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Review - Effect Audio Axiom

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Also available on YouTube in Spanish: Acho Reviews YouTube 

The Axiom have been kindly sent to me by Effect Audio as part of the international tour they arranged. The only request was that an honest review of the IEMs was published on Head-Fi. No other requests or comments have been made but, as always, it is good to consider the fact that it has not cost me anything to try these IEMs.

You can find the official webpage for the Axiom here:


This review has actually been an interesting one to put together, as there are many things that break away from what is considered “usual”. As I have done my best to avoid knowing anything about the Axiom, this has meant that I have had quite a few discoveries as I have been reviewing this set of IEMs. I will try my best to put all of these experiences into this review in a comprehensive way but please forgive me if I jump around a little as we go on. It will probably also turn into quite a long review, so refreshments may be a good idea 😉

Starting with the brand, Effect Audio is a company that is better known for it’s high end cables, with various models ranging from around 100€ all the way up to nearly 4.000€. The cable which I have received with the Axiom I believe is the Cleopatra, which retails at around 800€ (although it is discounted to around 500€ if purchased together with the Axiom). I will discuss more about the cable as we work through the review.

The IEMs, which I believe are the first IEMs from the brand, were released late last year and, together with an even more recent release of the Axiom XP which are not yet available, are the only IEMs on their website. The Axiom have a retail price of just under 1.500€, with the new XP version coming in at a price that has yet to be confirmed but is forecast (according to Effect Audio) to cost around 2.300€.

This puts the Axiom straight at the top of the list of most expensive IEMs I have reviewed, even without factoring in the cable. In fact, the cable is more expensive than the vast majority of IEMs that have been featured on Acho Reviews. While price is not a guarantee of quality, it is something that creates expectation and also means that the smaller details are scrutinised a lot more, at least by me.

Until now, my favourite IEMs have been the Symphonium Helios, which also happen to be the most expensive IEMs I have reviewed, until now. So will the Axiom prove to be a step up? 


The unboxing of the Axiom has been one of the most bizarre unboxing experiences I have had with IEMs. In fact, it is probably the most “different” unboxing experience I have had with any headphone related product.

Inside the usual brown shipping box, I received a black box with a flip-top lid along with a simple plastic zip lock bag, showing the EA logo on the front, containing the cable.

Inside the black box there was a smaller box, sealed in transparent plastic, this time more colourful and with the branding of the IEMs. It may sound silly but it actually took me a while to work out how to open this box. I mean, it’s not that it is difficult to open a box but I didn’t expect it to be opened via a pull tab/wire that runs around the box.

Inside the green box, we get another black box, this time with the logo that you see in the image above. Removing the lid from this box finally presents us with the IEMs sitting inside a cardboard cutout in the centre. 

Below the IEMs, in more cardboard cutouts, we find the included accessories. These are a second set of modules (more about that shortly), 3 sets of tips, a small screwdriver and a couple of plastic cards, along with something that also surprised me, a bag of dried flowers instead of the usual silica gel packet. 

I actually feel the dried flowers are a nice and original touch, however, the above is all that is included.

Now, I have said many times that I do not complain about the lack of accesories as I prefer the money to be invested in the IEMs themselves rather than a bunch of accessories that I may or may not use, but… when spending 1500€ on a set of IEMs, I do expect a little more than what is included here.

I applaud the lack of plastics used in the packaging and although they could have also used a lot less cardboard (don’t forget that I had to open 4 boxes to get to the IEMs), I don’t really have any complaints about the way these are packed and presented, it is only the lack of contents that I find lacking at this price point.

The reason, according to Effect Audio, that there is no cable included with the IEMs, is that the majority of people will not use the included stock cables and will opt to use an aftermarket cable, so they are cutting down on waste. While I can understand that, and am all for saving the planet by reducing as much waste as possible, I feel that a set of IEMs at this price should be at least usable straight out of the box. 

They do state the following on their website: “Please note that every Axiom will not ship with a stock cable. Customers are highly encouraged to reuse whatever they have or may also choose to opt-in to our perpetual Cable Bundle programme.” Their Cable Bundle program does offer a discount on their normal cable prices, however, the cheapest cable they offer to bundle is $291 or in the case of the Cleopatra cable I have received, $599 (reduced from $799), which now puts the IEMs firmly in the 2000€ range.

This is without mentioning the fact that no case is included, only 3 sets of tips in total, and basically nothing that you would expect to find inside a normal set of IEMs at a much lower price point, nevermind 2k.

The Cleopatra cable comes in a zip lock bag as I mentioned. Now I am not certain if this is the actual retail packaging or not, but it would have been nice if they avoided plastic here also and opted for a simple but more elegant cardboard solution.

Build and aesthetics…

Let me start by saying I have absolutely no issues at all with the build quality or aesthetics of the Axiom. The IEMs are built using a combination of Aluminium (shell), Titanium (nozzle) and Natural Stone (face plate). They are well built and although aesthetics are a totally personal choice, I think they look elegant and have no doubt that they look like an expensive set of IEMs.

The shape and size of the IEMs is also nice and comfortable, although I did have some issues with fit. I find the nozzle to be rather short and added to the weight of the Cleopatra cable, I always felt them pulling on my ears and struggled to get them to seal correctly. This was solved by swapping to Xelastec tips, which made them much more comfortable for me and eliminated the seal issues.

They are not extremely light weight but they don't feel too heavy when wearing them, especially considering the use of natural stone in their build. According to my scales (which I weigh all IEMs on, as can be seen on SoloSpec), they come in at 10.2 grams per IEM, which is not exactly lightweight.

The Cleopatra cable seems to be very well built but is not my personal choice if choosing a cable. I find it to be rather heavy, creating the pull that I just mentioned, and the outer clear cover is not my preferred choice either, I tend to find them a little sticky.

All in all, in regards to build and aesthetics, I feel that a lot of time and effort has been put into them and it shows.


Before getting into the usual sound process, let me mention the included modules. The Axiom comes with two sets of modules, one with 2pin connectors and the other with MMCX connectors. 

On the Effect Audio website, they state the following: “The MU (Modular Unit) System stands for our new approach into designing in-ear monitors. Each module houses the connectors and other key electronics within a compact unit. This allows the user to dictate how each Axiom is to be used, rather than the norm of having users adjust to the designs offered by manufacturers.

Stay tuned in the coming days as we strive to unlock additional features with the MU System.

Now, here is a comparison of the Axiom using the two different modules. For these measurements I used cables from a different manufacturer because I have two identical cables that just have different connectors, so the Cleopatra cable was not used for this specific graph:

As you can see, there is basically no difference between the two (the minor differences can be due to insertion and fit differences on the rig), which lead me to believe that the only thing that changes are the connectors. I actually reached out to Effect Audio and they did confirm that there will be different modules available soon with different sonic qualities but the two included are in fact only different in the connectors used.

While EA say (in the paragraph above) that we should “stay tuned” as they “strive to unlock additional features with the MU System”, I can’t help but feel that at the moment they are including a extra set of modules for no reason in each package (I personally would not use the MMCX having the 2Pin version, and I guess it would be vice-versa for others). Would it not be more cost effective to have just one module included, offering the choice of MMCX or 2Pin at purchase, and maybe investing those savings into including a cable? Or a case? Or something?

Anyway, I digress, as usual, so let's talk about sound.

I have used the Axiom connected to a selection of set ups but most of my listening time has been via the iFi Audio Gryphon, using the single ended output. Although the cable I have received is balanced (2.5mm), I found that I got best results using it on the SE output for reasons that I will mention as we go on. 

Starting off from the subbass, there is a fair amount of presence here but as we reach the lowest notes, there is a roll off. This may not be as apparent as it would be if there wasn’t such a large presence of mid bass (which I will get to next), but focusing specifically on subbass, and putting them through the usual test of “Chameleon” by Trentemoller, there isn’t as much rumble down low as there could be, being more focused on the midbass.

Speaking of midbass, I feel that here we have the opposite problem. The midbass is overly present and runs well into the lower mids. They do actually do quite a decent job of staying quite clear and detailed given the presence that they have in these regions, but I can help but notice that they aren’t getting the most out of these frequencies.

Listening to my usual selection of acoustic based music, this additional presence does add warmth to the lower end but it is too much to be considered natural. Listening to things like “Give Me One Reason” or “Crazy”, I found that the low end of the guitars were overly warm and did not seem natural, at least as I am used to hearing them on other set ups. Yes, I know that “natural” for one person is “unnatural” for the next, but all I can do is base my opinion on having heard these tracks hundreds of times on systems ranging from budget IEMs through to higher end planars and speakers (such as Genelec and Meyer Sound set ups).

Things that fall into the more rock side of things, such as Rage Against The Machine or Led Zeppelin, do not come across as being affected as much as the simple tracks that I usually listen to, but I feel that it is more due to the effects being used on the instruments and the fact  that other frequencies jump out more, which I will get to in just a second.

The mid range does seem to be a little recessed as we reach the higher end of these frequencies, however, it is not terrible. Vocals can seem to take a little step backwards depending on the presence of the low frequencies but the issue I have found the most is when we start to climb out of the mid range and start entering the higher frequencies.

There is a peak somewhere in this range that makes vocals, especially female vocals, have a harsh sibilance to them that can be quite unpleasant. It is not on every song but it is present on a very large portion of the music that I listen to, along with a large percentage of my test tracks that I use to evaluate IEMs (which you can see here). 

I did find that this sibilance was improved (or made worse) depending on the source. In fact, the Axiom does seem to be far more affected by the source than any other IEMs (or headphones) that I have had experience with.

Using the balanced output of the Gryphon, this sibilance was exaggerated quite a bit, making them quite unpleasant to listen to, especially if volume levels are increased (my usual listening levels are quite low). I played around with different sources (Go Blu, BU2, Asgard, Atom, etc.) and found that the sibilance was most kept in check by using the single ended output of the Gryphon while being fed (via USB) from a Shanling M2X. I don’t know why the M2X seems to create less sibilance than when I feed the Gryphon from my PC but that is what I have discovered.

Other than this sibilance, I actually found the treble to be quite smooth, with a roll off in the upper registers that I feel could be improved. It doesn’t come across as dark but this lack of extension is made more apparent by the (excessive?) presence of the mid bass and lower mids. Again, I would not consider these a dark set of IEMs, just a set with a bit too much mid bass and not enough extension in the highs.

As far as soundstage, I find them to be rather good. It is not a soundstage that is huge, in other words it’s not an Arya v2, but it is quite impressive for a set of IEMs. The impression of soundstage is also helped by the fact that the image placement inside said space is also rather good. I had no issue locating and placing instruments, I did not have to strain to be able to separate layers, they just seem to be well laid out and have space between them.

The detail of these IEMs is also good and, although I wasn’t wowed by the details, they do show that the drivers used in these IEMs are of good quality and are very capable of performing very well. I feel that the Helios is more detailed, or at least that is the impression that they give me, but I have no complaints about the details present in the Axiom.


I have to say that I am very grateful to Effect Audio for sending out these IEMs for me to try as it has been a review that has kept me on my toes. Each step has been something that I wasn’t quite expecting and although there are many things that have left me wanting more, I have found that I enjoyed the experience of reviewing something that is so different to everything else that has come across my desk lately.

Unfortunately, different is not always better. I feel that Effect Audio has had some ideas that are very good but not quite executed as well as they could have been.

The build and aesthetics are great, in my opinion, and I feel that they do give a sensation of a premium product, of which I have absolutely no complaints.

I understand where they are coming from with their idea of not including a cable. Yes, it is probably true that the majority of people dropping 1.5k on an IEM will also purchase a cable of their choice to go with it. However, apart from the fact that I would expect something of this price to be usable straight from the box, I would have also thought that a cable manufacturer would have wanted people to get a taste of how good their cables are by including a decent cable in the box with the hopes that it would lead to them moving up in the chain with the same brand.

The removable module is also a good idea in my opinion, when it gets to the point of offering different modules with different sounds, however, including modules that only change the connection method is not really something I see as a benefit, especially when not including a cable. If someone is going to purchase a separate cable, or reuse the one they already have and love, then they already know what connection type they want and just offering the Axiom in either 2Pin or MMCX as a choice when purchasing would be more than enough (in my opinion of course). Either include two different sounding modules with the same connectors or just include one module, with other modules available separately (even if at a later date), and drop the price, or include a cable for the same price.

The sound is not something that has impressed me too much. I feel that they are a set of IEMs that are quite capable and could be made to sound very good with some slight changes in the tuning (which maybe future modules will bring), but at present they are not something that I would choose based on sound alone, especially not at this price. Again, a different module that changes (fixes?) this would be great, but that will add more to the overall price (unless you get to choose the included module upon purchasing) and would mean I would end up with two modules that I don’t use.

I am sorry if this review comes across as negative, which I am sure it does, but at the price of 1500€ (or >2k€ with the cable), it leaves the door open for a lot of critique and focus on the small things that maybe would not be so apparent at a lower price point.

As I said, I like the fact that Effect Audio are thinking outside the box, it's refreshing to come across things that are different, I just hope that future modules and models can expand on these ideas and improve the implementation of them.