Genelec 8050B Speaker Review (and how to read speaker measurements)

Summary

ビデオでは、オーディオサイエンスレビューのアミルが、プロフェッショナルモニターのジェネレック8050bをレビューしています。このスピーカーは、波導の統合、8インチのウーファー、クラスABアンプ、そして背面のポートなどの特徴があります。測定方法として、近接場スキャナーを使用し、スピーカー自体の動作を測定し、部屋の反射を排除しています。スピーカーの周波数応答、ディストーション、および水平・垂直方向性の評価を行い、その性能を詳細に解説しています。

Takeaways

• 📢 このビデオは、Genelec 8050Bというスピーカーのレビューであり、メソッドロジーと測定方法について説明しています。
• 🔍 Genelecはフィンランドの会社で、プロフェッショナルなモニターを長い間作っており、世界でトップ2、3位のブランドの一つです。
• 📏 8050Bは8インチのウーファーで重く、キャストアルミニウムで作られた非常に-solidなボックスです。
• 🌐 統合されたウェーブガイドは、ツイーターとウーファーのレスポンスをクロスオーバー領域でスムーズに合わせるためのものです。
• 🔊 このモデルはアクティブモニタで、ウーファーとツイーターそれぞれにアンプがありますが、従来のクラスABアンプを使用しています。
• 🔧 背面には大きなポートがあり、低周波応答を拡張する役割を果たしていますが、周波数が低いと急激に減衰するというトレードオフがあります。
• 🎛️ スピーカーには周波数応答を調整するための複数のコントロールがありますが、エレクトロニックイコライゼーションの方が好ましいと述べています。
• 📈 スピーカーの測定では、ルームリフレクションを排除するために近接場スキャナーを使用し、非常に正確な結果を得ることができます。
• 📊 スピーカーの測定結果は、SPINデータ（スピノラマ）として示され、これは標準化された測定方法です。
• 👂 聴覚テストでは、スピーカーのトーンの良さを判断する上で重要な要素をいくつか確認しますが、聴覚テストは測定値を補完するものであり、完全に置き換えるものではありません。
• 💡 このスピーカーは低頻帯の力を求める場合、サブウーファーが必要で、非常に大きな音量で再生する場合に限界があります。

Q & A

ゲネレック8050Bスピーカーの特徴は何ですか？

ゲネレック8050Bはフィンランドの会社が製造するプロフェッショナルモニターで、8インチのウーファーを備えており、鋳造アルミニウムで作られた非常に-solidなボックスです。また、統合されたウェーブガイド技術を採用しており、ツイターとウーファーのレスポンスを滑らかに一致させるように設計されています。

ウェーブガイドとは何で、どのような役割を持っていますか？

ウェーブガイドは、ツイターのレスポンスを狭める仕組みで、クロスオーバー領域でウーファーのレスポンスと一致するように設計されています。これにより、ツイターとウーファーの間で不連続さが生じるのを防ぎます。

このスピーカーはアクティブタイプですか、それともパッシブタイプですか？

はい、これはアクティブタイプのモニターで、ウーファーとツイターそれぞれにアンプが搭載されています。ただし、これは古いデザインのため、最近のクラスDアンプではなく、従来のクラスA/Bアンプを使用しています。

スピーカーのバックサイドにはどのような特徴がありますか？

バックサイドには大きなポートがあり、これは小型のエンクロージャーで低周波応答を拡張するために使用されています。また、周波数応答を調整するためのいくつかのコントロールがあります。

スピーカーの測定方法として特に重要なポイントは何ですか？

スピーカーの測定では、部屋の反射を排除することが重要で、実際にスピーカー自体の動作を知るためにアンエコイックチャMBERを使用することが伝統的な方法です。しかし、低周波ではアンエコイックチャMBERでも正確ではありません。

クリッパブル近場スキャナーとは何ですか？

クリッパブル近場スキャナーはロボットシステムで、スピーカーの近くで円筒測量を行い、反射を排除することでスピーカーからの直接音と反射音を区別することができます。

スピーカーのスピンデータとは何で、何が重要ですか？

スピンデータとは、スピーカーの周波数応答を視覚化したグラフであり、標準化された測定方法です。重要なのは、オンアクス（直接音）がフラットであることと、反射音も同様にフラットであることです。

スピーカーのディストーション測定はどう行われますか？

ディストーション測定では、86dB SPLと96dB SPLの2つのレベルで測定され、これはスピーカーが音量を上げた時にどの程度ディストーションが増えるかを示します。

水平方向性とは何で、スピーカーの性能にどのような影響を与えますか？

水平方向性はスピーカーから音が水平方向にどの程度広がるかを示し、良い水平方向性は音のトノロジーが周囲で一貫性を保ちます。これは特にミキシングや録音の際に重要です。

ウォーターフォール分析とは何で、スピーカーの測定においてどの程度の役割を果たしますか？

ウォーターフォール分析は、スピーカーのインパルス応答を可視化したもので、共振やディストーションを特定するのに役立ちます。しかし、解釈が難しいため、他の測定値と組み合わせて使用されます。

スピーカーのリスニングテストとはどのようなものですか？

リスニングテストは、スピーカーの音質を主観的に評価する方法で、測定値から得られない情報を得るために行われます。リスニングテストでは、スピーカーの音の広がり、深さ、または特定の周波数帯での表現力を評価します。

スピーカーの価格帯はどの程度ですか？

ゲネレック8050Bの価格は高めで、1台あたり1400ドル程度で、2台セットで3800ドルになります。これはヨーロッパ製の高品質な製品であるためです。

スピーカーのパフォーマンスを向上させるためのアドバイスはありますか？

スピーカーのパフォーマンスを向上させるために、低周波範囲を補うためにはサブウーファーを組み合わせることが推奨されます。また、音量を極端に上げず、リスニングテストで感じた不満をエクイлайザーで補正することも有効です。

Outlines

00:00

🔊 オーディオレビューのスピーカー紹介

アミルがオーディオサイエンスレビューでスピーカーのレビューを行い、特にスピーカーに興味がない視聴者にもメトリクスとリスニングテストの方法論を学べる良い機会であることを紹介。レビュー対象はジェネLECの8050Bというスピーカーで、プロフェッショナルなモニタとして世界的に有名。このスピーカーは8インチのウーファーで重く、キャストアルミニウムで作られた-solid box。また、インテグレーテッドウェーブガイド技術を採用しており、ツイーターとウーファーのレスポンスを滑らかに合わせる。

05:03

🔧 スピーカーの測定方法と機器紹介

スピーカーの測定方法としてアネコイックチャMBERの使用が伝統的であるが、実際の測定では低音域では反射が生じる問題がある。そこで、CLIPPABLE NEAR FIELD SCANNERというロボットシステムを使用し、スピーカーから反射を排除した測定を行う。このシステムは非常に高価であるが、最も正確な測定結果を得られる。

10:04

📊 スピーカーの周波数特性とリスナーの好み

スピーカーの周波数特性は、リスナーの好みに大きく影響する。研究によると、ほとんどのリスナーがニュートラルな音の特性を好む。スピーカーの軸上の特性は平坦で、小さなノッチが存在してもほとんど聴衆には問題ない。しかし、スピーカーは音を全方位に放出するため、反射音も聴衆に届く。理想的なスピーカーは軸上と反射音の両方で同様の周波数特性を持つ。

15:04

📉 スピーカーの予測された室内応答

スピーカーの軸上音と早期反射音を組み合わせることで、一般的な室内での音の応答を予測することができる。プロモニタはフラットな応答を好むが、このスピーカーでは軸上音に欠陥があり、低音域での発振が限界があることが示唆される。

20:05

📝 スピーカーの個別ドライバー応答とポートの役割

スピーカーのツイーターとウーファーの個別ドライバー応答を測定し、それぞれが周波数帯でどのように動作するかを分析する。また、ポートの応答も測定され、低周波数での助けを提供する一方で、共振現象が発生する可能性があることも示されている。

25:05

📊 音響空間におけるスピーカーの特性

スピーカーの水平および垂直方向の指向性は、音響空間での音の広がり方を決定する。理想的なスピーカーは周波数によらない一定の音束を放出し、左右の音色差がないように設計されている。また、反射音の同調性も重要で、空間の広がりやリスナーの位置に応じた音の変化が少なく、音の質が一定であることが望ましい。

30:07

👂 オーディオサイエンスレビューの聴覚テスト

アミュラーはスピーカーの測定結果を聴覚テストと比較し、聴覚で確認できない微妙な違いや問題点を特定する。また、スピーカーの失真を測定し、聴覚で検出されるかどうかを判断する。聴覚テストは、測定値から予測される音質と実際の聴覚体験のギャップを埋めるために重要な役割を果たしている。

35:07

🔊 スピーカーの配置と設計の重要性

スピーカーの配置は音質に大きな影響を与える。特に、スピーカーを耳の高さに配置し、聴衆が少しでも動いた場合でも音色差がないようにすることが重要である。また、コーアクシャルドライバーやツイーターとウーファーの配置がスピーカーの指向性に影響を与えることを説明する。

40:09

💡 オーディオサイエンスレビューの総括

アミュラーはスピーカーのレビューを総括し、スピーカーの周波数特性、指向性、失真、および室内応答の測定方法を解説した。また、聴覚テストの重要性を強調し、スピーカーの配置や設計の選択肢についても触れる。最後に、スピーカーの好みや評価の主観性についても言及し、聴衆に対して理解を深めることを促す。

Keywords

💡ジェネLEC 8050B

ゲネLEC 8050Bは、フィンランドの会社でプロフェッショナルモニターの製造を長い間行ってきたブランドのスピーカーモデルです。このビデオでは、そのサイズや重さ、素材、そして組み込みされたウェーブガイドなどの特徴について説明しています。ビデオのテーマはスピーカーのレビューであり、このモデルはそのレビューの中心となる製品です。

💡ウェーブガイド

ウェーブガイドとは、ツイーター（高音ユニット）の応答をナローバンドにし、ウーファー（低音ユニット）の応答と一致させるためのデバイスです。ビデオでは、ウェーブガイドがクロスオーバー領域でツイーターの応答をどのようにナローにし、スムーズにウーファーとマッチングするかについて解説しています。

💡パワードモンイター

パワードモンイターは、スピーカー自体にアンプライザーが内蔵されたもので、ビデオではゲネLEC 8050Bがこのタイプのスピーカーであると紹介されています。アンプライザーはウーファーとツイーターそれぞれに備えられており、ビデオでは従来のクラスDアンプライザーとは異なるクラスA/Bアンプライザーが使用されている点に触れています。

💡クロスオーバー

クロスオーバーは、スピーカーのツイーターとウーファーが異なる周波数帯を扱う交界处です。ビデオでは、クロスオーバー時にツイーターとウーファーの応答がどのように連動し、ウェーブガイドがその間の不一致を解消する役割を果たすかについて説明しています。

💡近場スキャナー

近場スキャナーは、スピーカーの測定を行うロボットシステムで、ビデオではスピーカーから反射を排除して正確な測定値を得る方法として紹介されています。このシステムはスピーカーの近距離での測定を行い、音場のデータから反射を除去することで、より正確なスピーカーの性能評価が可能になります。

💡スピンデータ（SPINorama）

スピンデータとは、スピーカーの周波数応答を視覚化するグラフであり、ビデオでは測定結果として提供されています。スピンデータは、スピーカーの音質を客観的に評価するための重要なツールであり、ビデオではこのデータがどのようにスピーカーの性能を示すかについて解説しています。

💡ディストーション

ディストーションは、スピーカーが音声を再生する際に生じる歪みを指し、ビデオではスピーカーの性能を評価する際に重要な指標として測定されています。ビデオでは、ディストーションがどのように測定され、スピーカーの性能に与える影響について説明しています。

💡ディレクティブ

ディレクティブは、スピーカーの音がどの方向に向かって広がるかを示す特性であり、ビデオでは水平および垂直のディレクティブの重要性について説明しています。スピーカーのディレクティブが良好であれば、反射音と直接音との間のトナリティの違いが小さくなり、聴覚上の満足度が高まります。

💡ルームフレンドリー

ルームフレンドリーは、スピーカーが部屋の反射音と相性が良く、音質に悪影響を与えないことを指します。ビデオでは、スピーカーのディレクティブが良好である場合、反射音がスピーカーの直接音と同様のトナリティを持つため、ルームフレンドリーであると評価されます。

💡ウォーターフォール分析

ウォーターフォール分析は、スピーカーの周波数応答を時間ドメインで可視化する手法であり、ビデオではその解釈の難しさと誤解を生む可能性について触れています。ウォーターフォール分析は、スピーカーの性能を評価する際に用いられるが、正確な解釈が必要です。

Highlights

Georgie 8050B是由芬兰Genelec公司生产的专业监听音箱，该公司长久以来一直制造专业监听音箱。

Georgie 8050B音箱采用8英寸低音单元，箱体由铸铝制成，非常坚固。

集成波导技术用于缩小高音单元的响应范围，以匹配低音单元的响应，实现平滑的声音过渡。

该音箱为有源监听器，配备低音单元和高音单元各自的放大器，采用的是传统的AB类放大器而非现代的D类放大器。

音箱背面设有尺寸较大的端口，用于扩展低频响应。

音箱提供了多种控制选项，用于调整频率响应，但作者倾向于使用电子均衡器进行调整。

介绍了测量音箱的正确方法，包括在消声室中进行测量以避免房间反射的干扰。

Clippable近场扫描仪的使用，这是一种机器人系统，可以在近距离测量音箱并消除房间反射。

即使在消声室中，极低频率的测量也可能不准确，因为仍然存在反射。

介绍了如何通过测量来预测音箱在普通房间中的声音表现。

Georgie 8050B的轴向频率响应非常平坦，接近理想状态。

音箱的早期反射和声功率表现良好，有助于形成平滑的预测室内响应。

通过测量各个驱动单元的响应，可以了解音箱频率响应不完全平坦的原因。

音箱的端口共振得到了很好的控制，没有对频率响应产生负面影响。

讨论了失真测量的重要性以及如何通过测量来确定音箱的极限。

Georgie 8050B在高音量下表现出可闻的失真，尤其是在低频区域。

水平指向性表现良好，使得音箱在不同位置的听感保持一致，这对于近场监听非常重要。

垂直指向性分析表明，音箱在不同高度的听感也相对一致，但存在一些频率上的凹陷。

讨论了音箱的房间友好性，以及如何通过控制反射来优化听感。

水瀑布图（Waterfall display）虽然美观，但在非活跃音箱上可能会产生误导。

尽管测量数据非常重要，但听感测试同样关键，可以揭示测量无法展现的音质特点。

Georgie 8050B在听感测试中表现出色，但在极高音量下出现了可闻的失真。

尽管音箱价格不菲，但考虑到其性能和制造质量，它仍然具有很高的价值。

Georgie 8050B的偏好得分非常高，表明它是一款处于艺术状态的音箱。

Transcripts

hello everyone this is amir from audio

science review

uh today i have a speaker review for you

um even if you're not interested in

speaker i thought it would be a good

video for you all to watch because it

goes through the

methodology for measurements and and

listening tests

so today's uh speaker in question

actually let me go back full screen um

this is genelec

8050b um finnish company

been in business making professional

monitors for a long time

probably top two or three brand in the

world

this specific sample is quite large

eight inch woofer

it's quite heavy actually it may not

look it but it's made out of cast

aluminum and it's quite a solid box

uh if we go to the review you'll be able

to see a better picture of it

it's got this integrated waveguide

waveguide is a way to uh narrow the

response of a twitter

to get it to match the woofers response

as it the frequencies go up the woofer

starts uh

step back woofer starts with basically

omnidirectional sound

but as frequency go up it becomes

narrower narrower and narrower

um the inverse is true of the twitter if

you just cross over to a twitter

twitter starts off also quite wide and

you get a discontinuity there

so what a waveguide wave guide does

is that it narrows the response of a

twitter at crossover region

so that it smoothly matches uh that of

the woofer

uh if you have a mid-range that's

another way to mid-range drivers another

way to solve the problem but

if if you don't have one trying to get a

tiny little uh

um oops a tiny little uh

twitter to uh blend in properly with a

woofer is next impossible so it's nice

to see this in there

you know a number of companies have

these wave guys in there

this is a powered monitor has spy

amplified

so it has an amplifier for the woofer

and has an amplifier for the tweeter

it's an older design so unlike the new

speakers where they all use class d

amplifiers this uses traditional class a

b amps

and they tend to not be as powerful as

the class d's are because they take a

lot of space in

in with heatsinking what have you

uh on the back you have a pretty good

size uh port

the port is there to extend the low

frequency

response you know especially in a small

enclosure like this

but then they tend to drop off like a

rock uh

afterwards um so there you know it's

almost there's no

free lunch there if you will but it's

you know 95 of speakers now in this

bookshelf size will have that

as a number of controls uh for uh

adjusting the frequency response

i tend to not want to use any of those i

use electronic equalization

in in my software because these things

are very static

and i like to tune the sound fully but

uh if you need to

just plug it in and use it then it's

fine it's got input sensitivity

uh set it to the minimum and still was

pretty sensitive i had to keep the

volume pretty low

anyway that's the speaker um

we're going to get into the measurements

the measurements here

for speaker a proper way to measure a

speaker is to make sure that the room

reflections are not there

you don't want to see a frequency

response that is specific to my room you

want to know how the speaker itself

behaves and that traditionally has meant

that you take the speaker

and you go to an anechoic chamber that

gets rid of the reflections and you

measure there

but even anechoic chambers anything of a

reasonable size is still not anechoic

meaning that as frequencies get lower

and lower it actually has some

reflections that come back to the mic

measurement microphone and screw up the

measurements

there are calibrations for that

and they mostly work but just know that

in very low frequencies

even anechoic measurements are not very

accurate i use a system called

clippable near field scanner it's a

robotic system

let me open the link uh hopefully

there's a good picture of it there

and uh you can see in here

enlarge this you put the

speaker in the middle and uh

the system will then use this uh boom

and it will scan the speaker and

take a cylindrical measurements from top

to bottom

and then uh if you instructed to get rid

of the

reflections in a room it will do a

second pass

and using the those two measurements you

can determine if the sound is coming

from the

speaker or it's coming from an outside

the wall and come back in if it comes

back from another direction

it will take it out of the system

because of that it has two benefits one

is that it measures very close distance

to the speaker

and the benefit of that is that if

there's ambient noise it doesn't matter

that's one of the benefits of a

well-done anechoic chambers that's very

quiet

this system does not require a quiet

room because the microphone is very

close to the speaker

and as a result the noise is dwarfed and

doesn't show up in the measurement

there's a problem with doing that in

that if you measure very close to the

speaker you're measuring what is called

the near field response

not the far-field response for the sound

has gotten integrated and

but this system mathematically will

calculate

what that sound field is at any distance

so even though it measures at a short

distance

he can project the sound at 1 meter 10

meter 100 meters whatever you want

excuse me

um so putting it all together it gives

you a

basically a measurement that is uh

more accurate than just about any other

method that you could come up with you

could go spend a million dollars in

another koi chamber

and not get this kind of result

nothing's free in life and this one

literally is not free

this that system that i show you with

all the bells and whistles that i use to

make the proper measurements

cost about a hundred thousand dollars so

it's not for faint of heart but i you

know when i decided to get into speaking

measurements i just didn't know how else

to do it you have to do it this way

to get proper measurements there are diy

techniques that you can put things on

the ground and measure and combine

measurements and that's what

some of the other magazines and the

websites use it's very time consuming

and to do it right takes a lot of you

know meticulous attention

uh i do a speaker review every other day

every third day

and there's just no way i could

measure speaker like that you know

using the other people's methods and

you'll see why it's not just one

measurement

by default i have the clipable nfs

system measure 1000 points

so it is sampling the sound field a

thousand points around

it can go higher and can go lower lower

can lose

can cause accuracy errors higher takes a

lot longer to run but i have tested some

speakers

with two thousand points um two thousand

points takes about four and a half hours

for measurements

uh one thousand points half of that

about two and a half hours

and then another 15 minutes a number

crunching afterwards so

just the raw measurement takes me about

three three and a half hours

on the system once there we don't just

get a simple frequency response

measurement

we get this beautiful graph and this

graph and the measurements is in the

standard nc standard

and also called cea or cta 2034

but the common name for it we call the

spin data or spinorama

and i highly encourage you to use the

word spin data because this sounds

like you know more than you do so don't

spell it out when

you go to somebody try to sell a speaker

just say you have spin data

and the guy says what you want to walk

out because they don't

know how to measure this um anyway

dr tool when he was a national research

council in in canada that was set up to

try to promote an audio industry in

canada

set up a in 70s uh 1970s try to

figure out you know do peop is there

some common theme to what speakers

people like

or is it just a free-for-all that you

know there's no commonality you build

different frequency response different

tonality and x group of people like

it and the other people hate it and

surprisingly it turned out

to be that vast majority of people like

the same thing

and not only do they like the same thing

but they like a neutral

sound when it comes to frequency

response

so if you look at this response over

here there's this top line says on axis

which is the i don't know if you can see

this black line on top here

and the research says that we want this

thing to have to basically

be flat and have no variations in it

now this speaker is extremely good it

comes within 80 90

of of that target of uh looking flat

it's got little notches up and down

there are more perfect speakers

professional speakers

and they all use dsp to filter out these

notches in and out this speaker is older

it doesn't do that

newer genelecs do that and they have

flatter response

but from audibility point of view a

little bit higher a little bit lower

it's just not material because the music

is recorded with no standards

so who knows if the track you listen to

has a little dip over here versus this

little peak

so if you like you can try to filter

these things and correct them but

once you get to this level it's good

enough

in my book now that's just on axis

meaning the direct sound

coming at your ear so that's one sound

it's a very important sound is this sets

the stage and the tonality that your

brain

perceives of a speaker but the speaker

also sends sound to

in all directions and he hits the

ceiling hits the floor

hits the wall behind you then goes back

it's the front wall

and all these sounds also come to you at

different arrival times

and the brain has this challenge that

not only does it

hear this the redirect sound but it also

hears the reflected sound and

hears the reflected sound differently in

the right ear versus the left ear

so if there is reflection on the right

it will come to my

right ear faster and also stronger than

it comes to my left ear

and then my face also will cast the

acoustic shadow

where some of the high frequencies won't

go to this ear as well as they go in

this ear

now if the ear try to just present both

of those

images to your to you you go nuts right

it's like

you know frogs think frogs see you know

uh images that are you know ghostly

images with their eyes

that would be cooler than the sound

where your ear will be hearing

many many sounds simultaneously that

would make us nuts so

from a point of view of of how we've

evolved that species our brain had

decided to

um

filter out all those other secondary

sounds

now the best job that he can do is

if those secondary sounds have similar

tonalities to

what the direct sound is if that's the

case the brain says oh

these are just reflections of the same

thing

and therefore they're not

informationally as important

if you will and that i'm not going to

present them as secondary data to you

and

it is for lack of better word it's

happier

so an ideal speaker will have a direct

sound that comes to you with a certain

frequency response

but also it's indirect sound that hits

the walls and come to you

and through other reflections also have

similar frequency response now they

don't have to have

identical frequency response and indeed

it's usually the case where their

frequency response tilts down

because that twitter at high frequency

just like that woofer that explained it

also starts to narrow down

and when it narrows down there's less

energy hitting the walls

and coming at you so uh

you know some of some high frequency

droop is fine

now not all reflections are the same

some reflections are stronger than the

others first reflections are the

strongest so reflection of the side

while coming to my ear stronger than a

reflection hitting a back wall hitting

the sidewall then coming to me

there's a group of reflections that

let me jump ahead a little bit called

early reflections

and involve a research that was done at

harmon which was they sampled a few

different listening rooms

and determined which are the most the

strongest reflections that combine

and arrive at you they're dominant in

signature

and they're the floor obviously there's

a ceiling

front wall sidewalls rear wall and then

some of all of those together

and as you can see for this genelec if i

sum all those together i get a pretty

nice smooth

sloping down curve as i mentioned we

would however we also have a dip

here which is at the crossover region so

this speaker is not as perfect as it

could be

again newer genelecs will not have this

kind of dip in them

or you know most perfect speaker

wouldn't have any

the uh if we take the uh

uh step back we can take this

information that i've talked

so far that is captured in an anechoic

chamber

and actually predict what sound you

would get in a typical room

and that brings us down to this

estimated

or predicted in-room response

so how do you do that well it's a mix of

different things but

predominantly is the on axis sound which

i said is

extremely important this early window

which we know is tilting down so as a

result when we add the two together the

final thing will tilt down

and then some of the base area comes

from what is called sound power which is

this

um going back this uh

dash red line and uh sound power is just

sound everywhere and bass is everywhere

so if you combine all of those things

together and make this do

you get a predicted in-room response and

a predicted interim response in here

says we have it tilt down

although pro monitors tend to have less

of a tilt because they believe in a

flatter response

for somebody using a pro monitor for

make some music

then you would listen for hi-fi although

i find this one it's

got decent amount of tilt but the

formula of how much tilt you need

that's to taste you know you may like

less

high somebody else may like more highs

but as a general rule monitors tend to

have

less of a tilt in there and here we see

that our main flaw is this little dip in

here

so if it didn't have this this is

extremely good

response okay let me go back to a graph

that i

skipped over which is these um

individual driver responses so

my fancy system with a thousand

measurements generated the graphs that

you saw

but i also do a simple test where i use

a robotic boom

and i bring it point blank in front of

each element that radiates sound in a

speaker

and just measure what comes out of it so

in case of a twitter is this uh

blue line that you see or t online uh

brought the microphone right in front of

a twitter

and ran the full 20 to 20 000 sweep

you see that it shows the high

frequencies of a twitter and it drops

but then it goes back up and appears to

show that there's bass response

there isn't so when i have the

microphone up here this guy is also

playing because

there's no way for me to isolate these

drivers

without tearing up the uh speaker so the

base is still goes up and pollutes that

so you want to ignore when you look at

my graphs in here

you want to ignore when it lifts back up

and

for twitter that responses is not coming

out of twitter so just ignore

everything from this 1.5 kilohertz down

for the twitter

i then do the same thing with the woofer

a good thing about a woofer

is that when i measure that this guy is

pretty directional the tweeter is pretty

directional so when i'm measuring the

woofer

the twitter doesn't pollute it hardly at

all so for the woofer we see this red

line

comes down during the crossover region

and down here

you know response gets you know messy

because the woofer isn't designed

to produce good response at high

frequencies but luckily our level is way

below that of the twitter so twitter

sound dominates

but some of these peaks and valleys that

you see in here maybe the reason our

frequency response isn't

perfectly flat in these things these

little ticks that you see

you know it is the sum total of these

peaks and stuff

the third radiating element is the port

so i

put the microphone all the way behind it

and do the same measurement

and here we see the port and we see how

it helps the low frequency response so

this is the woofer

it loses its response base as the

frequencies go down

but then the port kicks in and gives it

a lift

up here around 40 hertz

okay so these two sum together

and basically give you a flat response

that then rolls off

down here um all ports unfortunately

have a artifact which we call resonances

so sound can bounce up and down inside

there

and amplify so a port normally would

have this response and you can see that

it keeps going down which is what we

want

and then all of a sudden it perks back

up

and starts to generate a lot more energy

it goes back down and has some other

because you have modes that are

horizontal and vertical and in all

different dimensions

and it has yet another one up here and

these are actually fairly controlled in

some cheap speakers i find resonances

coming all the way up

very close to the response of the woofer

or the twitter

and as a result you get peaking in the

frequency response due to that resonance

which doesn't sound good

so um here there's their control but

they're enough

in here little peaks in here but to

again cause these little

humps that you see in the frequency

response and usually you can tell the

resonances when the humps are repeated

in all three curves you can see these

three

are repeated and if we go down here yeah

we can see them over here this is the

resonance

so typically pulling those down helps

with clarity

i find these resonances are little

sinking

you know the birds inside the speaker

they get activated and all of a sudden

they sing along and you know if they're

highs you can pull them now again this

is just one or two db so

i would not worry about it so

far the assessment is quite good but

we're not done this

science sort of ends here and says that

like tonality

is everything in the speaker tonality is

everything

in a speaker in that it dominates

preference

so if i have two speakers one has boomy

bass the other one doesn't have boomy

bass

you're not going to like the one with

the booming bass it doesn't matter if it

has lower distortion and twitter

somewhere else

if it's going pro or there's too much

bass or it's too bright

you're not going to pay attention to

anything else about that speaker because

it's just too bright

this isn't controlled blind test so

but if we have two excellent speakers

with similar frequency response similar

you know early windows similar

everything

my opinion then distortion matters and

we want to measure that and we want to

find the limits of a speaker

know that distortion measurements are

somewhat tricky

in that they can be impacted by

reflections which i can also fix and

you know the science there of how you

measure distortion is

you know it's not the most perfect thing

so don't be horrified about some of

these graphs that you see

so i make two measurements for

um distortion one of them at 86 db spl

the other one is 96. this 96 is similar

to

soundstage network that uses nrc's

anecdotal chamber

for distortion measurements they

reported at 90 i reported at 96 but it's

exactly the same level

um but then i thought when i first

started doing this that

not all speakers do well with

uh are able to produce 96 db spl

so i do one at 86 db so we have both

what's nice about both is that we can

see

whether distortion is proportional to

level or

all of a sudden we have elements that go

nuts

if you will here we actually have very

good

uh distortion in that now you might say

whoa distortion is shooting up above

that but at very low frequencies our

hearing is not very sensitive

so those harmonic distortions that we're

showing in here are not

audible certainly and not at 86 db spl

when we increase volume to 96 db which

is the one on the right we can see the

bass gets worse and that's always it's

like physics

speakers most perfect one is not moving

the moment you move it is voice coil and

magnet geometry changes

and the response is just not as linear

it's the more you push it the less

linear it gets

it's just happier when happiest when you

stop producing sound

so we increase this and so on we can see

all those other peaks in here also go up

but still pretty controlled

there is a peak in here that we

discussed in the forum

um that does go nuts over here

and the people thought it's related to a

resonance of that twitter at 27

kilohertz

and that this measurement i can get

confused thinking that's the second

harmonic

of something at 13 and a half kilohertz

it sounds plausible to me um if it is a

27 kilos resonance then there is no real

audible distortion in here it's

happening above our hearing range

now this you're not going to see this

kind of measurement

elsewhere most people don't show it like

this and nrc certainly doesn't show it

like this

but i find that this kind of distortion

uh as shown as a percentage over here

and it's a linear scale is very

revealing because we can see the small

and we can sort of predict that this is

shooting up the more common display

people have

is uh showing the distortion as an

absolute level

uh together with frequency response so

if i put the two together

you can see you know their relative

scales to each other but

i find that this is a hard graph to

remember it's very busy

and so forth um but we still have our

little peak over here and we have our

base distortion

in crappy speakers this base distortion

could actually shoot up above our

frequency response which means the

distortion is above 100 percent

when that happens i guarantee if you

play anything in this low bass region

that speaker distorts like nobody's

business

so it's good when there's a gap in here

between these two

um i have made an arbitrary decision to

have 50

db as the threshold for fantastic

speaker don't ask me to justify

it just is and great speakers come very

close

and you can see in here above 100 hertz

this speaker

essentially uh has no distortion and if

this is not real then

you know from 100 hertz uh on this is

extremely good distortion

distortion comes in base low base and it

just is no way around it other than much

larger speakers many more drivers they

don't have to move as much

so when i've measured tower speakers

they're properly designed

these distortions are lower but this is

a small boss got one driver and it's got

to move and the more it moves

the more uh distortion we get okay so

overall

we're 90 95 good good news over here

the next um display

the graph is a pretty critical one it

says if we keep the

loudness the same what will how

wide what happens to the width of a

of that level an ideal speaker that just

sends a shaft of

sound to you with no variation

based on frequency will will look like

these two lines over here

we don't have an ideal speaker here but

we have a darn good one

and we can see this red curve which is

where

sound drops off 6 db is almost hugging

my two ideal lines in here

they're not symmetrical because when i

measure the speaker i can't always align

it perfectly so

assume that they are symmetrical so this

is a response to a very good speaker

what does this mean in practice means

i can go to the left and i can go to the

right

and have the sound drop off 6 db yet

tonality won't change and that's a cool

thing in a

in especially in a near field setting

where you're you know mixing recording

editing

sound and you're going to move around

left and right the client may be sitting

next to you

and you want everybody to hear the same

sound you don't want all of a sudden the

highs to drop off like a rock

when you move a few and just left and

right so horizontal directivity is very

important it's called directivity which

means

how's the sound being controlled and

that wave guide that i talked about

causes this middle region to be so

perfect and so nice

so it means the handout from woofer to

the twitter is

essentially perfect and the nice thing

about getting this

and if i go out i can also show this as

a heat map contour thing and you see the

same thing

you see this you know red area is the

loudest sound and you can see how smooth

this

is and what's nice about is that when

you get this kind of

sound it means that the speaker

is what i call room friendly because the

reflections have the same tonality as a

direct sound

it's okay to have reflections and side

reflections actually could be beneficial

from a

reference point of view because they'll

take a speaker and broaden

its its location and what that does is

that instead of sound coming from one

little point source

comes out of a sort of a wider region

between it

and and the wall and the spatial quality

is something that people

like in controlled settings in studios

people tend to absorb all the

reflections but just know that you have

the option of not absorbing reflections

unless they're needed and if you go back

to my previous graph in here

you can actually tell which reflections

you want to absorb which ones you don't

a ceiling bounce in here is the red one

you can see this dip that we have we

prefer to not have a dip

what's the cause of the dip is because

the ceiling response is pretty weak in

this area

so sound shooting up from this guy going

up is a little weak

in this region so if you can put an

absorber on your ceiling or have a tall

ceiling

that means you'll have less of this dip

most of the time i find that the floor

bounce

blue is a problem you can see the floor

balance also goes down

and is also responsible for that so in

99 cases

i recommend having a thick carpet on the

floor uh shacky carpet or something with

some depth to it because you're trying

to absorb frequencies from thousand

hertz up

and you need about one or two inches

there for effective absorption there

so most of the time you want to have the

floor reflect

absorbed and if you can with the ceiling

do the same

rest of the reflections on this speaker

are so good

there's no reason to absorb them you

know and indeed if you absorb too much

you wind up building a very dead room

that's

not good for enjoyment of music now

this is horizontally we're measuring the

you know what the reflections are

on each side we can also measure

reflections

up and down and that's how we determine

what the reflections look like for

ceiling and floor

and there we see the pictures still

quite

good for a two-way speaker two-way

speakers tend to be quite chewed up

and this guy is very very smooth except

for this hole that it has

and you know sometimes with all these

crab eyes or lobster eyes

and these you'll see so there's a hole

in here that says look

if you go too far above the speaker or

too far

i mean twitter well actually the

reference axis for this is right at the

edge of the woofer

if you go too far above this or too far

below

this you're you fall in these two

ditches and the moment you fall into

those two ditches

at two kilohertz you'll get a much more

pronounced dip

and you don't want that obviously two

killers super important

uh audible range and you don't want to

have a dip so if we look to the left in

here we see

that if you you can go above 20 degrees

up

and about 30 degrees or 40 degrees

low and you're still okay so general

advice for this thing should be that

it's at ear height

that way if you slouch a little bit and

you go up a little bit it's still

cool if it's placed much higher than

that tilt them down

so that the on axis is sent to you

so know that the on axis is the cleanest

sound and it is for most speakers

so if you're going to tilt the speaker

some other way know that you're not

listening to the best sound of the

speaker

a few speakers of design where the off

axis is better

usual because of some pla flaw on access

and they want you to tilt a little bit

but as a general rule speakers should be

tilted directly at you

and if you don't like the tonality use

equalization to fix it

but here you have as much freedom as you

can get the only speakers that are

perfect

um in this regard are coaxial

versions and indeed general like higher

end ones use coaxial drivers with

twitter

sitting inside the woofer so whether you

look at it vertically

or horizontally it makes no difference

we have this problem because as we go up

or down the

time difference between these two

changes

and how they add up and subtract changes

whereas horizontally the two are the

same distance

and we get a much better nice response

when the

twitter's inside the drive woofer then

it's a coaxial thing

and uh you know tracks well now

just making a coaxial driver doesn't

mean the sound is better

there might be other compromises power

capability

and there might be other issues sticking

a twitter inside a woofer that's moving

has can have its own problems general

ones are done extremely well and i've

reviewed those but

don't just assume that you want a

coaxial driver it's uh

it's got a stronger marketing message

than a technical one

the design has to be right i also run a

waterfall

this display can be extremely misleading

and i don't show it for

non-active speakers i know that i can

muck with the parameters of this and

make the display anything i wanted to

show

i do tune it a little bit so in this

case we see the port resonances that

we'd seen earlier but other than hmm

that's all you want to go past this

that's the

this waterfall display people fall in

love with it because it's so pretty

but know that it's prettiness factors

far more than its usefulness

um the hardcore objective is on a sr

forum don't like the fact that i listen

to speakers

they say the measurements say everything

as much as i i've measured on 140

speakers

in in 14 months so i'm quite trained

to what speakers sound like because i

listen to them so often and i'm always

comparing measurements to listening

tests

but i tell you though there are things i

listen for in lesson tests that

not measured and um i always say

electronics are 100 valuable the

measurements are

speakers are about 80 90 percent uh

measurements predict the final outcome

and

headphones are about 60 to 70 or maybe

80

so depending on the headphone uh the

measurements may be

excellent that may be you know not so

excellent

and therefore you got to fill the gap

with something and i filled the gap

with speakers and headphones by

listening

and uh you can ignore it if it really

bothers you and you say

i'm all about objective stuff and all

about the graph

more parity ignore this section but

i want to be the person that does a

sanity check on the measurement say okay

you know we have this frequency response

and it's got these

you know little imperfections in it are

those audible are they not audible do

they need fixing

and if they need fixing i build

equalization for it and then i'm able to

turn the filters on and off instantly

and i can quickly determine whether i

like to sound

with them on or without them you might

say well you're biased maybe you like

something and you don't all right you

can do the same thing you should set up

the same eq you turn them on and off if

you

see that they improve sound then great

you have i've already done the work for

you

and by the way i don't go correct every

little niggling things i correct major

errors

in this case i turn on this genelec and

play my reference list i have a revell

system so on two speakers

and i'll have a long list of tracks that

i think are great

demo material i'll run them against this

just as beautiful two different

companies with two different brands two

different products two different

approaches

yet they both follow the same research

that says hey make on axis flat

and make all faces as similar as you can

to that when you do that the same music

sounds just as beautiful and just as

familiar to me so to me

uh close my eyes i may tell you that's a

reveal speaker is not a generic

that's the beauty of standards that's

the beauty of research

so in this case one of you cases where i

turned it on

sounded great i said hey why even bother

doing an eq now normally that would then

say that i'm going to give it my highest

ranking which will be the golfing or the

soccer

panthers in the review but you didn't

see that you saw the one that says i

like it

why is that right when i was gonna

finish and go take pictures of the

speaker

i got to a bass heavy track and i turned

it up and i was like whoa

what is that what is that i noticed that

the uh

a bass drum hit would be boom at low

volume

then it would go at a little bit higher

volume and if you turn the volume way up

you go

sorry i can't repeat the sound any

better than that but basically if it

felt like a

feedback loop where the bass is trying

to go up and someone's pulling it down

and letting it go up let it go

up instead of one clean bass hit

it would go and the more you pushed it

the louder it got

the worse the distortion was quite

audible this is not some oh it's a

placebo effect no there's nothing

i mean it's just you just crank it up

now granted this was loud volume

and i'm only listening to one speaker

with two speakers would be twice as loud

so i wouldn't have to crank it up

so i would say at low to medium then to

moderately high level

you're not going to have this issue but

it doesn't have limitless power

and that's the number one failure i'll

find in most powered monitors

is that they have this limit i think

it's mostly due to amplification

and limiters they put in there and

indeed the clipping light that

turns red on this and it did exactly

that so

when i heard the distortion except for

the slight amount it wouldn't come on

but the moment i turned it up to even a

little bit past that

that light would blink and during my

testing at 1960 vspl that distortion

thing and low frequency that

light came on solid and you shut off so

in my view the amplifier in it is not

powerful enough

uh you need a subwoofer luckily if you

just roll it off

past 40 hertz i'm below 40 hertz 10 is

happy

so you know you just need a sub to fill

in that sub base area

which i value a ton you may not and

so it is not what i call the ideal

speaker

um i've tested one or two speakers or

ideal actually the

jbl 708p is the first powered speaker

i've tested that has no limit meaning as

much as i like loud

sound fantastic and deep bass

i could not get that speaker to bottom

out um

whereas this one i did so generic makes

larger

speakers more powerful ones they have

some insane looking ones

so obviously they don't want to have

this little guy

be you know everything uh even if they

could

so and part of that maybe this class ab

amps are just

anemic they have the power rating but i

don't trust their power rating i think

they're saying is

150 watts or so 150 what what i mean is

it's at a peak power some fake number

what distortion i don't know

so anyway um if you don't try to go

nuts with this as far as volume it's a

fantastic speaker

beautiful tonality warm sound

great low distortion sound it's just

fantastic i mean i have no complaints at

all

very good bass by the way when it's

producing without distortion

i mean it's just a great speaker it's

not

cheap it's a building made in uh you

know europe there are

1400 each i think

they go up uh nineteen hundred dollars

each so a pair of them will set you back

thirty eight hundred dollars

but other than max power trying to put

together this kind of performance and

passive speakers will be very hard

i mean to get two speakers to have this

kind of performance and amplifiers to

drive them and everything

is very hard so in general powered

speakers just

rule the world from this size down if

you don't need insane levels

trying to you know match them with

passive speakers very hard

um because you know they just have a

more optimal design they have two

amplifiers

electronic crossovers there's no losses

there

and much more optimized and if you have

dsp in them they just get so

perfect that it's very hard to replicate

that

so anyway this has gotten to be a very

long video almost 40 minutes so

i won't keep going um by the way for

speakers there's a preference score that

gets computed by one of the members

the preference score can misfire is also

not for near field

but it's got a very high score for the

speaker of 6.3 anything in sixes

is essentially state of the art i forget

what our highest number is maybe 6.7

it can misfire i can show you two

speakers

with identical score and you wouldn't

say that they're they're the same

is you know the science is good but it's

not excellent so

i don't compute it for that reason but

for speakers you do want to you know

sort of look at this and

maybe rule out anything that's extremely

poor in in this preference score

okay hopefully you got a good sense of

how speaker

measurements and testing is done by

audio science review

text version of this review is available

and for this and

as i mentioned 130 other speakers okay

hopefully uh you didn't fall asleep

during this video

see you in future episodes bye-bye