Introducing the FATfreq x Effect Audio: Quantum

[Or1onSLi]

Just unboxed! Gonna take it for a drive on the MUB1 and then XD05T.

Welcome to the club!

 

[SCYJ]

30 minutes in, and this already sounds like a winner!

I am genuinely surprised. This punches way above my expectations. Wow. Crazy level of tuning. I've never been a planar fan, but this is actually tuned so incredibly well. Bass does NOT sound planar at all

I'll post impressions next time, need more time with it. This is great value.

 

[EnigmaFotos]

30 minutes in, and this already sounds like a winner!

I am genuinely surprised. This punches way above my expectations. Wow. Crazy level of tuning. I've never been a planar fan, but this is actually tuned so incredibly well. Bass does NOT sound planar at all

I'll post impressions next time, need more time with it, but at 30% RRP (the early-backer Deuce promo), this is great value.

My same thoughts. I wasn’t too excited about it (not like @MakeItWain)and it blew away all expectations.

 

[audioaura]

30 minutes in, and this already sounds like a winner!

I am genuinely surprised. This punches way above my expectations. Wow. Crazy level of tuning. I've never been a planar fan, but this is actually tuned so incredibly well. Bass does NOT sound planar at all

I'll post impressions next time, need more time with it. This is great value.

Awesome to hear Quantum's exceeding expectations! Curious to see how your impressions evolve with more listening — sounds like they really nailed the tuning on this one.

 

[karloil]

30 minutes in, and this already sounds like a winner!

I am genuinely surprised. This punches way above my expectations. Wow. Crazy level of tuning. I've never been a planar fan, but this is actually tuned so incredibly well. Bass does NOT sound planar at all

I'll post impressions next time, need more time with it. This is great value.

Same reaction while 1st time hearing it at CJ. The SQ was a huge surprise - honestly punchey WAYYYY over 64Audio Solo for a fraction of the price. I totally passed over the Legion because of this.

SQ then the talk with FF turned me around with this brand - specially the nice discount - twas a no brainer purchase!

 

[DenverFi]

This is my third FatFreq after the Scarlet Mini and Deuce. I’ve had other planars like the Timeless II (one earpiece broke) and Supermoon in addition to some over ear open backs.

FatFreq has 100% solved the planar “sizzle”. Cymbals are crystal clear with out any fatigue. I’ve been putting a solid 2 hours a day on these since they came in a couple weeks ago. They’re just incredible and so hard to find fault with. Threw some divinus velvet wide bores on for comfort. One of the few sets that makes me keep going through my library to find out how different tracks sound.

 

[Idahodoc]

Totally agree! And…I would encourage all to 1) listen with a wired DAC/amp, and 2) make sure it is powerful enough. Don’t get me wrong, it sounds great on my iFi GoBlu! But give it a non-BT wired connection and a little more power and I actually sense a tactile bass rumble using the Fiio BTR17 or the Gryphon. Plus much greater articulation and enhanced timbre. This IEM is so good that it can actually utilize the greater resolution of a digital non compressed data stream bs compressed BT; some of my good but lesser IEMs don’t distinguish much between streams. This one MAKES me put up with the hassle of a wired DAC/amp! Amazing value. And DEFINITELY use the enhanced soundstage NOAH modules. Just mind blowing! Well recorded tracks, especially jazz and classical, are laterally placed in a wide soundstage. Which makes me appreciate FF tech, but also the amazing signal processing of the human brain!

Definitely punches WAAY above its price. Way past Solo, and really likely all the 64Audio Basshead IEMs. I have the Nio and it will fall out of my rotation. Redefines planar IEMs.

 

[VoxVirtus]

Totally agree! And…I would encourage all to 1) listen with a wired DAC/amp, and 2) make sure it is powerful enough. Don’t get me wrong, it sounds great on my iFi GoBlu! But give it a non-BT wired connection and a little more power and I actually sense a tactile bass rumble using the Fiio BTR17 or the Gryphon. Plus much greater articulation and enhanced timbre. This IEM is so good that it can actually utilize the greater resolution of a digital non compressed data stream bs compressed BT; some of my good but lesser IEMs don’t distinguish much between streams. This one MAKES me put up with the hassle of a wired DAC/amp! Amazing value. And DEFINITELY use the enhanced soundstage NOAH modules. Just mind blowing! Well recorded tracks, especially jazz and classical, are laterally placed in a wide soundstage. Which makes me appreciate FF tech, but also the amazing signal processing of the human brain!

Definitely punches WAAY above its price. Way past Solo, and really likely all the 64Audio Basshead IEMs. I have the Nio and it will fall out of my rotation. Redefines planar IEMs.

I recommend KA17 personally. it's got the juice to really push these things.

Good song to listen to on them is Jaws by Sleep Token... the drummer has a way to turning an entire song into the sickest drum fill you've ever heard.

 

[SCYJ]

Fatfreq Quantum (MUB1, Velvets Wide-Bore):

- Bass doesn't sound planar. Surprising amount of subbass. It punches and slams well, with decent dynamics. Sounds like a well-implemented BA bass, or even close to a DD. It's not overpowering, but neutral-forward. Clean and doesn't cover over other frequencies.
- Mids are neutral-warm, which surprised me. Vocal timbre is "natural", tho it definitely shows that planar dryness. Lacks abit of "wetness". Sounds bit "hazy". On some tracks, female vocals can come abit forward. Oddly, despite coming across as thicc-sounding with good note weights, male vocals lack abit of body.
- Treble is neutral but very airy and sparkly. No peaks at all! Not lost in the background, but ever present. Right amount of treble body.
- HUGE soundstage. Decent dynamics, layering, resolution. At 30% RRP (the early-backer Deuce discount), this is fantastic value.
- Requires alot of power. On MUB1 medium gain, my volume dial (65-72) is slightly higher than that required by the Grand Maestro (63-69).

(with XD05T)
(I didn't do a direct A/B, just switched from MUB1 to XD05T after a while)

- Deeper subbass extension, but midbass seems to be flatter than that of MUB1.
- Mids are clearly more warm and emotional, more note-weight and vocal body, but the tubey hazyness adds to the planar dryness (if that makes any sense lol).
- Treble remains sparkly and extended.
- Biggest noticeable difference is that the tubes seem to really slow down the planar speed. Doesn't sound as incisive or bright, but that is obviously to be expected.
- Personally I'm 50/50 between the two. The MUB1, while neutral-warm, is still neutral enough to show the planar's brightness. But the XD05T gives added warmth, neutralizing the planar's characteristics and giving an overall more balanced sound.
- With the tubes, Quantum's tonality felt very similar to the GM.

 

[MakeItWain]

Fatfreq Quantum (MUB1, Velvets Wide-Bore):

- Bass doesn't sound planar. Surprising amount of subbass. It punches and slams well, with decent dynamics. Sounds like a well-implemented BA bass, or even close to a DD. It's not overpowering, but neutral-forward. Clean and doesn't cover over other frequencies.
- Mids are neutral-warm, which surprised me. Vocal timbre is "natural", tho it definitely shows that planar dryness. Lacks abit of "wetness". Sounds bit "hazy". On some tracks, female vocals can come abit forward. Oddly, despite coming across as thicc-sounding with good note weights, male vocals lack abit of body.
- Treble is neutral but very airy and sparkly. No peaks at all! Not lost in the background, but ever present. Right amount of treble body.
- HUGE soundstage. Decent dynamics, layering, resolution. At 30% RRP (the early-backer Deuce discount), this is fantastic value.
- Requires alot of power. On MUB1 medium gain, my volume dial (65-72) is slightly higher than that required by the Grand Maestro (63-69).

(with XD05T)
(I didn't do a direct A/B, just switched from MUB1 to XD05T after a while)

- Deeper subbass extension, but midbass seems to be flatter than that of MUB1.
- Mids are clearly more warm and emotional, more note-weight and vocal body, but the tubey hazyness adds to the planar dryness (if that makes any sense lol).
- Treble remains sparkly and extended.
- Biggest noticeable difference is that the tubes seem to really slow down the planar speed. Doesn't sound as incisive or bright, but that is obviously to be expected.
- Personally I'm 50/50 between the two. The MUB1, while neutral-warm, is still neutral enough to show the planar's brightness. But the XD05T gives added warmth, neutralizing the planar's characteristics and giving an overall more balanced sound.
- With the tubes, Quantum's tonality felt very similar to the GM.

Awesome review/breakdown man!

Yeah, the Quantum's bass is fantastic and is as close to a DD bass as I've heard with just the right blend of speed and impact.

 

[hnafiem]

Fatfreq Quantum (MUB1, Velvets Wide-Bore):

- Bass doesn't sound planar. Surprising amount of subbass. It punches and slams well, with decent dynamics. Sounds like a well-implemented BA bass, or even close to a DD. It's not overpowering, but neutral-forward. Clean and doesn't cover over other frequencies.
- Mids are neutral-warm, which surprised me. Vocal timbre is "natural", tho it definitely shows that planar dryness. Lacks abit of "wetness". Sounds bit "hazy". On some tracks, female vocals can come abit forward. Oddly, despite coming across as thicc-sounding with good note weights, male vocals lack abit of body.
- Treble is neutral but very airy and sparkly. No peaks at all! Not lost in the background, but ever present. Right amount of treble body.
- HUGE soundstage. Decent dynamics, layering, resolution. At 30% RRP (the early-backer Deuce discount), this is fantastic value.
- Requires alot of power. On MUB1 medium gain, my volume dial (65-72) is slightly higher than that required by the Grand Maestro (63-69).

(with XD05T)
(I didn't do a direct A/B, just switched from MUB1 to XD05T after a while)

- Deeper subbass extension, but midbass seems to be flatter than that of MUB1.
- Mids are clearly more warm and emotional, more note-weight and vocal body, but the tubey hazyness adds to the planar dryness (if that makes any sense lol).
- Treble remains sparkly and extended.
- Biggest noticeable difference is that the tubes seem to really slow down the planar speed. Doesn't sound as incisive or bright, but that is obviously to be expected.
- Personally I'm 50/50 between the two. The MUB1, while neutral-warm, is still neutral enough to show the planar's brightness. But the XD05T gives added warmth, neutralizing the planar's characteristics and giving an overall more balanced sound.
- With the tubes, Quantum's tonality felt very similar to the GM.

Which module are you using? The stock NOAH SuperStage modules?

I’ve been experimenting the Quantum with the velvets wide bore too, had quite an interesting results with wide bore and blue modules. The soundstage is wide still on these and the amount of texture in the bass is very very pleasing to hear despite having still quite an amount of sub bass.

Have yet to try them with any tube setups. Been driving them off my DX180 or the M15i on my iOS devices. So far I’m really pleased with my blind buy cos i missed their booth at CanJam Singapore somehow.

 

[SCYJ]

Which module are you using? The stock NOAH SuperStage modules?

Yup! It's da besttt

I’ve been experimenting the Quantum with the velvets wide bore too, had quite an interesting results with wide bore and blue modules. The soundstage is wide still on these and the amount of texture in the bass is very very pleasing to hear despite having still quite an amount of sub bass.

Love the Velvets Wide Bore, those + SuperStage = insane staging imo.

Have yet to try them with any tube setups. Been driving them off my DX180 or the M15i on my iOS devices. So far I’m really pleased with my blind buy cos i missed their booth at CanJam Singapore somehow.

Yeah they still sound amazing on neutral-ish sources! Bright and energetic. Tubes give it a slightly more balanced sound.

 

[hnafiem]

Yup! It's da besttt



Love the Velvets Wide Bore, those + SuperStage = insane staging imo.



Yeah they still sound amazing on neutral-ish sources! Bright and energetic. Tubes give it a slightly more balanced sound.

maybe I’m just more attuned to a more tame treble like the pilgrim noirs. Still not so used to the airy and sparkly side of these iems but I’m still starting to like them quite abit cos they still satisfy my mids and sub bass vibes so well. So thicc and punchy. Like it’s still quite coherent to be fair.

I tried a new combo with the quantum’s. I got myself the special edition CanJam cable from Flash Acoustics at CJ SG 2025. They have been amazing on the quantum. Has a bit more punch and kick in the mids towards the sub bass whilst keeping the brightness and sparkle of the quantum.

 

[SbassX]

maybe I’m just more attuned to a more tame treble like the pilgrim noirs. Still not so used to the airy and sparkly side of these iems but I’m still starting to like them quite abit cos they still satisfy my mids and sub bass vibes so well. So thicc and punchy. Like it’s still quite coherent to be fair.

I tried a new combo with the quantum’s. I got myself the special edition CanJam cable from Flash Acoustics at CJ SG 2025. They have been amazing on the quantum. Has a bit more punch and kick in the mids towards the sub bass whilst keeping the brightness and sparkle of the quantum.

If it’s still delivering on the mids and sub-bass while staying coherent, that’s a win for sure. How’s the layering and separation feeling with the new cable?

 

[audioaura]

Which module are you using? The stock NOAH SuperStage modules?

I’ve been experimenting the Quantum with the velvets wide bore too, had quite an interesting results with wide bore and blue modules. The soundstage is wide still on these and the amount of texture in the bass is very very pleasing to hear despite having still quite an amount of sub bass.

Have yet to try them with any tube setups. Been driving them off my DX180 or the M15i on my iOS devices. So far I’m really pleased with my blind buy cos i missed their booth at CanJam Singapore somehow.

That’s awesome to hear, sounds like the Quantum really delivered! Do you find the blue module changes the mids much with the wide bore tips, or mostly just the bass and stage?