Symphonium Audio Crimson

Preface

I purchased the Symphonium Crimson with my own money in early January of 2025, all thoughts and opinions are my own.

Overview

Introduction

The Symphonium Crimson is an IEM where Symhponium worked to refine and improve upon previous issues people brought up with their IEMs. The biggest one people appreciated was the shell size reduction and refinement, previously Symphonium's IEMs had been quite large, heavy, and unwieldy, the Crimson is smaller and more naturally shaped than previous IEMs such as the Titan and Triton. Symphonium also implemented new technologies listed on the Crimson's page on their site, these include PHAT™ and FLAT™. "With PHAT technology ensuring no unnecessary frequency inversions or phase cancellation and FLAT technology ensuring low impedance and immunity from impedance mismatch."

Sound

I will dig deeper into my full sound impressions later.

Overall the Symphonium Crimsons feature a balanced tuning, but more specifically a W-shaped tuning. The bass has a shelf emphasizing the sub-bass and sloping through the mid-bass, the upper mids are slightly forward keeping vocals clear and clean through the bass and treble, and the treble is quite bright in both the lower and upper treble regions. The Crimson is very well-textured and extremely resolving and has a very clean and somewhat balanced/bright sound.

Unboxing

• Symphonium Crimsons

• Custom 4W or 8W Altalune Novaron cable

• Aluminum puck case

• Divinus Velvet eartips

• Azla Sednafit Standards

• Warranty and model # card

• IEM cleaning tool

• Cloth pouch for each IEM

The Crimsons come with a very satisfying unboxing experience. Everything feels extremely high quality and adequate, considering the price of the IEMs. The cable is one of my favorite cables of all time. It is an amazing, rich copper color, very soft and flexible without compromising its sturdiness. The case is solid aluminum with a stone-washed silver color and shiny lettering engraved on the top. The inside is soft so as not to scratch the shells of the IEMs. 

Design / Build

The Symphonium Audio Crimson has a sleek aluminum shell with a premium-looking deep red anodized finish. Its forged carbon faceplate adds a unique marbled texture, both smooth and solid to the touch with red flakes matching the crimson aluminum. That said, the shape is not the most ergonomic, its sharp triangular shape and weight kept it from sitting comfortably in my ear.

Sound

Bass

Now people who claim BA bass is always worse than DD bass have never tried a set quite like this one. The Crimson has some of the most detailed bass I've tried. It's not like most bass you'll hear that punches and attacks, but, you'll hear everything (though meaning you may not feel it.) On the spectrum between clinical and fun bass, this is definitely on the side of clinical, it is very detailed and just clean. While I appreciate this type of bass and I think it fits this set and its tuning style very well, it may not be the kind of bass someone who Is looking for weight, punch, and thicker note weight would want. If you are getting the Crimson, I don't think you'd be looking for a fun set so this bass sits very well where it is.

Midrange

This is simply put, what I would call a "clean" midrange. There is no lower midrange boost or bloom or any dip, the lower midrange is very smooth and separated from the bass with no bleed or soupiness, and with no thinness or hollowness. Moving to the upper midrange, it gets a little forward going up from 1khz to 3khz giving vocals a "glossy" aspect, at times it is a little shouty due to the bass not having a heavy body behind it but I never found it too annoying. Instruments and vocals are very well textured, not the most natural sounding but very detailed and accurate. 

Treble

The treble is my biggest complaint on the Crimson (other than the fit.) As soon as I started listening the treble was immediately jarring, it sounded like good treble, with good detail and texture, and kept away from being grainy, but there was just way too much of it. It wasn't very sibilant but it was more than I would like to use daily, but the biggest problem was the upper treble. There was just too much upper treble and air for it to be enjoyable and a lot of the time I had with these was spent with using EQ to tame it and make it more tolerable. The upper treble issue affected the bass too, it could have felt much thicker and more punchy if I didn't need to turn down my volume to normalize the treble amount. I could see someone who is treble tolerant (or has partial hearing loss) really loving this, but since I can hear upper treble quite well, it was just too much.

Technical Performance

Now moving past the worst aspect of the Crimson, this is the best part of the Crimson. I am going to go into this section by stating that I am under the belief that treble is the main if not only part of the frequency response that really determines technical performance. Due to the treble being pushed forward, these sound very spacious, open, and accurate soundstage and imaging-wise. This is set that I have mentioned is really technical and clinical, and this is very apparent here, the sound is very detailed and separated, and each sound is very easy to pick out in a mix and focus on. These are the best technically performing of all the IEMs I have tried. 

Conclusion

The Symphonium Audio Crimson earns an S+ ranking on my list, standing alongside the Supernova and Singularity. This rating comes from its unparalleled technical performance and resolution, as well as its exceptional aluminum and forged carbon construction.

This is an extremely technically capable and resolving set of IEMs, and this causes a bit of a drawback in the tuning of the treble. These do everything very well and very clinically, but they are also very bright and sharp. I recommend these to anyone looking for an amazing pair of IEMs that boasts technical performance, but for anyone looking for something less technical and easier on the ear, I'd recommend the Nightjar Acoustics Singularity if you want a much more bodied low-end, and warm midrange.