This review page is supported in part by the sponsors whose ad banners are displayed below
Thus far you’ve heard the testimonials of Kenny the Rogers versus Oscar the Wide. By now you probably have some notion on whether the JB4 (or JB3) could be for you. Before I quietly sneak out, I should let you know what I think of course. The JB4 is not an all-round speaker. It never was intended to be. The biggest disappointment to heathens is that like any widebanders, when fed with the wrong type of music and partnered with the wrong type of amps, it can be shrilly sharp and potentially fatiguing.

Oscar and I both agree that matching the JB4 to single-ended triodes can’t really go wrong. However, even the best possible synergy from JohnBlue’s own TL66 monos and speaker cables (theoretically speaking - I haven’t yet tried their top model), creates no guarantee that you’ll get the best performance from your entire music collection. That really applies to any system but widebanders rather narrow your chances. For strengths, spatial width, depth and imaging solidity are second nature to the JB4 yet careful balancing between left and right channel remains critical to optimize pin-point sharp staging accuracy. In that respect I found the attenuator-fitted TL66 monos  absolutely handy and vocal recordings the best tool.

Jordi Savall’s Invocation à la Nuit [Alia Vox AV 9861 A+B] is not only one such tool but also shows off the very best in the JB4. For instance, “Romance del Conde Claros” and “El Mariner” are two beautiful traditional Catalan songs with colorful arrays of folk percussion instruments – that very natural lower octave energy one swears doesn’t belong to 4” driver but is there. This is the kind of music that never fails to cast a spell over widebander devotees. Yet at all costs stay away from The Rite of Spring and its kind. As I keep stressing, the amp remains the most crucial in the synergy chain. Oscar used a 2A3 amp and preferred the JB3 over the JB4.

With the TL66, I’d definitely choose the 4 over the 3. As I reported in my TL66 review, when I rolled the Mullard EL34, the magic of valve bloom was splendid and brought out the best from the JB4. From my arsenal, the Dared VP-20 was another good match. The 6L6 push-pull amp tends to extend the lower frequencies without turning the highs spiky or the mids sluggish. The KingRex T20 with SLAP! battery power is another decent contender. After all, the JB4 is not that difficult to drive. For speaker placement, the JB4 works better in a long-wall setup with added breathing space on the sides than a short-wall orientation. In both Kenny’s place and my own, the JB4 ploughs a deep soundstage even with just a 12” clearance from the front wall.  

Is it justifiable to pay $1,000 for this type of sound? I cannot answer on your behalf even though it’s competitively priced compared to the Omega Super 5 which boasts a proprietary 4.5” driver and higher 93dB sensitivity at 8 ohms (the JB4 is 89dB at 6). Omega aside, you’ll be facing an even tougher choice between JohnBlue’s proprietary driver versus a Fostex or Lowther where some might carry a much lower price tag like Unity Audio’s Inner Spirit for example. There’s always a psychological threshold when investing into less ‘mainstream’ brands. When I related those concerns to Tommy, he reassured me that JohnBlue has become mainstream in Taiwan and is fast establishing a stronghold in Europe.

Regarding the JB4 in particular, he pointed out that not only had a lot of R&D gone into its 4” driver, the proprietary binding posts are high-purity copper with 10µ” gold plating for signal integrity. According to Tommy, the return signal is critical to the lower frequencies and he entrusts that to his special cable design which is 3 x 1mm multi-strand 6% silver-plated copper in a special winding geometry around a 1mm single-core 6% silver-plated copper wire. Tommy encouraged me to open up the speaker cabinet to see the sound chamber for myself. The cabinetry is of extremely high quality with seamless real wood veneer all around. All sides are 2cm thick MDF and the front consists of a 1.5cm thick inner baffle to which the driver is mounted. Coupling to that is an outer 1cm thick veneered baffle with a circular convex flare shaped like a 4.65” very shallow 'horn'. Inside the sound chamber sports a compact back-loaded horn featuring a unique diffuser panel that forms a partition between front and rear chambers. This partition is crafted from 2.5cm thick MDF with 20 x 2cm Ø holes in a symmetrical layout. It also functions as a sturdy brace for resonance control, quite sophisticated for a compact 7.5”x11.5”x10.5” 13.8 pounder.

All these solutions add up to the sound the designer dreamt to hear. If only you share the same dream...

Condition of component received
: No blemishes on the surface, all internal wiring intact but broken heart and bruised ego suspected.
Final comments & suggestions: LS 3/5a loyalists need not apply.
JohnBlue Audio Art website