In this review, we will be comparing HD4 and HD6, two Powered Bookshelf speakers by Audioengine. Being Powered speakers, they both have built-in amplifiers so you don't need an external power amp or an integrated amp to power them.
Let's have a brief look at the main features
of Audioengine HD4 and Audioengine HD6 first before getting into our more
detailed comparison.
| Key Specs | Audioengine HD4 | Audioengine HD6 |
|---|
| Brand | Audioengine
United States · founded 2005 | Audioengine
United States · founded 2005 |
|---|
| Design | 2-way | 2-way |
|---|
| Built-in amplifier | 60-watt RMS (120-watt peak) | 100-watt RMS (200-watt peak) |
|---|
| Tweeter | 0.75" Soft-Dome | 1" Soft-Dome |
|---|
| Woofer | 4" Aramid | 5.5" Kevlar |
|---|
| Frequency response | 60-22k Hz | 50-22k Hz |
|---|
| Max depth / sample rate | 24-bit / 48 kHz | 24-bit / 192 kHz |
|---|
| Bluetooth | Built-in 5.0 | Built-in 5.0 |
|---|
| Weight | 2.40kg / 5.3lbs | 5.50kg / 12.1lbs |
|---|
| Dimensions (H x W x D) | 9.125" x 5.4375" x 8.875"
231.8 x 138.1 x 225.4mm | 12.375" x 7.1875" x 12.5"
314.3 x 182.6 x 317.5mm |
|---|
HD4 and HD6 are members of Audioengine's HD series of speakers. Below you can find the loudspeakers from this series.
The sections below take each area in turn: drivers, frequency response, physical size and what you get in the box.
Drivers
Both HD4 and HD6 are 2-way speakers.
Audioengine HD4Audioengine HD6
TweeterWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
Audioengine HD4 |
Audioengine HD6 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
0.75-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 4-inch
|
1 x 5.5-inch
|
HD4 features a 0.75" Silk Soft-Dome Tweeter and 1 x 4" Aramid Woofer. On the other hand, the HD6 features a 1" Silk Soft-Dome Tweeter and 1 x 5.5" Kevlar Woofer.
Frequency Response
HD4 has a frequency range of 60-22k Hz whereas HD6 has a frequency range of 50-22k Hz. With a minimum frequency of 50Hz, the HD6 can go significantly deeper on the low side and provide stronger bass compared to the HD4's min frequency of 60Hz.
The graph below depicts how these two speakers compare with the max, min and average Low Frequency values of other speakers in the Bookshelf class in our database.
Low Frequency
Bookshelf Speakers
Neither pair reaches down to 20Hz, the usual definition of full-range, which is normal for speakers of this size. If you want the bottom octave for movies or bass-heavy music, add a subwoofer to whichever you choose. Visit our Powered Subwoofers section to find out more about the available options.
Cabinet Type and Port Position
HD4 has a front firing port whereas HD6 has a rear firing ports. Audioengine HD4's front-firing port gives more flexibility in placement in regards to proximity to walls compared to Audioengine HD6 with its rear-firing port.
Physical Specs
The size of a speaker can sometimes be an important decision factor due to space constraints or in some cases purely for esthetic reasons. In this section, we are going to compare Audioengine HD4's and Audioengine HD6's external dimensions. Audioengine HD4 has external dimensions of 231.8 x 138.1 x 225.4mm (9.125 x 5.4375 x 8.875inch) whereas Audioengine HD6 has external dimensions of 314.3 x 182.6 x 317.5mm (12.375 x 7.1875 x 12.5inch).
Audioengine HD6 is clearly the larger of the two speakers. Its body is 44.5mm wider, 82.5mm taller and 92.1mm deeper than Audioengine HD4.
Size, drawn to scale
Both speakers and both views share one scale, so everything here is directly comparable. Hover a box for its dimensions.
One scale for both, standing on the same surface and pushed back to the same wall, so the deeper one visibly sticks out further.
Audioengine HD6 needs about 86% more floor or shelf area. Audioengine HD6 is 92mm deeper, so it stands that much further out from the wall. Audioengine HD6 is 83mm taller.
Base Surface Area Comparison
Base surface area of a loudspeaker may become a determining factor when the space in your room or desk is limited.
The base surface area of the Audioengine HD4 is approximately 311.3cm2 / 48.3inch2 and base area of the Audioengine HD6 is approximately 579.8cm2 / 89.9inch2. The HD4 requires 46% less surface area than the HD6 which gives it a small advantage on placement in tight spaces.
Weight Comparison The weight of a loudspeaker can become an important factor if you need to move and reposition the unit often. Weight of a speaker can also "sometimes" be an indicator of the rigidity of the enclosure and the quality of the internal components used. The Audioengine HD4 weighs 2.40kg / 5.3lbs and the Audioengine HD6 weighs 5.50kg / 12.1lbs. This makes the HD6 129% heavier than the HD4.
Here is a comparison of how HD4 and HD6's weights compare with the average, max and min weights in Powered Bookshelf class.
Weight
All Bookshelf Speakers
What's in the Box of Audioengine HD4?
Here are the items that are included inside the box of HD4:
- Powered speaker
- Passive speaker
- 2 Grilles (pre-installed)
- 6-feet AC power cord
- Bluetooth antenna
- 5-feet microUSB-to-USB cable
- 6.5-feet Speaker cable (banana connectors on each end)
- 5-feet Stereo minijack cable
- 6-feet Stereo RCA cable
- 2 Microfiber speaker bags
- 2 MIcrofiber cable bags
- Quickstart Guide
- Product Line Brochure
What's in the Box of Audioengine HD6?
Here are the items that come with the HD6:
- Powered speaker
- Passive speaker
- 2 Grilles (pre-installed)
- 6-feet AC power cord
- Bluetooth antenna
- Remote control
- 13-feet Speaker cable (w/ banana connectors on each end)
- 6.5-feet Stereo minijack cable
- 2 Microfiber speaker bags
- MIcrofiber cable bag
- Quickstart Guide
- Product Line Brochure
 Port Position |
Front
vs
Rear
|
Gives more flexibility placing close to walls |
 Height |
231mm
vs
314mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
311cm2
vs
579cm2
|
Takes less floor space |
 Price per pair* |
449USD
vs
699USD
|
costs less (*prices may change depending on the seller, location and time) |
 USB Port |
microUSB
vs
No
|
USB port adds flexibility |
 Headphone Output |
3.5mm
vs
No
|
Connect your headphone |
 Woofer Size |
5.5 inches
vs
4 inches
|
Larger woofer |
|
Low Frequency Response |
50 Hz
vs
60 Hz
|
Generates deeper bass |
 Digital Input |
Optical
vs
No
|
Connect digital inputs directly |
| General |
Audioengine HD4 |
Audioengine HD6 |
| Brand |
Audioengine |
Audioengine |
| Speaker Type |
Powered Stereo Speakers |
Powered Stereo Speakers |
| Frequency Response |
60-22k Hz |
50-22k Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
60-watt RMS |
100-watt RMS |
| Watts Peak (Max) |
120-watt RMS |
200-watt RMS |
| Max Bit Depth |
24-bit |
24-bit |
| Max Sample Rate |
48 kHz |
192 kHz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
4" |
5.5" |
| Woofer Composition |
Aramid |
Kevlar |
| Tweeter Size |
0.75" |
1" |
| Tweeter Type |
Soft-Dome |
Soft-Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Firing Direction |
front |
rear |
Physical Specs |
|
|
| Height |
231.8mm (9.1") |
314.3mm (12.4") |
| Width |
138.1mm (5.4") |
182.6mm (7.2") |
| Depth |
225.4mm (8.9") |
317.5mm (12.5") |
| Weight |
2.40kg (5.3lbs) |
5.50kg (12.1lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Available Colors |
Black, Walnut |
Black, Walnut, White, Cherry Wood |
| Mounting Bracket |
No |
No |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Aux Inputs |
3.5mm, RCA |
3.5mm, RCA |
| USB Port |
microUSB |
No |
| Phone Input |
No |
No |
| Subwoofer Output |
Wired |
Wired |
| Digital Input |
No |
Optical |
| HDMI Input |
No |
No |
| Headphone Jack |
3.5mm |
No |
| Ethernet Port |
No |
No |
Other |
|
|
| Parts Warranty |
3 Years |
3 Years |
| Labor Warranty |
3 Years |
3 Years |
Siblings in Audioengine's HD series, so they share a family sound. It comes down to size, output and price.
| Area | Better | Why |
|---|
| Bass | B | Audioengine HD6 digs deeper - 50Hz against 60Hz. |
| Built-in power | B | Audioengine HD6 has the bigger amplifier (100W vs 60W RMS). |
| Connections | B | Audioengine HD6 adds digital inputs. |
| Size | depends | Audioengine HD4 is easier to place; Audioengine HD6 is bigger, which usually goes with fuller bass. Your room decides. |
| Expandability | depends | Audioengine HD4: a sub output; Audioengine HD6: a sub output. |
| Price | A | Audioengine HD4 is cheaper - $449 against $699, about 36% less. |
A Audioengine HD4 B Audioengine HD6
depends neither is better in the abstract - it turns on your room, your system or how you will use them. Only specs published for both speakers are judged; anything missing on either side is left out rather than guessed.
Which should you choose?
The usual trade-off: Audioengine HD6 measures better, Audioengine HD4 costs about about 56% more% less. Whether that gap is worth the money is the call only you can make - and in a normal room it is often smaller than the numbers suggest. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 60Hz anyway, which makes the cheaper Audioengine HD4 much easier to justify. In a large or open-plan room, Audioengine HD6 has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, Audioengine HD4 is the easier speaker to get right.
And remember what a spec sheet cannot show: how each looks in your room and whether the finish suits it, what dealer support and warranty are like where you live, and how they actually sound to you. If you can hear them first - ideally with your own music - that will tell you more than any number above.