JBL Reference Series 420: 14 Years New


Today we’re checking out a pair headphones that are old, irrelevant, and well out of production; the JBL Reference Series 420.

Released in 2007, the 420 was the base model in JBL’s Reference Series of headphones. Released at the same time was the 610, a Bluetooth model sharing more-or-less the same design. When in university, I was looking to get a quality set of headphones. In the running were the Bose Triport, some budget Grados, and the JBL Reference 420. The Triports won out and the 420 became a distant memory. I don’t recall how much these were at the time, but with the limited info I can find online they seemed to retail anywhere from 150 to 394.95 USD.

While perusing Facebook Marketplace recently I came across an unopened pair of 420s for only 10 CAD. Memories of that early purchasing conundrum came rushing back, and I scooped them up right away to see what I was missing out on after all these years.

It has been 14 years since the JBL Reference 420 was released. Are they still worth picking up if you can find a set? Let’s find out, shall we?

What I Hear

Note: Like the Bose Triport, the Reference 420’s signature is sensitive to positioning on the head. Slide them back to boost treble and clarity. Slide them forward to soften the treble response. I find this hinders the excellent clarity a bit too much and makes the bass slightly loose, so they spent most of their time in the former position.

The first thing I did was plug the Reference 420 into the Radsone ES100, load up my Favourites playlist on Youtube, and play some League of Legends. After a few games to the sounds of a a varied mix of tracks from pop (Black Eyed Peas – Girl Like Me), to drum and bass (Wilkinson – Afterglow), some 80s synth (Kavinsky – Nightcall), classic rock (Supertramp – Rudy), rap (Sa-Roc – Forever), and a wide variety of other genres, I came away pretty damn impressed. The Reference 420 has held up well and remains a great sounding headphone in 2021.

Treble on the Reference 420 is bright and shimmery. Both brilliance and presence regions sound peaked, with bias leaning towards upper treble regions. Notes are tight and clean throughout with a lean, controlled presentation, mostly free of any splashiness. They hit hard and decay quickly leaving the 420 quite competent with fast, busy tracks that have lots going on up top. The 420 also has an unexpected amount of detail on tap too with fine nuances being picked up a replicated with great clarity. The upper treble peak, at higher volumes or with already bright tracks, can get tiring though so if you’re sensitive to 7k and up, you might want to avoid these.

The midrange is clearly recessed and set behind the treble and bass regions when it comes to emphasis. Despite this, vocals are weighty, coherent, and plenty detailed. Mid-bass does bleed into males vocals somewhat, but not enough to mask what is being said. Female vocals are where the 420 shines though, giving them an intimate warmth that really meshes well with the overall tune. I was also pretty impressed with the 420’s timbre quality. Running through King Crimson’s live album “On Broadway”, instruments sounded accurate and comparable to products like the HiFiMan Sundarw, AKG K553 Pro, and others. Cymbals were a hint metallic which is about as bad as it got. Sibilance is something I find to be an issue with plenty of older headphones, but the Reference 420 is quite forgiving here. It won’t correct it on tracks like Aesop Rock’s “Blood Sandwich”, but it doesn’t add to it which is perfectly fine.

Bass is where the 420 comes into it’s own. Extension is great with the 420 able to provide a pounding, visceral experience on most tracks. This is backed by a prominent mid-bass region that adds warmth and density to the presentation. As noted earlier, there is some bleed into the lower mids that somewhat affects male vocals, but it’s not overly distracting and in my experience does little to take away from the experience. Whereas upper regions are very quick and snappy, bass on the 420 is a little slower, something I appreciate on headphones. It lets the rumble of deep notes linger which comes across more natural to me. Detail and texture are also quite good with grungy bass lines like those from The Prodigy and Tobacco sounding appropriately low-fi.

While they may look like open- or semi open-back headphones thanks to those large silver grills that mirror JBL’s computer speaker designs of the day, they’re closed. As a result, the presentation is fairly intimate with sounds staying close to the head. That said, they don’t lack depth and present tracks in a fairly well-rounded, even manner. Imaging is also unexpectedly good with plenty of nuance as sounds move from channel-to-channel. The Reference 420 also does a good job of keeping individual track elements convincingly separated and individual. While it’s not going replace the awesome experience you get from a good semi-open or open back set of cans, the Reference 420’s sound stage is perfectly competent.

Overall I’m kind of floored at how entertaining and competent sounding the Reference 420 is. Sure, they have a v-shaped signature, but their bass is tight and textured, their mids are lush and coherent, and their treble is full of sparkle and well controlled. While not huge, the sound stage is well-rounded with solid technical abilities. Beyond a bit of mid-bass bleed and some fatigue caused by the upper treble peak at higher volumes and over long listening sessions, I can’t complain. This is still a great sounding set of headphones 14 years after their initial release and is one I’m absolutely going to keep using. If you can find a set in good shape for a low price, get them.

Over The Ear The Reference 420 certainly looks and feels the part of a mid-2000s product. The design is rife with glossy, piano black and chromed plastics that are magnets for dust and finger prints. Within literal seconds of removing them from the package, dust had already settled on the ear cups. It’s actually quite impressive how quickly it happened. Fit and finish isn’t great either. The component plastics that make up the headband are full of uneven gaps. The pivot point connecting the right ear cup to the headband creaks and snaps uncomfortably when in motion. The sliding mechanism is free of any detents so when extending the headband, it’s impossible to match sides reliably. You will also likely need to re-extend on each listening session since there is nothing keeping the sliders at your preferred length. The headband padding is quite plush and while not particularly thick, it doesn’t really matter because the headphones weigh so little at only 170 grams. The ear pads are also fairly thin but again, this doesn’t matter too much. The drivers are slightly angled and the foam is very soft and plush resulting in a very comfortable fit. They fit my tiny head perfectly. It’s too bad the glue holding the pads together completely disintegrated during its 14 year sleep. As a result, the faux-leather exterior has separated from the more plasticky interior, revealing the inner foam. They’re still usable, but I need to hunt down a suitable replacement asap. At least they’re easy to remove, despite four small dabs of glue in the cardinal directions holding them securely in place. Note that in their documentation JBL says the headband and ear pads are real leather. There is no way that’s true…

The fixed cable continues the underwhelming build impressions. With its cloth sheath, it looks and feels quite similar to the cables found on plenty of Marley earphones. Thin, light, a bit stiff, easy to tangle and kink. It’s not great. At least the straight jack is a tiny slab of rubber that will fit into any phone or DAP case with room to spare. The strain relief heading into the ear cup is flexible and long enough to be useful. Even so, I don’t expect this cable to last long, especially if you are somewhat careless with your belongings. This is one that will need to be babied.

The Reference 420’s compact, lightweight design is suggestive of a product intended to be used on the go. To me, that means it also needs to isolate well. Oh boy, does it ever. I don’t know how JBL did it, but the 420 isolates brilliantly. This is pretty easily the best isolating set of headphones I’ve ever used, and that includes some noise cancelling sets like the A-Audio Legacy and the Ultimate Ears UE6000. When walking outside, I make sure to slide one ear cup back to keep an ear free so I can hear cars and other pedestrians. There’s no chance I’ll hear them otherwise. Gotta stay safe out there.

In The Box The Reference 420 comes with the sort of packaging that would be completely unacceptable on a 150 USD product nowadays; bulbous blister packaging. Once you’ve managed to cut your way through this nasty, hard plastic shell, the Reference 420 pops out of a form fitting plastic insert which covers the accessories. In all you get:

  • Reference 420 headphones
  • Carrying case
  • 1/4” adapter
  • Airplane adapter
  • 1 metre extension cable

Overall a pretty mediocre unboxing. Blister packaging is a gift from the Devil and should be banned worldwide. I’m so glad most brands have moved on from this nightmare of a container style. At least it’s recyclable, and I suppose it’s a good for those that only care about the product. It is cheap to manufacture, adds little to the overall cost, and can be recycled. The included accessories are solid thankfully. The 1/4” adapter and extension cable are handy to have for when I want to plug the 420 into my main headphone amp. The airplane adapter is pretty much obsolete at this point, but 2007 was a very different time so I’m sure it was a welcome inclusion back in the day.

Final Thoughts If you didn’t gather by now, I really, really like the JBL Reference 420. While many aspects of the product are extremely dated, from the packaging to the design, materials, and build, the sound quality is what matters most. That without question, holds up very, very well, especially for the 10 CAD I paid. I love the deep textured bass and shockingly good detail and clarity on offer from top to bottom. In addition, the Reference 420 is extremely comfortable despite the odd headband shape, and the passive isolation is like nothing I’ve experienced before.

If you can find a set in good shape and at a price you are comfortable with, go for it. I’d be very surprised if you didn’t enjoy yourself. Just know that at this point the pads will likely have deteriorated and will need replacing, so factor that into the cost. I still have yet to find a suitable replacement, but the stock set are still working well enough, for now.

Is the Reference 420 is still worth picking up? Absolutely. I would love to see JBL update these with some modern conveniences like a removable cable and folding design, and do a time-limited re-release. I have a feeling the retro design, impressive isolation, small size, and excellent sound quality would draw some attention.

Thanks for reading!

– B9

Disclaimer I purchased the Reference 420 second-hand but unopened/unused for 10 CAD on Facebook Marketplace. The impressions here are my own subjective thoughts and do not represent JBL or any other entity. If you want to buy some for yourself, I hope you are well trained in Google-fu and wish you luck in finding a set.


  • Frequency Response: 20Hz – 20kHz
  • Sensitivity: 96dB SPL/mW @ 1kHz
  • Impedance: 32ohms

Gear Used For Testing LG Q70, Earstudio HUD100, Earmen TR-Amp, Asus FX53V, TEAC HA-501

Some Test Tunes

Supertramp – Crime of the Century

Slipknot – Vol 3 (The Subliminal Verses)

Daft Punk – Random Access Memories

Aesop Rock – The Impossible Kid

King Crimson – Lark’s Tongues in Aspic

King Crimson – Starless and Bible Black

Infected Mushroom – Legend of the Black Shawarma

The Prodigy – The Day is My Enemy

Steely Dan – The Royal Scam

Porcupine Tree – Stupid Dreams


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