Fosi is mostly known for desktop amplifiers, so seeing them jump into the IEM market isn't something new. The IM4 enters a very crowded sub-$100 category, where there are already plenty of strong options.

After spending quite a bit of time with it, I can confidently say this isn't an IEM that tries to reinvent the wheel. Instead, it focuses on doing almost everything well while offering one of the most complete packages in its price range.

Test Gear

• Tanchjim Space Pro
• TRN Black Pearl
• CS31993 Dongle
• Usual Test Playlist

Build & Accessories

The first thing that stood out to me was the build quality.

The shells are fully CNC-machined aluminum and feel dense without becoming uncomfortable. They have a smooth matte finish that feels premium in hand and does a good job resisting fingerprints.

Comfort is honestly one of the biggest strengths of the IM4. The shell follows a pseudo-custom shape that naturally sits inside the ear without creating pressure points. Even after long listening sessions I never felt the urge to take them out.

Accessory package is excellent.

Inside the box you get three different styles of eartips, a solid carrying case, and an additional pair of brass nozzles if you want a slightly brighter presentation. The stock cable is surprisingly good as well. It doesn't tangle easily, has a working chin slider, and feels much better than what I normally expect around this price.

Sound

The IM4 follows a tasteful V-shaped tuning with a healthy amount of bass, clear vocals and enough treble energy to keep things lively.

It isn't a basshead set, nor is it trying to be an analytical monitor. It sits comfortably somewhere in between.

Bass

Bass is easily one of the highlights.

The IM4 has plenty of mid-bass impact, giving kick drums and bass guitars real physical weight. The sub-bass extends nicely, although it isn't the deepest or most rumbling presentation I've heard.

What I enjoyed most was how dynamic the bass feels. Notes hit with authority but remain controlled enough that they don't bleed into the midrange.

It simply makes modern music enjoyable.

Midrange

The midrange is slightly forward compared to many V-shaped IEMs.

Vocals have good presence and instruments sound clean and separated. Female vocals especially come through with excellent clarity.

That being said, the upper-midrange isn't perfectly smooth. On certain recordings vocals can sound a little sharper than they should, giving them a slightly artificial timbre. It isn't something I noticed on every track, but it does show up occasionally.

Male vocals carry enough warmth to avoid sounding thin, although they don't have the fullness of warmer tuned sets.

Treble

Treble has enough energy to keep the presentation engaging without becoming overly bright.

Cymbals sound crisp, there's decent extension, and the upper treble adds some welcome air to the presentation.

Where the IM4 slightly struggles is around the mid-treble region. Sensitive listeners may notice occasional sharpness depending on the recording, but thankfully it rarely crosses into genuinely fatiguing territory.

Technicalities

Technical performance is okay for the asking price.

Imaging is accurate enough for gaming and busy music, instrument separation remains respectable, and the stage feels wider than it is deep.

Detail retrieval won't embarrass more expensive competitors, but it also isn't the defining feature here.

Conclusion

The Fosi IM4 doesn't rely on one standout trick.

Instead, it combines premium build quality, excellent comfort, generous accessories, a genuinely good cable, and a fun sound signature into one very complete package.

Is it perfect? No.

The upper mids could be smoother, and the treble occasionally reminds you this is still a sub-$100 IEM.

But as an overall package, it's very difficult to complain

Fosi is mostly known for desktop amplifiers, so seeing them jump into the IEM market isn't something new. The IM4 enters a very crowded sub-$100 category, where there are already plenty of strong options.

After spending quite a bit of time with it, I can confidently say this isn't an IEM that tries to reinvent the wheel. Instead, it focuses on doing almost everything well while offering one of the most complete packages in its price range.

Test Gear

• Tanchjim Space Pro
• TRN Black Pearl
• CS31993 Dongle
• Usual Test Playlist

Build & Accessories

The first thing that stood out to me was the build quality.

The shells are fully CNC-machined aluminum and feel dense without becoming uncomfortable. They have a smooth matte finish that feels premium in hand and does a good job resisting fingerprints.

Comfort is honestly one of the biggest strengths of the IM4. The shell follows a pseudo-custom shape that naturally sits inside the ear without creating pressure points. Even after long listening sessions I never felt the urge to take them out.

Accessory package is excellent.

Inside the box you get three different styles of eartips, a solid carrying case, and an additional pair of brass nozzles if you want a slightly brighter presentation. The stock cable is surprisingly good as well. It doesn't tangle easily, has a working chin slider, and feels much better than what I normally expect around this price.

Sound

The IM4 follows a tasteful V-shaped tuning with a healthy amount of bass, clear vocals and enough treble energy to keep things lively.

It isn't a basshead set, nor is it trying to be an analytical monitor. It sits comfortably somewhere in between.

Bass

Bass is easily one of the highlights.

The IM4 has plenty of mid-bass impact, giving kick drums and bass guitars real physical weight. The sub-bass extends nicely, although it isn't the deepest or most rumbling presentation I've heard.

What I enjoyed most was how dynamic the bass feels. Notes hit with authority but remain controlled enough that they don't bleed into the midrange.

It simply makes modern music enjoyable.

Midrange

The midrange is slightly forward compared to many V-shaped IEMs.

Vocals have good presence and instruments sound clean and separated. Female vocals especially come through with excellent clarity.

That being said, the upper-midrange isn't perfectly smooth. On certain recordings vocals can sound a little sharper than they should, giving them a slightly artificial timbre. It isn't something I noticed on every track, but it does show up occasionally.

Male vocals carry enough warmth to avoid sounding thin, although they don't have the fullness of warmer tuned sets.

Treble

Treble has enough energy to keep the presentation engaging without becoming overly bright.

Cymbals sound crisp, there's decent extension, and the upper treble adds some welcome air to the presentation.

Where the IM4 slightly struggles is around the mid-treble region. Sensitive listeners may notice occasional sharpness depending on the recording, but thankfully it rarely crosses into genuinely fatiguing territory.

Technicalities

Technical performance is okay for the asking price.

Imaging is accurate enough for gaming and busy music, instrument separation remains respectable, and the stage feels wider than it is deep.

Detail retrieval won't embarrass more expensive competitors, but it also isn't the defining feature here.

Conclusion

The Fosi IM4 doesn't rely on one standout trick.

Instead, it combines premium build quality, excellent comfort, generous accessories, a genuinely good cable, and a fun sound signature into one very complete package.

Is it perfect? No.

The upper mids could be smoother, and the treble occasionally reminds you this is still a sub-$100 IEM.

But as an overall package, it's very difficult to complain.

Fosi is mostly known for desktop amplifiers, so seeing them jump into the IEM market isn't something new. The IM4 enters a very crowded sub-$100 category, where there are already plenty of strong options.

After spending quite a bit of time with it, I can confidently say this isn't an IEM that tries to reinvent the wheel. Instead, it focuses on doing almost everything well while offering one of the most complete packages in its price range.

Test Gear

• Tanchjim Space Pro
• TRN Black Pearl
• CS31993 Dongle
• Usual Test Playlist

Build & Accessories

The first thing that stood out to me was the build quality.

The shells are fully CNC-machined aluminum and feel dense without becoming uncomfortable. They have a smooth matte finish that feels premium in hand and does a good job resisting fingerprints.

Comfort is honestly one of the biggest strengths of the IM4. The shell follows a pseudo-custom shape that naturally sits inside the ear without creating pressure points. Even after long listening sessions I never felt the urge to take them out.

Accessory package is excellent.

Inside the box you get three different styles of eartips, a solid carrying case, and an additional pair of brass nozzles if you want a slightly brighter presentation. The stock cable is surprisingly good as well. It doesn't tangle easily, has a working chin slider, and feels much better than what I normally expect around this price.

Sound

The IM4 follows a tasteful V-shaped tuning with a healthy amount of bass, clear vocals and enough treble energy to keep things lively.

It isn't a basshead set, nor is it trying to be an analytical monitor. It sits comfortably somewhere in between.

Bass

Bass is easily one of the highlights.

The IM4 has plenty of mid-bass impact, giving kick drums and bass guitars real physical weight. The sub-bass extends nicely, although it isn't the deepest or most rumbling presentation I've heard.

What I enjoyed most was how dynamic the bass feels. Notes hit with authority but remain controlled enough that they don't bleed into the midrange.

It simply makes modern music enjoyable.

Midrange

The midrange is slightly forward compared to many V-shaped IEMs.

Vocals have good presence and instruments sound clean and separated. Female vocals especially come through with excellent clarity.

That being said, the upper-midrange isn't perfectly smooth. On certain recordings vocals can sound a little sharper than they should, giving them a slightly artificial timbre. It isn't something I noticed on every track, but it does show up occasionally.

Male vocals carry enough warmth to avoid sounding thin, although they don't have the fullness of warmer tuned sets.

Treble

Treble has enough energy to keep the presentation engaging without becoming overly bright.

Cymbals sound crisp, there's decent extension, and the upper treble adds some welcome air to the presentation.

Where the IM4 slightly struggles is around the mid-treble region. Sensitive listeners may notice occasional sharpness depending on the recording, but thankfully it rarely crosses into genuinely fatiguing territory.

Technicalities

Technical performance is okay for the asking price.

Imaging is accurate enough for gaming and busy music, instrument separation remains respectable, and the stage feels wider than it is deep.

Detail retrieval won't embarrass more expensive competitors, but it also isn't the defining feature here.

Conclusion

The Fosi IM4 doesn't rely on one standout trick.

Instead, it combines premium build quality, excellent comfort, generous accessories, a genuinely good cable, and a fun sound signature into one very complete package.

Is it perfect? No.

The upper mids could be smoother, and the treble occasionally reminds you this is still a sub-$100 IEM.

But as an overall package, it's very difficult to complain.

CCA Falcon Instead of chasing bass quantity, it focuses on clarity, positioning, and a surprisingly clean presentation that feels almost purpose-built for gaming

Test Gear

• Tanchjim Space Pro
• TRN Black Pearl
• CS31993 Dongle
• Usual Test Playlist

Build & Comfort

The Falcon uses a resin shell paired with a metal faceplate and honestly looks better than its price suggests. The semi-open design gives it a slightly more premium appearance while also helping with the airy presentation.

Comfort was excellent for me. The shells are lightweight and I had no issues using them for long sessions.

The stock cable is serviceable and the included tips are actually better than what CCA usually bundles with their budget sets.

Sound

If I had to describe the Falcon in one sentence:

This is a gaming-focused neutral-bright IEM disguised as a dual DD music set.

Bass

The biggest surprise is the bass.

For a dual dynamic driver setup, the Falcon is surprisingly restrained. Sub-bass is present when the track calls for it, but it never becomes the center of attention. Mid-bass is quick, controlled, and lean rather than punchy.

Bassheads should probably look elsewhere.

That said, I think the lighter bass is intentional. It helps keep the presentation clean and prevents low-end masking, which is exactly what you want for competitive gaming.

Midrange

The midrange is where Falcon starts making sense.

Vocals sound clean, open, and very easy to follow. Female vocals in particular have a bit more energy thanks to the elevated upper mids. Instruments are well separated and the overall presentation feels transparent.

Lower mids can sound a little lean at times, but the tradeoff is a very uncluttered presentation that works great for both gaming and vocal-focused content.

However this is not at all for Vocal lovers, vocals are still recessed and take a back seat in music.

Treble

Treble is definitely the star of the show.

Falcon has plenty of energy up top, giving cymbals and higher frequency details a crisp and lively presentation. Despite being bright, I didn't find it harsh or particularly fatiguing.

The biggest thing I noticed was how easy it was to pick up small details in tracks. Footsteps, directional cues, and subtle background sounds are presented very clearly.

Technicalities

For the price, Falcon performs surprisingly well.

• Above-average detail retrieval
• Wide stage
• Accurate imaging
• Good instrument separation
• Fast transient response

The semi-open design helps create a spacious presentation and imaging is easily one of its strongest points.

Comparison – Tangzu Wan'er Red lion

The Wan'er is the safer all-rounder.

It has more bass presence, fuller vocals, and a generally warmer presentation. The Falcon on the other hand sounds cleaner, brighter, and noticeably more technical.

If your priority is music enjoyment, I'd probably lean toward the Wan'er.

If gaming, positional accuracy, and detail retrieval are your priorities, Falcon takes the lead

Conclusion

Instead of delivering huge bass and a fun V-shape, it goes for clarity, openness, and technical performance rather then vocal forwarded musical presentation

Yet to make a full review but as far as first impressions goes, the first thing you'll immediately notice is the bass quality on this is absolutely fantastic. It's very fast considering single dd and bass hits in your ears.

Thanks to amazon cc, got this at a good discount

In the pic here is Juzear Fiesta

First Impressions

The Juzear x ViDa Fiesta is a hybrid IEM featuring a dynamic driver paired with multiple balanced armatures. On paper, it looks like another warm-leaning hybrid but irl it's a budget basshead set with no compromises.

The Fiesta is unapologetically musical. It doesn't chase neutrality, nor does it try to impress with an exaggerated technical presentation. Instead, it focuses on delivering a rich, enjoyable listening experience that keeps you coming back for "just one more song."

Build & Accessories

Build quality is excellent. The shells feel premium in hand and have a reassuring weight without becoming uncomfortable during longer listening sessions.

The included cable is also a highlight. You do not get a cable with interchangable connection in this one, instead juzear went one step ahead and include 2 Separate cables right in the box. One 3.5mm with mic and another 4.4mm balanced. Having 2 high quality cable inside the box at this price point is something i appreciate very much.

Comfort was surprisingly good for me. Despite the shell size, I had no issues wearing the Fiesta for extended periods.

Sound

Bass

The bass is undoubtedly one of the Fiesta's strongest qualities.

This is not the type of bass that aims to shake your skull. Instead, it focuses on delivering texture, body, and authority. Sub-bass reaches deep with satisfying rumble, while mid-bass carries enough punch to make drums and bass guitars feel alive.

If i have to describe in one then it has that kick in your ears. There are very few sets at around 100 dollars which deliver bass in such quantity and not mess up mids and trebble.

What impressed me most was the control. Despite the generous quantity, the bass rarely feels bloated or overwhelming. It provides warmth to the entire presentation without completely taking over the mix.

Midrange

The midrange is where the Fiesta develops its own personality.

Vocals are slightly warm and carry a rich tonality that works exceptionally well with male singers. Instruments sound full-bodied and natural, giving the overall presentation a pleasing sense of weight.

The tradeoff is that the upper midrange isn't particularly aggressive. Those who prefer highly energetic female vocals or a very forward vocal presentation may find the Fiesta a bit relaxed.

Treble

Treble follows the same philosophy as the rest of the tuning.

Rather than chasing maximum sparkle and sharpness, the Fiesta opts for a smoother and more controlled presentation. Details are present, cymbals retain their energy, and the treble never feels dull.

What I appreciated most is that the Fiesta remains detailed without becoming harsh. Even during longer sessions, I never felt the need to lower the volume because of treble fatigue.

Technical Performance

The Fiesta performs well technically, though that's not what defines it.

Imaging is accurate, separation is respectable, and there is enough detail retrieval to keep things interesting. The soundstage has a nice sense of depth, which complements the warm tuning particularly well.

It won't be the most analytical set in its price range, but it doesn't need to be. The technical performance is more than sufficient to support the musical tuning Juzear was aiming for.

In short technical performance is not much different from something like defiants

Comparison

vs Punch Audio Portazo

These two take very different approaches.

The Portazo focuses more on energy, impact, and excitement. It has a more aggressive presentation with stronger bass attack and a livelier overall character.

The Fiesta, on the other hand, feels more refined and mature. It sacrifices some of that immediate excitement in favor of better balance, smoother treble, and a richer overall tonality.

If you want something fun, energetic, and punchy, the Portazo remains a great choice.

If you're looking for a warmer, smoother, and more relaxing listen that you can enjoy for hours without fatigue, I would lean towards the Fiesta.

Conclusion

What it offers is a rich, bassy and genuinely enjoyable listening experience backed by excellent build quality, strong accessories, and a tuning that prioritizes musicality above all else.

if you have anything to ask then please let me know.

I've enjoying both the New Juzears and as far as first impressions go The fiesta is an absolute bass bomb. It's actually a well tuned basshead level set at around 100 dollars without much compromises with other frequencies.

While the Defiants go for a more balanced approach.

I have already made a detailed review of Defiants Gamefedilty edition few weeks back here - https://www.reddit.com/r/iems/comments/1tbtpkq/got\_the\_juzear\_defiants\_gamefidelity\_edition/?utm\_source=share&utm\_medium=mweb3x&utm\_name=mweb3xcss&utm\_term=1&utm\_content=share\_button

Detailed review of Fiesta - https://www.reddit.com/r/iems/s/yDpAF94tcg