Network Acoustics Tempus Ethernet Switch & Muon Pro Ethernet Filter

[tmallin]

In my personal pantheon of things which determine the subjective quality of a home audio system, speakers are at the top as the most important factor. Just below the speakers is the room and just below that, room acoustics.

You won’t get deep bass at satisfying levels from a tiny speaker no matter how fine your listening room is and how much attention you pay to room treatments. Electronic equalization of the speakers can fix many things, but it can’t meaningfully extend the ultimate low-frequency roll off of your speakers without severely impairing their overall clean SPL capabilities. Equalization also cannot correct the sonic effects at the listening position of sound reflected off the surfaces of your listening room; it only corrects the direct sound heard from your speakers.

Large listening rooms are nice and are really necessary to properly hear the magic dipole speakers can create. For dipoles to create this magic, both the speakers and listener need to be at least seven or eight feet from the walls behind them and this is physically impossible in a small room. If dipoles are less than that distance from the wall behind them, the backwave tends to sound like slap echo, not just adding to the sense of space and openness. Now, I have “successfully” used the Sanders 10e hybrid electrostatic open-baffle panel speaker in my small room, but to do that I threw a lot of acoustic absorption at the back wave, basically erasing it from audibility above a few hundred Hz. Yes, the result sounded very good, but some would rightfully object that this also erased the “magic” of which dipole speakers are capable in a larger room. Thus, I usually stick with forward-facing cone and dome speakers in my small listening rooms.

But even with cone and dome forward facers, no matter how wide or narrow the dispersion pattern of the speakers, in my small room I’ve always found that the use of significant amounts of acoustic foam arranged near the first-reflection areas (areas where, from the listening position, a reflection of any part of the speaker may be seen in a mirror placed flat against that room surface) of the room surfaces is necessary to bring out the best in the spatial presentation of any pair of speakers. With some speakers it’s more necessary than with others, but still I do not regard this absorption as optional. Contrary to Toole’s beliefs, I have long found sidewall reflections particularly obnoxious, especially in a small room where the speakers are of necessity at most only a few feet from the side walls. With most speakers, damping the wall behind the speakers, the wall behind the listener, and the floor is also quite helpful and, to my ears, necessary. Ceiling reflections are less vital to damp in my experience. Damping not only enhances all aspects of the spatial presentation, it also eliminates slap echo and obnoxious brittleness, brightness, and grunge from the upper mid and high frequencies, undoubtedly caused by the relatively “early” reflections of these frequencies from the room surfaces.

So, speakers, rooms, and acoustics need to be optimized for best sound. In addition to acoustic treatments, I’d include vibration isolation of your electronics in this category. But once you’ve taken care of these, are you done?

What about your electronics choices? Well, while amps and other electronics do have sounds of their own, audio electronics have now reached a level of refinement where the differences, while real, are fairly subtle compared to speakers, rooms, and acoustics. Yes, there is a little more or less precise imaging and/or expansive soundstaging, a little less or more of residual hiss and hum, and subtle apparent changes in frequency response. And of course you need enough power from amps to avoid clipping, the sound of which is definitely obnoxious, as is the sense of strain which enters with many amps when clipping is approached. But given enough power from your amps, the sonic changes produced by such electronics, while certainly noticeable and which sometimes will rise to the level of “better” rather than just “different,” with modern electronics the differences are never cringe-inducing. Spending huge amounts on these will not bring proportionate improvements to the sound quality of your system, only relatively subtle improvements at best.

But I’ve found over the years that even after all the acoustical elements are optimized, other aspects must be addressed. While speakers, rooms, and acoustics are definitely the most important in terms of achieving “good sound,” they only deal with what I’ll call the output of your audio system. These don’t deal with the inputs to your system, the program sources.

Linn was correct, after a fashion. No matter how excellent your speakers, acoustic set-up, or electronics are, they cannot erase problems originating in your sources. These include power line issues and internet/ethernet issues.

I have long found that the purity of the electrical power you feed your system can have an audible important effect on the quality of sound you hear even once you have taken care of the acoustical output of the system. My discussion of my power filtration adventures can be found at this link. As an addendum I would just add that with my current system it’s easy enough to bypass all my power line filtration and A/B compare the sound with and without this electrical treatment. While not a night and day difference, the difference is definitely what I would call significant and annoying: flatter soundstage, less defined imaging, and especially various high-frequency nasties which give the sound an irritating bright/edgy/brittle edge. Why the power supplies of electronics do not adequately filter out various nasties, I really don’t understand, but the end result of such experiments is always the same: I hurriedly reconnect the equipment to the filtered electrical service.

And with a streaming-only system like mine, I’ve found that another at least as significant need for filtration involves the quality of the data stream coming from the World Wide Web. Again, why the nasties which cause “digital sound” are not filtered out by the way data is transmitted through the internet and then reassembled in the streamer, I really don’t understand. Again, with my current system it is quite easy to bypass the filtration. The result is not pretty: a clearly and immediately apparent significant degradation in sound quality. Without the filtration, the sound is relatively flat and digitally nasty. Not terrible, but quite significantly worse—less relaxed and lifelike. As with electrical filtration, I can’t restore the ethernet filtration fast enough.

 

[tmallin]

[Continued from Post #1]

I have experimented for years with various filtration schemes. See, for example my discussion at this post and this post. I’m sure there is more yet to do, but I wanted to talk about my latest advance in this area, the Network Acoustics Tempus Switch and Muon Pro ethernet filter, connected up with the Network Acoustics Muon Pro streaming cables.

I won’t go through a detailed review of the sonic changes. This prior review seems quite accurate to me in detailing the subjective changes wrought by these devices.

I will just emphasize the importance of the filtration applied by these Network Acoustics devices to my sonic satisfaction. As helpful as the warm tonal balance of my AR-303a speakers and acoustic foam treatment of my listening room are to making things sound naturally “right,” even with my power line filtration and prior ethernet filtration via the GigaFOILv4 Inline Ethernet Filter, there was still just a bit of audible digital edge compared to real unamplified music or, dare I say it, the best analog reproduction. There was also just a bit of audible compression to the dynamics compared to an unfiltered ethernet connection. The GigaFOILv4 Inline Ethernet Filter (which provides a back-to-back ethernet to fiber optic to ethernet conversion all in a small box) was at least as good at ethernet filtration as any other ethernet filtration system I’d tried, including that incorporated in the Lumin L2 with fiber optic connections feeding my Lumin X1 streamer/DAC.

My first experiment with the Network Acoustics devices came with my insertion of the Muon Pro ethernet filter in my simpler Blue Room System. Once the device fully broke in, the transformation in terms of relaxed naturalness and honest detail without brightness was remarkable. I found myself wanting to hear what this and that sounded like in the Blue Room after listening in my main audio room. Yes, the Audio Room system still sounded better in many ways due to the better acoustical treatment in that room. But something was missing. That was the point I decided to go with the full Network Acoustics treatment for my Audio Room.

Briefly (for me), the sonic improvements compared to my prior GigaFOILv4 Inline Ethernet Filter include increased subjective macro-dynamics as well as increased dynamics on the micro moment-to-moment scale even on held notes. There is a further increase in the proverbial black background, but notes never seem to pop out of nothingness—there is always an increased “there” there. Instruments sound remarkably more like they should tonally and also in their “presence” as in really being there in front of me, but always with the appropriate recording venue “there,” not as in being present in the room with me, unless the recording was made to sound that way.

Massed strings are yet smoother and more beautifully true to life. The soundstage increases in all dimensions—not unrealistically so as with BACCH processing, but more like a larger window on a now-very-real-sounding event. The feeling of envelopment or immersion is increased. Bass is yet a bit more powerful and startling and the highs seem more cleanly extended out to ultrasonics. Any remaining residual overbrightness is just gone. Differences from one recording or program source to another are enhanced even though the differences don’t sound nasty at all.

And the timing of notes and the presentation overall is improved—all things PRaT-related take a significant upswing. There is added rhythmic propulsion to music, the kind that induces more involuntary time keeping, head bobbing, body swaying, and conducting. It’s a truly remarkable positive effect in terms of music enjoyment.

Apparent distortion in any program source drops. Apparent clarity and audible detail increase, but without any increase in apparent brightness. As stated above, residual overbrightness is actually reduced.

But most of all, I keep coming back to that feeling of a tremendously relaxed yet exciting presentation. Everything seems so right, so natural, so aligned in time as it is in real life but never has been before with digital or even analog media. The sound is just there, in front and around me. It’s intoxicating in terms of musical pleasure.

With the Network Acoustics equipment, even low bit rate internet radio stations sound like this, as long as the station is not applying compression or other obnoxious processing to its signal. Listen, for example, to the Your Classical MPR stream. In fact, one of the marvelous sonic effects of the Network Acoustics equipment is how much better such low bit rate internet radio sources can sound if they are not overly processed. The sound of carefully curated Sirius/XM sources such as the Grateful Dead Channel is yet better than before in terms of capturing that feel of a real Dead concert. The WFMT stream is a classical music source I’ve listened to regularly since college days, first on FM and later via streaming. The sound of that stream is greatly and inexplicably improved with the addition of the Network Acoustics devices. It has never sounded this good, even back in analog FM days when it was very clearly the best available FM signal in the Chicago area and I listened to it through the very best FM tuners and FM antennas available.

Let me add that to get to this sonic improvement takes very considerable break-in time, considerably more that the 200 hours mentioned in the support materials. I think the documentation for the Tempus Switch mentions 400 hours, but I’d say give these items AT LEAST three full weeks of constantly transmitting data to get settled in and experience the effects I’ve described. And the road to this settled-in state is more than a bit bumpy. What you won’t hear during break-in is overly bright sound—ever. In that respect it is totally unlike unfiltered ethernet. But expect the sound to be alternately stunning in its surrealism, closed in and more than a bit lifeless and dark, small rather than expansive, or a bit cloudy/murky in terms of detail. Images can sometimes seem confused as well. But don’t despair. Everything will eventually sort itself out and you will, I sincerely believe, be very glad indeed you purchased these Network Acoustics devices.

I should also add that, as good as the filtering provided by the Network Acoustics devices or any of the other internet data cleaners I’ve used in the past is, for reasons unknown to me, these devices do not negate the necessity of periodically power cycling my Xfinity router. If you begin to hear anomalous sound from your system--left/right imbalance, a smaller or more recessed soundstage, generally decreased apparent volume, a less dynamic presentation, are but a few examples—don’t despair. Just power cycle your router, unplugging it for a minute or two and then plugging it back in again. You may be amazed if you don’t regularly do this. This has been the case with all routers/modems I’ve had over the years, so I don’t think this is just an oddity or fault of my particular Xfinity router. I suggest routinely power cycling your router at least every two weeks.

Back to the Network Acoustics gear: These are essential to fully realistic sound reproduction at home from your streaming system. I’ve never heard digital disc, LP, or even analog tape playback sound this real, as in true to the sound of unamplified music heard from a good seat in a great concert hall. And this realism fully translates to increased enjoyment from all other sorts of music, including totally artificial electronic music.

Yes, the cost is high. These devices together cost about the same as the Lyngdorf TDAI-3400 which I use in both my Audio Room and Blue Room systems. But the increased realism resulting from this cleaning up of the source cannot, in my experience, be had in any other way.