Commercially Produced Electrically Recorded Sound Is Turning 100 This Year

Commercially produced electrically recorded sound is turning 100 this year, will it still be around for the next 100 years?

Various experiments with electrical recording actually began back to 1919. This system was perfected at the Bell Telephone Laboratories back in 1924 and the first commercial electric recordings were issued by Victor and Columbia back in 1925. The electrical recording that birthed the multi-million dollar music industry we know today is a system that used a microphone at the performing end. The microphone generated tiny electrical impulses that represented a replica of the original sound; a thermionic / vacuum tube based amplifier increased the strength of the signal picked up by the microphone so the electrical impulses can be strong enough to power the cutting head or a recording stylus.

Although the early results of the electrical recording system were characterized as strident in comparison to the earlier acoustic recording system, they boasted the then impressive frequency range of 100 Hz to 5,000 Hz. One of the editorials by Compton Mackenzie on the November 1925 issue of Gramophone magazine on the introduction of electrical recording goes: “the exaggeration of sibilants by the new method is abominable, and there is often a harshness which recalls some of the worst excesses of the past. The recording of massed strings is atrocious from an impressionistic standpoint.” Having read about this back in 1995, Compton Mackenzie’s comments on the first batch of commercially produced electrical recordings back in 1995 reminds me of criticisms of the sound quality of Redbook CDs in comparison to vinyl records during the heyday of the mid 1990s vinyl records revival.

Given that the electrical recording system allowed the manufacture of recorded sound a lot less expensive in comparison to the Edison era acoustic recording system, in 1925, the Brunswick Company marketed the first all electric phonograph. The Radio Corporation of America (RCA) purchased the Victor Corporation in 1928 and a year later, RCA converted the Victor plant largely to the manufacture of radio sets, while Edison discontinued production of all phonographs and records. During the first years of the Great Depression that began during the last quarter of 1929, the phonograph and record business dwindled but later took an upswing during the 1930s. Record playing attachments for plugging into 1930s era radio sets were introduced which also made the 1930s to be known as the “Golden Age Of Radio”. Also, juke boxes – first developed by Edison – also enjoyed a vogue during this time.

Early electrical recordings - also known as 78 rpm shellacs - that are now “celebrating” their 100^th Anniversary were largely ignored by enthusiasts during the start of the 1990s vinyl records revival because “younger” audio enthusiasts who grew up listening to vinyl back in the 1960s and 1970s were largely ignorant on how to play “pre World War II era” shellacs. Thanks to “older” audiophiles giving advice on how to play 78 rpm shellacs back in the 1990s, younger audiophiles can begin collecting 78 rpm shellacs as a hobby. Back then the Garrard 401 turntable was the most cost effective way to play older shellacs. Columbia records first batch of electrical recordings were recorded at 80 rpm until the late 1920s and thus an 80 rpm capable Garrard 401 populating the second hand record shops back in the 1990s came as a “godsend”. 

Does Age Related Hearing Loss Matters?

Given the popularity of age related audiological tests on You Tube, does age related hearing loss actually matters in practice?

By: Ringo Bones

As a true blue audiophile, you may have already checked out those You Tube channels that has audiological tests designed to determine the so-called age of your ears. Whether via click-bait or the fact that the de-facto audio bandwidth of You Tube doesn’t go beyond 16,000 Hz, those tests are just too intriguing to ignore.  Whether it gave you a sobering realization that there are sound frequencies you can no longer hear now, unlike back when you are still 18, probably got you cringing after spending 10,000 US dollars on a hi-fi loudspeaker you can finally afford but has doubts whether your ears are “healthy” enough to appreciate them, fear not because there are others like me who now harbors doubts whether age related hearing loss really matter in practice – as in real life listening to audio systems and live concert events.

Virtually all acoustic / audio related literature and online fact-sites lists the human auditory range – i.e. the frequency of sounds we can hear – at 20 Hz (lowest frequency) to 20,000 Hz (highest frequency often abbreviated to 20 KHz) give or take a few hertz up or below this. Sadly, age related hearing loss is an inescapable fact of life. But have you noticed how the tests are done – i.e. using low distortion sine waves, usually below 0.1 percent THD – and they are quite revealing when if you are in your mid to late 40s and you can no longer hear those high frequency sine waves above 15,000 Hz. Sobering, yes, but does it matter in real life? Let me cite a couple of broad examples.

As the lockdown eased in my neighborhood a month ago and our local hi fi store started demoing its latest stock of Focal Kanta Number 2 loudspeakers, it sounded quite impressive when playing Chesky audiophile LPs. But when a Mobile Fidelity Sound Lab reissue of Saturday Night Fever soundtrack LP was played in the VPI turntable, most listeners – i.e. audiophiles who turned 18 back in 1975 and who are now in their 60s – complained that the Bee Gees sounded “too bright” when played to the Focal Kanta speakers while those listeners under 25 years of age where impressed on how the Focals sound as if there were cymbals and horns playing in the hi fi store. Given that those older folks – who even probably old enough to have actually been in a Bee Gees concert back in the 1970s complained on how the Kanta sounded too bright despite of their age related hearing degradation preferring instead on 1970s era JBLs or Altec Lansing Voice of the Theater speakers, while the younger listeners were awed by the way the Focal Kantas sound as if the cymbals and horns were actually playing live in the hi fi store, instead of a playback from an LP only highlights my doubts on how age related hearing loss really plays out in practice. And another thing, if age related hearing loss really does matter in practice, how come drummers 50 years and older not ditching their Zildjian cymbals for brighter sounding Paiste cymbals? As long as your presbycusis – i.e. age related hearing loss – doesn’t prevent you from having a normal conversation with your fellow human being, it’s probably best to just sit back and enjoy the music or the concert.

Headphones: Less Than Ideal Hi-Fi Gear?

Even though it was deemed an indispensible component when the Sony Walkman became king back in the 1980s, are headphones, until now, has always been a less than ideal way to listen to music?

By: Ringo Bones

Dubbed by conservatives as the most antisocial way to listen to music back when Sony’s Walkman was new, the shortcomings of the ubiquitous headphones has recently been brought back into the spotlight after the shortcomings of a flagship Apple product – i.e. the Apple AirPods wireless headphones and their Mainland Chinese made knockoffs – as early users complained of excessive background hiss, not to mention early users old enough to remember 1980s era cassette tapes saying that the hiss levels are worse than that of dubbing a copy of a copy of a prerecorded cassette tape album. But are headphones really the weakest link of all the sound producing transducers in our high fidelity audio hobby?

Despite its shortcomings, audio enthusiasts old enough to have taken sound quality seriously back in the 1980s had surprisingly managed to make due of listening to music via headphones. Weird between-the-ears stereo soundstage when listening to plain vanilla 2-channel stereo cassette recordings and producing more background hiss in comparison to conventional loudspeakers notwithstanding. But let us explore more on the headphone’s hiss issue given that, especially when listening to prerecorded cassette tape albums as your primary music source, is already inherently hissy in the first place.

Hiss is more noticeable through headphones than speakers for several reasons. Since headphones lie closer to the ears of the listener in comparison to loudspeakers, any hiss that the headphones’ produce is readily transferred to the eardrums. Headphones are more sensitive than loudspeakers – i.e. headphone sensitivity are typically measured in decibels per milliwatt as opposed to decibels per watt when measuring loudspeaker sensitivity – so headphones are more likely to pick-up the faint residual hiss produced by your audio rig, like that in the preamplifier stage. And headphone models that isolate your ears from outside sounds can also prevent such sounds from masking hiss, denying the user from using Mother Nature’s naturally generated dither noise.

Linaeum Tweeters: Exotic Tweeter For The Masses?

Often described as the lowest cost alternative for budget conscious audiophiles disenfranchised with the dome-tweeter sound, is the Linaeum Tweeter a true-blue “exotic tweeter” for the masses?

By: Ringo Bones

When RadioShack collaborated with Mystical Audio Limited to release their Optimus PRO series of hi-fi loudspeakers back in the mid-1990s, it was hailed by audio experts and reviewers as the “best sounding loudspeakers they have ever heard in the $300 to $500 price range”. While actual audiophiles who can’t afford ribbon-tweeter and planar-magnetic tweeter equipped exotica in the four-figure to five-figure price range had hailed the RadioShack Optimus PRO series as a veritable godsend at the time. I mean hearing what an actual 1990s era grunge guitar band produced in a budget-conscious audiophile’s listening room after concluding budget dome-tweeters seem to just don’t cut it sonic wise can be a revelation back then.

Sadly, the bass and lower midrange sound quality of the RadioShack Optimus PRO series was sonically below par in a side-by-side comparison to their old-fashioned dome-tweeter equipped competition in the $250 to $1,000 price-range. Not to mention that the inherent nature of the Linaeum Tweeter design will produce a harsh high frequency sound quality if operated below 3,000-Hz in the audio spectrum. But what makes the Linaeum Tweeter a value-for-money alternative to the good old-fashioned dome-tweeter in the entry-level hi-fi loudspeaker market?

What’s so special about the Linaeum Tweeter? In a conventional tweeter, a coil of wire is suspended between the circular poles of a ring-shaped magnet that moves a cone or a dome-shaped diaphragm backwards and forwards according to the dictates of the electrical signal, allowing it to produce audible sound from the power amplifier’s electrical signal. In the Linaeum Tweeter, there is still a voice coil, but this time it is flattened into a vertical shape and suspended between opposed rectangular magnetic poles. The voice coil still moves backwards and forwards, but instead of driving a cone or dome-shaped diaphragm, it pushes and pulls the vertical joining point of two semi-cylindrical 3-inch long sheets of stiff plastic film, each of which is fixed at its own end. Imagine two empty beer cans side-by-side, the point where they touch is where the voice coil is attached. Under the influence of the electrical signal from the power amplifier, the two semi-cylinders rotate back and forth, the resultant traveling waves producing sound.

The advantages of the Linaeum Tweeter design over a conventional cone and dome-shaped tweeter design are a uniformly wide horizontal dispersion pattern of the produced sound and good linearity, both of which lend the Linaeum Tweeter some of the attributes of a good, but far more expensive, planar drive unit. If as in the RadioShack Optimus PRO LX series, two sets of diaphragms are placed back-to-back with a common magnet structure, sharing a common voice coil, those at the rear pull when the front one’s push. The resulting sound radiation to the rear should  produce an enhanced feeling of “airiness” to the loudspeaker’s sound in all but the most “acoustically dead” –I .e. unreflective – of listening rooms.

The Linaeum Tweeter further gained its reputation as the “exotic tweeter for the masses” after RadioShack decides to discontinue the Optimus PRO LX series and sold them heavily discounted – including the after-market replacement Linaeum tweeters – around after 9/11. Some RadioShack outlets had even sold the Linaeum Tweeter as low as $15 per pair further on. Now virtually impossible to find outside of heavily inflated priced working ones offered on e-bay, adventurous hi-fi enthusiasts had managed to experiment with them during the first two decades of the 21^st Century. If operated above 3,000-Hz, Linaeum Tweeters offer more natural and realistic sounding high frequencies that dome tweeters in the $100 to $500 price range. When operated at 6,000-Hz or higher as a super-tweeter, the Linaeum Tweeter can easily make a DIY loudspeaker sound as if it is 10 to 20 times the price of its actual purchase price.

What Does a 1990s Era Hi-Fi Sound Like?

Did 1990s era hi-fi sounded like it should because hi-fi enthusiasts finally wanted to hear more of the music – instead of the audio gear?

By: Ringo Bones

Why did 1990s era high fidelity audio managed to cast such a long shadow that every well-reviewed audio gear are now commanding serious second-hand prices? Well, if you’re like me who got started to appreciate hi-fi audio as a hobby during the mid 1980s but only managed to acquire the disposable income needed to buy a much coveted kit during the early 1990s, it is safe to say that almost – if not all – well reviewed budget hi-fi gear, especially speakers, that entered the market between 2010 to 2019 is not that much different, sound wise, from their budget counterparts of the 1990s.

Maybe it is because 1990s era hi-fi enthusiasts finally decided to hear more of the music – instead of the hi-fi gear – that tonal neutrality and timbral accuracy finally managed to trickle down to budget hi-fi gear back then. Remember during the mid 1980s budget amplifiers, and signal sources – CD players, tape decks and turntables – were inherently designed to drive an inherently colored loudspeaker, that only a handful of 1980s era hi-fi gear are cherished compared to their rivals made a decade later.

During the latter half of the 1990s, even a relatively colored-sounding loudspeaker – like the Cabasse Farella 400 – especially the early model ones with an unmodified crossover network and driven with an entry-level Rotel RA-920AX integrated amp can manage to sound way more neutral and musically realistic when compared to an original JBL 4312 loudspeaker driven by an integrated amp manufactured In the mid 1980s. I mean to my ears at least – the Cabasse Farella 400 managed to produce a more realistic sounding acoustic guitar sound from a recording on a redbook spec CD than the late 1970s era JBL.

How Many Subwoofers Do You Actually Need?

Even though you could get away with just one, how many subwoofers do you actually need to achieve natural sound at a reasonable cost?

By: Ringo Bones

Believe it or not, subwoofers were already sold by hi-fi retail stores around the mid 1970s. Sadly, those early subwoofers were very notorious for sounding as if an electric bass guitar connected to a loud bass guitar amp is playing along with the music in your listening room – even when playing small-scale chamber music. After the early design excesses were weaned out, subwoofer in the home has undergone a hiatus that made it desirable again in a few years time.

The subwoofer gained popularity again in the 1980s due to a great number of affordable small loudspeaker systems designed with very small woofers / main drivers – i.e. 5 to 7 inches or so and, sadly, most pain-in-the-ass interior decorators find them attractive. Sadder still, the growing impracticality for many hi-fi enthusiasts to own loudspeaker systems with 12-inch or 15-inch or larger main drivers for reasons of cost, space or room aesthetics (thanks to your pain-in-the-ass interior decorator) finally made subwoofers a viable option when it comes to system building.

During the early 1990s, a partial, but interesting solution to the problem was the introduction of the three-piece system. This generally consists of two quite small loudspeakers that cover the frequency range down to 100-Hz or so. Such a loudspeaker system with a 5-inch or 6-inch main driver are fairly easy an inexpensive to design and manufacture. But a loudspeaker system with the bottom two octaves missing is not very satisfying to the seasoned audiophile, so a third component is added – the subwoofer.

The rational of using a subwoofer is that the main front left and front right loudspeakers can be designed to give appreciable power output and have optimal performance at very low frequencies because the two main left and right front loudspeakers no longer has to reproduce the very low frequencies. And while the subwoofer no longer has to reproduce the higher frequencies assigned to the front left and right loudspeakers, that one subwoofer box can now – in theory – be placed in a more or less out-of-the-way location in the room since the low frequencies – i.e. below 100-Hz – have very little directionality. It was generally thought – since the mid 1960s – that a single monaural channel for frequencies below 100-Hz was needed and also because frequencies below 80-Hz were, allegedly, mixed to monaural anyway. This latter factor was a result of the limitations – and still is - of the mechanical reproduction process used in making vinyl records and back then, open-reel tapes are a way, way more expensive alternative to vinyl playback. But when properly connected, two subwoofers operating in stereo absolutely sounds more gorgeous that a system with just one, even in casual listening.

The assumptions that justified using a single subwoofer has some basis in fact because three piece systems have been, and are still popular when space and room styling (thanks pain-in-the-ass interior decorator) take precedence over other acoustic considerations. Audiophiles who preferably listen to rock music usually place the subwoofer to the left because the bass guitarist is usually mixed to the left of the soundstage, while those who listen to large scale Classical music place the subwoofer to the right because in a majority of orchestral recordings, the low frequency instruments tend to sound as if they are located on the right of the soundstage. However, over the years, I have some concerns and reservations about the technical justifications for the three-piece system.

It can also be quite a shocker to know that not all, or even most, loudspeaker setup absolutely needs a subwoofer or two to make them complete in the low bass. To my ears, it might be the wisest decision to get a truly full-range loudspeaker in the first place, since it will have been designed as a unit and have a smoothly balanced response over its full range. However, in the case of smaller bookshelf-type loudspeakers, considerable advantage can be had by removing the lower two octaves of the sound from the two main left and right loudspeakers and diverting them into a good subwoofer. The advantages are that the subwoofer now handles the hard-to reproduce very low frequencies due to much higher power requirements freeing the smaller loudspeakers from the greater power and displacement demands of reproducing the very low frequencies. This can result in lower distortion in the small loudspeakers and considerably improved sound quality from them. It also allows planning for system growth – that is if you first invest in a good, small pair of loudspeakers, you can augment them later by increasing bass capacity with a subwoofer.

But the question now is whether one, two or perhaps more, subwoofers should be added. If only one subwoofer is added, the result would be a three-piece system with monaural bass response below 80 or 100-Hz. If two subwoofers are added, the result is the two bookshelf-sized loudspeakers virtually becoming two full range loudspeaker system with a full stereo low bass capability. But does it matter if we have stereo or monaural low bass? To my ears and my over 30 years experience in being an audiophile, I believe that it does for at least two reasons. The first is that we have a much better program material today from the Redbook Compact Disc, various high resolution digital audio formats like DSD and 24-bit 192-KHZ sampled PCM audio – and even low rate data online streaming in MP3 and the like compared with entry level vinyl in the low bass frequencies.  

The second reason is not quite so obvious, but very important if you want your system to accurately reproduce low bass frequencies in a timbrally accurate manner, whether it is from a Fender Mustang electric bass played through an Ampeg GS-12R equipped with 7591A output tubes, an upright acoustic bass, or even a full-sized church organ with 64-foot pipes. Believe it or not, there is considerable interaction between the room and the low frequency loudspeaker units. We all know that placing the bass loudspeakers in near a wall or in a corner of the room changes the amount and distribution of the bass frequencies in the room. At low frequencies, strong and widely spaced room modes are occurring. These modes manifest itself by the fact that as we move about the listening room, some locations have a lot of bass while other locations have a lack of bass. Also, the locations where more or less bass frequencies are heard also moves around the room when you shift the position of the low frequency loudspeaker.

The problem with a three=piece system is that we only have one loudspeaker producing the low frequencies, thus the room is only excited from one point and we have a set of modes – i.e. those parts in your room where the low frequencies are either too strong or too weak – that are quite audible. When two bass loudspeakers – or two subwoofers – are placed in a room and are excited by a full stereo bass signal, each will have its own set of modes. But the benefit this time is that it is not as likely that the lack or excess of bass from one loudspeaker will fall exactly the same point as for the other loudspeaker. This would result in a considerably better uniformity of bass response is obtained when the room is excited from two low frequency sources – in comparison when excited from just one low frequency source. But if using two subwoofers is better than using just one, would using more than two provide even far better results?

A fellow audiophile of mine has a set-up that uses eight REL Acoustics Q100E subwoofers in the frontal 60-degree arc of his hi-fi rig. Four were connected to the left channel and the other four were connected to the right. According to him, this set-up was a quantum leap in terms of performance from his previous set-up when he just used two REL Acoustics Stadium II subwoofers – about four times larger in terms of volume than the REL Q100E. But how does it sound? To my ears, it is probably the most timbrally accurate set-up when it comes to producing bass below 100-Hz. Not only that, on some minimalist chamber music recordings, it transformed his listening room into a medieval era chapel where the music was recorded!!! Probably due to the room modes are now vanishing low.

Drone Cones: Rotten Bass?

Even though the theory behind passive radiator loudspeakers – i.e. drone cones - is persuasive and mathematically ordered, do they have a reputation of producing rotten sounding low frequencies?

By: Ringo Bones

Despite having a history that dates back to the early days of cone type loudspeakers, passive radiator equipped loudspeakers – i.e. drone cone equipped loudspeakers – probably gained widespread popularity around 1972 when Polk Audio founder Matthew S. Polk released his Polk Monitor 7 loudspeakers back in 1972, and since then, the global audiophile community developed a love / hate relationship around the idea behind drone cones / passive radiators. But do drone cones / passive radiators truly deserve the reputation for producing rotten sounding bass frequencies?

From a design standpoint, passive radiators are actually a form of vent substitute and thus tend to follow vented loudspeaker design methodology and design characteristics. Also known as “drone cones”, they have two very important advantages over bas reflex vent designs. First, they eliminate vent colorations – as in resonant pipe sounds – wind noises and the internal high frequency sound reflected out of the vent. Second, passive radiator / drone cone designs are practical for small enclosures – i.e. bookshelf sized hi-fi loudspeakers – when the resulting design equations call for vent lengths that exceed the internal box dimensions of the loudspeaker’s enclosure. From a design standpoint, passive radiators are also simpler to deal with, having fewer alignment algorithms that lead to calculation of losses. On the downside, passive radiators have a steeper cutoff – and this offer less transient stability – that vented / bass reflex designs (vented / bass reflex loudspeaker design already roll-off their lowest frequencies at 24 db / octave), a slightly higher cutoff frequency and greater overall losses (Q˪) than vented / bass reflex designs.

A widely popular misconception about passive radiators / drone cones is that they operate in the low frequency regions, mechanically crossing over to the main / active bass driver at a higher frequency and extend the bass of that driver. Actually, the passive radiator / drone cone operates in conjunction with the main active driver – or woofer – at low frequencies, sharing the acoustic load and reducing driver excursion, thus reducing the total harmonic distortion produced by the main bass driver. Working as a variant of a bass reflex vent, passive radiators / drone cones only add as much as they subtract. From a design standpoint, this implies that passive radiators have the same positive attributes as a bass reflex vent – such as higher power handling and lower resulting harmonic distortion.

From a historical standpoint, passive radiator loudspeaker designs were first described by Harry Olson in his patent “Loudspeaker and Method of Propagating Sound”, issued back in January 1935. Except for an article by Olson in 1954, very little was published about passive radiators / drone cones until Nomura and Kitamura in their IEEE paper in October 1973 and Richard Small’s Journal of the Audio Engineering Society paper in October 1974. At around this time, Polk audio became the well known manufacturer of passive radiator / drone cone equipped hi-fi loudspeakers when Matthew S. Polk released the Polk Monitor 7 with its famed 10-inch passive radiator / drone cone. Scores of other manufacturers have produced their own version of the passive radiator / drone cone hi-fi loudspeakers since then, like Bowers and Wilkins with their DM620i, Boston Acoustics with their compact HD9 monitor loudspeakers, Technics’ SB-M300 loudspeaker and the British – German hi  fi collaborative effort ALR / Jordan Note 7 whose passive radiators / drone cones can have various weights attached to them to match their low frequencies to the listening room’s dimensions they are intended to be used.  Given that, more or less, hi fi loudspeakers with passive radiators / drone cones produced to the years have more or less received favorable – and sometimes exemplar – reviews, then why do passive radiator equipped loudspeaker designs harbor the reputation of producing rotten, sluggish sounding bass?

Around the 1990s, almost all science enthusiasts – especially science enthusiasts who are also audiophiles – have read in various science journals, like Scientific American and their ilk, about how Mother Nature abhors three things the most – i.e. a singularity, a vacuum and an audio signal passing through a real-world capacitor. And given the steep cut-off of passive radiator/ drone cone designs, this only spells bad news from a sound quality perspective – especially in the pace, rhythm and timing department despite of their ability to produce prodigious quantity of bass in comparison to similarly sized hi fi loudspeakers.

I have an audio-buddy who has bought a second hand B&W DM620i loudspeakers back in the mid 1990s, he notices how the speakers lacked finesse when it comes to resolving subtle low bass to upper bass details. Even though I found the B&W DM629i’s overall presentation and adequate enough for casual listening of small-scale ensemble Classical Music like string quartets and the like, this won’t be the loudspeaker I’ll be using if I want to find out if a certain hair metal recording had its recording session engineer been using a dynamic range compressor with a sidechain access to “clean up the bottom end” by using the kickdrum as a “key” to limit the overall dynamics of the bass guitar – as in the compressor pushes the volume of the bass guitar down whenever the kickdrum is hit.

Loudspeakers With Rear-Firing Tweeters: The Least Room Fussy Hi-Fi Loudspeakers?

For the budget audiophile skeptical about acoustically treating your listening room, are loudspeakers with rear-firing tweeters the best value-for-money solution?

By: Ringo Bones

Budget-conscious audiophiles had always been skeptical about “pricey” acoustic room treatments. They argue that their listening rooms …” is neither a recording studio, nor a mastering or recording post-production studio…” And both anecdotal and empirical evidence seems to reinforce this very idea by the time they manage to afford those relatively pricey second hand Quad electrostatic loudspeakers either the original ESL 57 from the 1950s or the newer one and far more common ESL 63 from the early 1980s. In practice, loudspeakers with rear-firing tweeters and their more elaborate counterparts – i.e. bipolar loudspeakers that radiate sound in both the front and the back – excel at sounding as if the very recorded acoustic event is actually happening in your listening room reproduced with timbral accuracy that conventional monopolar loudspeakers (i.e. those that radiate sound only in the frontal 180-degree arc) seem to lack. But in all things audiophile, not all bipolar / dipolar / loudspeakers with rear firing tweeters are not created equal.

Back when the late, great Audio Hall Of Fame speaker designer Arnie Nudell released the Eosone RSS series back in the early 1990s, many budget-conscious audiophiles got their first exposure of a budget loudspeaker that can reproduce the timbral accuracy of the cymbals in a basic rock combo drum-kit. But there are bigger, pricier ones that are found to be wanting from this time period.

Despite of the brownie points earned for a clean, full sound in a majority of hi fi magazine reviews, the Snell Type B loudspeaker was criticized by more than a few audiophiles as having its rear-firing tweeter for being a tad too loud. Some even suggested gluing a penny over the rear tweeter in order to make it sound better. Maybe a better solution is for the designer (s) of the Snell Type B to incorporate an l-pad attenuator / rheostat in the first place to attenuate the rear tweeter to make it around 12 dB SPL quieter than the front tweeter while preserving its high-pass filter crossover point or maybe include an on-off switch for the rear tweeter in “worst-case scenarios” for an overly bright listening room.

Bipolar loudspeakers – especially those manufactured by Mirage as in their Bipolar series - gained popularity back in the 1990s due to their rather “psychedelic phasiness” that they introduce to electric guitar recordings. Though criticized for not exactly accurate, they could take this effect too far by making those early Eric Clapton recordings when he’s playing through a small-ish tweed guitar amp, most bipolar loudspeakers tend to make tweed guitar amps sound acoustically small despite of the rich harmonics of the tone being produced. And sometimes bipolar loudspeakers exaggerate the “acoustical size” of some famous electric guitar recordings – i.e. that era when Eric Clapton preferred Gibson Explorers played through Marshall full stacks.

Open baffled loudspeakers – especially ones with an open baffle midrange configuration -  are praised for reproducing female vocals with a timbral accuracy as if there was no microphone and onstage monitor loudspeakers - in short, the timbral accuracy of an unamplified female voice. Despite of their virtues, open baffle loudspeakers have one glaring shortcoming, they could sound devoid of any extraneous reverb bas in they sound drier than “Prohibition era Georgia” when paired with a very low jitter digital front end. This effect is very noticeable on electric guitar recordings that are injected directly into the mixing board with distortion and tonal effects only in the preamplifier level – as in the timbral roar of the 1980s era hair metal guitar solos championed by MTV. 

The Walsh Type Tweeter: The Greatest Tweeter Most Audiophiles Never Heard Of?

Given the rarity of still functional Infinity and Ohm Walsh loudspeakers in the 21^st Century, is the Walsh-type tweeter the greatest sounding tweeter that a new generation of audiophiles never even heard of?

By: Ringo Bones

During the 1970s, there was a legendary tweeter invented by famed audio pioneer Lincoln Walsh that was first widely used by the Ohm Loudspeaker Company given that they were the first ones to acquire the patents, Infinity then got permission to use these famed tweeters a few years later. Given that they were praised during their day as the “most realistic sounding” tweeter technology, how come the “Walsh Tweeter” is now largely forgotten?

For those who are lucky enough to still own a still functional pairs – though you can use Google to find out what are these kind of tweeters or what they look like – the Walsh Tweeter is that inverted gold cone on top of the Infinity loudspeaker box. The Walsh-type tweeter is essentially a standard tweeter motor with the voice coil and magnet attached to an ice-cream-cone-shaped thin metal with damping inside. Invented by Lincoln Walsh, the Walsh Tweeter is often associated with the Ohm Loudspeaker Company who acquired the patents on their Ohm Walsh series.

The technology seems rather simple: Instead of a traditional horizontal dome acting as a hemispherical piston facing the listener, the Walsh Tweeter was a vertical pump attempting a 360-degree sphere of high frequencies as in “omnidirectional radiation” of sound waves. Many audio manufacturers still covet the design – like Warren Gregoire and Associates with their Ikonoklast3 loudspeakers and MBL – though it struggled at higher frequencies because of its high moving mass and large shape, although the MBL’s tweeter design differs that from the Walsh-type tweeter because the MBL uses a flexible metal balloon instead of a rigid ice-cream-cone-shaped radiator. Both designs have trouble reaching past 12,000 Hz and is often used with a “conventional shaped” dome tweeter being used as a “super tweeter” to generate signals above 12,000 Hz.

Given their limitations, anyone lucky enough to own a still functional Ohm F loudspeaker swore that the Walsh Tweeters are the ideal tweeter for reproducing Classical string quartets or similar small ensemble Classical works, although some say Jimi Hendrix sounds “more interesting” on a pair of Ohm F loudspeakers. The same holographic front-to-back imaging thing also occurs on a pair of more recent Ikonoklast3 loudspeakers and similar MBL Radialstrahler 101 loudspeakers.

ELAC Debut 2.0 OW4.2: 21st Century Hi Fi Budget Wonder?

When it comes to entry level hi fi loudspeakers in the 200 to 300 USD price range, is the ELAC 2.o OW4.2 represent the 21^st Century’s hi fi budget wonder?

By: Ringo Bones

Before ELAC’s designer Andrew Jones joined the German based hi fi manufacturing firm ELAC, he began work at KEF from 1983 until 1994. Then he later went on to Infinity and later with Sony and it was with the Japanese firm that he gained familiarity with designing hi fi loudspeakers using “exotic” materials like beryllium for tweeter diaphragms. But does his engineering experience translate to finally making an entry level budget loudspeaker in the 200 to 300 USD price range that would be universally loved by audiophiles the world over?

When I first heard of the ELAC Debut 2.0 OW4.2 last year, memories of budget loudspeakers of its price class made during the past 25 years came flooding in and begged for comparison. Fortunately, one of my audiobuddies kept his old Mission 731 LE loudspeakers bought back in 1995 – though he has moved on to much better speakers – i.e. his mega-buck albeit entry level Magneplanars. If 25 years of inflation is taken into account, the mission 731 LE would be much more expensive today than the ELAC Debut 2.0 OW4.2 and yet the 21^st Century ELAC’s raison d’être is to provide novice audiophiles a taste of the high end with a much lesser impact on the wallet.

The entry level ELAC’s Kevlar cones (Kevlar is the same aramid fiber used to make bullet proof vests) allows it to be played loud without breaking up and yet maintain reasonable efficiency, but unfortunately, there’s a somewhat broad suck-out in the midrange which if your idea of hi fi loudspeaker fidelity is how close it replicates hearing baritone Leo Nucci belting out the best parts of Verdi’s Rigoletto at La Scalla while sitting only 50 feet away without any electronic amplification, then you may find the entry level ELAC a little lacking in this department. If your loudspeakers you currently have can do that much better than the budget ELAC, then maybe you should spend your upgrade money in buying records and CDs instead. Nonetheless, the ELAC Debut 2.0 OW4.2 is very adept when it comes to mainstream pop and electronic dance music reproduction, albeit only up to a certain volume level and it serves as a gateway for millennials wanting a taste of high end at beer budget prices like the Mission 731 LE did for gen X’ers during the 1990s.

DNA: Music Recording And Playback Format Of The Future?

With traditional independent record stores now closing and malls no longer selling Red Book Compact Discs, will DNA prove to be the “future-proof” music format of the future?

By: Ringo Bones

With traditional independent music stores – ones that sell vinyl LPs and Redbook 16-bit 44.1 KHz sampled compact discs closing and big malls no longer selling Redbook CDs, it seems that it would only be a matter of time that every Generation-Xers music collection could be consigned to the dustbin of history much sooner than expected. Thankfully, to celebrate the 20^th anniversary of the release of their most successful album, UK based electronic music group Massive Attack released their Mezzanine album on DNA back in October 2018.

Massive Attack worked with Andrew Melchior at the technology consultancy 3^rd Space Agency – the man who helped Bjӧrk convert her performance of “Stonemilker” into virtual reality for her 2015 MOMA show. According to Melchior: “The advantage with DNA is that our civilization could crash into dust and rebuild itself using entirely different technology, meaning they couldn’t access our computers or disks, since every human carries DNA, we can expect any future civilization to work out how to play back DNA-stored information. Which means the first thing a future civilization would learn about us might be Mezzanine.”

Using the DNA molecule to store vast amounts of digitally encoded information is more than just a science fiction pipe dream that was first popularly presented in the Superman movie franchise Man of Steel. The idea has first been published back in 1964 to 1965 when a Soviet era physicist named Mikhail Neiman published his work on the subject in the journal Radiotekhnika. But the first successful execution of encoding digital data onto a DNA molecule was back in 2012 when Harvard biologist George Church encoded one of his books onto a DNA molecule.

The electronic musicians Massive Attack worked with scientists at TurboBeads, a commercial spin-off from the Swiss science, engineering and mathematics university ETH Zurich, to adopt a technology pioneered by maverick US biotechnologists Craig Venter when he created a synthetic chromosome of a bacteria species in the laboratory with four “watermarks” written in the DNA. Robert Grass, professor at ETH Zurich’s Functional Materials Laboratory and his colleague Reinhard Heckel used similar chemical techniques to translate Mezzanine’s digital audio stream into genetic code. “We store digital information in a sequence of zeroes and ones, but biology stores genetic information using the four building blocks of DNA,” Grass explains. “We compressed Mezzanine’s digital audio then coded it as DNA molecules by converting the binary 0s and 1s into a quaternary code – with adenine representing 00, cytosine representing 01, guanine representing 10 and thymine representing 11. The resulting DNA resembles natural DNA in every way, although it contains no useful genetic information.”

According to Massive Attack band member Robert del Naja: “The storage potential of DNA is huge.” Indeed, one milligram of the DNA molecule could store the complete text of every book in the US Library of Congress and have room to spare. Del Naja also states: “If you think about DNA versus the ridiculous amounts of server farms that have got to be cooled 24/7 all around the world, this looks like a much better solution going forward. It allows us to archive music for hundreds of thousands of years.” Unfortunately as of late no word yet on the newfangled format’s sound quality.

MIT Terminator Network Loudspeaker Cables: A Misadvertized Audio Product That Actually Works?

Despite of the rather “misleading” efficiency graphs in their adverts during the 1990s, does the MIT loudspeaker cables actually a “misadvertized” products that actually does its intended purpose – i.e. improve sound quality?

By: Ringo Bones

A few months ago, I was fortunate enough to rummage upon a used 1990s era MIT Terminator Network loudspeaker cable in a garage sale. Priced at around 20 US dollars a set, it was almost a steal. Even more fortunate, the former owner who is a radiologist used the box of the cable when testing a newly purchased CAT scan for a hospital and noted the values of the capacitors and inductors in the box from the X-Ray results – i.e. the component labels of the capacitors are clearly visible and the inductor’s values are determined by its dimensions and number of turns. I wonder why these products managed to improve the dynamics of solid-state amps by making them perform dynamic swings that has only been previously the domain reserved to classic McIntosh vacuum tube power amplifiers. With the LC filter component values sets its working frequency at around 45 Megahertz, I started to wonder if the working principle of how the MIT loudspeakers improve sound quality is similar to James Henriot’s  Whest Dap 10 Processor – i.e. the elimination of the so-called “analog domain jitter”?   

  

When Stereophile reviewer Jonathan Scull quoted Matthew Bond of TARA’s white paper on the difference between Musical Interface Technology’s products versus TARA’s from an August 1998 review of TARA Labs The One interconnect, loudspeaker cable and digital datalink. Most readers are familiar with cables that use network boxes in-line with the signal – i.e. MIT (Musical Interface Technology) Fadel Audio Art and Transparent Cable come to mind. According to Matthew Bond’s own view regarding these   issues: 

“These boxes contain low-pass filter networks that filter radio frequencies (RF) from the audio cables. These should not be confused with TARA’s Isolated Shield Matrix. The differences in both function and effectiveness are extreme.”

“A filter network removes RF from the audio signal by filtering out or rolling off all high-frequency energy above a certain range. This generally affects the upper end of the musical spectrum. Furthermore, these filter networks are directly in the signal path. When the signal is interrupted and fed through these low-pass filter networks, the cable’s electrical characteristics are changed to make a modified cable interface with limited and unnatural filter characteristics. The high-frequency bandwidth is reduced. The audio band is affected also, as it is subjected by the filter network to rippling, and slower rise time (in the case of the fourth-order Bessel low-pass filter). Furthermore, in a filter network RF modulation has not been addressed properly because of the heterodyning effect still occurs in the audio band. Additionally, the amplitude of the extremely high-frequency harmonics of the music are filtered off, along with the RF distortion, by generic capacitors and inductors in the network. The effects of a filter network are therefore subtractive and ultimately color the original signal. The Isolated Shield Matrix does not filter RF it grounds it outside of the signal path. It transfers RF and EMI energy from the cable without filtering the signal, thereby allowing ore high-frequency information to be passed through unaltered.”

The problem is unofficially known as “analog domain jitter” and even though Whest Audio founder James Henriot doesn’t understand the disease but thinks he’s found a cure while promoting his Whest Dap. 10 Processor featured in the July 2005 issue of Stereophile. Could Musical Interface Technologies MIT network cables manage to improve the sound by the same principle of eliminating “analog domain jitter”?

The Whest dap.10 works entirely in the analog domain above 30,000 Hz, far above the range of human hearing. It is also well above the 20,000 Hz limit at which your DAC’s filters curtail CD sound. According to James Henriot, frequencies you can’t hear affect the ones that you can hear. Other audio designers since the 1990s have stated the same thing and so have musicians talking about their instruments. Musical Fidelity founder Antony Michaelson who is also an accomplished musician who plays the piano and clarinet in a classical setting also stated that things occurring above the audible range have an effect on the sounds that you can hear.

According to James Henriot:“All amplifier circuits produce a set of harmonics related to the incoming signal. The output of a CD player is no different. Often referred to as “ghost images” in a Fast-Fourier Transform display result, the time shift causes minor ripples above 30,000 Hz. We think that these ripples have a profound negative impact on CD reproduction, possibly by beat interaction, which dribbles its way down into the audible frequency range. All electronic circuits – especially sold state ones – may have a way of knocking harmonics out of sync, resulting in a less musical and more electronic sound. Does this mean that building a musical sounding solid-state amplifier is akin to building a concert grand piano with all those string compensators?

Does Power Supply Electrolytic Capacitors Have a Finite Lifespan?

They may last forever in so-called “textbook conditions”, but do capacitors used in real-world situations really have a finite lifespan?

By: Ringo Bones

The topic of capacitor mortality entered the conversation radar of my audiobuddies late last year when Sunfire founder Bob Carver voiced his concern after many of his Tracking Downconverter / PWM power supply equipped power amps “flooded” the online second hand market. And given a majority of these are from the mid to late 1990s and on average are 20 years old – or a bit older, Carver cautions the potential buyer to first service and / or troubleshoot these amps, especially check the power supply capacitors since given the pulse-width-modulation type power supply nature of these amps, the main electrolytic capacitors have a theoretically much shorter lifespan than power amps using conventional linear power supplies. Another power amp that’s very popular in the online second-hand market is the Musical Fidelity A1, which requires a careful main power supply capacitor examination since it runs hot at 50 to 65 degrees Celsius and the inside where the capacitor lies could get much hotter.

The power amplifier’s overall layout and operational temperature plays a very important part on the “mortality” of its main power supply filter capacitors since the leakage current of insulators and consequently all capacitor types, increases with temperature due to Arrhenius’s Law. The power dissipated in a capacitor subject to alternating current stress or ripple is a product of effective series resistance and RMS current. The effective series resistance and impedance of capacitors are both dependent on which frequency they operate and hence must be ascertained at the relevant frequencies. Assuming sinusoidal waveforms – as in a typical linear power supply – RMS current can be easily determined. With other waveforms – as in those Bob Carver power amplifier designs equipped with Tracking Downconverter / pulse width modulation type power supplies, the only accurate method requires the use of the Fourier analysis of the capacitor voltage waveform to determine the frequency components and hence permit calculation of the current for each harmonic involved. For those preferring to avoid the complications of Fourier analysis, a workable rule-of-thumb is to check the temperature rise of the capacitor case. If less than 5 degrees Celsius above the ambient temperature of inside the power amp’s casing of say 55 degrees Celsius maximum, leave well alone; if greater (as in hotter) – investigate immediately.

The normal failure mode of aluminum electrolytic capacitors is gradual parametric degradation after years of operation. But I’ve noticed to cool running power amp designs whose insides are only 3 to 5 degrees Celsius higher than the ambient room temperature, the main power supply electrolytic filter capacitors seem to measure within its parameters after 25 years of regular operation –i.e. 4 to 5 hours a day being played; Whereas for other capacitor types, normal failure mode is by short circuit. This parametric degradation results from the finite volume of electrolyte and the consumption of available oxygen.

The leakage current of normal capacitor operation consumes minute quantities of oxygen from the electrolyte, releasing a corresponding amount of hydrogen which is either reabsorbed in the electrolyte or escapes to the atmosphere. Excess quantities of gas result if: 1) the said capacitor is subjected to DC voltages way beyond its rated capacity. 2) The capacitor used in power supply filtering is subjected to alternating current for several minutes perhaps due to a short circuited rectifier diode and the power supply fuse not blowing. 3) The DC bias is externally reversed by circuit action and / or alternatively internal reverse DC bias due to excessive ripple or discharge currents. 4) Series or parallel connected capacitor banks not having suitable voltage or current sharing provisions.

When considering capacitor failures, it is essential to remember that all electrolytic capacitors comprise of two polarized capacitors back-to-back connected in series. This is implicit in the construction methods, both for polar and non-polar devices, which differ only in effective working voltage of the two capacitors. So if that Rubycon Black Gate electrolytic capacitor you installed in your power amp back in 1988 sill makes your low-power solid state design sound as if it is a single-ended triode tube amp, then it consider yourself lucky and keep it in place.  

Can Graphene Semiconductors Make Future Solid State Audio Power Amps Sound Like Vacuum Tube Amps?

Given that electrons can travel more than 100 times faster in graphene than in copper, will the upcoming graphene based semiconductors make solid state amps sound like vacuum tube amps? 

By: Ringo Bones 

Though they’ve been identified as far back as 1947 as being 207 times stronger than steel and make electrons travel 100 times faster through them than through copper wires, the carbon allotrope graphene was only manufactured / synthesized in significant amounts back in the 1970s by Manchester University physicists Prof. Andrei Geim and Konstantin Novoselov which made them the recipient of the 2010 Nobel Physics Prize. But more recently, various methods to manufacture graphene in higher volumes and far lower costs than before have recently made them economically viable enough for semiconductor applications. Given faster electron flow / electron mobility and high tensile strength, could upcoming graphene semiconductors someday make solid state hi-fi amplifiers sound like their famed vacuum tube counterparts? 

During the 1990s many research articles were written about why hi-fi solid state power amplifiers sound different from their thermionic vacuum tube counterparts. But during the latter half of the 1990s, solid state integrated amplifiers that used “high electron mobility” semiconductors – i.e. solid state devices that used indium antimonide that are "blocked out" to protect the secret of their designs whose electron flow is up to 50 times that of copper wire and or power transistors enclosed in nonmagnetic packaging like TO-3 packaged 2N3055 NPN transistors in brass as opposed to the bog standard magnetic stainless steel. Even though these amps tend to be overpriced – average price between 3,000 to 5,000 US dollars each were their equivalent circuit counterparts using bog standard output devices tent to sell on average one-tenth of their price. Many audio engineers and hi-fi enthusiasts have wondered whether the difference in sound / timbre of solid state power amps and vacuum tube power amps is largely due to the speed of electrons travel through their output devices. 

Electrons and electromagnetic waves propagate in vacuum at a maximum speed of 299, 792, 458 meters per second – usually rounded to 3-million meters per second or more famously known as 186,000 miles per second or 670-million miles per hour. A 12-gauge copper wire carrying a 10-ampere DC current, the speed of the electrons traveling through it is about 80 centimeters per hour – or about 0.0002 meters per second. A current traveling through a silicon-based semiconductor is about the same. While a velocity of an electron by the time it reaches the anode after being accelerated by the anode’s field is truly mind boggling by comparison. For example a vacuum tube with a fairly typical anode voltage of 450-volt DC, the electrons will hit the anode at approximately 12-million meters per second or 28 million miles per hour.  

Remember those “overpriced” integrated amplifiers that use exotic high electron mobility solid state devices that sound like vacuum tube power amps? The average electron mobility rating of the active output devices that these amp use are 50 times that of typical silicon based output devices. Is electron mobility / electron speed the secret to better subjective sound quality? Well, electron flow in a typical indium antimonide semiconductor is around 0.01 meters per second and on graphene based semiconductors is 0.02 meters per second – quite a lot faster than a silicon semiconductor’s 0.0002 meters per second. Will high electron mobility spell improved subjective sound quality for upcoming graphene based solid state high fidelity audio amplifiers?

Are Physical Digital Formats Better Than Digital Downloads?

From a sound quality perspective – are digitally downloaded music stored in solid state memory sounds inferior in comparison to their physical digital counterparts? 

By: Ringo Bones 

Ever since legal digital music downloads became a commercially viable reality that benefited both artists and record labels, it has been touted by environmentally concerned individuals as a “green” way of selling music around the world because this means that there are no shipping of CDs and other physical formats around the world that produce significant amounts of carbon dioxide emissions. Musical distribution carbon footprint would be limited to the power used by servers and PCs or other devices used to download the music and this could be much lower if those devices are powered by renewably-generated electricity. From an electronic engineering perspective, digital music stored in solid state memory has “supposedly” eliminated the problems of digital jitter in comparison to 120-centimeter CD or DVD discs played in a transport. But why is it that an increasing number of audiophiles have noticed that downloaded music, more often than not, sounded inferior in comparison to its physical counterparts?

Ever since the popularity of universal players that are able to play any 12-centimeter disc – whether it be 16-bit CDs, DVD-video, DVD-audio and Super Audio CDs – and digitally downloaded music via a USB slot, many budget conscious audiophiles, including me, had noticed that digitally downloaded music, even high resolution ones that are in FLAC (Free Lossless Audio Codec) format tend to sound inferior to their physical format. In my own experience, using a 150 US dollar Oppo universal player, physical Redbook 16-bit 44.1-KHz sampled CDs tend to sound better than their downloaded 24-bit 192-KHz FLAC encoded counterparts. The most common recordings that are usually available in both that can be compared side-by-side using a universal player are Miles Davis’ Kind of Blue album and Martin Taylor’s Spirit of Django album. 

To my ears, it seems as if the downloaded versions sounds as if it has the sound quality of a typical 100 US dollar CD player while the physical versions sounds as if it has the sound quality of a typical 500 US dollar CD player. And to Stereophile magazine leaders, most downloaded music played on universal players priced between 150 to 500 US dollars via its USB slot has a digital sound that Stereophile contributor Michael Fremer used to describe back in the 1990s as “everything gets flattened out – including dynamics. Given that solid state storage devices supposedly doesn’t have the digital jitter inherent in CD / DVD / SACD drives, why is it that digitally downloaded music – even hi-rez ones – sound inferior to their physical counterparts?  By the way, digitally downloaded music only started to sound as good as of better than their physical formats only after I’ve burned them into their requisite 12-centimeter recordable CD or DVD discs using a PC with Windows Media Player that can handle FLAC encoded music data.