We’ve been emphatic supporters of JBL’s budget studio monitors since we first spent time with the company’s LSR305 active studio monitors in 2014. With a shockingly wide stereo image, seriously flat response, and the ability to reproduce bass frequencies well beyond what we’d normally expect from speakers their size (and price), we’ve been recommending the mighty JBL line to anyone looking for a killer pair of budget studio monitors for years now.
JBL has since refined the speakers to create the new 3-series MkII line. We tried the middle model in the series, the 306P, and we’re happy to report that these speakers are even better than their predecessors — and that’s saying something. As far as we’re concerned, the 306P MkII are among the best sounding studio monitors you can buy at their astonishingly low price point, and even well above it.
Out of the box
Unlike some competitors in the space, which aim to influence sales with flashy boxes at Guitar Center and other big box stores, the 306P MkII arrive in unassuming cardboard boxes — the first indication that the company has pinched pennies wherever possible to put its money into sound quality. Inside are just the speakers and power cables, as well as an instruction manual for each. As with most studio monitors, you’ll need to grab connection cables and a digital audio interface to feed them signal.
Features and design
The jet-black aesthetic of the LSR300 series is dressed up a bit more on the MkII, with shimmering plastic now surrounding the tweeter and woofer of each speaker like a snazzy tuxedo jacket.
In addition to the purely aesthetic change to the front of the speakers, those with a keen eye will notice that JBL has also tweaked the design of its patented Image Control Waveguide technology around the tweeter for an even better stereo image than the LSR305. What looks like a pillow-y cushion cradling each tweeter is actually an extremely precise employment of top-tier acoustic engineering, designed to widen the speakers’ sweet spot.
The plastic surrounding each tweeter and woofer shimmers like a snazzy tuxedo jacket.
The Waveguide tech is one of the biggest benefits you get when you buy an entry-level speaker from a massive audio company like JBL. The technology was first developed for the company’s M2 Master Monitors, which originally retailed for a cool $26,000.
Under the hood, JBL has also tweaked the tweeter and woofer, aiming to provide a more linear frequency response at higher volumes. Each speaker is powered by two 56-watt class D amplifiers (one for each woofer, one for each tweeter), providing a huge amount of volume for such a small-profile speaker. As with the previous iteration, you can get the new 3-series in 5 inch and 8-inch woofer variants alongside a 1-inch tweeter, but the company has also added a 6.5-inch version for the 306P model we tested. It’s a nice middle ground that offers increased bass performance from the 5-inch but is perhaps better suited to smaller rooms than the 8-inch speakers.
The rear of each speaker features a three-prong power input, a power switch, and both XLR and TRS balanced inputs. There are also low frequency and high frequency adjustment switches, which can be employed to adjust for less-than ideal locations — allowing you to roll off a bit of the bass if you place them in corners or directly on top of a desk, and boost or roll off high frequencies, depending on the acoustics of your room. There’s also a volume knob on each speaker, allowing you to adjust volume directly or set them so that they won’t ever go above your desired max volume, regardless of how hard you push the signal to them.
As with most studio monitors, you’ll want to have a dedicated audio interface or other device that can send line-level signal to the speakers via ¼” TRS or XLR cables from your computer or other outboard audio device. We suspect most people interested in a studio monitor style speaker already have one, but there are a number of great interfaces on the market at affordable price points for those who do not.
The Waveguide technology was first developed for JBL’s $26,000 M2 Master Monitors.
We tested the 306P MkII speakers in a home studio (an acoustically treated basement), plugging them into a Presonus Quantum interface via the TRS monitor output section on the back, and connecting the cables to the XLR inputs on the back of the speakers.
The speakers were placed on stands in a typical near-field listening setup — an equilateral triangle about four feet apart and four feet each from the listening position — with the tweeters positioned at ear level. Because of their placement and the room treatment, we didn’t need to employ EQ or high frequency trim adjustments. We set the volume to the halfway position on each speaker for the majority of listening, though we did raise it and lower it evenly on either side at various points during testing.
Just seconds into our first reference track — perennial audio testing favorite The Chain from Fleetwood Mac’s Rumours — we were thrilled with the 306P’s waveguide technology, which offers an extremely wide soundstage that doesn’t exhibit the same high-frequency phasing issues we often notice when moving our heads around the sweet spot with other affordable monitors. In fact, the off-axis performance of the JBLs is pretty incredible, offering relatively flat sound no matter where we moved in the room.
At close range, they project a massive center image, anchoring the gorgeous bass of The Chain at the center of the expansive stereo-panned guitars and vocals.
It’s downright astonishing how flat the frequency response is when the speakers are placed in a properly treated room. Every instrument was vivid and dynamic in the mix, and the speakers offered much stronger bass response than what we typically get from anything in their size or price category. Whether listening to gorgeous lyrical compositions from Big Thief and Amen Dunes, or settling in for an afternoon of rocking out to Ty Segall, we were smitten with the depth and detail offered by the JBL 306 MkII when listening to high quality audio.
But let’s face it, most people are looking at these speakers because they need something with honesty and reliability for mixing music, podcasts, or video audio at home.
It’s downright astonishing how flat the frequency response is.
When used alongside Pro Tools 12 and our interface for mixing, we had a very easy time balancing mixes, adjusting equalization settings, and adding compression, finding that our mixes always translated as expected to other devices and listening settings. Our only gripe was that the speakers had a small amount of amp hiss when in a very quiet room with no sound playing, but that’s to be expected of any powered speakers with this volume potential and at this price point, and it became unnoticeable whenever sound was playing at any volume.
As in most mixing environments, having a balanced room to place the speakers in is a key component to crafting an accurate mix, but the JBL 3-series speakers themselves were easily up to the task of making excellent mixes with plenty of depth. Simply put, there’s no reason someone with sufficient skill couldn’t mix a fantastic sounding album, podcast, or other project on these speakers. Unlike comparable options we’ve heard in this price category, the 306 MkII are very transparent and honest — just what you need to do proper work that will sound good anywhere.
JBL offers an excellent 5-year warranty on professional loudspeaker products (except enclosures). Amplifiers are warrantied for three years, and enclosures for two. The warranty covers materials and workmanship.Our Take
The JBL 306P MkII are an exceptional pair of studio monitors, absolutely worth buying for content creators who want a more serious window into their audio at an affordable price.
Is there a better alternative?
Frankly, we haven’t heard a pair of studio monitors that perform this well at the $400 price point. That said, those who are interested in a serious pair of project speakers may also want to check out the Yamaha HS5 and KRK Rokit 6 G3, both of which remain popular among home content creators.
How long will they last?
JBL has a very long history making excellent products, and we know countless people who have hung onto their older LSR 3-series speakers for years with no complaints. We expect that to be the same for the follow-up model as well.
Should you buy them?
Yes. If you’re looking for a set of affordable studio monitors to help you make the most of your projects, we can’t recommend anything more highly. These are easily the best we’ve tested at their price point and are just what you need to take your work to the next level.