This article is on a very interesting line of isolation products designed to improve the performance of audio and home theater systems.

Like many specialty audio companies, Harmonic Resolution Systems, or HRS for short, was born when a very talented engineer decided to quit their day job and apply their skills in an area no one had thought too much about. Mike Latvis, the chief engineer of HRS, had been designing isolation equipment for commercial aircraft, military aircraft, and missile defense systems for decades. As a holder of several US patents, his credentials on isolation speak for themselves.

Mike knew from his experience in the commercial and military world that critical electronics can be affected by external vibrations, both airborne and mechanical. As an audiophile and a musician, he wondered if he applied what he knew to isolating high-performance home audio gear if it would make a big improvement in sound.

He looked around at the products on the market in the late 1990s and there were very few products addressing the audio world directly. He decided to make some prototypes to find out for himself how important a low noise floor was to audio system performance. He shared this early work he was using in his personal system with some very experienced audio experts in Hamilton, Ontario. They immediately wanted to know how they could get some for themselves and HRS was born.

We can tell you from experience, the difference in some systems can be shockingly good. The first time we heard one of the isolation bases, we really could not believe our ears!

HRS produces a complete line of noise reduction products ranging from very affordable products to large scale custom stand systems. The goal at HRS is to design products for every high-performance system in the world and bring the magic of a low noise floor to music lovers everywhere. All of the products are designed to exacting standards with materials that are meant to last a lifetime.

We are going to focus today on the more affordable products and help you understand which might fit best for your system.

Why is Isolation Important?

If you enjoy sitting in front of your music system and getting that feeling of the artists being in the room with you, a very low system noise floor is one of the critical elements that can take your experience to a new level.

The companies who design the gear that makes up your great system go to painstaking lengths to compare which parts sound the best. Many of those companies work diligently to reduce noise within the components as they know how important this is to system performance.

If your speakers and/or subwoofer can reach down deep, and you like to listen at moderate to live levels, your speakers are sending all kinds of vibrations into your listening room. Some are airborne and some are coming up from the floor to your equipment. All of the components that touch the musical system are very sensitive to noise disrupting, damaging, and masking the intricate detail of the musical performance.

Vacuum tube gear is so sensitive if you lightly tap one of the tubes in the signal path with a pencil eraser, you’ll hear a high pitched ping through your system. The same holds for phono cartridges. The digital circuits used for clocking in DACs are very sensitive as are capacitors in the signal path. There really is a possibility for signal degradation in just about every part of the musical path.

What are Good Isolation Techniques?

To prevent vibrations coming up from the floor into your gear, you need something to completely isolate them from external disturbances. HRS makes a full line of isolation bases and custom structures to hold the bases that allow you to create an entire rack of isolated equipment. The bases have patented technology using custom elastomer compounds and structural materials with unique properties to dissipate energy before it can reach your equipment.

Designing the isolation system to work within a small weight range is something HRS discovered that allows their gear to do a better job than if they just had one model for all kinds of gear. This is why you will see many options on their bases and you can even later get them modified for a different weight range should your gear change drastically.

For airborne vibration, you need to find a way to keep your gear from being susceptible to the noise coming directly to the component through the air. HRS uses a combination of constrained layer damping feet under the equipment and constrained layer damping and mass loading plates on the top to make it less likely your gear will micro vibrate with the airwaves coming from your speakers.

The team at HRS uses some pretty serious test and analysis equipment along with rigorous listening tests during the design phase of every piece they make. Then everything is precision manufactured using high-end CNC machines. The combination of high tech and old-world craftsmanship result in products that not only function well but are beautifully made. All HRS equipment is made by experienced professionals in the US with all final assembly done by local craftsmen at their factory in Buffalo, NY.

Let’s take a look at the products they produce for each category.

Chassis Noise Reduction

HRS Nimbus System

The HRS line of products to reduce chassis noise consists of two parts, the Nimbus System and HRS damping plates. The Nimbus System is actually made up of two parts, the Nimbus Coupler, and the Nimbus Spacer.

The Nimbus Coupler is a special, high tack self-adhering proprietary HRS polymer with a very specific geometry, stiffness, and energy dissipation characteristics. This custom material was developed by Mike Latvis working with a Polymer Chemist he had worked with for 3 decades on many high-performance noise-related programs. After dozens of custom material trials and hundreds of listening tests, the Nimbus Coupler became a reality.

The Nimbus Spacer comes in various heights. When we first looked at these, we were a bit confused as to just what you needed (like you may be).

The idea of the Nimbus System is to put the Nimbus Couplers between the component and the shelf it is sitting on so both get the benefits of the proprietary material. HRS wants you to position them as shown in the drawing below.

Basically, you divide the bottom of your component into 4 equal-sized rectangles and the Nimbus System needs to sit in the middle of each rectangle. Of course, you can move them slightly out of these positions to avoid the feet and the screws that prevent the Coupler from lying flat against the bottom of the chassis. We also suggest you move them closer to things like transformers or drives for some additional improvement.

If your component is bigger than around 19” by 19”, you will usually benefit from adding one to the center and some very light components work fine with just three.

Since the height of the feet on components varies, HRS makes different sized spacers you use with the Nimbus Couplers to make sure all that is touching the shelf is the Nimbus System and not the component feet. The idea is you buy a complete Nimbus assembly, which is two Couplers and one Spacer to get the height that you need. These complete assemblies are from $142 to $159 each depending on the height (1”, 1.5”, and 2”) and you need four of them.

However, being the type of equipment geeks that like to figure out how to get the best bang for the buck, we asked, why can’t you just remove the component’s feet and use 4 single Nimbus Couplers? This adds up to $180 as opposed to close to $600 using 4 of the whole assemblies.

The Nimbus Couplers are about .3” tall which makes them shorter than most equipment feet, but we have found almost all components have a little center screw you can take out and the foot comes right off. If you don’t want to do this, you can of course, just use the appropriate height Nimbus Assembly to raise up your component to clear its feet, but 5 minutes and a screwdriver will save you around $400.

The Nimbus Couplers are almost 3” in diameter and pretty sticky. Once you get them properly positioned, you can tell even by just putting your hand on your component that it feels much more dead and less likely to pick up airborne vibrations than before. For those of you still spinning CD’s, they really held damp out vibrations from your CD’s drive motor.

We like to start out with the CD player or DAC first, then add the preamp or integrated amp, followed by the power amp. We do hear bigger improvements on the front end than the power amp, which makes sense. Anything that happens to the signal, in the beginning, gets amplified by the rest of the system.

If you are like us, you will notice more clarity and separation of individual instruments using the Nimbus Couplers. We have only encountered one situation where we do not recommend the Nimbus Couplers, and that is on the plexiglass bottomed Audio Research gear.

HRS MKII and DPX Damping Plates

The next part of the HRS chassis noise reduction system is to use their damping plates on the top of your component. These plates come in black or silver to match your gear and are available in 3 sizes and two thicknesses. They are all 4.5” wide but come in lengths of 5.5”, 9.5”, and 14.5”. Once again, the question comes up as to how is the best way to go?

The answer is, get the biggest plate that will not cover up any ventilation holes. If you try one and like the result and still have room for another one, there is nothing wrong with two as many people feel some larger products benefit from two. We feel the MKII .7” thick models work really well and the thicker ones (DPX provide even more noise reduction with a 1.3” thickness.

Like the Nimbus Couplers, if your gear has a sheet metal, metal plate, or billet metal chassis, they work great. If the top cover is made out of a plastic or resin material, we don’t hear any benefit.

The combination of the Damping Plates and the Nimbus system will do wonders to reduce chassis resonances.

Equipment Isolation

HRS has a huge range of isolation bases for high-performance audio equipment. They have spent many years using science to develop some very serious isolation bases. Some of them are super heavy and cost over $4,000 for the base alone, but for the person with components at the extreme end of high-performance audio, they offer a big improvement.

They recently introduced a new, more “affordable” base called the HRS E1 Isolation Base. Like all HRS bases, there are a variety of sizes to choose from. Also, as with all of their isolation bases, every single one is designed to work with components of a specific weight. There are four weight ranges, and four different types of feet, for each size so you can perfectly match it to your gear, and to your listening environment.

The new E1 base uses four different types of materials. The plinth uses a new constrained layer damping system HRS developed for the E1 and it's housed in a beautiful billet machined aircraft-quality aluminum front. The E1 then uses custom pressed resin fabric composite top and bottom plates coated with a highly scratch-resistant outside surface. They also have special feet on the bottom to further reduce vibrations.

The smallest E1, which will easily fit most components and turntables, is $1,095. While this is by no means inexpensive, it can work wonders for some components - especially turntables that are picking up vibrations from your speakers and creating acoustic feedback. We have used this base to take turntables that fed back so badly you could barely turn the volume up, to change them into systems where you could crank things up as loud as you wish. It is really amazing.

The E1 also works great with new or vintage tube electronics to really open up the sound. Just like the Nimbus products, we think you will hear the biggest differences from the source components out. Turntables, CD players, DAC’s, phono preamps, and preamps seem to benefit the most, and of course, anything with tubes inside.

A new development for the E1, when fitted with special feet, is headphone preamps by providing a path for internal vibrations to exit the chassis. This can dramatically reduce background noise, providing better clarity and music enjoyment. The special G Series footers for grounding a plinth are available on all HRS base models. The neat part is, should you wish to later use the base for a different type of component, HRS can help you change back to the normal feet.

To find the best E1 for your system, start by choosing the 17” by 19” or 19” by 21” size. You’ll then have four weight ranges and either Black or Silver to choose from. You will never be stuck with the wrong weight as it is a simple matter to change this out later on.

Turntable Damping

HRS has also taken everything they have learned about vibration isolation and applied it to a couple of record clamps. Record clamps gained popularity in the 1970s and have been around since with a myriad of types on the market. They can serve two functions — first to help reduce a slight warp in a record, and secondly to couple the record better to the platter to help damp out external vibrations.

With all of their patented isolation techniques, HRS has come up with two great clamps that, like their isolation bases, are designed to go with different turntable platter weights. Both have a proprietary polymer that decouples the record weight from the spindle.

The ADL, short for Analog Disk Light, is made from a custom-designed damping polymer and a billet machined heat-treated aluminum alloy. It is machined down to less than one-thousandth of an inch tolerance for both perfect alignment and balance. That is impressive. It only weighs 315 grams so it can be used on any turntable, even those with spring suspension systems. The ADL is available in a black or silver finish.

The ADH, or heavyweight, is the same design but uses a non-magnetic stainless steel alloy. This one is designed for turntables that have a platter heavier than 15 pounds. This one only comes in a natural stainless steel finish.

The improvements with these weights is huge in some systems — resulting in less surface noise, more dynamics, better separation of instruments, and more clarity.

Overall Recommendation

No matter which of these components you decide to try, they are designed to augment each other so you can’t go wrong starting with any of them. If you really enjoy sitting in front of your stereo system and being drawn into the music experience quickly, you are the type of listener that will appreciate the improvements these HRS products can offer. The only drawback is that they are addictive — once you hear the improvement, you will likely want more!