Over the Top Review

Silent Speaker

as reviewed by Steve Lefkowicz

Ok. Let’s say I had two speakers that on paper appear at least somewhat similar in concept, both being floor standing, two way, bass driver around 6½ inches, and designed to offer generally full range sound. Let’s say that one costs a little more than the other. For that extra money, you get a slightly deeper bass response and a little more definition in the bottom end. Let’s add in that the more expensive model is a little more transparent and has a somewhat more extended airier top end, to along with somewhat better overall level of detail. It also has more pinpoint imaging specificity.

Now, let’s say the lower priced model has greater dynamics, a fuller, more natural sound, and has the large sense of scale to make music sound more natural. Let’s also say that though not going quite as deep in the bass, in the range where most bass instruments play, it has more impact, weight and loads the room better.

Let’s then add that both speakers offer the type of long-term comfort to allow for daylong listening sessions with no fatigue, unless induced by the associated equipment.

Then finally let’s ad in that the more expensive model ease very easy to drive, and sounds equally good with moderate to low powered tube amps and with higher powered amps, while the lower priced unit really prefers more power and maybe sold state?

Which would you choose?

I guess the next question would be just how much more does the more expensive speaker cost? How about just over $3000 more, based on the price when I reviewed it a few years ago? Now, $3000 more might not too bad if we are talking speakers in the $20,000 and up range, but you know I don’t review products like that. Actually, in spite of being $3000 more expensive, the pricier speaker still sold for under $4000. That doesn’t leave a lot of wiggle room for the cheaper speaker now, does it.

Actually, the lower priced speaker, the Direct Acoustics Silent Speaker being reviewed here, had a complete, and delivered to my door price of just $511. The price to your door would vary only by the difference in shipping costs.

Who are Direct Acoustics, and what is the Silent Speaker? Direct Acoustics is the current company run by one Winslow Burhoe. Burhoe is a name that may be well known to many of you, especially if you are over 40 years old. Burhoe started back at AR (Acoustic Research) back in the days when they were a serious manufacturer of high quality speakers. He then worked for KLH back when they, too, were a manufacturer of high quality speakers. He then left KLH and in 1970 formed his own company, Epicure Products, Inc., manufacturing EPI and Epicure speakers.

EPI speakers were based on a module that Burhoe designed using an eight-inch woofer and an inverted dome tweeter (I’ve seen this listed as being both ¾ inch and one inch, though I am positive it was then billed as a ¾ inch unit). The woofer was unique in that it needed no crossover, as it naturally and smoothly rolled off at higher frequencies. The tweeter had just a capacitor attached, to give an effective crossover point of 1.8kHz. This module was used in a variety of cabinets (and in some cases, like the EPI 180 that I used to own, in multiple combinations) offering different levels of bass extension and maximum output. Back in the day (1970s) the small EPI 100 was one of the most popular speakers on the market. I owned the slightly larger model 110 and in 1975 upgraded to the model 180 (discontinued by then, but the dealer had a demo pair left), which I felt were a better choice than the competition at the time from Advent, JBL and others. I used the 180s for many years, before replacing them with a pair of used Acoustat Monitors in 1983.

After departing from EPI, Winslow Burhoe started another company, Burhoe Acoustics, and produced another line of exceptional speakers. A friend in college (late 70s) had the top of the line Burhoe Blue, and his was the best sounding system in our dorm, even though other systems there used speakers from JBL, Klipsch (Heresy), Advent, EPI, Bose (an original 901 system!) and KLH. It wasn’t until a new kid moved in with stacked Advents driven by a pair of modified Dynaco ST70s and a Lenco turntable that someone finally surpassed this system. Curious that my niece just graduated from Penn State two years ago, and none of her friends on campus had dedicated, high quality music systems. Most just played MP3 downloads on their computers. How times have changed.

For more information in the history of EPI, you should check out the Human Speakers web site (www.humanspeakers.com) who service and rebuild EPI speakers, as well as Genesis, Burhoe and a few others. Human Speakers has a good reputation and I believe the acknowledgement and endorsement of Mr. Burhoe himself.

After that, Burhoe continued and worked for Boston Acoustics, Energy (I believe he had a hand in the original Energy 22) and Nuance.

Direct Acoustics has been around for several years, as they have a review posted on their web site dated from a 1995 issue of Audio magazine, though I believe they have gone in and out of production a few times, based on availability of the necessary drivers. They are in current production however, so this review should be considered relevant to a current available product.

The Silent Speaker is a relatively small floor standing speaker, measuring 13 ½ inches wide by 9 inches deep. They stand 25 tall, but the top slopes downward, so the front is only 22 inches tall. Both drivers are mounted on the sloped top section. They are designed to be placed near the wall (the owner’s manual indicates against the wall, not just near it, but more on that later). The speakers are fairly lightweight, weighing in at just less than 30 pounds each. The driver complement (still based on the same module concept) consists on one 6½- inch mid/bass driver and a one-inch soft dome tweeter. The mid/bass driver still has no crossover or filtering, as it is designed to naturally roll off at higher frequencies. There is a 24dB/octave crossover for the tweeter, centered at a very low 1600Hz. If I remember correctly, my old EPIs crossed over at 1800Hz, and a low crossover point has always been a significant part of Burhoe’s designs.

The speakers arrived a day before I left for a ten day vacation, so I hooked them up to an FM tuner and let them play at normal listening levels until I got back. I figured that should be enough break in time, so I started my evaluation immediately upon my return.

The first order of business was of course finding the ideal placement for these. My room is 24 by 14 feet, and I usually have speakers along the long wall facing across the short wall. Over the years I have found this work best in most cases. With the Silent Speakers, it was not even a choice about which wall to use, as both of the shorter walls are taken up with doorways, or windows. So the speakers were centered on the long wall, being moved closer together or farther apart until everything just seemed to come together musically. This left them 115 inches apart measured inside edge-to-edge, right up against the wall (actually, about 1½ inches out, as needed for he cable connections).

Using my B&K amp for initial listening, this setup was a lot of fun, but the bass was overwhelming and out of balance with the rest of the music. I then tried moving the speakers away from the wall until again, thing just sounded right. This was only about 5 ½ inches out, and in fact I used an SACD jewel case (the long dimension) between the speaker and wall as a guide for making sure everything was lined up evenly.

I listened this way for the next few days, and still felt the bass was a bit much, but rather than move the speakers farther from the wall I instead simply set them up with a hockey puck under each foot they do not use spikes). This raised the speakers up about an inch and then everything sounded right. Every audiophile should have a bag of hockey pucks at their disposal!

So, now, finally, how do the Silent Speakers sound?

I’ll start by saying I think these are probably (almost assuredly) the best $500 speaker you can buy. Period. No, they are not perfect, and like all products they have their limitations and characteristics, you will have to decide for yourself whether you think they are the best $500 speaker you can buy.

Let’s start with the good points about these speakers.


No speaker I have heard in this price range can come close to the scale and power of the Silent Speakers. Big music sounds appropriately big, and big instruments likewise sound naturally big. Most high quality $500 speakers are small two way mini monitors, and though many of them have great midranges and top ends, none can match the shear size, scale and power the Silent Speaker. What small mini monitor can reproduce a full symphony orchestra satisfactorily? I have heard a few, but they cost way more than the $500 these will cost. Solo piano works sound sensational, as both the tone of the piano and size of the sound actually match. The scale these speakers produce I normally expect only from large planer designs, or a few very large conventional speakers.

Bass response

The Silent Speakers go quite low (low 30s in my room) with power and weight in the low notes that no other current $500 speaker I know of can match. In comparison to my Sound Dynamics 300ti system, they are certainly weightier, especially noticeable on string bass in jazz or blue grass tunes, or electric bass in rock. The Sound Dynamics are certainly a little more detailed in the bass, but lack the sheer power and energy of the Silent Speakers, which load the room and fill it with true, satisfying bass. However, you have to play with positioning to get the bass right, and, as I mentioned already, raise the speakers a little off the floor or move them out from the wall a little.

Tonal Balance

Throughout the most important ranges from upper bass to upper midrange, the Silent Speakers are neutral enough to pose no issues. I can’t get caught up in minor deviations from neutrality the way some audiophiles are, because my experience is that room interaction, associated equipment and the various recordings themselves all impact tonality. How can I therefore say that it is the speakers that have a particular minor deviation from neutrality? If it is a large tonal abnormality, then fine, but once things get close, then I whatever I report will still likely sound different if you put the speakers in your system in your room.

However, one thing I like about the tonal balance of the Silent Speakers, at least as compared to what you normally expect from this price range, is that if anything, it is slightly weighted towards the lower frequencies rather than the higher ranges. The upper frequencies sound somewhat rolled off (though the measurements I made didn’t show any significant roll-off below 15kHz), imparting a fairly mellow overall balance. These speakers are not as airy or extended as some other speakers (like the Sound Dynamics). The overall tonal balance is certainly never bright, as so many low priced can be.

Imaging and Soundstaging

This is an area that many of you will disagree with me, but I think the imaging characteristics of these speakers are not just acceptable, but in their own way, superb. As one would expect from a speaker placed just a few inches from the wall, there is not a lot of image depth. Nor, for that matter, is there the pinpoint, specific location of everything that you get out of small mini monitors (which I think generally make too many instruments sound unnaturally small). However, what you do get, and what I think is very valid, is a massively huge stage, both laterally and vertically, as if the entire wall behind the speakers was now a window (or maybe a movie screen) that has become the stage. Enhancing that effect is the fact that, except for some added sound effect or from very poor recordings, no sounds ever appear to come directly from the speakers. The Silent Speakers do the disappearing act better than pretty much any speaker I have ever reviewed (please note that this is true in my system using the Audio Space Line-2 preamp, but not quite so much when using my PS Audio 4H passive preamp, where the stage is a little smaller).

One example of this is the beginning of the track Wish You Were Here, from Pink Floyd’s album of the same name. At the beginning, the guitar is played through (or least made to sound like) a table radio, coming from just one speaker. With the Silent Speakers, this sounds like a real table radio sitting on top of the speaker, as if it was a small table. Then, when the lead guitar starts up (a superb recording of a guitar) it sounds remarkably natural both in tone and in size, floating in space is if the guitarist was standing right there between the speakers.

Last comment image-wise, is that there is no real sweet spot, or maybe it’s that the sweet spot is about ten feet wide. I can sit anywhere on the coach in my listening room and the sound doesn’t really change. It is a little brighter when I stand up, but that’s about it. These are great speakers if you actually move around or do other stuff with music playing!

I don’t normally discuss imaging this much in my reviews, but I have been continually taken in by the overall imaging of this system.


This is simple, for $500 you don’t need to add anything for stands, maybe just around $8 for hockey pucks! Floor standing speakers do have that advantage over similarly priced stand mounted speakers. Also, you can save some money on cables, as these speakers do not allow for bi wiring. Also, for whatever reason (I won’t speculate on technical matters) I heard little significant difference between the two speaker cables I used for the review (Nordost Flatline and Solar Wind). Through my Sound Dynamics, the differences in these two cables are quite clear: I used the Flatline most of the time.

As indicated earlier, these speakers of course have their weak points too. All products have their strengths and weaknesses, and the key is finding products whose strengths and weaknesses correspond most closely with your own personal listening biases and tastes. One would naturally expect that lower priced products would have more pronounced weaknesses; though I have to admit in many cases I have found that not to be true. I can think of a few speaker manufacturers whose product lines start with a five-figure price tag, and that I just don’t get. I can hear and appreciate their strengths, but their weaknesses, as I hear them, fall right in the areas in which I prefer not to compromise.

So what do I hear as limitations in the Silent Speakers? Here they are.


These speakers slightly obscure detail. They don’t make a bowl of mush out of the music the way mid-fi speakers at the big box stores do, but they don’t have that extreme clarity that you get from other competitive speakers. The leading edges of transients are somewhat soft. This is most noticeable on one particular instrument, the snare drum. Though other parts of the drum kit sound fine (and cymbals in fact, sound exceptional), the snare always sounds a little on the soft side. It’s not that they sound recessed or distant, just a little indistinct.

High Frequencies

Considering that you are listening to the tweeters somewhere between thirty and sixty degrees off axis, it is not too surprising that the higher frequencies are a little rolled off. I suppose if you listen to a lot of new age music or audiophile favorites with chimes, bells and other such tests of high frequencies, this may bother you more than it bothers me. The top end is certainly okay, not rolled off like the paper tweeters from the 60s and early 70s, but not as extended or airy as you can get out of some other, even similarly priced current designs. You certainly don’t want a heavily damped or padded wall behind these speakers, as they are designed to have the sound reflect off the wall behind them. The higher frequencies do actually remind me of the top end of the old EPI and Burhoe speakers, which were considered quite good in that regard at the time.

The somewhat rolled off high frequencies and slightly diminished detail do make the speaker sound a little less transparent than some other speakers I’ve reviewed. This is hard to quantify, as just as describing “transparency” to someone is often very difficult.

Power requirements

This is more of a personal thing for me, and may not matter to you at all. My primary amp is a 15-watt tube amp using just a single KT88 per channel. This amp works great with my Sound Dynamics, Linn Kans and Loth-X speakers. The Silent Speakers need much more power than this. My 105-watt B&K was fine and Burhoe recommends 200-watts for “full dynamic range”. I think a good push pull or ultralinear tube amp of 50-watts at a minimum would probably work, but 100-watts or more would be better. Now I wish I still had that Rogue integrated amp on hand, as that was rated at 90-watts. There are many good solid state integrated amps from the likes of Rega, Creek, Simaudio, Music Hall, Naim, Exposure and on and on, that would likely work well with these speakers. I would really like to try the small Channel Islands Audio 100- or 200-watt amps on these before I return them.

Soundstaging and Imaging

Wait a second; didn’t I list this under the speaker’s strengths? Yes, in fact I did. But this is to acknowledge that if you do insist on that small, pinpoint (and I think unrealistic) super specific imaging that you get from many “high-end” speakers you might not appreciate the large, expansive soundstage that the Silent Speakers produce. Again, just a matter of taste and expectations, not really right or wrong, and I do prefer the imaging of these speakers.

So, what does it all mean?

I was describing these speakers to a fellow PFO reviewer, and we both reminisced over our fond memories of early EPI speakers. One thing I have noted during the review period with the Silent Speakers is that all the characteristics that I remember as why I liked those EPIs so much are evident in the current design. I think the Silent Speakers are probably a great deal better than the old EPIs, but the very things that made the EPIs special live on in this speaker. It’s the comfort and all-day listening pleasure that gets you.

A few years ago I reviewed eight speakers in this price range for a single article in Listener magazine. One thing I noticed then was that, as good as some of those speakers were, I still preferred my Sound Dynamics 300tis, and often set them back up to refresh my ears and re-establish my point of reference. This time around, though I still like my Sound Dynamics a great deal, and feel their higher level of detail and high frequency extension make them a better speaker for reviewing purposes, I find that for sitting and enjoying music, I tend to prefer the Silent Speakers.

Well, there you have it, a truly remarkable offering in the world of affordable speakers. Steve Lefkowicz


* Frequency Response: 40Hz to 10,000Hz ± 2dB, 30Hz to 17,000Hz ± 4dB, 20Hz to 20,000Hz ± 6dB

* Dimensions: 13½” wide; 9″ deep; 22″ at front, 25″ at rear

* Power Maximum: 50 watts continuous

* Power Recommended: 200 watts recommended for handling transients

* Rated Impedance: 6 ohms

* Minimum Impedance: 4 ohms

* Crossover: The woofer is designed mechanically and electrically to roll off naturally, no additional filtering is necessary from the crossover. A two-pole network adds to the natural roll-off of the tweeter, additional components equalize the tweeter response to achieve maximum flatness in the prescribed room location.

* Frequency: 1600Hz,

* Woofer Slope: 24dB/octave

* Tweeter Slope: 24bB/octave

* Driver Complement: Woofer: 6.5″ with ±” linear travel, Tweeter: 1″ soft dome type with magnetic cooling fluid

* Shipping Weight: 30lb.

Silent Speakers Retail: $486 a pair (plus shiping)
Direct Acoustics Incorporated, Research and Development Laboratories TEL: 617. 538. 2015 web address: www.directacoustics.com


LOUDSPEAKERS Sound Dynamics 300ti.
ELECTRONICS PS Audio 4H preamplifier and phono stage, Antique Sound Labs MG-SI15DT-2 or B&K ST-140 (105-watt version) amplifiers.
SOURCES Linn LP12, Ittok tonearm and Dynavector 19A moving coil cartridge and Marantz SA-8260 SACD player.
CABLES All interconnects and speaker cables are Nordost Solar Wind. All power cords are factory stock.
ACCESSORIES The Linn sits on a Sound Organization wall mount shelf made specifically for the LP-12. The Marantz SACD player rests on four Bright Star IsoNodes and sits on an original Sound Organization floor stand also intended for the Linn. The ASL amp usually rests on three Solid Tech “Feet of Silence.” The Sound Dynamics speakers sit atop a 12 inch tall set of $50 wood stands that tilt back five degrees. All the rest of the electronics sit on lightweight particle board shelves attached to tracks mounted on the wall. Monster Power HTS2000 power line conditioner, Headroom “Little” headphone amp, Beyerdynamic DT770 Pro headphones, Nikko Gamma FM tuner, I use no specific acoustic room treatments other than my old ice hockey goalie pads (which work quite well in the room corners).