move the board up and down slowly. Do the cones and component move up and down too? Yes? OK, then the cone isn’t isolating vertical motion. Move the board slowly left and right. If I’m not mistaken, the cones and component also move sideways at the same time. So cones provide no left/right isolation either. Now move the board slowly front to back. The cones and component also move front to back too, right? Of course they do. This is because the cone is not an isolation device of any kind, and it is not a mechanical diode. Cones are simply a kind of foot that couples something, an audio component for example, to something else, usually a rack shelf. Moving the shelf slowly is no trick. Higher-frequency vibrations will behave exactly the same way the board and cones and component behave when the resonances are slower.

Why do cones work then? Because anything you use as a foot changes the sound of the component: marbles, steel or titanium balls, bubble wrap, CD jewel cases, wood blocks, rubber balls, tennis balls -- anything and everything you place in contact with the component or the shelf the component sits on will change the sound you hear. Cones are no different. And each variety of cone sounds different. Brass, composite, ceramic, carbon fiber, aluminum, every and any material sounds different, and none of them are automatically better than any other material. You can pay $10 for some cones and $100 or more for others.

In the end, you are paying for different mechanical resonance properties in the cone -- and perhaps for "sex." What’s sexier: a cool-tech new material or brass or plastic? Yet there is no way to guarantee that the cool-tech device will be of any more value sonically than some other alternative until you try it and compare it to other feet. Each different cone does have a signature to the sound it imparts to a system. In fact some manufacturers offer different versions of their cones, each sounding slightly different -- it’s all in the mechanical resonances. Each version of the cone has slightly different mechanical properties and those mechanical properties translate to a particular sound. The concept to keep in mind is that while those sonic signatures will remain consistent, systems will react differently to them. Expensive cones do not isolate better; they only resonate differently. Expensive cones are not more effective vibration blockers; they only resonate differently.

How do you deal with feet then? Experiment, try lots of different types, and do not assume that you should use the same foot under every component. Personally, I keep a "foot library." At any given time there are three to five sets of feet in the library that are not being used because other kinds of feet sound better to me at that particular point in time. A year or two ago I resurrected some Navcom (soft rubber) puck-style feet for use under some power-line conditioners. In five years I could never find anything the Navcom feet sounded good under until the PLCs. You never know when something in the library will become useful again.

Geometry, my dear, geometry…

Since cones don’t isolate, what about other shapes for feet, cylinders for example? You could use cylinders for feet if you wanted to and they would sound different than cones because cylinders resonate differently. Cylinders also have a different contact patch on one end compared to a cone. That different contact patch spreads out the load. Four pounds on a cone point might represent a load of five to ten pounds per square millimeter. But make the cone into a 1"-diameter cylinder and the loading of the contact area changes to about .08 pounds per square millimeter. This has just got to sound different. There is no possible way it could sound the same. Because of differences in the load and contact area, the resonances interact with the cone or the cylinder at different frequencies and different amplitudes. The amount of energy involved is the same in both cases; it is just distributed differently. Ditto for cubes and rectangular solids. Understand that some people might even prefer the sound of a brass cylinder to a brass cone -- there is no way to know for sure unless you try both shapes. But since there aren’t any cylinders being sold as feet that I’m aware of, unless you have your own machine shop, it may be tough to make a comparison.

Soft, hard…I’m so conflicted!

If cones are all different-sounding and there is no best cone, what about softer feet? Same thing. They all have different mechanical resonance signatures and they all sound different -- significantly different than hard feet. You should be trying different types of soft feet in your system too. The ones that don’t ring your bell, set aside for some future use. The ones that do ring your bell, try them under several different components before deciding how many sets you might want to add.

Presto change-o

Tired of the way your system sounds? Antsy for an expensive upgrade? Move the feet around and try some different ones you already own. Chances are you’ll find another combination that sounds different and therefore better.

You gotta have spikes or cones under speakers -- BUZZzzzz!

Here’s yet another long-held high-end myth. You gotta have cones because someone tried cones somewhere along the line and they seemed to improve the sound of every speaker. Problem is, nobody tried any non-cone/non-spike substitutes. We all assumed that you had to pierce the carpet and dig the point of the spike/cone through the padding into the subfloor to really get the speaker hooked up with the floor. If you had tile or wood floors you were partially excused -- you could use pennies or nickels under points to keep from marring the floor. What if this turned out to be incorrect information? What if there is a foot out there that sounds as good or better than any spike or cone -- under loudspeakers or anywhere else?

My pulsar is beating

Nordost has come up with the unlikely Pulsar Point, the non-cone cone. They have all the advantages of cones and none of the disadvantages. In the photo of the Pulsar Point you can see how the two parts of each Pulsar Point are constructed.  I drew this so don’t blame Nordost if it doesn’t look professional. There’s only so much time I was willing to invest in the illustration! The Pulsar Point has two pieces, the top and the bottom. The top is simple. It is a cylindrical thick disk of aluminum with a slight cup (depression) machined into the downward-facing surface. The top could be flat, but every Pulsar Point I’ve seen so far happens to have 6mm or 8mm threads in the top, so screws can be used to hold the top in place on the bottom of various components.

The bottom is harder to describe. It looks like the tip of a very large bullet with a round groove in the top. The groove separates the rounded tip of the bullet from the rest of the body. This blunt rounded tip rests in the center of the cup on the top half. The ridge around the blunt tip supports the top when the top is loose and you are setting a component onto it, a clever and worthwhile design trick.

One hundred dollars gets you four aluminum Pulsar Points. Personally, I find four non-adjustable feet almost impossible to use. You can never get all four loaded with the same weight. So I took to using three per component with great results and for every three sets you buy, you end up being able to support four components, a decent deal, if not exactly cheap.

I really like the way Pulsar Points sound in my system. They impart a sense of dynamics and drive to the system that other feet don’t. They also seem effective over a wider frequency range than most feet. Black Diamond Racing cones are the only others I’ve tried that seem to affect as broad a frequency range, though they sound quite a bit different -- less dynamic and more delicate than Pulsar Points. Brass cones sound more lightweight and lean towards an emphasis of the mids, upper mids and lower treble. Pulsar Points bring out detail with out any sense of emphasis anywhere. Other cones sound lumpy in comparison. There will be multiple bands where improvements are heard interspersed with other bands that are not changed or that may sound even a little worse. This effect is not obvious until you hear Pulsar Points in comparison to other feet. The other feet I used as references seemed just fine on their own -- until I heard the Pulsar Points. I’ve ended up replacing the Twinkle-Toes on two LaserBase equipment isolation/support stands with Pulsar Points to great effect. The Pulsar Points sound a little better and cost half as much as the manufacturer’s option. Pulsar Points are also on duty under the preamp’s outboard power supply, where they decimated all challengers most convincingly.

I’ve also tried four different floorstanding loudspeakers with Pulsar Points versus the spikes or cones supplied with the speakers and in all four cases the Pulsar Points sounded clearly better. Unfortunately, the thread sizes in the Pulsar Points don’t match the thread sizes used for the stock spikes or cones, so I haven’t been able to secure the top half of the Pulsar Point to the loudspeakers yet. A good stiff shove will slide the speakers off the Pulsar Points, but that’s OK in my house where there are no kids or pets to raise the hazard level. Nordost does plan a wide array of thread sizes eventually, so the future will undoubtedly be more stable.

My speaker-and-Pulsar Point experiment totally wrecked my long-held "knowledge" that you had to spike your speakers to get good sound. I compared Pulsar Points to black anodized Tip-Toes and to Michael Green Audio Points (Audio Points are now sold by the machine shop that used to make them for Michael Green while Michael Green is now making MTD brass cones on his own equipment). The Pulsar Points clearly won these comparisons by sounding more open than Tip-Toes and more uniformly balanced top to bottom than the Audio Points. There was no downside to the Pulsar Points either; there was no time when I wished I could combine some area of performance of the Tip-Toes or Audio Points with the strengths of the Audio Points. Compared to generic carpet-piercing spikes with lock nuts, the Pulsar Points were just in another plane of performance altogether; everything about the sound of the speakers with Pulsar Points was better. After a few hours of supporting a 95-pound speaker, the Pulsar Points make a circular impression in the padded wall-to-wall carpet. There is no contact with the subfloor when using Pulsar Points. You have a flat aluminum surface about 1.5" in diameter against the carpet and that’s it. Move speakers around for months and you’ll never put a hole in the carpet backing. I can’t help wondering just how great Pulsar Points would be under stand-mounted monitors, but I have none in-house to test at this point.

Magneto and titanium man… and the crimson dynamo…

Nordost is threatening to unleash titanium Pulsar Points on the world for the rather substantial sum of $500 for four. Sounds expensive until you realize that a 1" titanium ball costs about $90, and there’s more than a 1" sphere of titanium in a Pulsar Point. Why release Pulsar Points in a different material? Every different material has different resonances. Titanium Pulsar Points sound different than aluminum. Will it be worth $500 versus $100? I can’t imagine, but Nordost demos of titanium versus aluminum at the CES and Chicago HI-FI Show certainly make it obvious that there is a significant difference in sound between the two. Will you like the titanium better? It’s sexier than aluminum, for sure, and that alone predisposes one for a bias to like the titanium better. I haven’t heard them yet in my system, but I expect to before too much longer.

By now there are readers out there about to pounce on me. Didn’t I tell you us that there is no "best" foot, and didn’t I just write a bunch of stuff about how cool the Pulsar Points sound? Isn’t that going against my own premise? Well, you could look at it that way, or you could look at it as just another bit of information and a foot worth trying. You can put the set in your foot library and wait for the day when they meet their destiny if they don’t work out right now. I can envision systems that they might not be suited for, but not too many. I suspect that there will be a wide audience for a foot that sounds like the Pulsar Point.

...Doug Blackburn

Nordost Pulsar Points
Price: $100 USD per set of four (aluminum)

Nordost Corporation
420 Franklin Street
Framingham, MA 01702
Telephone: (508) 879-1242
Fax: (508) 879-8197

Email: info@nordost.com
Website: www.nordost.com


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