<s>
Master	B-Algorithm
Quality	I-Algorithm
Authenticated	I-Algorithm
(	O
MQA	O
)	O
is	O
a	O
three	O
part	O
process	O
applied	O
to	O
digital	O
audio	O
music	O
recordings	O
consisting	O
of	O
:	O
1	O
)	O
modifying	O
and	O
controlling	O
the	O
end	O
to	O
end	O
digital	O
filter	O
response	O
;	O
2	O
)	O
preparing	O
the	O
high-quality	O
audio	O
for	O
transfer	O
to	O
a	O
smartphone	O
or	O
audio	O
device	O
using	O
a	O
lossy	B-Algorithm
audio	O
compression	O
format	O
;	O
and	O
3	O
)	O
decompressing	O
the	O
recording	O
for	O
playback	O
.	O
</s>
<s>
In	O
May	O
2021	O
,	O
the	O
Apple	B-Operating_System
Music	I-Operating_System
streaming	O
service	O
announced	O
a	O
Lossless	O
Audio	O
pricing	O
tier	O
,	O
which	O
was	O
described	O
as	O
a	O
"	O
death	O
knell	O
"	O
for	O
MQA	O
.	O
</s>
<s>
In	O
the	O
same	O
month	O
,	O
Alpine	O
Alps	O
became	O
the	O
first	O
aftermarket	O
car	O
audio	O
company	O
with	O
full	O
TIDAL	B-Application
integration	O
.	O
</s>
<s>
Head	O
units	O
are	O
capable	O
of	O
MQA	O
Core	O
decoding	O
when	O
playing	O
TIDAL	B-Application
Masters	O
.	O
</s>
<s>
MQair	O
is	O
the	O
4th	O
codec	O
to	O
receive	O
this	O
,	O
alongside	O
LC3plus	B-General_Concept
,	O
LHDC	B-Algorithm
and	O
LDAC	B-Algorithm
.	O
</s>
<s>
It	O
can	O
unfold	O
regular	O
MQA	O
files	O
and	O
regular	O
PCM	B-Algorithm
music	O
files	O
.	O
</s>
<s>
The	O
technology	O
supports	O
both	O
MQA	O
and	O
PCM	B-Algorithm
audio	I-Algorithm
up	O
to	O
stereo	O
384kHz	O
,	O
with	O
the	O
encoded	O
data	O
rate	O
able	O
to	O
be	O
scaled	O
seamlessly	O
from	O
20Mbps	O
to	O
below	O
200kbps	O
.	O
</s>
<s>
MQA	O
encoding	O
is	O
lossy	B-Algorithm
;	O
it	O
hierarchically	O
compresses	O
the	O
relatively	O
little	O
energy	O
in	O
the	O
higher	O
frequency	O
bands	O
into	O
data	O
streams	O
that	O
are	O
embedded	O
in	O
the	O
lower	O
frequency	O
bands	O
using	O
proprietary	O
dithering	O
techniques	O
,	O
allowing	O
for	O
an	O
apparent	O
reduction	O
in	O
sample	O
rate	O
and	O
hence	O
file	O
size	O
.	O
</s>
<s>
After	O
a	O
series	O
of	O
such	O
"	O
origami	O
"	O
manipulations	O
,	O
a	O
dithered	O
and	O
shaped	O
version	O
of	O
the	O
original	O
audio	O
,	O
together	O
with	O
a	O
touchup	O
stream	O
(	O
the	O
compressed	O
difference	O
between	O
the	O
original	O
and	O
modified	O
streams	O
)	O
,	O
are	O
distributed	O
as	O
a	O
single	O
24-bit	O
stream	O
,	O
with	O
the	O
most	O
significant	O
bits	O
occupied	O
by	O
PCM	B-Algorithm
audio	I-Algorithm
compatible	O
with	O
non-MQA	O
playback	O
equipment	O
.	O
</s>
<s>
Depending	O
on	O
the	O
implementation	O
,	O
as	O
few	O
as	O
13	O
bits	O
may	O
be	O
reserved	O
for	O
PCM	B-Algorithm
audio	I-Algorithm
,	O
with	O
the	O
lower-order	O
bits	O
rendered	O
as	O
noise	O
by	O
equipment	O
without	O
an	O
MQA	O
decoder	O
.	O
</s>
<s>
MQA-encoded	O
audio	O
can	O
be	O
contained	O
with	O
file	O
formats	O
such	O
as	O
FLAC	B-Application
,	O
ALAC	B-Algorithm
or	O
CD-DA	O
;	O
hence	O
,	O
it	O
can	O
be	O
played	O
back	O
on	O
systems	O
either	O
with	O
or	O
without	O
an	O
MQA	O
decoder	O
.	O
</s>
<s>
Other	O
than	O
the	O
sampling	O
and	O
convolution	O
methods	O
,	O
which	O
were	O
not	O
explained	O
by	O
MQA	O
in	O
detail	O
,	O
the	O
encoding	O
process	O
is	O
similar	O
to	O
that	O
used	O
in	O
XRCD	O
and	O
HDCD	B-Device
.	O
</s>
<s>
Unlike	O
popular	O
lossy	B-Algorithm
compression	I-Algorithm
formats	O
like	O
MP3	B-Application
,	O
AAC	B-Application
and	O
WMA	B-Application
that	O
use	O
perceptual	O
encoding	O
based	O
on	O
psychoacoustic	O
models	O
,	O
the	O
lossy	B-Algorithm
encoding	I-Algorithm
method	O
of	O
MQA	O
is	O
similar	O
to	O
aptX	B-Algorithm
,	O
LDAC	B-Algorithm
and	O
WavPack	B-Application
Hybrid	O
Lossy	B-Algorithm
,	O
which	O
uses	O
time-domain	O
ADPCM	B-Algorithm
and	O
bitrate	O
reduction	O
.	O
</s>
<s>
It	O
is	O
common	O
for	O
consumer	O
DACs	O
to	O
include	O
user	O
selectable	O
filters	O
,	O
including	O
apodizing	B-Algorithm
filters	O
intended	O
to	O
improve	O
time	O
domain	O
transient	O
response	O
without	O
knowledge	O
of	O
the	O
production	O
filters	O
,	O
whereas	O
MQA	O
controls	O
the	O
DAC	O
filter	O
to	O
complete	O
the	O
MQA	O
designed	O
end	O
to	O
end	O
time	O
domain	O
filter	O
response	O
.	O
</s>
<s>
Singer	O
and	O
musician	O
Neil	O
Young	O
has	O
expressed	O
dislike	O
for	O
the	O
MQA	O
format	O
,	O
saying	O
the	O
masters	O
are	O
"	O
degraded	O
and	O
manipulated	O
"	O
when	O
encoded	O
to	O
MQA	O
and	O
has	O
consequently	O
removed	O
his	O
music	O
from	O
Tidal	B-Application
,	O
after	O
finding	O
out	O
that	O
his	O
catalogue	O
on	O
the	O
service	O
was	O
encoded	O
in	O
MQA	O
without	O
his	O
permission	O
,	O
criticizing	O
Warner	O
Music	O
Group	O
(	O
which	O
owns	O
Reprise	O
Records	O
that	O
Young	O
has	O
released	O
most	O
of	O
his	O
catalogue	O
through	O
)	O
for	O
encoding	O
music	O
whose	O
masters	O
are	O
no	O
better	O
than	O
CD-quality	O
in	O
MQA	O
.	O
</s>
<s>
In	O
an	O
interview	O
for	O
online	O
publication	O
Positive	O
Feedback	O
,	O
engineer	O
Andreas	O
Koch	O
is	O
critical	O
of	O
MQA	O
due	O
to	O
its	O
lossy	B-Algorithm
algorithms	O
and	O
compression	O
,	O
along	O
with	O
its	O
licensing	O
requirements	O
;	O
also	O
saying	O
that	O
a	O
format	O
such	O
as	O
this	O
"	O
does	O
not	O
solve	O
any	O
problem	O
that	O
the	O
world	O
currently	O
has.	O
"	O
</s>
<s>
The	O
GoldenSound	O
audio	O
equipment	O
review	O
website	O
examined	O
MQA	O
through	O
the	O
use	O
of	O
author-created	O
audio	O
tracks	O
released	O
on	O
Tidal	B-Application
.	O
</s>
<s>
Shortly	O
after	O
contacting	O
MQA	O
for	O
clarification	O
about	O
the	O
issues	O
,	O
the	O
files	O
in	O
question	O
were	O
deleted	O
from	O
Tidal	B-Application
.	O
</s>
<s>
Software	O
decoders	O
are	O
sold	O
by	O
Tidal	B-Application
(	O
in	O
the	O
"	O
HiFi	O
Plus	O
"	O
and	O
"	O
Masters	O
"	O
pricing	O
tiers	O
)	O
,	O
and	O
Roon	O
.	O
</s>
