The Rules Of The Road

The route map to system building satisfaction


The first step to building a really good hi-fi system is understanding that the only person who can provide those ‘which product’ answers is you. So rather than trying to offer you short cuts that turn out to be dead ends, spurious ‘recommendations’ that ultimately don’t deliver, perhaps it’s time to approach this problem from the other end. If magazines can’t (and really shouldn’t try to) provide universal recommendations, perhaps they should work on making it easier to arrive at really meaningful answers of your own. With that in mind, and couched in the form of a loose assortment of half a dozen motoring truisms, three devoted to establishing a decent operational foundation for your system, three concerned with selecting the system itself, here are the golden rule of system building success. Following them won’t guarantee musical satisfaction (there’s a bit more to it than that) but ignore even one and you’ll be severely limiting your system’s potential. How do you build a system? Here’s how…

Rule 1. Don’t try and run a top fuel dragster on diesel

When you listen to an audio system, you are actually listening to your AC supply. The electricity that comes out of the wall is the raw material that is converted into sound – and just like any other process, the resulting performance depends on the quality of the fuel you use. The increasing use of wireless communication systems, switching power supplies, and the massive increase in electrical components loading the national grid all contribute to a situation where AC quality is at an all-time low. What we tend to forget is that a lot of those problems emanate from within our own houses, with multiple appliances, computers, mobile/wireless phones, and data systems all polluting the immediate area. Running a single, dedicated mains spur to feed your audio system, preferably wired with a screened, heavy-gauge cable, and selected sockets and hardware in the fuse-box is possibly the single most cost effective contribution you can make to the performance of your audio system. It might not offer the instantaneous gratification of a NOS injection system, but believe me, the benefits are both permanent and absolutely fundamental.

Rule 2. Don’t try and drive a Ferrari across a ploughed field

Let’s be honest, you wouldn’t do it: indeed, you probably couldn’t do it – not enough ground clearance or suspension travel. The Ferrari is definitely designed to run – in fact, will pretty much only run – on perfectly smooth surfaces. Your audio system is the same. Think of discontinuities in the signal path or external mechanical interference as the furrows of that field and you begin to get the picture. Each microphonic intrusion or change in the materials or nature of the cables connecting your boxes together will erode performance, destroying the linearity and musical coherence you are trying so hard (and spending so much) to preserve. In turn, what that means is that you need to pay attention to what sits between your equipment and the floor and what connects it together. So choose racks and shelves that are dispersive and non-resonant in nature – which means avoiding welded steel, glass and if possible MDF. They need to provide a stable and level surface and also consider what (if any) isolation the structure provides from the outside world, between the rack and the floor or the rack and its shelves: and no, spikes don’t count. Likewise, choose your cables (all of them, including the power cords) from a single, coherent range, where a manufacturer uses the same conductor, dielectric materials and design concept across all the products.

Rule 3. It’s all about traction…

All the power in the world is no good to you if you can’t hook it up – and spinning wheels don’t get you very far. In motoring terms you can talk about torque and tyres, but it’s the road surface that is ultimately the limiting factor. For audio systems, the equivalent constraint is the signal to noise ratio, or noise floor: it’s the other side of the isolation/integration argument outlined above – just even more critical. In this case it’s all about grounding – mechanical and electrical. In real terms, what you are seeking to isolate or protect isn’t the equipment but the signal path within it and that’s an important distinction. As well as mechanical energy reaching the signal path from the air and the floor, via the rack, the equipment generates internal mechanical energy too. Transformers vibrate, as do capacitors as they charge and discharge and other components as they pass the signal. The actual level of the energy might be low, but it is right where the signal is, making it disproportionately destructive. To make matters worse, the soft ‘isolation feet’ fitted to most products actually trap that energy inside your electronics where it smudges the signal and raises the noise floor. Hard couplers that ground the chassis to a dispersive supporting surface (which could be as simple as a plywood or laminated bamboo shelf) provide an exit path for that energy – generally with pretty dramatic results. The resulting drop in noise floor, increase in dynamic range and improvements in timing and rhythmic articulation can have a profound impact on just how listenable your system is. Ever wondered how those ‘isolation’ cones worked? Now you know – and it’s not by isolating the equipment!

Likewise, there’s no substitute for a clean ground when it comes to reducing the electrical contribution to the system’s noise floor. Use a single, star-grounded distribution block to power your equipment, with the centre of the star connected not just to the main AC ground but also to a separate ground-post buried in your garden and you’ll experience an equally dramatic reduction in grain, a blacker background behind the music, richer, more vibrant colours and more emphatic dynamics – all crucial to your system’s musical expression and sense of emotional communication. Once again it’s a cheap and easy fix that delivers results it’s hard to credit – until you experience them.

Once you’ve paid attention to the basic steps outlined above you will have established conditions of operation that will give your equipment a fighting chance of performing somewhere near its potential – and you a fighting chance of hearing what it’s doing and the musical impact of any changes or choices you might make. Now it’s time to look at the system selection guidelines…

Rule 4. Don’t try to bolt a big engine to a tiny transmission

There are certain critical junctions in any system; joins where the parts need to mate seamlessly if the whole is going to become greater than the sum of the parts. In a car, it goes way beyond whether the mating parts use metric dimensions or not: the design team needs to consider power and torque curves, gear ratios, and performance goals. Audio systems are exactly the same, except that the critical junctions are not necessarily quite so obvious. We tend to divide systems into three parts: source components, amplification, and speakers. In fact, we should divide them in two: everything up to the amplifier inputs and everything after them. The electrical relationship between the driving amplifier and the speaker load it is connected to is so critical that it cannot possibly be separated if you want to get everything out of both components. The speaker/amplifier pairing should be chosen together (even if you are not buying them together), matched to each other and the room in which they’ll be used. That’s the only way to achieve the best possible performance.

blog comments powered by Disqus

Featured Articles