 |
||||||||
| Don't expect many of the structure borne vibrations to make it to your platform: A brief look at the frame and bracket structures My friend and fellow moonie John Potis asked a good question: how much of the rack's performance is owed to the rack structure or frame and how much is owed to the isolation platforms? Here's the only answer I would venture. I've owned the isolation platforms for nearly a year. I used them originally for my turntable and preamplifier, but now use them as amp stands. They work great on their own and the only way I know to get them to perform better is to put them in the M1R rack. The effect is clearly additive. We've discussed the isolation bases and now we can turn to the rack itself and the quite extraordinary brackets. In talking about the rack, let's focus on its frame or substructure. The frame itself is a relatively stiff structure with a relatively high resonance frequency, which is then tuned for optimal broadband isolation and noise reduction. This is accomplished in part by tuning the rack to a natural frequency that is significantly greater than the natural frequency of the decoupled isolation platforms. The process requires additional attention to material stiffness and damping. Speaking of which, the frame is constructed of a variety of materials then covered by a stiff external 'skin'. The skin protects the internal energy absorption system and renders it independent of the finish the customer chooses for the rack. Thus, the resonance control system remains uncompromised by the finish to allow for furniture grade wood finishes, custom paint and exotic custom finishes. The HRS certainly belies the expression that beauty is only skin-deep. Now we come to the bracket. As we noted, it is important that the frame be tuned to a natural frequency that is significantly greater than that of the decoupled shelf system i.e. the M3 isolation bases. It is crucial to the rack's ability to maximize broadband noise reduction that each of the four custom isolators on the M3 Isolation Base contacts the M1R Rack system on a custom-machined ultra high-frequency billet-machined aluminum brackets (four per shelf). The only contact between each of the M3 Isolation Base custom footer system and the M1R Rack System brackets are four line elements at a near-zero total surface area. The near-zero contact area is also geometrically perpendicular to the primary mode shape of the M1R Rack System frame. The near-zero surface area means that there is virtually no path for energy to pursue, from the structure of the rack to the aluminum frame of the isolation base. So not only do the footers of the base offer six degrees of freedom, they are connected to the brackets as a line element whose effective surface area approaches zero. While claims about six degrees of freedom are rampant in the industry, the more important characteristic is the footers' stability, and the need to insure that there is no path that vibrations can pursue through the connector to the shelf. The line-element, zero-surface area point of connection (combined with a broadband six-degree-of-freedom isolator) is to my knowledge unique to the HRS rack. The brackets have at least two other virtues as well: one practical, the other relating to the overall science of broadband noise reduction. The practical value is that it allows you to alter the number of shelves you use and the distance between them. The inside of the racks are fitted with holes into which the brackets can be placed. In effect you get adjustable shelves. From the viewpoint of noise reduction, the other great virtue of the bracket system is that it eliminates the need for long horizontal bracing. Fewer and fewer good racks rely on long horizontal bracing, and the reason is pretty easy to understand. Using long horizontal cross members to support final shelf systems can provide an opportunity to create relatively low and mid-frequency resonance problems that will amplify input vibration. Just hit a crossbeam on many lower-priced rack systems and they will ring with relative large amplitude compared to input amplitude. Steel tubes, for example, will often amplify vibration by 100 times or more. As the distance from the vertical support structure to the contact point with the shelf increases, the amplification problems can worsen. The brackets allow the science of the frame to interact optimally with the engineering of the isolation platforms, each unit a tour de force of exceptional engineering in its own right. The bracket allows the system as a whole to work synergistically as designed. Nothing about this product suggests that it was rushed to market. |
||||||||
 |
||||||||
At the end of the day Serguei Timachev claims for his Indra cable that it adds nothing and thus allows you to hear your components – for better or worse. There is a difference between hearing what the designer had in mind and hearing what a design is capable of. More often than you might imagine, a designer does not really know what his designs are capable of. One can follow a path of trying to recreate the environment in which the original designer did his work. But one might miss -- just as the designer may have missed -- what the design is capable of. In the case of the Shindo electronics I use in my reference system, following Ken Shindo's approach would mean placing all my equipment on very heavy hardwood shelves. I toyed with the idea for a while. Alternatively, you can look for a rack that sounds good with the equipment you have: choose a good-sounding wood for example. Some folks like maple, some cherry. Choose between plywood and MDF and so on. Such an approach does nothing in the end to control unwanted energy. It simply tries to find a sympathetic match between the characteristic sounds of the components and that of the rack. One is just amplifying pleasantries and not doing much to insure a clean or accurate environment. Change your equipment, change its character, and you may well have to change your rack as well. Instead of the rack functioning as a safe haven for your equipment, your rack becomes another piece of equipment with a distinctive sound of its own and your goal is to integrate that sound with the sound of your other products. There is nothing 'wrong' with pursuing this approach but it can prove maddening. It's hard enough to mate the tonal and other characteristics of components; why add the difficulty of matching the sonic characteristics of the components and the racks. At the end of the day, I chose to go the way of the safe haven. And a safe haven is what the HRS products have proven to be. Periodically, I have taken some of my components off the shelves and placed them on other racks or on tuning feet on the floor. Doing so noticeably degrades the sound in obvious ways. A great example occurred about a month or so ago when two friends who are inclined to follow the Japanese approach -- which is to place electronics on hardwoods, then to tune if necessary by the use of Harmonix feet -- came by. They had been prodding me for some time to take the amps off the M-3 bases and place them on the floor. They came prepared with tuning feet for adjustments if necessary. They expected to hear deeper bass, experience greater warmth and an even greater emotional connection to the music. What are friends for? Why not? Each took hold of one amplifier and removed it from the shelf and placed it on the hardwood floor. Within a minute of turning the music on, they were putting the amps back onto their shelves/amp stands (M3 Isolation Bases). No point wasting time with the tuning feet. It's almost always that noticeable. Music played through components on the HRS rack has a seductive ease. There is no brittle or non-musical character to it. Everything sounds unforced and natural. Notes come and go but never seem to be in a hurry. Nothing is ever truncated. It is easier to listen at low volumes and more enjoyable than ever to listen at louder volumes. Once you experience first-rate resonance control, you cannot go back. You hear artifacts everywhere, much the way I used to hear crossovers in speakers after spending so much time with crossover-less full range drivers. I am not urging you to rush right out and order an HRS rack. You might want to begin by ordering one of their isolation bases for a source component, though. If you are interested in a rack, get in line. One thing's for sure - I'm not about to give up my place in the production line for you. And there is a line, needless to say. Whether you purchase an HRS rack or not, the key point is that you begin to take seriously the impact of the sonic environment on your music playback system. If you cannot clean up the environment in which you listen to your music, you need to be attentive to minimizing its impact on your system. You owe it to yourself and to the system you have invested in. |
||||||||
 |
||||||||
My aim here has obviously been to review the HRS MIR rack. I think the world of it and wouldn't think of being without it at this point. But my main purpose is to illustrate that there is important science in real resonance control, and that the failure to be attentive to the consequences of unwanted noise in your system can be bad indeed. Not every approach to resonance control should be taken seriously, however. I once had someone who represents an excellent company that specializes in tuning feet try to explain to me how they work by saying that the feet are able to transform odd-order harmonic distortions into even-order distortions. Enough said. An equipment rack is not just a place where you put your components. If that's how you treat it, you will not merely get less out of your system than you can; you will likely hurt its performance. A good rack is the best homeland security you can purchase for your investment. I have a large investment in my audio system and I use it not only for pleasure but also for reviewing, for making assessments of the performance of other components. With that in mind and in the war on unwanted resonances, I'm putting my money on high quality science and engineering, especially when the fellow leading the charge loves music like I do. I put my money on the HRS rack system. I would strongly encourage you to consider doing so as well. But even more than that, I encourage you to take seriously the importance of resonance control to the overall performance of your system. The rewards you reap will be large and if you choose well, be consistent from component to component. You have a lot invested in your system. Protect that investment. |
||||||||
 |
||||||||
| Publisher's Comment: Unlike my current evaluation of an equipment rack which compares it head-to-head against another one for context, the opportunity did not arise for Jules to arrange for an in-house comparator to the M1R. Hence this write-up is more general in nature and predominantly an exploration of the HRS design philosophy rather than an in-depth description of how it performs vis-à-vis other competing products in this still relatively young product segment. Should a future opportunity arise whereby one of our reviewers can revisit today's product while having another high-level stand in house, we'd be very interested in adding more specific comparative data to Jules' observations. Srajan Ebaen HRS responds: I would like to thank Srajan for having Jules Coleman review the Harmonic Resolution Systems M1R Audio Rack and for providing focus to the critical importance of mechanical noise reduction on true high-end audio performance. Harmonic Resolution Systems believes that one of the weakest element in many audio systems is the lack of focus on mechanical noise control and its ability to significantly improve audio signal quality. Mechanical noise is often the root cause of many system ills that people are trying to resolve indirectly by changing other components. I would also like to thank Jules Coleman for the hours of dedicated listening, questions and research that he put into this subject matter in order to write such a complete and professional review on the Harmonic Resolution Systems M1R Rack System and mechanical noise reduction in general. I am pleased that Jules found the performance of the M1R unrivalled and state of the art. I am equally pleased that Jules' wife found the M1R to be the most attractive audio component she had seen. Harmonic Resolution Systems is dedicated to providing high performance in an very aesthetically pleasing package that will enhance even the most discriminating living environment or dedicated audio room. This is why Harmonic Resolution Systems also provides services to match the rack system to the customers décor and offers a number of modern or exotic furniture grade finishes. The primary objective of the M1R design is to offer a true reference level rack system that is commensurate in performance to the rest of a true high-end audio system. The M1R is also designed to form a complete noise reduction system that works together with the other Harmonic Resolution Systems products pictured in the review such as the Harmonic Resolution Systems Damping Plates, Nimbus products and ADL record weight. We are glad to hear that Jules believes we hit the mark with the M1R and I am looking forward to delivering and setting up the second M1R rack Jules is purchasing for his system." Best regards, |
||||||||
 |
||||||||
 |
||||||||
| Manufacturer's website | ||||||||
 |
||||||||