I tried out the JBL LSR310S studio monitor subwoofer.

When we speak of studio monitors, what many people typically imagine is putting one speaker on the left sides and one on the right side of a display to mix and listen to music. And for most people, a full-range studio monitor is sufficient. I was one of those people. But may famous brands, including JBL, almost always have a subwoofer in their standard studio monitor series.

I figured I have to try one out!!

So, what differences will there actually be if you add more subwoofers?

I figured the best way to experience this was with the best-selling JBL 305P MKII and LSR310S subwoofer.

This is the JBL 3 MKII series LSR310S subwoofer.
Considering the compact size of the 305P MKII, I anticipated a certain size of subwoofer, because the woofer unit was 10 inches. But it was bigger than I expected.
The gloss black panel is cool!!

By the way, the bottom of the subwoofer looks like this.

Four rubber feet and an elegant glossy woofer unit seated in the center. JBL's unique "slipstream" design has a bass reflex port visible on the front, and the downward output from the unit, allows for extended, rich low frequencies with depth.

The connections are very easy -- place the LSR310S between the studio monitors and just connect it to the device that outputs the sound source.

The LSR310S only has two INPUTs and two OUTPUTs. As there are only two of each, there is no confusion related to connections (lol)

Next, I will explain the differences in the output depending on the three types of CROSSOVER that can be selected.
Depending on which type of CROSSOVER is selected, the high-pass filter for the output signal from the LSR310S OUTPUT changes. The important point is that the signal does not pass straight through.

80Hz

Output signal of less than 80Hz from subwoofer

Output signal of greater than 80Hz from OUTPUT

This is perfect when combined with the 305P MKII, 306P MKII, 308P MKII! The manufacturer recommends matching each Volume knob to the same position, and that is exactly as it should be. To explain the sensation, the subwoofer plays the low range and a good balance is maintained, and when compared to when I was listening with only the 305P MKII, the sound was the thicker and more realistic. Also, because the signal being output from the 305P MKII cuts the low-frequency, the upper part of the low range and the mid-high range are also clearer and easier to hear.

XLF

Output signal of less than 120Hz from subwoofer

Output signal of greater than 120Hz from OUTPUT

This setting makes the range of the subwoofer sounds wider than at 80Hz, and further increases the low range. This setting is recommended when listening to or making low-pitched music such as club music. The low range from 5 inches and the low range from 10 inches are completely different. And the comfort-level is different!!!

External

Output signal without subwoofer high-pass filter

Signal is not output from subwoofer OUTPUT.

This is for those who want to cross with more freedom. If you use an external crossover (channel divider), you have the freedom to adjust the slope characteristics and frequency. This is more for experts. As a caveat, the input signal will be output from the woofer as is without passing through a filter, so be sure to use a crossover so as not to damage the unit.

Note that the signal level output from the OUTPUT is not affected by the LSR310S VOLUME.

Personally, I recommend gradually increasing the VOLUME of the LSR310S from zero to your desired sound, or raising the VOLUME to the same position as the 305P MKII to start and then increasing or decreasing it to find your desired sound .

When I set this up in the DTM room in the Sound House showroom, I listened to a variety of genres of music.
Looking at this photo, I think you’ll understand "surprisingly large" feeling I talks about at the beginning.

The result of actually comparing the sounds with and without the subwoofer…

I felt the subwoofer may not be necessary.
But it's better to have one.

I think that’s what it comes down.

For those who want to hear more vivid bass by with their ears and those who want to "feel by vibrations", the addition of a subwoofer is quite effective and highly recommended.