JBL Synthesis HDI-3800 Floorstanding Loudspeaker Review

Posted on 3rd December, 2020
JBL Synthesis HDI-3800 Floorstanding Loudspeaker Review

Mark Gusew samples a loud and proud floorstander out of California, USA…


HDI-3800 Loudspeakers

USD $5,000

JBL is having something of a purple period right now, producing a diverse range of highly capable speakers at prices to suit many budgets. The HDI-3800 you see here retails for $5,000 in North America and packs three 200mm mid and low range drivers to go with its 25mm horn-loaded compression driver and High Definition Imaging waveguide. If that's too big for your listening room, the company has the slightly smaller HDI-3600 with triple 165mm lower drive units – and there's the HD1-1600 bookshelf model too, plus the HDI-4500 AV centre channel and a powered subwoofer. 

The company is of course famous for its high-frequency compression drivers, which it has made for many years and used in all number of its pro audio speakers. Yet we're now seeing the technology trickling down into far more affordable designs, all of which are engineered at the JBL facility in Northridge, California.

Look closely at the HDI-3800, and you'll see its patented 2410H-2 compression driver up top, set inside the company's HDI waveguide. This high-frequency unit uses a 25mm annular ring diaphragm, made of the same lightweight Teonex polymer diaphragm material seen in JBL's D2 range of transducers, including the legendary 4367. The diaphragm is V-shaped to reduce breakup modes and eliminate time smear, says the company. It can safely handle a lot of power, and is capable of producing explosive dynamics and sustained high volume levels without compression. The shape and geometry of the waveguide is specific to JBL – and Harman International, its parent company – whose engineers popularised horn design. 

Below, the three 200mm low-frequency units have been engineered to have high output levels with very low distortion. Serious drivers with rigid cast frames, they use long-throw voice coils, JBL's symmetrical field motor and flux stabilisation rings, plus copper shorting rings. The cones are made of black anodised aluminium which the company dubs Advanced Aluminium Matrix cones. The general idea is that they're light yet extremely rigid, so operate in a linear and pistonic manner with minimal breakup modes. The bottom two cone drivers are bass-only, working up to 800Hz whereas the upper driver is a bass/mid unit that crosses over at 1,800Hz. The horn-loaded HF unit then takes over.

This speaker measures 1,101x300x418mm, weighs 38kg and should appear elegant in any room. The box's radiused edges give a simple but elegant look. Internally it is heavily braced in strategic places to stiffen up the front baffle. All the drivers, plus the rear-firing port and the binding posts have been recessed into the cabinet to provide a smooth and classy finish. The drive units have a cover plate around the mounting area to hide the fasteners, and the fit and finish is generally to a high standard. The HDI series is available in either automotive quality high gloss black or a walnut real wood satin veneer; my review pair was the latter and looked absolutely immaculate. The front grill is black cloth and attaches magnetically.

Quoted frequency response is a wide 37Hz to 30kHz at -6dB points, and it has a lower than average nominal impedance of 4 ohms, according to JBL. One traditional highlight of this company's loudspeakers is sensitivity, which in this case is put at a healthy 92dB (2.83V @ 1M). This means it should work nicely with tube amps from the 4-ohm tap, or from most decent solid-state designs. For my review, I enlisted the services of the splendid Dan D'Agostino Master Audio Systems Progression integrated amplifier, plus my usual Melco N1A digital server and Oppo 203 silver disc spinner, the latter used as a transport. 


Straight out of the packing carton, the HDI-3800 sounded a little boomy in the bass, but fast began to improve – to the point where I was struck by its transparency and evenness. In terms of soundstaging, it auditions as big as it looks, and it's also highly expressive in dynamic terms, possessing great reserves of power handling. Tonally it's well balanced, and the sound disperses really well into the listening room. Interestingly, the waveguide is really impressive and doesn't sound like a typical horn tweeter.

Get Lucky by Daft Punk is a track that plays to the strengths of this big JBL floorstander, with the driving rhythm resolved very cleanly. As the volume grows, so does the energy, scale and impact of this song, especially in the bass. Yet that tweeter keeps up with the bass all the way, and never feels stressed or becomes harsh. Indeed I found the HDI-3800 to be quite colourful, with a touch of subtle warmth to the upper bass and lower midband. 

One benefit of this is that it helps slightly thinner toned recordings still sound correct, such as that characteristic super-dry seventies rock sound. An old favourite of mine is Joe Walsh's Life's Been Good, and with many modern audiophile loudspeakers, it doesn't seem quite right. Yet hearing it through this JBL proved highly satisfying – it was wonderfully wide-ranging, with a bass punch and excitement that's all too often concealed. Listening to this speaker will make many rethink their preconceptions about how speakers should sound. 

The HDI-3800 is still fairly well balanced tonally, though. The midband is all there but tends not to draw attention to itself by sounding either overly forward or recessed. Instead, this speaker hedges its bets and ultimately wins the day. For example, listening to Anabasis by Dead Can Dance, there was plenty of top-end detail, yet still, the speaker managed to disappear and let the music take over. 

Some JBLs of the past have been a little too well lit – or lacking in subtlety to pull off such a feat, but not so the HDI-3800. Rather, the listener is able to entirely focus on this loudspeaker's obvious fine attributes – including JBL's trademark speed, athleticism and dynamism. This speaker has the ability to make music come to life, thanks to the transient speed of the drive units and ability to go loud at the drop of a hat, so to speak. Also, the sizeable heft from those three 200mm drivers is quite a thing. 

All this means that a pair of these speakers is a good way to annoy the neighbours – listening to John Patitucci play bass on Messaien's Gumbo was quite a thing. The instrument had slam and speed, and the music showed very good rhythmic cohesion and definition, with deep bass extension to complement the expressive mids. On the first pass, Hunter by Björk felt dark and brooding due to the original recording's sheer bass weight, but the innate speed of this speaker meant it was fleet of foot and reproduced the music with oodles of natural agility. 

Another forte of this big speaker is its capacious soundstage that extends well beyond it, making for an immersive, three-dimensional experience. As a pair, they image very well, and it isn't confined to the centre seat, but generous and broad so that anyone sitting anywhere between the loudspeakers gets the full three-dimensional experience. The result is a speaker that in my opinion, is comfortably better than my usual reference, the Revel F228Be. This is an interesting comparison, not least because both brands are from the same Harman International parent company. 

Both are physically similar in size, and both produce a big sound that can go very loud without any distress – yet the JBL HDI-3800 sounded comfortably better in my opinion. For example, the opening piano on Within by Daft Punk was clearly more transparent and cleaner, with better dynamic expression on the bass and kick drum. In isolation, you wouldn't complain listening to the Revel, but up against each other, the JBL has more speed, kick and bass weight. It also extends deeper and has more punch; indeed, it just feels freer to express itself with a broader, deeper soundstage.

A pair of physically smaller Chario Cygnus floorstanders that I had to hand sounded faster, with quicker starting and stopping of notes and the impression of being more of a razor-sharp listening tool. That's the benefit of smaller drivers, although when the music content changed, any rock track with drums and heavy bass guitar sounded much like a utility truck trying to do the work of a semi-trailer. In other words, unlike the JBLs, they really struggled.


A large loudspeaker by most people's standards, and with lots of visual impact, the JBL HDI-3800 is a memorable listen. It's so good at making music come to life that lovers of both classic rock and classical music will find it works for them. The fact that it proves so impressively versatile is its greatest surprise. 

The bulk of this floor standing model may limit suitability for smaller homes – so keep in mind the smaller HDI series designs – but given a larger listening environment, it might astonish you. The sound is fast, tonally pretty neutral and has great dynamics, underlined by an iron fist of a bass that delivers a hefty punch. In the midband, vocals are smooth yet highly understandable – and this happens to make this speaker a no brainer for a home theatre situation, especially in conjunction with the other AV focused models in the range.

Existing JBL fans may be surprised just how sophisticated the new HDI-3800 sounds, and what fine value it is for the asking price. Indeed the Synthesis range has been reborn and is now super competitive. If you're not yet a JBL aficionado, then I strongly suggest you audition a pair and hear for yourself their broad capabilities. JBL has come out swinging and has hit a home run.

For more information visit JBL Synthesis

Mark Gusew's avatar

Mark Gusew

Starting his first audio consultancy business in the early ’80s whilst also working professionally in the electronics industry, Mark now splits his time between professional reviewing and AV consultancy.

Posted in:Applause Awards 2020 Loudspeakers Floorstanding Hi-Fi
Tags: jbl  harman 


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