INM 1 by Matthew Marcelo


Review by: Paolo Tellano


Source/choice of tips/cables:

Ibasso DX120 (High Gain, Super slow roll off)

Kabutips by Kabutech Customs

FLACs and DSDs

Price: $145 (approximately ₱7650)

Introduction on the maker

Matthew Marcelo (, is a local DIYer. He converts/terminates cables, reshells, and, most importantly, creates IEMs. He does all of these on his own. That’s probably the reason why the production on the
INM 1 would inevitably be slow. A couple of individuals in the audio community are already in touch with him. A lot of them has given him praises for the INM 1. Give him a personal message on his Facebook account, he’ll be more than pleased to let you borrow a demo unit. That’s if it isn’t on tour. Lolz


I was in no way paid by Matthew or anyone affiliated with him. At best, he paid the shipping of the demo unit so I can review it. So kudos to him for that. Also, his IEM will be my temporary “departing” gear. I tried to rid myself of every bias because I really love this IEM. It’s not perfect, but if you like its strengths and view its apparent “weaknesses” as given characteristics, you’d be quite surprised what this humble DIY IEMs can bring to the table.


It comes in a rugged looking hardcase. Inside the following can be found: 1 pair of Spinfits (medium), a thick cable, and the IEMs themselves. As the maker says, it’s just straight up audio. No gimmicks here. Tip-rolling will be highly dependent on the customer.


I asked the maker about the materials used for the cable. All he told me was Canare L-4E5C Mini-Star-Quad. I’m not a hardware dude, but all I can say is that these are thick. I loved this fact because you can take it out and about. You can let the maker know if you want earguides on them or not. The splitter looks (and feels) like it is made from metal. Strain relief is adequate, you don’t really need it because these cables are tough and thick. Aesthetically, nothing is really popping out. In my opinion, these are great for people who are commuting. It’s sturdy plus it isn’t prone to tangling either.

Fit and build

My only nitpick with the fit is the protruding feeling. The shell is a bit large. Some of my friends who have smaller ears had trouble keeping them in place. But for me and my gigantic ears, these IEMs fit really well. Indeed, it seems to branch out of my ears. However, the right tips (Small Kabutips) gave me one of the most comfortable fits I’ve tried. I had no problem keeping these in my ears, alongside hours of playback. So yes, the fit is a hit or miss. Good thing it was a hit for me.

The build is excellent! The shells don’t feel like glass that I need to keep an eye on every minute. Again, perfect for beaters. These can take the grind, especially for people who don’t take care of their gear that much. To add to that, the cables won’t break on you anytime soon. I feel like these can be used to strangle someone.



The INM 1 is a neutral to bright sounding IEM. It’s probably for people who value their clarity more than low-frequency fun. It’s not thick-sounding nor does it have a huge perceived stage.

Sub bass

Average depth, it doesn’t rumble too much. Quantity is average but well defined. It seemed to reach adequately in Drake’s “God’s plan”, nothing mind blowing in the extensions and quantity really. On the bright side, it paves way for the rest of the frequencies to shine.

Mid bass

It’s not punchy. What’s unique about its mid bass is that it’s not overly tight. The decay is quite natural. Some IEMs tend to have such a quick decay that it sounds unnatural. That isn’t the case here. Nathan Azarcon’s bass licks sound so natural and detailed on these.


My favorite part of this IEM. It’s not full-bodied nor is it too forward. I had a friend that critiqued it for being too flat. In my opinion, it’s clean and accurate. The response can be quite analytical in some tracks (check: 50 ways to leave your lover – Bamboo). Also, Bruno Mars’ track called “Too Good To Say Goodbye” and “Chunky” usually have really upfront vocals in some of the IEMs I used to own. However, that wasn’t the case with the INM 1. Here, it’s detailed but it sounds lean. Female vocals are positioned more forward than male vocals.

Upper mids

I hear a bit of a peak in this frequency. Especially with snares (check: Readymade – Red Hot Chili Peppers), my sensitive area. But it’s just nearing a bit harsh but it never really got bad in my opinion. This frequency and the treble saved this IEM from sounding too analytical.


My treble-tester has always been Michael Jackson’s tracks. This IEM is able to bring about great treble extension with quite a lot of shimmer without sounding too sibilant. Michael Jackson’s “You Rock My World”, specifically the early bridge part, was well rendered in the treble region. All details are present but it never did sound harsh, but do take note that I have high treble tolerance.

Soundstage and Imaging

It’s more wide than it is deep. It doesn’t have a colossal stage but imaging and separation are good. Instruments are separated adequately. It’s not holographic in any way. Stage is a bit narrow.


This IEM is one of the best you can bag for under $200 (Around ₱10,000). I wouldn’t say it’s DM6 complete but it is more neutral than it. It’s more neutral than the Toneking T4 and the imaging and separation aren’t excellent. However, the attraction for me is how clean and transparent it sounds without overrepresenting any of the frequencies (just a tad bit of emphasis in the upper mids and treble). It’s an inch or two away from being analytical, but I love it. People who love their low frequencies might find these a bit too flat. Lastly, it was just too comfortable for me. I mean sound is of primacy, but if I can get both sound and comfort I’d really be convinced. The INM 1 proves that DIY is getting better and better. That’s in every aspect (i.e. sonically, pricing, and build quality).

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