About ACS

ACS is a company that has, at least until recently, served the pro audio community with a range of Custom In Ear Monitor solutions. Andy Shiach is the founder, and he was there at the start of it all, in the 80s, when people were using adapted walkman earbuds, or simply going deaf very quickly and not using any hearing protection on stage. Pro Audio Custom In Ear Monitors were borne from reasons of safety. Etymotic, Sensaphonics and JHAudio were there near, or at the start, of the revolution. Without a doubt, ACS were in the mix. Andy used his knowledge as an audiologist who had worked with the tiniest of ears, and his heart, being that he is, sadly, a victim of tinnitus, as are so many musicians who have been through the sound barrier on one too many occasions. ACS was the Company I came across in 2015 when I started researching about Customs. They are based in the UK and USA. I came across an ACS voucher on EBay, and I bought a custom ear shell for my Westone W20 IEMs. That process, (which affects all custom purchases I hasten to add) was not without problems. The longer the journey, the greater the reward, or the fuel bill.

That started a quest for something a little more special. It eventually led me to to the ACS World HQ In Oxfordshire. I was treated like royalty by some really nice people in Banbury. The stars must have aligned that day. I asked if anything could be done to make my DIY ear impressions more accurate. Andy Shiach himself made my impressions right there on the spot! I was sent a set of Evoke Studio PRo CIEMs some 10 days later. And here we must deviate, and bring you all up to date. I am now the owner of a ACS Classic Emotion 5 BA CIEM. It has been provided in return for an unbiased review. It replaces the Evoke’s which developed a defective bass driver after 6 years. ACS felt that they wanted me to show you what changed they have brought in those intervening years. They are also extremely keen to see what the consumer will make of these in ears. So, ever helpful, here I am!

What is a CIEM?

A CIEM is a custom in ear monitor. It is made for you. It will only fit your ears perfectly. Ears are like fingerprints – unique. As you know, from time to time, I have stated in these columns that a universal IEM (I’ll call them IEMs from now on) has a “near” custom fit. There is no fit like a custom. If an IEM had a “custom” fit, then they’d only be able to sell 1 – the rest would be returned in exasperation. The range of designs and number of companies providing CIEMs is staggering these days. Back when ACS was founded, there were a handful. You can get as many different colour combinations as you can driver configurations for your Custom IEM (CIEMs from now). More on that later. What you want to know is how? How do you get a large company to make a unique in ear, ship it to you quickly, and still have them make a profit from it? I can answer questions 1 and 2; for question 3, I can only guess that this must be why customs cost a lot more money than the average IEM.

The process for getting a CIEM

It’s complicated. Sorry, I have to be honest with you here. You can’t just expect to get these on Amazon Prime, by return of post. Patience, grasshopper. That is what is required. And a little luck…. I have very little of either. Are you the same? So read these next few lines and be under no doubts – you need to wait, and it might be worth the wait. First of all, you need to contact the company. For ACS that’s a quick visit to their website . You make your choice and you are emailed a voucher. Armed with the voucher, pop along to your local audiologist. The audiologist will have a look at your ears, and if they deem them safe to make an ear impression from, they will put a gloopy solution into your ears, one at a time. The solution will gradually harden and form a mould. Attached to the solution was a tiny piece of cotton wool on some thin nylon. That way, there is no chance any of the solution can dribble through your ear canal and down into eardrum. Once the mould has gone off, they pull gently at the nylon and, hey presto! One of your ears has been fingerprinted! A normal person has nothing to worry about. If you are a surfer, or an open water swimmer, or suffer from ear wax build up, you may be in for problems. Let’s put that to one side for a moment. Your ears are fine. The audiologist sends the impressions back to ACS, who pay them. So there’s no hidden charge for you. ACS get to work on your CIEM and your choice of colour scheme and laser embossing on the shell, if you want to take it to that level. They let you know when the CIEMs are cooked and ship them to you, in the UK this will normally be by Royal Mail Special Delivery. I am talking about ACS as regards the above info, of course, other companies will use other couriers as their own setups.

Custom v Universal

Although the CIEM was invented for the professional musician, increasingly the consumer has turned their envious eyes towards this coveted weapon of choice, as seen at every decent gig on the planet. I mean, if they’re good enough for Metallica, they must be good, mustn’t they? It was obvious it would happen. Although we worship our bands, should we worship their CIEMs in the same way? I remember seeing many studio full size headphones being worn in videos and photos and thinking “that wouldn’t be my on ears of choice”. Are CIEM’s, like some of these Studio offerings, meer workhorses? I suspect that for customs it’s a different approach, because they’re unique, and worn at every live gig. Some musicians can afford the very best. Wouldn’t they demand the very best for something as important as a live mix that protects their hearing at the same time?

IEMs are less hassle. You can get hold of them quickly and they will have an okayish fit and you can probably sell them on and recoup some of your money if you upgrade. CIEMs take time to get hold of, often it’s difficult to try them first, there won’t be quite so many people who have them for research purposes, they may even need to be returned to get the fit just right, they will be very difficult to sell as used items. The portable hobbyist may not be too concerned about hearing protection, and this is one of the major selling points of a CIEM. Many of us, despite all of this, will be convinced that we are missing out on the magic unless we get our hands on a Custom. It’s that simple. It’s madness. But not to us. And so the Custom In Ear people have started to equip the audio community with significant numbers of bespoke in ears….

About the Emotion Classic

CIEM’s tend to be very sensitive. They’ve been designed to go very loud, very quickly. That’s coupled with the fact that they’ll be much closer to the 2nd bend of your ear canal. The device you’re wanting to use them with will go loud enough, trust me on this. The ACS Classic has over 120 dB sensitivity… The impedance of the ACS is 83 ohms, which is pretty high. Each device I’ve used them on has had to be turned down significantly compared to comparisons, such as the RE2000 pictured above. The Classics use a multiple Balanced Armature Driver Setup. 5 Knowles per side. This is a change from what I’m used to seeing in the IEM World, which often goes for a DD for bass slam and BA, (or something more exotic), for the rest. My Encore Studios l, from ACS, were bass monsters. They had linum Bax cables that were minutely thin and connections that went almost all the way into the CIEM’s shell. The Classics have a more standard look; a conventional cable with Kevlar reinforcement. The linum Bax cables were pretty amazing, but they were a swine to take it and out of the Encores. They had a memory wire function which meant they mostly recoiled to the same state as they were uncoiled. There was still a decent chance of getting into a tangled mess… Other changes from the old range; 1 bore instead of 3, and a deeper recess between the nozzle and the bore. I suffer from ear wax build up and often had to dig deep into the CIEM’S than was wanted in order to keep them clean.

The sound – what’s changed v Encore and compared to HiFiMan RE2000 Silver IEMs

The Encore Studio was designed to appeal to the bass lover in all of us. It had crazy, massive low end grunt, and made the rest of my collection cower in fear when these were on show. The mids and highs had to be rolled back to allow that much bass, and that’s how it was, back then. In very much a similar vein, the Emotion Classic has plenty of bass. There is a deep, warm viscerality to the sound signature of the ACS Flagship. These CIEM’s have been made with drummers in mind. They are worn by Roger Taylor, the drummer, vocalist and songwriter for 1 of the World’s biggest bands; Queen. Yes, I have pretty much the same CIEM’s as Roger, less the live backpack that the pro artist’s need.

The RE2000 Silver is retailing at exactly the same price as the Emotion Classic; £679. Both HiFiMan (from £1499) and ACS(from £829) have brought their prices down recently. The RE2000, setting aside fit, comfort, sensitivity and looks, which would all easily be bested by ACS, is my preferred sound signature. It is more linear, allowing more clarity into micro effects, stereo imaging and sound stage. I tried the ACS on many platforms, the result was always the same. The ACS will appeal to the consumer looking for lots of grunt, who hates sibilance and wants a more live feel to their music. Please don’t think that ACS just makes bass beasts. I have a pair of IEMs from them, a purchase from eBay; the Evoke Studio IEMs. They had a much more linear presentation than the Emotion. They were the only IEM I could find, at a similar price, that could better the sound quality of the Beryllium KBEAR Believe.

The range of items used for the comparison


Choose wisely. ACS has a range of products, as has other companies, some of which will not be the best match for your musical palette. If I have interested you in ACS, have a read through what their range is aimed at before you take the plunge and just plump for the Flagship, you know, just because, you can. You know what I’m saying! There are some that the Emotion will fit, like a velvet glove. For others, an Evoke style presentation may not cost you quite so much, and yet net a far greater reward. If you can, get a demo with a pair that have been adapted for universal. If you like them; I can say this with authority, the enjoyment you’ll get from your own customs will be huge ? As always folks, tread carefully out there,and your shoes will last you a lifetime

If this track is your preference, then maybe the Emotion is the 1