Notes on hi-fi equipment and noise

Mains induced noise, poor quality mains leads, lack of good screening and/or earthing, high dither (digital jitter), poor D-to-A conversion, amplifiers, servers, transports and DACs with poor noise isolation and certain loudspeaker cables that act like an antenna with the amplifier’s feedback circuits:  these are key factors that each contribute toward collective high-frequency noise riding on an audio signal’s high-frequency content that can be confused as an unacceptable brightness or untidy harshness in the treble balance that is nearly always incorrectly assumed (or attributed) toward being poor loudspeaker design practices in force.  

Some notable loudspeaker system designs tend toward rolling-off the upper treble response, as seen in many published loudspeaker tests, as well as is evidenced through listening sessions.  This makes for a more relaxing sound that is smoother in balance and easier upon the ear on a wider range of hi-fi systems;  a softer balance that ultimately masks RFI/EMI noise from being audible, but such loudspeaker designs generally affect a considerable degree of repression to the fidelity of realism in their reproduction.  Additional curtailment to detail retrieval is with the abundant use of overly complex crossover networks that address performance imbalances on speaker system designs in pursuit of the most linear (flat) frequency response while simultaneously absorbing and masking subtle details across the entire frequency spectrum, as well as blunting the ultimate dynamic range presented within a given recording.

The original IAS Beaulieu minimalist series crossover design, as implemented by the late Alan Willis, and re-deployed unchanged within the new IAS Beaulieu 40R loudspeaker system, but now using the more organic sounding Duelund components, lends itself toward a more revealing and expressive quality of sound, as used with the carefully matched speaker units.  The level of resolution denies absolutely nothing, yet sound quality is refreshingly real, and without the slightest hint of listening fatigue endured, even over prolonged listening sessions when heard on suitably high-quality hi-fi systems.  Only the limitations within the recording process or a room’s acoustic dictate the reach in fidelity.  

However, there is no gain without first addressing the aforementioned salient factor of unwanted noise artefacts from creeping into a given hi-fi system’s electronics and the audio signal’s path if aiming for the very best quality of reproduction from the IAS Beaulieu 40R loudspeaker system.  This is ever more present in an age filled with the cheap and interference-emitting switch-mode power supplies that are abundant within mains-powered household appliances that serve only to ruin sound quality through air-borne radio frequency interference as well as mains supply induced electrical emissions interference, (RFI and EMI in shorthand reference).  Neighbourhoods are full to brimming with such apparatus that all serve to dilute the purity of the mains supply reaching the socket point in the wall.  There is also an ever-increasing abundance of mobile phone and transceiver telecommunication systems filling every bit of air space to further pollute the sound.  

Most high-end equipment manufacturers or equipment designers will go to great pains in investing their product with carefully executed industrial design practices that encompass high-quality power supplies that hold back and suppress unwanted noise within the mains feed, additionally paying heed toward resistance to external sources of noise by including first-rate screening on their metal chassis enclosures through the use of alloys or copper-lined casing to further improve rejection or suppression of RFI/EMI artefacts from creeping into the audio-signal path.  EMC regulations (electro-mechanical compatibility) directives since 1996 have placed legal imperatives to electronic devices to limit such emissions from their appliances.   

However, not all manufacturers can afford to go to such lengths, yet still have very high-quality audio circuits deployed within their products, but whom operate at a lower price point of the marketplace.  Such products are prime candidates for upgrading the performance, and in-turn, reducing the high-frequency noise that will be evident on openly revealing loudspeakers like the IAS Beaulieu 40R. This includes correctly shielded items, including high quality mains leads, mains conditioners, earth grounding boxes and last but not least, well designed loudspeaker cables.  Such accessories are diverse in choice, with some being little more than packaged hi-fi jewellery with absolutely no research or development investment to their credit, with little or no real sonic benefit.  But with the right choice of accessory, so much can be achieved with real-world performance upgrades to sound quality using carefully chosen hi-fi components that cost a fraction of some of the industry’s more expensive products that sit within the high-end category.

This includes certain digital-to-analogue converters which suffer from pre and post echo ringing, or CD transports that do not use buffering stages to limit misread data and jitter.  With the right choice of product, the standard of sound quality achieved with good leads and the aforementioned apparatus to combat noise will render realistic sounds of absolute fidelity.

Last, but not least, the quality of amplification used is another area that comes under scrutiny for faithfulness of reproduction.  This single aspect can make or break a system from merely sounding very good with many amplifiers to literally recreating the sense of real-life sounds being heard when connecting superlative quality power amplifiers to the IAS Beaulieu 40R loudspeaker system.  At best, the amplifier needs to remove any noise from getting into the audio signal path and to offer not only the greatest levels of transparency but also to be able to control the loudspeaker diaphragms during complex programme content with minimal distortion and slewing artefacts that affect the presentation and timing.  

The IAS Beaulieu 40R is an extremely fast and efficient loudspeaker system across the entire frequency spectrum, and being a horn-loaded design, requires an amplifier that doesn’t exhibit overhang tendencies in the bass and lower midrange frequencies as this will reveal mildly audible colourations into the presentation on certain closely-miked sounds.  With better amplification designs, the IAS Beaulieu 40R presents the audio spectrum within a completely neutral and transparent sound-field that has to be heard to be truly believed.  One that sets the bar to the highest standard.  One that can open the largest, most revealing 360-degree soundstage to a given live presentation, as recorded or broadcast.