If you clicked on this review having not really heard anything about Apollo audio you will be forgiven. This Canadian based company started up in just 2013 with the goal of “redefining audio performance of portable audio gears”. A big claim indeed! They currently have a range consisting of three dynamic driver earphones, two balanced armature earphones, two full sized headphones and two portable DAC/Amps. A pretty solid range for a company that has been established for such a short time period and Sonny will be checking out one product from both the balanced armature and headphone categories in the very near future. They also show not signs of slowing down with new products already having been announced.

The entire dynamic driver earphone range is based on the same general aesthetic design and same 11.5mm dual diaphragm dynamic driver, they are all also the same price at $370 or approximately £250. The differences aesthetically are purely changes in materials. The firebolt is a 100% copper housing that is actually machined from a single piece of copper rather than mould casting which they claim “reduces distortions and enhances sound reverberation”.

The Woodbolt is handcrafted from solid Rosewood and each shell takes 4 hours to manufacture. The density of the wood and large wood pores is why Apollo chose to use this particular wood for the earphone, along with the sonic qualities obviously.

Both these earphones have a two tone finish to the almost turbine like housing so the Woodbolt actually has a copper coloured wrap around it which is also where the cable enters the housing, the Firebolt uses a  chrome coloured strip for the same job. One thing I will say is that although the Firebolt is advertised as being made from copper, it is unmistakably brass in colour. They must have some sort of coating on the copper shell; it’s worth mentioning just in case you were expecting a copper coloured housing. There is also third model, the Stormbolt that we will not be looking at.

The Tech:

The interesting thing about this line of dynamic earphones though is that Apollo has implemented a single wide band Dual diaphragm driver.  Within it, there is an independent passageway for each diaphragm on the single dynamic driver. They argue this delivers “rich low boosted bass, alluring mids with micro detailed high frequencies”. This is a more unusual technology so we were keen to give it a try and see how it fared up against similarly price earphones using more standard technology.

Accessories, The Cable, Careful When Tip-Rolling:

With each product you will receive a hard carrying case (you know the waterproof otterbox type), 3 pairs of silicone tips and an aluminium card of authenticity, which is a nice touch. Not a huge selection of accessories but I suppose it’s all you need for a portable product. You may have noticed that both of our earphones have different coloured cables, this is because despite having fixed cables, there is an upgrade cable option at the time of purchase for $120. This option gives you an 8 braid, sliver plated, hand braided, OFC copper cable with a right angled Oyaide jack plug.

Now I want to talk about the cables a bit. First of all I really like the jack and Y-split on the stock cable, they are finished really well, nice graphite grey colour and they feel pretty solid. Another positive is that the strain relief on the earphone is pretty well made and looks like a pretty durable solution.  Unfortunately though the stock cable is in fact one of the worst feeling and looking cables I am yet to come across, especially after the Y-split , something that you have to feel and hold to  understand where I am coming from. It’s also really microphonic, any jolt, knock or movement is heard at an amplified volume in your earphone and unfortunately this just isn’t going to work on a portable product. There are a few cables with similar microphonic issues but they tend to be stock removable cables that will just be switched over. But the feel of the cable and how it wraps and tangles is really not good, I don’t like it.

The upgrade cable then? Well most of you will have seen 8 braid cables before and, well this really doesn’t look like an 8 braid cable in terms of size and weight which I suppose is a good thing, however it still possesses the flaws of the standard cable. Look at it with its blue and black braid on this copper earphone, it just not attractive to me at all. I’m not in a position to comment on the sound upgrade because the two cables are on two separate earphones and are fixed which is unfortunate. 120$ is a lot of money, and unfortunately I cannot personally recommend that outlay for this cable especially when you consider what this cost gets you from the likes of Effect Audio for example and that’s for a removable cable, custom built for your needs.

Another point I will mention about our unit is that there isn’t anything that says which channel is which, other than the tips. Now if, like us, you tip roll to get the best sound and comfort, you will have to have colour coded tips or you will have to listen every time you use to find which channel is which. They have said that this is something they are going to change and I imagine this change will be applied to the next batch of bolt earphones made.

Comfort And Isolation:

The next point I want to make is about the weight of these earphones, specifically the differences in weight. The Firebolt is hugely heavy as an earphone in comparison to the Woodbolt. This suggests two things and will also fall under two preferences. The heavier Firebolt makes it seem like a really high quality well machined product, but could potentially put someone off as any jump or quick walk let alone run will cause them to move and dislodge you will potentially lose a seal quite easily. The Woodbolt being really, properly light for its size just disappears in your ears. It’s great for comfort but some people might find that this gives them a cheaper feel. In terms of comfort though I haven’t had an issue with either product, but I know some people are more sensitive to the weightier IEM! I will also point out that during my tip experimentation, as you would expect, this has a large effect on isolation. Dual flanges offering the most, foam tips happen to offer me the least. I found it much easier to get sustained comfortable isolation on the Woodbolt’s due to the lightweight housing. The Firebolt was more of a “shove it so deep it won’t fall out” job, which as you can imagine wasn’t the most comfortable but this was only if I was going out and about; otherwise isolation was adequate for an IEM, not outstanding and not poor.

Will the Fire Set the Wood Alight?

Two earphones, same driver you say, might sound similar? Jesus no, these earphones are poles apart in terms of sonic characteristics and capabilities as far as I’m concerned. Just in case there are a few of you reading this that will skip to the earphone that interests you the most, I will begin by saying, if you like a bass heavy earphone skip to the Woodbolt, If you prefer a lighter more neutral and airy sounding earphone go right to the Firebolt.

Let’s begin with the Woodbolt:

Specifically, the general signature is where we will start. I mentioned briefly, this is a bassy earphone and it has a warm bottom end for sure. It is generally a very different sound to the Firebolt though. Despite this I think it will be the most commercially favoured of the two, I don’t consider it to be an audiophile sound but there are many people that will love this sound I’m sure.

Bottom end is a little bloated for my taste, the decay is pretty slow indeed so you lose a large sense of attack or agility, it’s not flappy and horrible by any means, I must stress that, but I would be lying if I said it was great quality bass. It also has a tendency to sound a little monotone which can become a bit annoying and distracting to me. Boy is there some air movement though, these can go low. Justin Timberlake’s 20/20 album has some rumbles in most songs and this reaches them in a way most earphones can’t, so that’s positive. Bass detail is a little lacking and timbre can sound a little off but this seems to be a bi-product of extracting this much bass out of the driver.  The added lower mid warmth has some benefits though.

The bottom of the mid-band continues the warm signature and it means woodwinds and double bass’ have a nice texture to them, it’s a bodied sound that is really enjoyable and truer to life than the copper cousin. This textured feel follows in to the male vocal range too, unfortunately though the top of the vocal range sounds shouty like there is a bit of a spike there. It’s a shame because it really is a smooth, nicely voiced mid-range up until the top.

There doesn’t seem to be a huge amount of treble presence, this does mean that they aren’t fatiguing or tiring up top though, no sibilance either, which is a good thing. You do feel there is something missing though, it’s just not quite there, not the complete package and I can’t help feeling there is a missed opportunity for a great bass heavy earphone with just a little more tweaking.

Due to the boosted bass this is a much bigger sounding presentation, a fuller more atmospheric sound. The steady bass decay means that any space between instruments seems to be filled with a bit of background warmth as opposed to silence as some people will love, some will hate as with everything in this silly hobby we have! In terms of size it’s not the biggest soundstage but it is not a compressed distant sound, these are better than that, they do give you a nice image especially when everything is nice and calm with the track you are listening too. Once everything gets more complicated we do get a bit messy and the shouty upper mids seem to take centre stage unfortunately. It may seem I’m being harsh on these because they aren’t a bad earphone I just have a feeling it is capable of more with a little more tuning.

Onto To Firebolt:

The Firebolt… This is a whole different ball game altogether it’s a radically different sound from the same driver. This is a rather neutral more detailed earphone, airier and more spacious sounding. I shall do the same as with the Woodbolt and talk about each area specifically to ease comparisons.

Bass is massively different; here I have a punchy agile bass response that really has a coherency with the rest of the audio spectrum. We have a really nice impact too which makes it a great pairing with acoustic tracks. For those of you familiar with the Dunu DN-2000, we actually have a little less weight and a quicker decay on the Firebolt. I really like the bass quantity, others may consider it a little bass light, but what it does deliver is good quality. It’s quicker, more agile and it is more tonally accurate in comparison to its wooden relative. It doesn’t extend too deep though, it does have a roll of at approximately 80hz I would say.  Nicely done then.

The neutrality of the earphone means the mids have a nice presence in the performance and are in no way overshadowed by the lower end; they are their own thing and are free from any bleed from below. There is a lovely spaciousness around vocals too, and with simple acoustic tracks it can sound really very good. If I’m being really critical though, they could be smoother; I have found some tracks to sound a little grainy through the mid-range. It’s not a luscious velvety vocal performance put it that way, but that’s not what these earphones are about, they are, clean and crisp, more of an analytical sound than a musical one.

Treble is pretty nice I have to say, it has the airy quality I love. Feed these earphones properly and they don’t disappoint in the top end. It’s a quick and detailed treble not necessarily what I would normally associate with a dynamic driver earphone so there is a lot to be said for this accomplishment.  There isn’t a sparkle or a shimmer to high hats but it’s a 370$ earphone so maybe that would be asking too much but then when did the Dunu Titan 1 dissapoint in that area. Treble has a good presence and it’s not fatiguing or harsh, no chance of sibilance here, or at least not on thinner tracks.

Imagery and soundstage are where we get a little overwhelmed. If you listen to mainly thinner textured tracks, acoustic, pop thinner jazz, then you will hear well-presented instruments within a “in your head” soundstage. However, rock, metal, classical or busy electronic stuff will become confused a little especially in the upper mids, it can all sound a little messy and gives the impression of harshness up there which can be, errrmm, uncomfortable I suppose.  It’s a thinner presentation due to the lack of warmth but as I say that’s not what these are about.


I really admire Apollo Audio Lab for tuning there dual diaphragm dynamic driver earphone in three different shells so there is a model for all tastes. I cannot tell you how fed up Sonny and I are with tuneable earphones. THIS is the way to do it in our opinion, make an earphone with one tuning and if you want different signatures have different earphones. It is as simple as that. Huge thumbs up to Apollo for that.

The Woodbolts are bass heavy earphones that have their issues and their highlights, despite this I feel they could be capable of more with just a little fine tuning to get them a little more refined and flatter in the upper mids.  I know there will be people that really enjoy their big, non fatiguing sound but at the moment they aren’t for me.

The Firebolts are a good choice for someone that likes a well-executed, detailed, more analytical sound but they aren’t without their faults such as the struggle with more complicated tracks.  Tough competition from the likes of Dunu with their DN-2000 cannot be ignored either and they remain on our pride of place as our preferred earphone. If you like this sort of signature they should be on your shortlist.

I commend Apollo for a bold first line of earphones and a promising line at that, I look forward to what they can produce in the future and have high hopes for the quality of product they will turn out on their next iteration of these earphones.

Josh Coleby