Tellurium Q Ultra Black Speaker Cable & Black Diamond Interconnects – Review

I don’t usually write reviews about cables unless I find something that impresses me. Also, the subject of cables is quite heated and full of contradictions among audiophiles.

I’ve often read comments that were dismissing my entire website for mentioning cables in some review, because if I do that, I cannot be trusted, of course.

That is of course an opinion that I respect, and for a while now, I stopped trying to convince people that sometimes, cables  make a difference.

What I can tell you, is that recently I have asked some of my non audiophile friends to tell me if they hear a difference in the same song while switching some cables. They didn’t know what I was doing, but they actually heard the difference and explained them to me, confirming my own findings.

Price is one of the main reasons which heat up the cable discussions. Indeed, some cables can be ridiculously expensive. Personally, as I have said before, cables should be the last thing you take care in your system as the rest part of the chain is usually more important. However, cables can be the last tweak that gives the desired voicing to your system.

But let’s get back you the main subject of this review, the Tellurium Q Speaker cableswhich were lent to me by The owner of avmall, Razvan, gave me this cable because he has the same speakers as the ones I have recently acquired, the Martin Logan Ethos, and loved this cable with them.

Tellerium Q Ultra Black Speaker Cables Review (1)

This company managed to draw my attention a while back when I was reading about their primary focus:

When Tellurium Q® was set up the focus was primarily on phase distortion and minimizing this problem inherent in all cabling, whoever makes them and where ever and however they are made. The reason it is a problem is simple, all materials (not just cables) in the path of a signal will act as an electronic filter according to the definition in the box below, whether you want it to or not. This is undeniable.

Please understand we use the word filter as its scientific definition and not necessarily as something being “filtered out” like with a mechanical sieve. We are primarily focussed on removing the smearing of frequencies through a timing shift and by doing this you get better clarity and transparency from Tellurium Q® cables.

This is the definition of an electronic filter:
“A filter is an electrical network that alters the amplitude and/or phase characteristics of a signal with respect to frequency. Ideally, a filter will not add new frequencies to the input signal, nor will it change the component frequencies of that signal, but it will change the relative amplitudes of the various frequency components and/or their phase relationships.”
Source: National Semiconductor Corporation

N.B. This is true of all speakers, amplifiers, DACs, CD players, cables etc…in fact anything in the signal path.
Once you accept the fact that your audio system is acting as multiple electronic filters smudging your music, then you have a choice:

a. Forget the cable is an electronic filter (completely in the face of science) and compromise by having a smeared sound or

b. Do something about it and engineer as clear and phase neutral a path for the signal as possible to get the most transparent sound that current technology will allow and preserve the original signal phase relations as much as possible.

This kind of makes sense to me, and Tellurium Q is not the only company that has approached this problem. MSB has recently been working on some interconnects cables that have a similar approach and theory behind. MIT cables also had similar theories for a while now.

Well, in this hobby as you may very well know already, a lot of products look very good on paper and in theory, but not all of them rise up to your expectations in the real world.

Tellerium Q Ultra Black Speaker Cables Review (7)

So let’s see how these cables sound.

Listening Impressions

The tests were performed with   MSB Analog DAC  with Quad USB  ,  Audio Gd Master 10, Martin Logan Ethos.

Tellurium Q has 3 product lines: blue, black, silver.

They have explained their purposes here:

The sound of Ultra Black speaker cable is summed up pretty well by them in the upper image. I also tested the ultra blue a while ago and they fit very well in their description as well.

So, well,  what can I say. I concur with their findings. End of review!

Just kidding, but their words could be easily used for my conclusions. They’ve done some of the work for me already. Can’t wait to hear something from the Silver family.

The Ultra Blue cable was too smooth and laid back for my taste, but the ultra black added the details, energy and some treble detail I wanted, but still keeping some smoothness.

I’ve had this cable in my system for 3 weeks already and I’ve listened to all kind of music from classical, jazz, rock, etc.

Black Diamond Interconnects

Tellerium Q Black Diamond - Review (8)

I’ve also tested the  Black Diamond Interconnects. What I can tell you is that their voicing  are very similar and the final results are available for both of them, maybe a little more details for  Black Diamond Interconnects.

However, when we are talking about interconnects between the DAC and speaker/headphone amplifier, I generally prefer good silver interconnects. The Diamond Black is a wonderful copper cable, but I do prefer a little more sparkly and more energetic treble.



The bass is well extended and natural. It doesn’t have an iron handed control like I’ve heard with other cables but still gets to be fast and energetic when needed to, giving a slight touch of warmness to the sound.

However, what I need to add here is that the extension is incredibly clean and natural and I must say that I didn’t manage to find that in another cable until now.


This is where all the magic lies with this cable. Every instrument and voice have natural and well detailed textures leading to a life like experience.

I’ve been listening to some live recordings which were incredibly real, from the sounds in the audiences, to the voices and instruments on the stage. Even the clapping was hauntingly lifelike, putting me right there in front of the audience.


The treble is smooth, detailed and well extended. While it does its job here and it integrates everything very well in the spectrum, it didn’t manage to catch my attention with something special in this area. I’ve tested cables that had more spark and details here, but sometimes managed to draw too much attention.

The important part here is that Ultra Black has enough detail and extension to make the treble quite pleasant to my ears and integrate it very well with the rest of the spectrum without drawing too much of my attention and without sounding harsh. However, if you want to open up your system, I am not sure that Ultra Black is the way to go and I would recommend to go with Silver.


The Ultra Black gives life to the voices, it gives them better presence and textures but also a very natural and pleasant tonality. They’re smooth but clean in the same time.


How ultra black handles the transients is very important to the ending sound signature it outputs. The attack is strong, but not too strong, followed by a fast but natural and detailed decay.

I’ve heard cables that had stronger attack and faster decays than Ultra Black leading to a more energetic experience, but the latter manages to create a very good balance between smoothness and energetic, leading to a musical and natural sound signature.

Actually, I wouldn’t call it smoothness, but rather a sense of finesse, as the sound is still tactile and manages to vibe with energy when it needs to.


The soundstage is very natural and holographical with this cable. Everything is very well put into place and gives you a sensation of space and realism.


Tellurium Ultra Black is a resolute cable that handles micro details and details very well and it is very easy to observe it on instruments, vocals and spatial cues in the scene. This adds to the sense of realism that this cable is already good at.


This is another place where this cable shines. Every instrument and voice sounds natural and real, leading to a very life like sound experience where you have your favorite singers or even orchestras in your room.


The sound also becomes cleaner with this cable, with blacker background, leading to better contrast in your music and livelier sound overall.

Tellerium Q Ultra Black Speaker Cables Review (12)


As you might already suspect, I ended up liking the Ultra Black very much as it has some features that I hold deer in sound reproduction features like : realism, resolution, transparency and musicality and how it manages to blend all of them together in such a pleasant manner.

This cable is not cheap at all, I know. If money is no object to you and you like the sound signature I described above, you should really try it.

Later Edit:

After a while of further tests, I decided I need to buy one for myself and I actually did.


  • Very good bass extension, good control and punch
  • Detailed and natural midrange
  • Well extended treble that is well integrated in the rest of the frequency range
  • Natural and lifelike tonality
  • Very good transparency
  • Good transient response (well balanced between energetic and smooth)
  • Musical sound experience
  • Very good soundstage
  • Very good details


  • expensive

To consider

  • some may like a little more sparkle on the treble
  • some may like a little more energy

I have edited the “Cons” title above to “To consider”, because the energy and sparkle in the treble are dependent on the whole system and I actually managed to get exactly what I want from the sound with these cables. Indeed you can have a little more energy and details in the treble if you go with the silver options from Tellurium.