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POSITIVE FEEDBACK ONLINE - ISSUE 1
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The Art of System Tweaking
by Clay Swartz

 

Tweaking a system is absolutely essential to getting the most out of it. A $20,000 system that is well tweaked will usually outperform a $100,000-plus system that has not been tweaked. Many times, I have listened to expensive systems that I expected would sound very good, but go away disappointed. The fault is not bad equipment, but a lack of care and knowledge about how good an audio system can sound.

One exception to this was my visit to The Audio Gallery in Lake Groove Oregon, where I was treated to the best sound I have heard anywhere. The system included Avalon Diamond Speakers, Rowland electronics, a Burmester CD player, and Cable Research cabling. The level of detail was amazing. The system did almost everything perfectly, its only slight flaw being a lack of low bass. Yes, the system was very expensive—about $115,000 including room treatment—but for the first time in my experience, a really expensive system lived up to and exceeded expectations. The room was fairly large, and had been heavily treated with DAAD traps by Acoustica Applicata. The speakers were probably ten feet from the back wall and six feet from the side walls. The mono amps were on the floor between the speakers, on spiked feet. An isolation stand was used for the electronics. Speaker cables were raised off the floor. Gary, the owner, said that the room was responsible for much of the sound quality. I brought two discs that were the same, except that only one had been treated (see my article in the first issue of Positive Feedback Online). The improvement on the treated disc was immediately apparent. Since Gary had a fluorescent light, we tried using it on some of his discs. The improvement was, again, immediately apparent. I also tried a set of some mpingo feet that I had been playing around with, and that had done wonders in other systems. Gary’s Avalon feet easily beat the mpingo feet. The really scary thing is that even more tweaks could be used, for even better sound, although this was the most tweaked system I had ever heard in a store. This was truly a wonderful listening session, put on by people that care about sound.

I will now describe the entire process of tweaking a system, any step of which will be likely to improve its sound. Keep in mind that tweaking is not an all-or-nothing process. Fully tweaking a system will probably take months, even years. The first consideration is the room. If you have a small room, give up on the idea of getting strong, deep bass. Uncontrolled bass turns sound into mush. It is better not to go too low in the bass, which creates massive room interactions unless you have a room and equipment that can handle it. There are various room treatment products, like corner tunes, tube traps, and acoustic absorbing material. In general, the biggest problems are in the corners of the room and the edges between walls, ceilings, and the floor. A perfectly dead room—an anechoic chamber—seems like a good idea, but it creates a very unnatural listening space, and requires a lot of volume and power for the sound to have any life. We are used to hearing reflections off the walls and ceiling. The problem is that the walls and ceiling in most listening rooms are far too close to each other to create live-concert types of reflections. Every room is different in its sonic character, and a great deal of experimentation is needed to balance the need for detail and clarity with the need for a live, room-filling sound.

A major area of concern is electrical power. If it is not too expensive, it is best to run at least two dedicated circuits to your equipment. If this is going to cost more than $500 dollars, however, your money is probably better spent on power line conditioners. Even with dedicated power lines, conditioners are needed for the best sound. Nevertheless, I find that it is best to plug your amplifiers directly into a dedicated circuit. High-quality power chords are price-effective tweaks. A good power chord can make a component sound like you spent twice the amount of money, though I feel that after $150, a point of diminishing returns is reached.

The next issue that needs to be addressed is speaker placement. Speakers almost always sound best when they are well into the room. The bigger the speakers, the more they need to be away from the walls. I would suggest starting five feet from the back wall and at least three feet from the side walls. It is also best if there is at least six feet of space behind the listening position. To create a large soundstage, the speakers should be separated as much as possible, but not so far that the center fill of the soundstage is lost. It is also a good idea to have them equidistant from the side walls. Seating is usually best at a point that forms an equilateral triangle with the speakers. Tweeters should be at ear height. The speakers may need to be toed in to get good imaging. This is particularly true of physically wide or non-line-source speakers. It is best if there is nothing between or behind speakers other than sound treatment. It is also best if nothing projects from the side walls in front of the speakers. Most audiophiles have to compromise in the last two areas, because of room limitations or to lower the cost of interconnects or speaker cables. This also happens when the system does double duty as a video sound system. Spikes should be used under speakers when their final positions have been determined. Again, hours of trial and error are needed to get the best results.

Equipment placement is important. Components should be placed on a sturdy, non-resonant surface, and isolated from any vibrations by the use of isolation feet, sand boxes, isolation platforms, destructive interference devices, and many other devices. Isolation feet are a must, and may be combined with other devices. I do not like air-bag isolation, because it does not combine well with mass loading. There are new, bearing-based isolation devices that have received good word of mouth. I find that this is not a good method. It requires a very level surface and no heavy or stiff cables. It is also susceptible to sliding and does not like mass loading. My favorite setup is a sand box (Bright Star Audio) with isolation feet between the component and the sand box. Isolation feet can make incredible improvements in the sound of a system. I was at a store that had a modified receiver system in use, and the modified DVD player had Sorbothane-covered lead feet. I replaced these with the mpingo feet I happened to have with me. I knew there was going to be an improvement, but I was not ready for the degree of it. Even with changing the feet under only one component, the system sounded like an extra $3000 had been spent. Be aware that what works best under one component may not be best under another, and experimentation is necessary.

The next tweak is mass loading of equipment and speakers. This is among the most important and cost-effective tweaks. I have a 25-pound lead sheet on top of each of my components. I separate the sheet from the component with rubber lab stoppers. A commercial mass-loading device is available from Bright Star Audio. I have 100 pounds of lead bricks on the base of my speakers, and 75 pounds of lead bricks on top of each speaker. My subwoofer has 125 pounds of lead bricks on top. I find that mass loading is essential to get the best sound from a system. It helps every speaker on which I have tried it, even with speakers as well built and expensive as the Avalon Ascents. On components, it helps damp internal and air-borne resonance.

I recommend the use of Shakti Stones and Onlines. (The Onlines and Stones are reviewed by Dave Clark and myself, "CD Tweaks, HDTV and the Audiophile, and Shakti Onlines," elsewhere in PF Online, Issue 1) At the same store I tried the mpingo feet, I put an Online at the speaker end of both speaker cables, and was again surprised—the improvement was nearly as large as with the mpingo feet. Only once have I run into a situation in which the use of the Onlines did not make a clear improvement. When a friend was using a tube amp and passive preamp, the Onlines were a definite improvement, but when he went to a solid state amp and preamp, the Onlines made the system sound more analog-sounding, but with a slight loss in detail and dynamics.

The next-to-last tweak is raising the speaker cables off the floor. There are commercial products that do this, or you can make your own. It is easy to see if this is worthwhile in your system with the help of two friends. While listening, have each friend lift the speaker cables off the floor. I think you will hear an improvement. If you do not, you have lost nothing except a little time. As long as we are talking about cables, it should be mentioned that they should be arranged not to interfere with each other. Do not run power chords parallel to signal-carrying cables, and try to keep the cables going to different components separated as much as possible.

Finally there is the five-step disc treatment I discussed in "CD Tweaks, HDTV and the Audiophile, and Shakti Onlines." It can be used on CDs, DVDs, and SACDs. This treatment is a necessity. You have no idea what is on your discs if you do not do it. Any of the steps produces a definite improvement. Together, they are a revelation. Some choose to not do the beveling because of the high cost of the machine or the debate about possible future problems.

With your system ready to do its best, it may be a good idea to upgrade your interconnects and speaker cables. These are very personal choices, because each cable has its own character. Experimentation is needed to find the ones that fit your system and your taste.

 

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