Acoustic Energy AE 100.2 bookshelf speaker review

[incubus]

Acoustic Energy 100.2 bookshelf speaker review

Since this is my first post and my first measurement of a commercial speaker please be patient with me. English is not my mother language so my text might be bumpy to read.
I have built some speakers myself following guidelines from DIY Hifi magazines available in Germany. So far I am not very happy with the results so I started measuring my speakers.
But I am a beginner and I have found this forum and I am so happy to finally be able to move away from pure subjective description to objective measuring.
Again, this is my first analysis of a commercial speaker and I would be glad if you could give me additional advice on things I can improve.


Tempted by many positive online reviews I have bought a pair of Acoustic Energy speakers: AE 100.2 for 350 EUR (before I found this forum).

Let's find out if they are truly any good using the following tools:

• Focusrite Scarlett 2i2 3rd Gen as audio interface
• DIY cables for impedance measurements
• Sonarworks microphone XREF20 with calibration file
• REW 5.20
• Windows 11 Laptop

SPL far field (1m):

I was measuring in my garden. The speaker box was 1.2 meters from the ground and the microphone was 1m from the speaker pointed at the tweeter.
The first graph represents the measurements without any smoothing, the second graph show psychoacoustic smoothing by REW. My neighbors are friendly people and I would like them to stay that way so I was aiming for roughly 80 db. I only have a Hifi amplifier so I cannot tell the watts it was delivering.

From 60 Hz at 76 db to 2 kHz SPL is fluctuating by 5 db which is acceptable from my point of view.
Looking from 2 kHz until 20 kHz we see a relatively flat response curve rising minimally from 78 db to 82 db.
Bass down to 60 Hz at 76 db is quite good for a bookshelf speaker.


THD :

Okay, I did not drive the speaker hard to really test for distortions. Nevertheless I can provide a cart showing distortion in % including THD and harmonics from 1st to 5th.
THD stays below 2% from 50 Hz to 150 Hz and below 1% from 150 Hz onward which means the distortion is 40 db quieter than the fundamental. I think that's a good value.


SPL near field with psychoacoustic smoothing:

Near field measurements show us cross over frequency at 1.8 kHz which is far from the 2.9 kHz stated by the company. The reflex port shows a nice drop off until 430 Hz, after that SPL increases again until 880 Hz. I have no idea why.


Impedance and Phase

Impedance has lows at 4.4 Ohms and 4.6 Ohms so according to the 80% rule I would call it a 6 Ohms speaker which lines up with the manufacturers specs.
The two peaks are typical for a ported box:
1st peak at 35 Hz
2nd peak at 88 Hz
The bottom between the first two peaks at 52 Hz is the resonant frequency of the box.

The second peak is higher than the first peak. This means that fb < fs.
fb = resonant frequency of box an
fs = resonant frequency of speaker in air

There seem to be resonances (or enclosure leaks) at 356 Hz and 740 Hz. The first one is more prominent than the second one.

Phase has two lows at -41.6° and -54.3° but luckily impedance is at 11 Ohm and 13 Ohm respectively. So load for the amp should be manageable.
I have been driving the speakers with an old NAD 3020i (20 watts @ 8 Ohm) and it got sufficiently loud (80 decibel) in my living room at low power settings (approx. 30%).

Crossover frequency according to impedance curve is at 1.8-1.9 kHz which is considerably lower than manufacturer data stating 2.9 kHz.

Last but not least some additional charts:

Step response typical for a two way speaker:

Waterfall:

Conclusion:
Since I am new to speaker measurement I am somewhat afraid to give an ultimate opinion. I think the speakers are of decent value for 350 EUR for the pair.
Listening to them for a few weeks I did not get tired of them although there is an increase in SPL in the higher frequencies according to the SPL graph.
What do you think of the measurements and my analysis so far. Any comments or suggestions?

 

[AdamG]

Acoustic Energy 100.2 bookshelf speaker review

Since this is my first post and my first measurement of a commercial speaker please be patient with me. English is not my mother language so my text might be bumpy to read.
I have built some speakers myself following guidelines from DIY Hifi magazines available in Germany. So far I am not very happy with the results so I started measuring my speakers.
But I am a beginner and I have found this forum and I am so happy to finally be able to move away from pure subjective description to objective measuring.
Again, this is my first analysis of a commercial speaker and I would be glad if you could give me additional advice on things I can improve.


Tempted by many positive online reviews I have bought a pair of Acoustic Energy speakers: AE 100.2 for 350 EUR (before I found this forum).
View attachment 303149View attachment 303150

Let's find out if they are truly any good using the following tools:

• Focusrite Scarlett 2i2 3rd Gen as audio interface
• DIY cables for impedance measurements
• Sonarworks microphone XREF20 with calibration file
• REW 5.20
• Windows 11 Laptop

SPL far field (1m):
View attachment 303126

I was measuring in my garden. The speaker box was 1.2 meters from the ground and the microphone was 1m from the speaker pointed at the tweeter.
The first graph represents the measurements without any smoothing, the second graph show psychoacoustic smoothing by REW. My neighbors are friendly people and I would like them to stay that way so I was aiming for roughly 80 db. I only have a Hifi amplifier so I cannot tell the watts it was delivering.

View attachment 303127
From 60 Hz at 76 db to 2 kHz SPL is fluctuating by 5 db which is acceptable from my point of view.
Looking from 2 kHz until 20 kHz we see a relatively flat response curve rising minimally from 78 db to 82 db.
Bass down to 60 Hz at 76 db is quite good for a bookshelf speaker.


THD :

View attachment 303129
Okay, I did not drive the speaker hard to really test for distortions. Nevertheless I can provide a cart showing distortion in % including THD and harmonics from 1st to 5th.
THD stays below 2% from 50 Hz to 150 Hz and below 1% from 150 Hz onward which means the distortion is 40 db quieter than the fundamental. I think that's a good value.


SPL near field with psychoacoustic smoothing:
View attachment 303131

Near field measurements show us cross over frequency at 1.8 kHz which is far from the 2.9 kHz stated by the company. The reflex port shows a nice drop off until 430 Hz, after that SPL increases again until 880 Hz. I have no idea why.


Impedance and Phase
View attachment 303132

Impedance has lows at 4.4 Ohms and 4.6 Ohms so according to the 80% rule I would call it a 6 Ohms speaker which lines up with the manufacturers specs.
The two peaks are typical for a ported box:
1st peak at 35 Hz
2nd peak at 88 Hz
The bottom between the first two peaks at 52 Hz is the resonant frequency of the box.

The second peak is higher than the first peak. This means that fb < fs.
fb = resonant frequency of box an
fs = resonant frequency of speaker in air

There seem to be resonances (or enclosure leaks) at 356 Hz and 740 Hz. The first one is more prominent than the second one.

Phase has two lows at -41.6° and -54.3° but luckily impedance is at 11 Ohm and 13 Ohm respectively. So load for the amp should be manageable.
I have been driving the speakers with an old NAD 3020i (20 watts @ 8 Ohm) and it got sufficiently loud (80 decibel) in my living room at low power settings (approx. 30%).

Crossover frequency according to impedance curve is at 1.8-1.9 kHz which is considerably lower than manufacturer data stating 2.9 kHz.

Last but not least some additional charts:

Step response typical for a two way speaker:
View attachment 303134
Waterfall:
View attachment 303137
Conclusion:
Since I am new to speaker measurement I am somewhat afraid to give an ultimate opinion. I think the speakers are of decent value for 350 EUR for the pair.
Listening to them for a few weeks I did not get tired of them although there is an increase in SPL in the higher frequencies according to the SPL graph.
What do you think of the measurements and my analysis so far. Any comments or suggestions?

A very solid and productive start for being new to this Objective Review stuff. Welcome aboard @incubus !

 

[LTig]

Acoustic Energy 100.2 bookshelf speaker review

Since this is my first post and my first measurement of a commercial speaker please be patient with me. English is not my mother language so my text might be bumpy to read.

Wow, what an entrance - welcome at ASR.

There is one wrong conclusion as I see it:

SPL near field with psychoacoustic smoothing:
View attachment 303131

Near field measurements show us cross over frequency at 1.8 kHz which is far from the 2.9 kHz stated by the company.

The crossover frequency is a little below 3 kHz. At this frequency both drivers go down in SPL, the woofer with increasing frequency, the tweeter with decreasing frequency. The tweeter is just a few dB too loud.

The reflex port shows a nice drop off until 430 Hz, after that SPL increases again until 880 Hz. I have no idea why.

These are port reflections resonances (EDIT: corrected).

 

[amirm]

Good work. Promoting to home page.

 

[sweetchaos]

Thanks for the measurements.

Have you seen napilopez's tutorial on How to measure speakers using the Quasi-Anechoic method?

 

[Billy Budapest]

+/-6dB is at 50Hz which is pretty good for a speaker this size. Far field frequency response looks pretty flat. Color me impressed for the price.

 

[Toni Mas]

Thanks for the measurements.

Have you seen napilopez's tutorial on How to measure speakers using the Quasi-Anechoic method?

Agree. Would add that nearfield measurements tell nothing reliable about crossover. Must be anechoic or quasi anechoic connecting drivers in isolation. Sum of drivers changing tweeter polarity can give usefull info if the xover is LR type, showing null at xover freq.

 

[alex-z]

Three things you can easily improve.

1. Put the speaker on a turntable to get directivity measurements.

2. Use a 60Hz tone + voltmeter to set your amp at 2.83 volts for testing. This will make your sensitivity and distortion graphs comparable to other reviewers.

3. Room EQ Wizard can show EPDR alongside impedance+phase with no extra work.

 

[Drengur]

Well done! Thank you for this.

 

[617]

Your English is great, as are your measurements. I would also encourage you to build a rotating platform for directivity measurements. If you gate the impulse response, you can get anechoic data above 300hz indoors.

 

[Deleted member 21219]

I've been a fan of Acoustic Energy for over 25 years, ever since a local retailer (now defunct) carried the Aegis systems.

Thank you for your work!


Jim Taylor

 

[AndreaT]

Nice work. Ugly port resonance, it might indicate a poor design: it seems that slotted ports have more resonances than round or triangular design.

 

[nygafre]

I’ve borrowed these for a week. For the price they are ok-good value imo. Similar to the OP’s findings I did not tire of them as well. But you notice the heightened tweeters, especially when watching movies. They have quite a room-filling sound (in layman terms).

 

[djigibao]

Acoustic Energy 100.2 bookshelf speaker review

Impedance and Phase
View attachment 303132

Impedance has lows at 4.4 Ohms and 4.6 Ohms so according to the 80% rule I would call it a 6 Ohms speaker which lines up with the manufacturers specs.
The two peaks are typical for a ported box:
1st peak at 35 Hz
2nd peak at 88 Hz
The bottom between the first two peaks at 52 Hz is the resonant frequency of the box.

The second peak is higher than the first peak. This means that fb < fs.
fb = resonant frequency of box an
fs = resonant frequency of speaker in air

There seem to be resonances (or enclosure leaks) at 356 Hz and 740 Hz. The first one is more prominent than the second one.

Phase has two lows at -41.6° and -54.3° but luckily impedance is at 11 Ohm and 13 Ohm respectively. So load for the amp should be manageable.
I have been driving the speakers with an old NAD 3020i (20 watts @ 8 Ohm) and it got sufficiently loud (80 decibel) in my living room at low power settings (approx. 30%).

Crossover frequency according to impedance curve is at 1.8-1.9 kHz which is considerably lower than manufacturer data stating 2.9 kHz.

Hi, tnx for test.
I would like to know, how to test Impedance and Phase with REW?
Is there a tutorial or video somewhere?

Thank You

EDIT:
I found something here:

Impedance Measurement

 

[incubus]

Hi, tnx for test.
I would like to know, how to test Impedance and Phase with REW?
Is there a tutorial or video somewhere?

Thank You

Hi djigibao,
I was following the REW handbook and the following guide:
http://archimago.blogspot.com/2019/08/measurements-speaker-impedance-part-1.html

For my audio interface Focusrite Scarlett 2i2 gen3 I needed a diy cable and I built it according to the REW handbook (see pdf below)

I hope that helps.
Kind regards

 

[incubus]

Your English is great, as are your measurements. I would also encourage you to build a rotating platform for directivity measurements. If you gate the impulse response, you can get anechoic data above 300hz indoors.

Thank you for your kind reply.
I have produced a windowed measurement (gated 6 ms) with psychoacoustic smoothing.

 

[ctrl]

I have produced a windowed measurement (gated 6 ms) with psychoacoustic smoothing.

For gated measurements you should not use "psychoacoustic smoothing". The gate itself already causes a severe smoothing in the mid and low frequency range. The "psychoacoustic smoothing" only hides further details or it exaggerated resonances - so don't use it.

From REW doc:

Psychoacoustic smoothing uses 1/3 octave below 100Hz, 1/6 octave above 1 kHz and varies from 1/3 octave to 1/6 octave between 100 Hz and 1 kHz. It also applies more weighting to peaks by using a cubic mean (cube root of the average of the cubed values) to produce a plot that more closely corresponds to the perceived frequency response.

For a better visualization you can use 1/48 or 1/24 smoothing. The CTA-2034-A standard specifies a resolution of at least 1/12 octave - more honest is less smoothing

 

[ctrl]

I have produced a windowed measurement (gated 6 ms) with psychoacoustic smoothing.

Don't want to confuse you, just to avoid possible mistakes, the gate seems to be chosen a bit large - maybe you have additional runtime in the measurement and all is perfect

You measured the speaker at 1m distance and 1.2m height in the garden, then the nearest reflecting surface should have been the ground.

In VCAD there is a toolbox that automatically shows you the additionally time of flight (time window) for the first/nearest reflection compared to the direct sound reaching your measuring mic.

Or you can do it manually with

g = sqr (h² + (d/2)²) ,unit m

and

gate = (2*g - d) / c , unit s

So without additional flight time, the gate should be <= 4.65ms (with 6ms gate the first reflection is included). But normally you can see the first reflection well in the measurement and set the gate accordingly.

 

[DSJR]

Interesting view on the old Aegis models, the ones I heard had a 'ccccchhhhhh' kind of upper mid-lower top colouration compared to their peers of the time.

Thanks muchly for the review and hope the OP keeps going with this. I believe AE took on new design skills ten to fifteen years ago and this I suspect largely bears the results out, the rising tweeter level par for the course I suspect (it's still way better than the almost vicious 'B&W Sting' I've heard in the past from this latter brand).

PLEASE keep going and have fun while you're doing it

 

[Toni Mas]

I am quite surprised by this rising response...