What Is Frequency Response? || Understanding the Measurements Part 1
Summary
TLDRこのビデオスクリプトでは、オーディオレビューのデータ意味を解説するシリーズの第1回として、周波数応答について詳しく説明しています。オーディオレビューでは、主観的な意見だけでなく、客観的なデータを提供し、リスナーが自分の好みに合った音質を選ぶ手助けをします。スピーカーの周波数応答は、リスナーが最初に耳に入る音を表すため、非常に重要です。理想的には、スピーカーは再生システムから出る信号をそのまま再生すべきですが、完璧なスピーカーは存在しません。スクリプトでは、周波数応答グラフの読み方や、±1.5dB以内が良好、±3dB以内が普通とされていますが、それ以上になると音の色味に影響を与えます。また、スピーカーの種類にかかわらず、低音域を補強するサブウーファーの重要性も触れています。
Takeaways
- 🎶 オーディオレビューの目的は、データを提供することで、個人的な主観的な意見に頼らないようにする。
- 📈 主観的なフィードバックと客観的なデータの両方を提供することで、聴く人々が異なる可能性のある聴覚体験をカバーする。
- 📊 オブジェクトデータは、オーディオレビューアーがただ「ミドルレンジが温かそうだ」や「ツイーターが詳細だ」と言わないようにするために重要。
- 📚 このシリーズのビデオは、データを理解するための教育的な目的で、観客がデータの意味を理解できるように説明する。
- 🔊 オンアクシス周波数応答は、スピーカーの性能を理解する上で最も重要な客観データの1つである。
- 🏠 アネコイック測定と測定された部屋内の応答は異なる。アネコイック測定は、部屋の影響を排除してスピーカー自体の性能を測定。
- 📉 周波数応答グラフのx軸は周波数で、y軸はSPL(Sound Pressure Level)で、これは音量の大きさを示す。
- 🔉 理想的なスピーカーは、再生システムから出る信号を変更せず、同じ忠実性を維持する。
- 📌 スピーカーの周波数応答が±1.5dB以内であれば良いスピーカーであり、±3dB以内であれば十分に良いが、それ以上になると問題が生じる可能性がある。
- 🚫 スピーカーが20Hzから20kHzまでの平坦な応答を提供することは困難であり、完璧なスピーカーは存在しない。
- 👂 高域周波数の異常が聞こえる可能性があり、それが聴覚に与える影響については、レビューで詳しく説明する。
- 🔗 説明書に記載されているすべての測定方法は、ANSI/CTA-2034-Aという標準に基づいており、無料でダウンロードできる。
Q & A
アロンスのオーディオコーナーというシリーズのビデオの目的は何ですか?
-アロンスのオーディオコーナーは、視聴者にデータを提供することで、主観的な意見に頼らずに製品を理解できるようにすることを目的としています。
アロンスはどのようにしてスピーカーをテストしますか?
-アロンスは、リビングルーム、ホームシアタールーム、近場、遠場など、様々な状況でスピーカーをテストし、異なるリスナーが聴く可能性がある様々な状況を網羅しようとしています。
主観的なフィードバックの問題は何ですか?
-主観的なフィードバックの問題は、私が聞こえるものがあなたに聞こえるとは限らないことです。私たちは異なる要素に注意を払っているかもしれませんし、低い周波数や高い周波数の聴覚損失があるかもしれません。
オブジェクトデータとは何ですか?
-オブジェクトデータとは、スピーカーの性能を客観的に示すデータであり、時間とともに提供されるデータが増えることで、リスナーは自分の好む音質や参照音を絞り込むことができます。
アロンスが提供するデータの基準は何ですか?
-アロンスが提供するデータは、ANSI/CTA-2034-Aという標準に基づいています。これは家庭用スピーカーのための測定方法の標準的な方法です。
オニキス応答とは何ですか?
-オニキス応答とは、部屋の影響を受けずに行われる測定であり、スピーカーが独自に何をしているかを知るためのものです。
周波数応答グラフのx軸とy軸は何を表しますか?
-周波数応答グラフのx軸は周波数を、y軸はSPL(Sound Pressure Level)を表します。周波数は音の低さや高さを意味し、SPLは音量の大きさを意味します。
理想的なスピーカーの周波数応答グラフはどうなっていますか?
-理想的なスピーカーの周波数応答グラフは、20Hzから20kHzまでの範囲で非常に平坦な線を持っています。これは、典型的な聴衆の聴覚範囲です。
スピーカーの周波数応答が±1.5dB以内の場合どう解釈されますか?
-スピーカーの周波数応答が±1.5dB以内の場合は、非常に良いスピーカーと見なされます。これは、軸上の応答が非常に平坦であることを意味します。
スピーカーの周波数応答が±3dBを超える場合どう解釈されますか?
-スピーカーの周波数応答が±3dBを超える場合は、他のスピーカーよりも優れているとは言えませんが、それでも良いスピーカーです。ただし、周波数応答がさらに外れると、音の色味に影響を与える可能性があります。
スピーカーの低周波数応答が不足している場合、どうすればよいですか?
-スピーカーの低周波数応答が不足している場合は、低音の出力を強化する良いサブウーファーを購入することが推奨されます。
Outlines
🎙️ オーディオデータの意味とは
このビデオは、Aaronのオーディオコーナーのエピソードであり、データの意味を説明するシリーズの一部です。チャンネルの目的は、聴き手が主観的な意見に頼るのではなく、データを提供することであり、Aaron自身がスピーカーを試聴する際の聴き取り感覚を伝えることも含まれていますが、聴き手に客観的なデータと共に提供することで、より正確な情報を提供する狙いです。また、聴き手が好む音や参照音を特定し、最も価値のある選択肢を見つける手助けをすることを目指しています。オーディオレビューアーが主観的なフィードバックを提供するのに対し、Aaronはデータを通じて理解を深めることを目指しています。
📊 オンアクス周波数応答の重要性
ビデオの中心は、オンアクス周波数応答について説明することです。これは、リスナーの耳に最初に到達する音を表すための共通の出発点であり、多くの状況で公正な表現とされています。周波数とSPL(Sound Pressure Level)のグラフを用いて、理想的なスピーカーは再生システムからの信号を変更せず、同じ忠実性を維持することが求められます。しかし、完璧なスピーカーは存在せず、周波数応答が平坦でない場合、スピーカーは独自の音の特性を加えます。また、人間の聴覚範囲外の周波数帯で応答が変化すると、音の性格が変わることがあります。このビデオでは、スピーカーの周波数応答がどのように音の質に影響を与えるのか、またその線形性とバランスについても解説しています。
📉 周波数応答の可視化と解釈
このセクションでは、周波数応答グラフの読み方と、±1.5dBおよび±3dBの範囲でのスピーカーの線形性の可視化方法について説明します。±1.5dB以内のスピーカーは非常に良いとされ、±3dB以内のものは良いが最優れものではありません。また、低周波数帯での減衰や、スピーカーの種類に応じた周波数帯の限界についても触れています。特に、低音周波数帯では、多くの书架型スピーカーが出力を減少させることが予想されますが、低音を補強するためにはサブウーファーの導入が推奨されています。このビデオでは、周波数応答の問題点に対処し、レビューでそれらを指摘する際に注意を払う方法が説明されています。
Mindmap
Keywords
💡データ
💡主観的なフィードバック
💡客観的なデータ
💡周波数応答
💡無響室応答
💡軸上の応答
💡dB(デシベル)
💡 ANSI/CTA-2034-A
💡線形性
💡低音
💡サブウーファー
Highlights
Aaron's Audio Corner aims to provide data to help listeners understand sound quality without relying solely on subjective opinions.
The channel includes various tests of speakers in different environments to encompass a wide range of listening experiences.
Aaron emphasizes the importance of objective data alongside subjective feedback for a more comprehensive understanding of audio equipment.
Frequency response is considered the most crucial aspect of objective data for understanding a speaker's performance.
Anechoic response measures speaker performance without room influence, providing a pure assessment of the speaker's output.
In-room response differs from anechoic as it accounts for room reflections and other environmental factors affecting sound.
ANSI/CTA-2034-A is the standard method of measurement for in-home loudspeakers, which Aaron's data is based on.
On-axis frequency response is the starting point for evaluating a speaker, representing the first sound to reach a listener's ears.
The frequency response graph's x-axis represents frequency, while the y-axis represents sound pressure level (SPL).
An ideal loudspeaker would have a flat frequency response line from 20 Hz to 20 kHz, matching the typical human hearing range.
Speakers that deviate from a flat response begin to impart their own sonic characteristics, which some listeners may prefer.
Linearity in a speaker's on-axis response is evaluated by how closely it remains within +/- 1.5 dB and +/- 3 dB ranges.
A speaker within +/- 1.5 dB is considered very good, while one within +/- 3 dB is good but not exceptional.
Beyond the +/- 3 dB range, speakers may introduce significant imbalances in sound, affecting the listening experience.
Bookshelf speakers typically have less bass and may show a roll-off below 50 Hz, necessitating a subwoofer for low-frequency support.
Aaron uses the example of the Cali IN5 speaker to illustrate how on-axis response can vary and impact the perceived sound quality.
High-frequency anomalies in speakers can be audibly detected and may influence the overall sound signature.
Aaron's reviews will note any issues with frequency response to help listeners make informed decisions about audio equipment.
Transcripts
welcome to another wonderful episode of
aaron's audio corner
uh this series of videos is going to be
based on providing you with an
explanation of
what the data means
i started this website and this youtube
channel approximately a year ago
the entire purpose was to provide you
with data
the reason i wanted to provide you with
data was so you wouldn't have to rely on
just my subjective opinion
now certainly i'll listen to the
speakers when i test them out and
i still tell you what i hear when i
listen to them in the in the various
fashions you know living room
home theater room near field far field
all sorts of different levels and i try
to test them out all sorts of ways
that way i try to you know encompass
what everybody else is probably going to
be listening
like but the problem with just providing
you with subjective feedback is
sometimes what i hear may not translate
to what you hear we may be listening for
different things you know we may have a
history of picking up on
low frequency elements and somebody else
may have a history of picking up on high
frequency elements
some people may have high frequency
hearing loss so when i provide you with
this
subjective information i want to have
objective data
to go along with that because the idea
is over time
when i provide more and more data you
can start to hone in on hey this is the
sound that i like
or i prefer a reference sound and this
is the best value
to get that or one of the best ways to
get that and then there's certainly
other factors as well like
looks you know the size of the speaker
all these things go together but
the objective data is absolutely
important and it's important to help you
weed through all the fluff because
there's tons of audio reviewers out
there that just tell you
the mid-range sounds warm or the
tweeters sound detailed and it's just
it's superfluous and i don't think that
in the long run that is
as helpful as seeing data and being able
to understand what the data means
it doesn't mean that you have to become
an objectivist it simply means that
you're educated
each of my videos tend to run a little
bit long because i feel compelled to
explain to you
what the data means and in doing so it
just it naturally takes a while to get
through everything because i also feel
the need to break things down on a more
elementary level
so i decided to take my own advice i'm
going to create this series of videos
to tell you what the data means and then
this way you can come back to it when
you look at one of my reviews
and you're curious about you know what
that means i can just simply point you
back to it
i can provide a link in the description
somewhere and say hey if you're curious
about how to read this data and
understand it at a more thorough level
see this series see this playlist so
the first video i'm going to kick off in
this series is going to be frequency
response
because in my opinion that is the
absolute
most important aspect of objective data
without a clear understanding of on-axis
frequency response
you really don't have a grasp on what
all the other measurements mean
so let's get to that before we go any
further i want to clear one thing up
anechoic response is not the same thing
as measured in-room response and what do
i mean by that well it's simply
a lot of people will provide you a
measurement of what they are
getting in their room and then somebody
will say oh i don't like flat in-room
response
you know and they misunderstand that
in-room response is totally different
from
an anechoic measurement an anechoic
measurement is
without the room influence you know the
ceiling floor
walls any of those reflections couch
anything nearby
that would mess up the frequency
response measurement
the reason that you want to separate the
speaker from the room
is because you want to know exactly what
the speaker is doing all on its own
and the reason you want to do that is
because with enough data you can predict
how a speaker is going to perform
in everybody else's room with a high
degree of accuracy
and that's very important i'll point
that out because people will talk about
in-room measurements as if
the same thing is an anechoic
measurement and they are two totally
totally separate things they could not
be further from
different the majority of the data that
i provide is based on a
standard which is this it is the ansi
cta standard
standard method of measurement for
in-home loudspeakers cta
2034-a and
revision 2020 i guess is what this
stands for frankly i don't know
but this document is free to download i
will provide a link
in the description below and you just go
to the website and you give them your
information they'll send you a download
link you can download it and go check it
out and it has
everything that i'm going to talk about
in this video except for a few things
which will be you know distortion and
compression
but for the most part everything that
i'm going to talk about in this series
of videos is going to be covered in this
document
starting with the on-axis frequency
response and we're going to grab from
them
the direct definition of on-axis
response since the contents in this
video are focused on
on-axis sound let me give you an example
of what i mean by
on-axis
this is a speaker the speaker is facing
right at you
that means the speaker is on axis if i
turn the speaker to the side
any direction that means it is off axis
even pointed down would be off axis
there's always a reference plane
typically with most speakers
the reference plane is the tweeter and
by reference plane i mean
where are you putting your ears at like
level wise you know if i put my ears
right here
then vertically my ears are on axis
with the reference plane now if i put
the speaker up here and turn it down
then i'm not on axis with the vertical
plane anymore
so that's just briefly what i mean by
on-axis and we'll talk about off-axis in
a later video
here we are this is the standards
definition for it and i'll read it out
to you
the on-axis frequency response is the
universal starting point and in many
situations
it is a fair representation of the first
sound to arrive at a listener's ears
to kick off this conversation i'm going
to use an example from a recent test i
did on the
cali in5 this is a graphic that has a
lot of information in it but we're going
to focus right now on
the black line that says on axis which
kind of runs through
here first of all how do you read this
graph
well on the x-axis down here is
frequency and on the y-axis
is spl what does that mean
frequency everybody knows bass you know
bass you hear the car
thumping next to you at the red light
your friends are talking about their
subwoofers everybody understands what
bass is
bass is low frequency most people's
voices
cover the span of about 200 to 3 000
hertz so you're talking about this area
right in here that's that's the typical
vocal region for
males and females and certainly there
are some exceptions when you go into the
higher frequencies which is generally
considered you know
one two kilohertz and above going to the
right
that would be sounds of like birds
chirping or
a whistle or the s as somebody's talking
and then when you're talking about how
much there is
that would be covered on this left axis
so for example
if i'm talking quietly then the output
would be in a lower
value of spl and if i'm talking loudly
the output would be at a higher volume
of spl and that's the basics of a
frequency response graph
when you're talking about loudspeakers
ideally what you want
is to not mess with the signal coming
out of whatever your playback system is
so for example
you've got a cd it's got a song on it
and let's say the song
is just a sign sweep and it's that
you've probably heard of sign sweep
before it goes
and that's it right um if the cd has
just a sign sweep on it then the speaker
should play
just the sign sweep only and it should
play it with the same fidelity that is
on
the actual cd medium and that would be
you know a equals b input equals output
unfortunately there is no loudspeaker in
the world that i'm aware of that will
provide you
with that exact thing because there is
no perfect
loudspeaker a perfect loudspeaker would
be a speaker that has a very flat line
from 20 hertz down here to 20 kilohertz
up here
because that's mostly the typical
listeners hearing range
when a loudspeaker gets outside of that
flatline as everyone that i'm aware of
does
that's when they start to impart their
own sonic characteristics to the sound
whether good or bad some people for
example may like a boosted high
frequency response so the high
frequencies tend to sound a little bit
louder
than lows some people like the opposite
some people may want
heightened vocals so they may want more
spl in the 200 hertz to three kilohertz
region so
in this ballpark area right here but the
bottom line again is that there is no
speaker on earth that is dead flat from
20 hertz to 20 kilohertz
at least that i'm aware of and if there
is then that would probably be
considered the reference standard
in terms of on-axis response this
graphic represents
the same black line that you saw on the
previous graphic
however it's just by itself i've got rid
of all the other ones
and what i've done here is i've
calculated the mean spl
over a range of 300 hertz to 3 kilohertz
so basically you know the typical human
voice region
and in doing so i've also said okay now
based on that mean spl what is the plus
or minus one and a half db region
and then what is the plus or minus 3 db
region the reason i've done that is to
help you visualize
how good the speaker's linearity is and
when i say linearity i just mean
you know how flat is the response on
axis
a speaker that is within plus or minus
one and a half db is really
a good speaker a speaker that is within
you know plus or minus 3 db
is a good speaker but it's not the
greatest of the great
and when you get beyond that that's when
you start having issues with you know
speakers really tainting the sound and
creating their own
imbalance in terms of timbre you know
what you hear the vocals may sound
louder than the
high frequencies or vice versa or just
any kind of imbalance overall to the
speaker response
and what i'm looking for here really is
a on-axis response that is well within
the gray window
within limits when i say within limits
what do i mean well
you know most bookshelf speakers are not
gonna have a lot of bass so you're gonna
expect to see some kind of roll-off here
what you do
and you know below what 50 hertz or so
this speaker just doesn't have a lot of
output
that's typical when you're talking floor
standard speakers you're
you're bound to get more output with the
lower frequencies but they still have
their limits
for the most part as well and generally
speaking no matter what speaker you use
floor stander or bookshelf speaker
you're still going to want to buy a good
subwoofer
to hold up and shore up the low
frequency response using this speaker as
an example you can see that it is mostly
within the
and a half db window but it does jump
outside of that at a few points and gets
into the plus or minus three db
window and then when you get to the very
high frequencies it is even outside of
the plus or minus three db window and
you may be wondering
are these effects audible yes they are
if you want to know what i thought about
how the speaker sounded and how
the high frequency you know anomalies
impacted what i heard
then make sure you go check out that
review and i will make sure to put it
somewhere up in the cards if i remember
to and that's it for the frequency
response video
like i said i wanted to keep this one
short and sweet and when there are
issues with the frequency response of
speakers that i've measured i will make
sure to try to note those as i go
through the review
hopefully that helps explain frequency
response a little bit to you and if
you've got any questions make sure you
ask in the comments below
5.0 / 5 (0 votes)