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AKG K391-NC Headphones Review

Tested using Methodology v1.0
Reviewed Feb 26, 2016 at 12:00 am
AKG K391-NC Picture
6.9
Mixed Usage
6.7
Critical Listening
7.1
Commute/Travel
7.0
Sports/Fitness
6.9
Office
6.8
Home Theater
Type In-ear
Enclosure Closed-Back
Wireless No
Noise-Cancelling Yes
Mic Yes
Transducer Dynamic

The AKG K391-NC are a good set of in-ear buds that sound great and isolate the listener really well. Their outstanding noise cancellation and leakage performance are recommended for noisy commutes. The sound profile works well for most music genres, but their in-ear design might not be for everyone.

Our Verdict

6.9 Mixed Usage

Above-average as everyday headphones. They're compact and have a good sound. They can also handle loud environments well, thanks to their great noise cancelling. This makes them versatile enough to use in most situations.

Pros
  • Outstanding noise isolation.
  • Accurate audio reproduction.
  • Very little sound leakage.
Cons
  • Unexciting design.
  • Uncomfortable "in ear" fit.
6.7 Critical Listening

Average for critical listening. Above-average sound quality but the small in-ear buds aren't optimized to produce a good soundstage, which isn't ideal for pure critical listening.

7.1 Commute/Travel

The AKG K391-NC have a great isolation performance, which makes them easy to recommend to anyone who travels a lot or has very noisy daily commutes. They'll reduce a significant amount of ambient noise, and they're easy to carry around.

7.0 Sports/Fitness

Above-average for sports. The AKG K391-NC will easily fit into most pockets, and they're stable enough to run with. As long as are comfortable with the in-ear fit.

6.9 Office

Above-average for studio use. Leakage is barely audible and won't disturb anyone around you even at higher volumes.

6.8 Home Theater

Above-average for home theater use. The AKG K391-NC have no latency but they also have a short audio cable. They have the range to watch TV from your couch unless you have an extension cord for the audio cable.

  • 6.9 Mixed Usage
  • 6.7 Critical Listening
  • 7.1 Commute/Travel
  • 7.0 Sports/Fitness
  • 6.9 Office
  • 6.8 Home Theater
  1. Updated Aug 10, 2017: Converted to Test Bench 1.0.
  2. Updated Feb 26, 2016: Review published.

Test Results

Design
Design
Style

The AKG K391-NC's design is very simple. They look good but are a little unexciting. The control module has a brushed metal finish that's also noticeable on the earbuds. The cable is black and the rest of the accents are a deep gray, matching the AKG branding.

6.5
Design
Comfort
Weight 0.2 lbs
Clamping Force
0 lbs

The AKG K391-NC are as comfortable as you would expect in-ear earbuds to be. The sleeves come in three sizes, so unless your ear canals are unusually narrow or wide, you should be able to get a comfortable fit.

4.9
Design
Controls
Ease of use Average
Feedback Mediocre
Call/Music Control Yes
Volume Control No
Noise Canceling Control No
Talk-Through No
Additional Buttons No

The buttons are in the right place, and the Control Module is small enough to fit any pocket. The in-line remote has a mic and call/music control. No volume up/down.

7.0
Design
Stability

The AKG K391-NC are decently stable headphones. Their in-ear design fits deeply into the ear canal making it hard for them to fall out during moderate physical activity. However, they won't be sufficiently stable for high-intensity exercises, and the control module and long cable can easily get hooked on something and pull the headphone out of your ears.

8.3
Design
Portability
L 4.72"
W 1.18"
H 1.57"
Volume 8.83 inยณ
Stand required N/A

The AKG 491 are highly portable headphones. The in-ear design is compact and doesn't take too much space which makes it easy to transport in a bag or purse. The control module adds a little more bulk than basic passive in-ear headphones but doesn't reduce their portability as they will still comfortably fit into most pants or jacket pockets.

5.5
Design
Case
Type Pouch

The AKG K391-NC come with a soft fabric pouch that will protect the headphones from scratches and doesn't add much bulk. However, the soft fabric isn't waterproof and won't protect the headphones from hard falls or water damage.

7.0
Design
Build Quality

Except for the in-line remote, which feels a bit flimsy, the rest of the headphone has an even and decent build quality.

9.2
Design
Breathability
Avg.Temp.Difference 0.8 ยฐC
Design
Cable
Detachable Yes
Length 5.42 ft
Connection 1/8" TRRS

The AKG K391-NC come with three cables (in addition to the non-detachable part): one USB for charging, and two 1/8" TRRS-TRRS with different plug colors.

Design
Front
Design
Angled
Design
Side
Design
Rear
Design
Top
Design
In The Box

  • AKG K391NC headphones
  • Silicone sleeves in three sizes
  • Flight adapter
  • Two cables for different smartphones
  • USB cable
  • Carrying pouch
  • AKG warranty card

Sound
9.3
Sound
Bass
Std. Err.
1.08 dB
Low-Frequency Extension
13.94 Hz
Low-Bass
-0.83 dB
Bass
-0.76 dB
High-Bass
1.38 dB
7.8
Sound
Mid
Std. Err.
2.88 dB
Low-Mid
4.29 dB
Mid
0.96 dB
High-Mid
-0.53 dB
7.5
Sound
Treble
Std. Err.
3.87 dB
Low-Treble
-0.19 dB
Treble
-0.5 dB
High-Treble
-3.3 dB
9.5
Sound
Frequency Response Consistency
Avg. Std. Deviation
0.1 dB
1.4
Sound
Soundstage
PRTF Error
12 dB
Openness
2.4
Acoustic Space Excitation
1.6
Correlated Crosstalk
-0.06 dB
6.4
Sound
Imaging
Phase Error
161.07ยฐ
Driver Mismatch (Amplitude)
0.61 dB
Driver Mismatch (Frequency)
1.52 dB
Driver Mismatch (Phase)
9.45ยฐ
6.7
Sound
Total Harmonic Distortion
Weighted THD @ 90
2.271
Weighted THD @ 100
20.972
Isolation
8.4
Isolation
Noise Isolation
Overall Attenuation
-22.95 dB
Bass
-17.79 dB
Mid
-18.85 dB
Treble
-33.54 dB
Self-Noise
15.82 dB

They have excellent noise isolation, especially at higher frequencies. Passive noise isolation is very good down to 500Hz. Below that, ANC kicks in, which maintains excellent isolation performance. The only point where they seem to struggle is around 400Hz.

8.4
Isolation
Leakage
Overall Leakage @ 1ft
31.14 dB

Very good leakage performance. The AKG K391-NC leak more around 4kHz, which means higher notes will escape.

Active Features
0
Active Features
Wireless
Type
N/A
Obstructed Range
N/A
Line of Sight Range
N/A
NFC
No
10
Active Features
Latency
Base Latency
0 ms
aptX Latency
N/A
aptX(LL) Latency
N/A
6.2
Active Features
Battery
Battery Type
Rechargable
Battery Life
37.5 hrs
Charge Time
5.5 hrs
Auto-off
No
Audio while charging
Yes
Passive Playback
Yes

The AKG 491-NC have a long battery life but take considerably longer than average to charge. This may be because they use an older mini-USB charging port. Unfortunately, this means you have to charge your headphones overnight which is not always practical. On the upside, they deliver above a day worth's of battery life, and you can use them while charging so they are decent headphones to use at the office or if you have access to a power source while on the bus, train, or plane.

0
Active Features
App Support

No compatible app.

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