In this review, we will be comparing 4309 and 4312G, two Passive Bookshelf speakers by JBL.
Let's have a brief look at the main features
of JBL 4309 and JBL 4312G first before getting into our more
detailed comparison.
| Key Specs | JBL 4309 | JBL 4312G |
|---|
| Brand | JBL
United States · founded 1946 | JBL
United States · founded 1946 |
|---|
| Design | 2-way | 3-way |
|---|
| Tweeter | 1" Compression Driver | 1" Dome |
|---|
| Midrange | — | 5" |
|---|
| Woofer | 6.5" Pure Pulp | 12" Pure Pulp |
|---|
| Frequency response | 42-30k Hz | 44-40k Hz |
|---|
| Sensitivity | 87 dB | 90 dB |
|---|
| Impedance | 4 ohms | 6 ohms |
|---|
| Power range | 25-150 watts | 10-200 watts |
|---|
| Weight | 10.98kg / 24.2lbs | 23.80kg / 52.4lbs |
|---|
| Dimensions (H x W x D) | 16-1/2" x 10-1/4" x 8-15/16"
419.0 x 260.0 x 227.0mm | 23-1/2" x 14-1/4" x 12"
597.0 x 362.0 x 305.0mm |
|---|
4309 and 4312G are members of JBL's Studio Monitor series of speakers. Below you can find the loudspeakers from this series.
What size room are the JBL 4309 and JBL 4312G speakers good for?
The size of the room in which you are planning to use these loudspeakers is an important decision
factor. Here we have compared their suitability to various sizes of environments considering their size
and max power parameters:
| Listening Environment* |
JBL 4309 |
JBL 4312G |
| Near-field |
Good |
Good |
| Small Room |
Good |
Good |
| Mid-size Room |
Average |
Average |
| Large Room |
Poor |
Poor |
| Very Large Room |
No way |
No way |
(* Approximate Room sizes: Small < 100sq. ft / 9 m2,
Mid-size: 100-220 sq. ft / 9-20 m2, Large 220-400 sq. ft / 20-36 m2, Very Large: >
400 sq. ft / 36 m2.
Average Floor Height: 9" / 2.7m. Typical room sizes differ from country to country, and the actual
listening experience changes depending on floor height, room shape, surface materials, listening
position, speaker locations, etc.)
The sections below take each area in turn: drivers, frequency response, physical size and what you get in the box.
Drivers
One of the fundamental differences between these two speakers is that 4309 is a 2-way design whereas the 4312G is a 3-way speaker. 3-way designs utilize a midrange driver in addition to the tweeter and woofer on 2-way designs. Designing a crossover for a 3-way speaker is a complicated process and generally increases the overall cost of the speaker.
JBL 4309JBL 4312G
TweeterMidrangeWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
JBL 4309 |
JBL 4312G |
|
Driver Setup
|
2-way
|
3-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
1 x 5-inch |
|
Woofer
|
1 x 6.5-inch
|
1 x 12-inch
|
4309 features a 1" Teonex Compression Driver Tweeter and 1 x 6.5" Pure Pulp Woofer with a Crossover frequency at 1.6 kHz. On the other hand, the 4312G features a 1" Magnesium/Aluminium Dome Tweeter, a 5" Midrange and 1 x 12" Pure Pulp Woofer with a Crossover frequency at 640Hz and 5000Hz.
Frequency Response
4309 has a frequency range of 42-30k Hz whereas 4312G has a frequency range of 44-40k Hz. With a minimum frequency of 42Hz, the 4309 can go slightly deeper then the 4312G's min frequency of 44Hz.
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.
Impedance and Sensitivity
4309 is a 4 ohms speaker compared to the 4312G which has a nominal impedance of 6 ohms. Lower impedance speakers, especially the ones that are rated at 4 ohms may put more pressure on the amplifier unit especially when played at high volume levels, so make sure the amp you pair with the 4309 can provide this impedance level.
These two speakers also have different sensitivity levels. 4309 sensitivity is rated at 87 dB and the 4312G's is rated at 90 dB. This 3 dB difference makes the JBL 4312G a more sensitive speaker compared to JBL 4309, hence will play louder with the same amount of watts.
Sensitivity
Bookshelf Speakers
Power Range
Power
range is the range of input power in watts RMS that a loudspeaker is designed to handle. Staying
within that range gives nominal performance; driving the speaker beyond its maximum wattage can damage it.
4312G can handle a max power of 200 watts RMS, whereas 4309 has a max power handling value of 150 watts RMS, 50 watts less than the 4312G.
Note that higher power handling does not make a speaker louder: that depends mainly on
sensitivity and impedance. The calculator below shows how loud each of these actually plays
on a real amplifier.
Which plays louder on your amplifier?
Starting with a popular amplifier - change it to the one you own, or any you are
considering, and watch both numbers move.
Input Type and Bi-Amping / Bi-Wiring
Both 4309 and 4312G features dual binding post speaker terminals for bi-amping or bi-wiring.
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 JBL 4309's and JBL 4312G's external dimensions. JBL 4309 has external dimensions of 419.0 x 260.0 x 227.0mm (16-1/2 x 10-1/4 x 8-15/16inch) whereas JBL 4312G has external dimensions of 597.0 x 362.0 x 305.0mm (23-1/2 x 14-1/4 x 12inch).
JBL 4312G is clearly the larger of the two speakers. Its body is 102mm wider, 178mm taller and 78mm deeper than JBL 4309.
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.
JBL 4312G needs about 87% more floor or shelf area. JBL 4312G is 78mm deeper, so it stands that much further out from the wall. JBL 4312G is 178mm 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 JBL 4309 is approximately 590.2cm2 / 91.5inch2 and base area of the JBL 4312G is approximately 1104.1cm2 / 171.1inch2. The 4309 requires 47% less surface area than the 4312G 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 JBL 4309 weighs 10.98kg / 24.2lbs and the JBL 4312G weighs 23.80kg / 52.4lbs. This makes the 4312G 117% heavier than the 4309.
Here is a comparison of how 4309 and 4312G's weights compare with the average, max and min weights in Passive Bookshelf class.
Weight
All Bookshelf Speakers
 Low Frequency Response |
42 Hz
vs
44 Hz
|
Generates deeper bass |
 Height |
419mm
vs
597mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
590cm2
vs
1104cm2
|
Takes less floor space |
 Price per pair* |
2000USD
vs
2500USD
|
costs less (*prices may change depending on the seller, location and time) |
 Max Input Power |
200 watts
vs
150 watts
|
Handle more power from your amplifier |
 Driver Setup |
3-way
vs
2-way
|
Have a dedicated mid-range driver |
 Sensitivity |
90 dB
vs
87 dB
|
Play louder with same amount of amplification power |
 Nominal Impedance |
6 ohms
vs
4 ohms
|
Less selective with amplifiers |
|
Woofer Size |
12 inches
vs
6.5 inches
|
Larger woofer |
 High Frequency Response |
40k Hz
vs
30k Hz
|
Generates higher frequency |
| General |
JBL 4309 |
JBL 4312G |
| Brand |
JBL |
JBL |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
25-150 watts |
10-200 watts |
| Sensitivity |
87 dB |
90 dB |
| Impedance |
4 ohms |
6 ohms |
| Frequency Response |
42-30k Hz |
44-40k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
6.5" |
12" |
| Woofer Composition |
Pure Pulp |
Pure Pulp |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Compression Driver |
Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
5" |
| Crossover Frequency |
1.6 kHz |
640Hz and 5000Hz |
Physical Specs |
|
|
| Height |
419.0mm (16.5") |
597.0mm (23.5") |
| Width |
260.0mm (10.2") |
362.0mm (14.3") |
| Depth |
227.0mm (8.9") |
305.0mm (12") |
| Weight |
10.98kg (24.2lbs) |
23.80kg (52.4lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Mounting Bracket |
|
|
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
Yes |
Yes |
Other |
|
|
| Parts Warranty |
|
|
| Labor Warranty |
|
|
Siblings in JBL's Studio Monitor series, so they share a family sound. It comes down to size, output and price.
| Area | Better | Why |
|---|
| Bass | evenly matched | Much the same reach (42Hz vs 44Hz). |
| Amplifier needs | B | JBL 4312G is more sensitive (90dB vs 87dB), so it goes louder on the same amplifier. |
| Amplifier match | B | JBL 4312G is the easier load at 6 ohms; the other is 4 ohms and wants an amplifier rated for it. |
| Headroom | B | JBL 4312G takes more power (200W vs 150W) - more in hand in a big room. |
| Size | depends | JBL 4309 is easier to place; JBL 4312G is bigger, which usually goes with fuller bass. Your room decides. |
| Expandability | depends | JBL 4309: bi-amping; JBL 4312G: bi-amping. |
| Price | A | JBL 4309 is cheaper - $2,000 against $2,500, about 20% less. |
A JBL 4309 B JBL 4312G
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?
JBL 4312G leads across most of the measured areas for a fairly modest premium, which makes it the easier pick if the budget stretches. JBL 4309 is the one to take if it does not. In a large or open-plan room, JBL 4312G has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, JBL 4309 is the easier speaker to get right. If your amplifier is modest, vintage or valve-based, JBL 4312G is the safer partner - the other will want more current or more watts to sound its best.
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.