I used the same ear tips on all IEMs, that come with the CZZ models, they are pretty good for the most balanced sound, the hump on top in the design definitely helps (except CCZ Melody, that one needed Final E tips for better bass performance).
Gears I used: Shanling UA2 for portable, Khadas Tone2 Pro for desktop
TRN MT1
Brand: TRN
Model: MT1
Earphone type: In-ear
Driver Unit: 10mm dual magnetic circuit DD unit
Impedance: 22.5Ω
Earphone sensitivity: 106dB/mW
Frequency range: 20-20000Hz
Pin Type: 2 pin 0.75mm
Line Length: 125cm
Color: Clear, Emerald, Clear Black
Mids on the bright side, good stage, mediocre separation, guitar sounding a bit thinner than normal, not the best timbre. The female vocal is better in tonality and forward. Piano tonality is also all right, also violin. All instruments playing more behind than they should. Mids are quite recessed on MT1, but vocals are rather ok than instruments.
Lows are better than mids, you can feel them. Sadly don’t have the desired DD rumble. Drum kicks, bass notes sound dry, not deep but kicks strong enough. The highs on the other hand are good on TRN to be honest. MT1 doesn’t pass the sibilance line (but sometimes comes close depending on your track), bright and elevated enough to give you some detail level which is good for my taste. Cymbals sound best. Highs have better timbre.
With power, though TRN MT1’s sound became twice as good, with all the problems almost fixed including dry bass notes, missing rumble, the tonality of the instruments, and even bigger soundstage, plus more controlled mids. For 7$ MT1 is an amazing IEM no doubt.
CCZ Coffee Bean
Brand: CCZ
Model: Coffee Bean
Color: Brown / Black
Driver Unit: 10mm Dual Magnetic Circuit Dynamic Driver
Interface: 2Pin 0.78mm
Plug Type: 3.5mm
Frequency Response Range: 20-20kHZ
Sensitivity: 111±3dB
Impedance: 18±2Ω
Wearing Type: In-Ear
Cable Material: OFC
Whether with mic: No mic / With mic (optional)
Whether can replacement cable: Yes
Cable Length: 1.2m
Overall very balanced and warm sounding. Mids are slightly more controlled than MT1, timbre is also better and tonality is on the natural side. Less bright, but the same good soundstage overall. Separation is also good. Male vocals have more texture, female vocals not so much. Bass notes not as dry MT1, better controlled and better rumble. I can start and finish Dream Theater – In The Name of God easily. Surprisingly good for the price. Does not scale like MT1 with better source.
KBEAR KS1
Brand: KBEAR
Model: KS1
Interface: 2PIN 0.78mm (TFZ)
Frequency response: 20-20kHz
Sensitivity: 109dB
Impedance: 16ohm
Color: black, white
Cable material: 4 core 4N pure copper cable
Plug type: 3.5mm L-type gold-plated plug
Driver Unit: Dual Magnetic Circuit Single Dynamic driver
Color: White, Black
Sound signature close to Beam. Slightly dark and warm. Stage not as good as above two IEMs, but lows are better controlled. But again not enough detail level, kicks well with a bit better texture. Female vocals are natural, instruments and vocals are closed together, altogether nice mids performance, treble is less elevated than MT1, on par with Bean. Tonality is good, male vocals are close to naturel, a bit back sounding. Does not scale like MT1 with better source. Sounds so close to Bean, but Bean has better upper mids.
CCA CSN
Brand: CCA
Model: CSN
Earphone type: In-ear
Driver Unit: 10mm dual magnetic circuit DD unit + CCA Customized BA
Impedance: 22.5Ω
Earphone sensitivity: 112dB/mW
Frequency range: 20-40000Hz
Pin Type:0.75mm
Line Length: 125±5cm
Color: Blue, Gray
CSN is an 1DD+1BA earphone. IEM shells are on the bigger side, you need to use two hands for a proper fit, barely fit my ears, not very comfortable. Bass is boomy. Balanced sounding IEM but with weaker separation and clarity. Male vocals are recessed. Tonality is average, the detail level is below average, the soundstage is also not as good as MT1 and Bean. In general sounds boring than the rest.
CCZ Melody
Brand: CCZ
Model: Melody
Color: Clear Black, Black
Interface/Connector：2Pin 0.78mm
Plug type: 3.5mm
Impedance: 16±2Ω
Sensitivity: 110±3dB
Frequency Response：20hz-20KHZ
Driver Unit: 10mm dual magnetic circuit DD unit + CCZ Customized BA
Wearing Type: In-Ear
Whether with cable： Yes
Whether with mic: No mic, With mic
Cable Length: 1.2m
Cable Material: 4N OFC
Color: Black, Clear black
This one sounds more like a 1DD+1BA set compared to CSN. With stock ear tips lows sounded thin and weak, had to change to Final E white tips which settled the sound dramatically. Best clarity in all 5 IEMs. String instrument tonality again best in 5. Tends to be bright on some tracks. Both male and female vocals have the same natural tone, not the best, but the same level in quality. Most natural sounding IEM in 5, you can easily use it for monitoring with different ear tips. Lows following the natural sound signature, bass guitar tones sound good, also drum kicks have enough amount and texture, scales well with a better source.
Conclusion
Is 20$ enough to enjoy music? The first thing I need to say is non of the 5 IEMs is bad, you can’t go wrong buying any of them for casual listening. Considering the money you have spent of course. Don’t expect the technicality of a higher grade IEM. If you want to spend less on an earphone with acceptable sound quality then no problem. If you want the best sound quality for a minimum amount of money let’s be honest you need to look twice as further for around the 50$ mark at least.