Achieving Desktop/Nearfield Audio Nirvana

When the Sony SA-Z1 speaker system I reviewed in issue 312 was packed up I looked at the empty space left behind and wondered, “How close to that reference-level sound can I get from other more conventional components in the same limited space?” And so, my trip down the rabbit hole with mini-sized desktop-based stereo systems began…and multiple months in, things are getting interesting with my tabletop time machine.

The Goal

When I reviewed the Sony SA-Z1 audio system I wrote, “The Sony system creates a three-dimensional soundfield that envelops the listener in the same way a finely tuned room-based system can, but it does it in a much more confined space.” The spatial precision of the SA-Z1’s soundstage presentation was state of the art. With small groups, such as my recordings from the Rockygrass Academy workshops, each individual player was precisely placed, with clearly defined dimensions and height and width cues. When I played a large orchestral recording or a big pop production, the soundstage width, height, and depth rendition followed the dictates of the recording with superb accuracy. If the recording was wide, so was the SA-Z1’s soundstage, but with mono recordings the image seemed no wider than a dime. That is the kind of performance I wanted to duplicate.

There was one sonic parameter where I had no doubt I could best the Sony system with a more conventional one—its mid and low bass capabilities. The Sony system had no subwoofer or provisions for adding one, while every system I’ve assembled in the same space has had a subwoofer. Mid and low bass were far more present with the subwoofer dialed in correctly than with the Sony system.

The Environment

The mid-80s, solid-oak, trestle-legged table in my workroom measures exactly 48 inches wide by 48 inches deep. It resides in the corner, near a window, in a nine by thirteen-and-a-half-foot room with a nine-foot ceiling. For my experiment, the table stayed in the same spot it was in when I reviewed the Sony SA-Z1 system, except I added substantial amounts of acoustic treatment, including ten 4″-thick, 16″ x 16″ Auralex Studiofoam squares; 30 Amazon-sourced, 2″-thick, 12″ x 12″ foam squares; six corner wedges; and a Persian rug on the desktop itself to kill midrange “table bounce.” After trying several different speaker stands, I settled on Rockville RHT8G desktop speaker stands, sourced from Amazon, and then modified them with acoustic damping material to fill their hollow center columns. 

The basic idea was to kill all the early upper-frequency and midrange reflections in the listening environment, and then dial in the bass via speaker placement and subwoofer settings. It was to be a miniature quasi-dead-end/live-end listening environment. Obviously, this is a lot more work, mostly trial and error, than simply plunking down the Sony system according to Sony’s terse instructions.

Some audiophiles might think, “Isn’t this system merely a big headphone?” No, this system is far more like a small room than a big headphone. The soundstage is spread in front, just as in a room-based system, not above or inside your head as with headphones.

The first couple of months I had all the electronics situated between the loudspeakers, which allowed for short loudspeaker cable runs of only one meter and line-level cables as short as a half meter. The problems with this were threefold: First, the metal electronics boxes introduced a diffraction issue—sound reflected off all those nice shiny surfaces. Second, the component locations limited speaker placement. And third, the electronics were in the highest sound pressure area where they were most likely to be affected by high SPLs. 

So, after realizing the error of my ways, I moved all the electronics to a cobbled-together mini-equipment-shelf consisting of two metal monitor stands sourced from Amazon that set me back $22.99. (I should mention that this whole affair was a personal project, financed on my dime.) I gaffer-taped the two stands in such a way as to make a very nice two-tier stand, that put the top tier ten inches off the ground. This was the perfect height, as I could easily reach a preamp’s volume control from my seated listening position. It also meant I had to replace all those nice short cable runs. Now I had a two-meter connection between preamplifier and power amplifier and a three-meter run to the subwoofer. At least the half-meter line-level connection between the DAC and preamplifier remained the same. I also repurposed two short, metal, On-Stage SMS-4500 speaker stands that were a bit too high to use with loudspeakers on my tabletop, as power-amp and AC-power-filter-box stands under the table.

Because this was a personal project, not an Absolute Sound assignment, I did not approach any U.S. cable manufacturers for loaner cables, but instead sourced all my cabling from the same overseas vendors as most of the audio components. I tried several radically different cabling configurations, including flat-strand, braided, and coaxial designs; they all worked, but some performed at a higher level than others with particular configurations of gear.

The Setup

Noise and hum are the enemies. The goal was to assemble a system that was quiet enough that you could put your ear right up to the tweeter and hear nothing—or, at worst, hear nothing more than a gentle distant hiss. Hums, buzzes, whines, or anything else that made it seem as if the music emerged from behind or in front of a curtain of additive electronic noise was simply unacceptable in an extremely nearfield system. I can’t begin to count the number of times I’ve connected together a promising combination of preamplifier and power amplifier only to be greeted by some form of additive base-level noise. For me, that’s the sound of system failure.

While specifications are good starting points for finding components that are quiet enough for nearfield use, even seeing 100dB signal-to-noise figures doesn’t guarantee background silence. Unfortunately, powerline noise has a major influence on overall noise levels at your loudspeakers, and that’s something that no manufacturer can control. Also, hum generated by the transformer and physically transmitted to the power amplifier chassis by contact proved to be a problem with some of the low-power amps I tried. Good luck finding any builder who tests, measures, or even notices whether their amplifier exhibits any transformer-generated hum!

A major advantage of a nearfield system is that you can employ lower-power amplifiers with medium-sensitivity (86–89dB) speakers that would require double or triple the output power to reach the same SPLs at the listening position in a room-based system. I’ve used everything from 8W single-ended tube amps to 150W transistor amps in this nearfield system. Some of the highest-fidelity results were from 15-to-25W solid-state Class A or minimalist, Texas-Instrument-chip-based power amps mated with simple single-input Class A preamplifiers. There’s something that sounds right about an audio signal without the crossover distortion of a Class AB circuit.

My signal chain for this system was simple. I used digital files from Tidal, Qobuz, and my own NAS played via Roon. The Roon endpoint was a Raspberry P4B running Diet-Pi software, with its USB output connected to a Topping D-70 and an iFi Zen DAC Signature. Depending on the preamplifier, I used either the Topping and iFi’s balanced or single-ended connections, and except in rare cases the volume control was maxed-out for a full 2V output via single-ended connectors, and 4V via balanced ones. I isolated the Raspberry Pi’s digital-power-supply wall-wart from the other component’s power supplies as a prophylactic measure, since these kinds of digital power supplies can be sources of AC noise for the rest of the system.

The Parade of Gear

You’ve probably noticed that, so far, I haven’t mentioned much of the gear I was using. This kind of a “survey” article is usually fertile ground for dropping seeds of manufacturer links hither and thither. But I must come clean: Much of the gear I used and listened to in this system was from Chinese sources. It’s stuff that is not yet being imported by any established U.S. distributors and is therefore completely unsupported. In good conscience, I can’t recommend (or even mention) gear that an average consumer can’t easily purchase and can’t expect the support of its creators from when it fails. That kind of gear is best reserved for audiophiles who have a gambling streak and some technical chops. And while I’ve never dropped a single dime in the slots at Vegas during all my years of attending CES, I could not resist the allure of some attractive reimaginings of classic high-performance circuits from Chinese hi-fi builders. Notice that I wrote “builders” not “manufacturers.” Many of the most interesting Chinese audio products are assembled by enthusiasts from readily available parts, including completely populated circuit boards, transformers, and chassis. I can’t tell you how many times I’ve seen certain popular chassis or boards used for slightly different designs from various shops.

So, I took a budget of several thousand dollars (approaching $3k, and still counting) and bought samples of eight different preamplifiers, both tubed and solid-state, six different power amplifiers, two power conditioners, and enough different power, line-level, and digital cabling to wire the entire system several times over. Most of the electronics I purchased were in ½- or ¾-sized chassis (hence qualifying as mini). I concentrated on these components because with full-sized electronics, especially power amplifiers, the shipping costs from China are much higher due to greater weight and larger-sized boxes. Also, the heavy stuff coming from China has a history of experiencing far more shipping damage. I even got a bunch of cool under-gear footers that featured a triple-ball-bearing contact point, textured rubber feet, and a rubber-damped center to put under the preamp, DAC, power amplifier, and power filter boxes for better ventilation, isolation, and that essential “stay in place and don’t move” capacity.

The Results (So Far)

What has all this building and unbuilding, hooking and unhooking gotten me? In the end, it’s brought many hours of satisfied listening. But that doesn’t help you much. What I discovered (or rediscovered) was that, unfortunately for audio compulsives, every component choice in an audio system can and does make a sonic difference (cue Billie Eilish, “duh”). 

The first challenge was to clean up my generally rotten AC power, which varies from 117 to 121 volts with copious amount of noise and hash as measured by two different noise-measurement devices. I’ve found PS Audio’s AC-noise-reduction components, including the Quintet, Dectet, and their active power stations, extremely effective, but I wanted to see if I could find something from overseas that would also work. On my second try, I found a device with two separate channels of transformer-filtered power that delivered quiet results. Since it only had four plugs (I need as many as seven sometimes), I added another all-metal AC-filter box from the same source and connected it via a short ½-meter AC cable to supply the extra two outlets I needed. 

I violated my attempts to assemble a completely Sino-centric system when I got to speakers. Even I don’t have sufficiently steely gamblers’ instincts for choosing loudspeakers based on a couple of pix and some less-than-complete printed specifications, so I stayed with loudspeakers I knew. So far, I’ve used five different loudspeakers in my mini-system, all two-way designs except for one, all mated with an M&K Sound MX-700 subwoofer (discontinued) or Omega subwoofer. The M&K subwoofer has a rather unusual design with one 8″ woofer firing downwards, while the other next to it fires upward into the cabinet. Also, this subwoofer was designed to be situated next to a wall, which was ideal for my setup. The Omega is a down firing 8″ that also allows for close wall placement. My loudspeaker entourage included the Audience 1+1 loudspeakers V3 ($2960/pr.), Silverline Minuet Supreme ($795/pr.), ATC SC-7 II ($1495/pr.), Role Audio Kayak ($795), and Omega Mini-Me (discontinued). The Silverline Minuet Supremes and Omega Min-Me’s were the most efficient, so they got the most time with lower-powered amplifiers.

How Good Can a Tabletop System Be?

Of course, the question on anyone’s mind who’s read this far is, “How close to the sound of your main room reference system did the mini-system get?” The answer is it’s extremely close, but not quite there yet.

With the very best combinations of gear I’ve cobbled together so far I’ve gotten this system to a point where it performs at a level equal to my main system in lateral focus, bass extension, speed, inner detail, and micro-dynamics, but there are still some aspects that are not yet up to reference level. Getting the same openness, both in the character of the bass and in the spaces between instruments or vocalists, has been challenging. There is still something in the way of electronic “stuff” present, where my main system delivers a void of empty space.

An area where I succeeded in besting the Sony system was the size of the sweet spot. With the Sony it was possible to move my head enough, while chair-dancing, for the image to shift slightly. With my current desktop configuration, I can dance to the music without boogying out of the sweet spot. A prime cut for this dance fever was BTS’ release “Butter,” which has a huge soundstage and a dynamic bass line that could tax a system not up to handling its dynamic requirements, but it hangs together beautifully on this nearfield system. 

Easily the most pernicious recurring sonic problem I had with the system is taming the lower midrange and upper bass so that it does not get huffy or thuddy, even with the subwoofer turned off. Because they have the most bass capability of the loudspeakers I used, the ATC SC-7 II had the most issues in this respect. Combined with a 1969 Hood design Class A power amp the ATC’s could whomp you like a Harry Potter’s magic tree. Fun, but not too real…

And while we’re on the subject of fun, I must add that playing mix and match with multiple, modestly priced components has been a blast, as well as educational in terms of what components I could successfully mate, and not mate, with other components. The system has kept me amused, and perhaps a bit more sane during the past unusually cooped-up year.

I’m planning on continuing to refine this nearfield system. I want to try some more sensitive loudspeaker designs and several more preamplifier and low-power amplifiers. Perhaps, editors willing, in six or nine months I’ll bring you up to date on how the system has progressed, and maybe, just maybe, begin naming names in terms of my favorite signal-chain component combinations…but first, if I may paraphrase words from this publication’s founder, “I must fully explore the full measure of the system’s potential greatness.” All the while, having fun, too.