Hi-Fi 喱樣嘢從來冇話邊一種會最好聲，反正所謂好唔好聲係好主觀，聽感主觀批判嘅嘢我從來都唔想去討論。 不過如果睇到 MQA 只諗到 data compression 我相信係完全唔了解咩係 MQA，MQA 絶並非 data compression 咁簡單。 MQA is a philosophy more than it is ‘just a codec’。 而且真正要符合 MQA philosophy 係要由錄音 mic、a/d 等硬件上開始著手環環相扣。 年幾之前因工作需要同 Bob Stuart 有過一次電話會議，佢會議後 send 咗唔少佢哋 MQA 嘅技術資料畀我參考，而我自己嘅體驗係越去了解 MQA 背後嘅理論就越知道更多當今數碼錄播技術上嘅盲點同埋人耳聽感嘅特質，甚至解釋到我之前喺數碼錄放處理過程中一直解釋唔到會直接影響音質嘅原因。 當然我完全冇必要去為 MQA 好唔好聲去護航，但我會建議花D時間深入D去了解 MQA 背後嘅理論，相信會有唔少得著。

其實dvd audio我都覺得係好野，不過無奈市場關係最後慢慢淡出市場。師兄能夠直接同bob stuart溝通有關mqa的技術，真令人羨慕。

"要由錄音 mic、a/d 等硬件上開始著手環環相扣。" - Totally agree.

I think everybody will agree that all great sounding LPs, CDs, SACDs, CAS files start with meticulous attention to every single component and process in the recording, storage and digitizing chain. This has been the case since the beginning of stereo recordings decades ago.

So I have this question - What does MQA have to do with the above?

I have listened to a good number of MQA files streamed from Tidal through my Lumin A1 network player. To my ears I really cannot hear any distinct advantage of MQA. Not all MQA files (from Tidal) sound good and a lot of "ordinary" 44.1/16 files (from Tidal) sound very good or better.

MQA is nothing more than just a lossy encoding process (from HD file or analogue). If the source is good then the file will sound good whether it is MQA or normal PCM encoded or not.

Let me ask another question - If a very well recorded and mastered source is to be encoded to DSD, 192/24, CD (44.1/16) or MQA (also 44.1/16) formats, which format will sound the best?

On Tidal the majority (I won't say all) of the MQA files are originally from either analogue tapes or HD PCM formats. Tidal HiFi subscription provides CD quality (44.1/16) or MQA (still 44.1/16 but with MQA encoding) formats depending on the album.

A friend of mine is using an Auralic Aries streamer and Metrum DAC (with MQA hardware decoding card). His finding is the same as mine - no discernible difference between MQA and non-MQA files from Tidal, and well recorded DSD files sound the best.

I am approaching new technologies with an open mind. But I have to convince myself with my ears that there is truly an improvement in sound quality.

For those of us who have been keen audiophiles for a long time, we have experience a lot of hypes in the industry. Time will distinguish the wheat from the chaff.

Happy listening :)

MQA 唔係只係 data compression，佢要配合 H/W 保證/修正 end-to-end phase shift，係傳統 format 中冇嘅。

既然係同 DSD 比要 apple to apple 要用最低 bit rate 嘅 MQA 去比? 有冇確定係同 MQA 15 比定係同 MQA 0 比?

以我理解，既然要符合 MQA 理念，一開始錄音嘅 mic, pre-amp, a/d, 等要先符合 MQA 要求，以普通 PCM 去處理本身質素已經相當保證，即使後段冇 MQA decoder，MQA 已經為前端起作用提升 PCM 本身音質 (*參考返前面 no decode 資料)，另外如果只針對後段器材質素本身所需要嘅修正不大，DSD 對後段保存 phase info. 某程度上有異曲同功，MQA 改善嘅效果故然變得有限，對有 MQA 版本嘅錄音，MQA 變成係整個 end-to-end 質素保證，因此 MQA is a philosophy more than it is ‘just a codec’。 亦無必要為咗去突顯 MQA 嘅效果專登去整差前緣部份。

DSD 嘅缺點係後段要做 DSP 處理更麻煩又少咗好多靈活性，由其我會為喇叭做 digital xover 同埋用 DSP 修正 xover phase shift 。 另一方面比較，關乎 phase performance，要發揮到優勢我個人認為唔少喇叭及喇叭分音器質素亦可能係一D用家聽唔聽到分別嘅樽頸位。

最後修改時間: 2018-07-08 21:42:45

In Tidal, found below MQA albums good sound:

Imagine Dragons - Evolve, Lady Gaga - Joanne, Ella Fitzgerald, London Symphony Orchestra - Someone to watch over me, Gregory Porter - Nat “King” Cole & Me, Frozen (Original Motion Picture Soundtrack )…

長長影子，如此推斷，咁即係對於現存嘅錄音棄守MQA係事倍功半？

I am Tidal user and have a MQA capable player/dac. I don't find MQA notably superior but higher res materials packed in MQA most of them do sound good perhaps due to the attention in remixing. Still, if shit in then definitely shit out.

We in HK are blessed with affordable first class network be it fixed line or mobile. But there are still lots of places where bandwidth is slow or costly then MQA still has its purposes for existence.

最後修改時間: 2018-07-09 16:49:32

我而家9成以上時間聽Tidal，我覺得MQA比non MQA明顯好幾多下！

我覺得MQA會多一點層次感，樂器和人聲的分離度都闊一啲，就好似由Spotify 轉去聽普通CD的感覺。

動態對比、同空間感及細節都好好多，最緊要係壓抑感非常少！

最後修改時間: 2018-07-09 19:32:33

長長影子兄是否任職類似Kent Poon那種專業人士？

End-to-end impulse magnitude response of MQA compared to typical 192 & 48 kHz systems and Air at STP and 30% RH.

dynamic range, limits & noise floor comparison

MQA recording noise floor example

MQA recording noise floor example

MQA recording noise floor example

And example of MLP lossless compression reduces the data rate from 4.6 to 2.9 Mbps

MQA ~ MQA8x

另外順帶一提，唔好以為送得越多 data 就一定越接近原音，所謂物極必反，冇意思嘅 data 及運算亦有機會為 DAC 帶來更多 noise 以及電源干擾等等，DSD 本身附帶嘅 noise 都一樣會影響音質，亦有唔少 DAC spec 都有標示越高 fs 或 clk rate，THD+N 亦隨之而增加。

我唔識 Kent Poon 本人，我亦相信佢都唔會識我，不過我估 Kent Poon 大概係偏向 audio 錄音技術應用，而我係偏向電聲技術研發。