JBL L100 Classic Bookshelf Loudspeaker Review - Modern Take on a Classic

JBL L100 Classic Introduction

A lot of things have changed in the home audio industry over the last fifty years. Advances in acoustic engineering, measurement, and manufacturing have propelled loudspeaker design to levels of performance that would have been unthinkable fifty years ago. The science of what comprises a good sound and how to achieve it was still relatively crude back then, although it was much closer to modern standards than the dawn of sound reproduction in the late nineteenth century. Nonetheless, even though audio equipment has improved tremendously over the past fifty years in both performance and affordability, it is much less popular than it once was. Fifty years ago was smack dab in the middle of the “golden age” of hi-fi (read our article: When Was the “Golden Age” of Audio Hifi?). High-fidelity sound systems were far more prevalent in those days, and many middle-class households had some kind of furniture-sized stereo system. In the midst of the audio hobby at its prime came the JBL L100 loudspeakers. JBL had already had some classic loudspeakers before then, for both professional and consumer applications, but in 1970 JBL launched the L100 Century. It would turn out to be THE JBL speaker, their most successful speaker ever released. It was so successful that it made #7 in our list of the top ten most influential loudspeakers over the last 50 years, and became one of the best-selling loudspeakers of the 1970s.

What made its popularity all the more impressive was that it was not a cheap loudspeaker in its day ($273 ea.). Adjusted for inflation, throughout the ’70s the pricing averaged about $1,500 to $2k each in today’s money (time of this writing: February 2021, just in case that sudden inflation hits after the publishing of this article). Few middle-class households would spend that kind of money on loudspeakers these days. Yet the L100 was so popular that it would be the choice of speaker to be used in Maxell’s iconic “Blown Away” ads in the 1980s which enhanced its reputation even more. Many people loved the sound and the distinctive look of the L100 speakers, and they were willing to pay for it. The L100s were more responsible for the rise of the more aggressive “West Coast Sound” than any other speaker, in contrast to the more polite “East Coast Sound” from manufacturers such as Acoustic Research, Advent, and KLH. It was a powerful speaker with punchy bass but wasn’t gigantically-sized among floor-standing speakers of its day. Furthermore, it has a unique look thanks to the “Quadrex” foam grille which made it stand out among typical fabric stretch-wrapped grilles. You can read more about the history of the development of the L100s in the article: Development of an Industry Standard - JBL 4310

So here we are, fifty years later, and JBL has relaunched the L100s. It’s not the same exact design, of course, and JBL has modernized the drivers, crossover, and elements of the cabinet, so while it might have a vintage look, it shouldn’t have a vintage sound. The pricing is in line with the original as well, when adjusted for inflation. It’s a tribute to the classic original, in fact, JBL calls this new one the “L100 Classic”. This is the speaker that we are reviewing today. While the L100 Classic is a speaker loaded with history, I am not going to evaluate it as though it were a historical artifact. The original was a speaker that was popular before my time; in fact, it was discontinued in the year I was born, so I don’t have the nostalgia for it that its design and marketing is partly banking on. How good is the JBL L100 Classic as a modern high-fidelity loudspeaker? That is the question we will attempt to answer in today’s review.

Appearance

The appearance of the L100 Classics is very much a matter of taste, but probably anyone reading this has already come to a conclusion about their vintage aesthetic one way or the other. You either love ‘em or hate ‘em, and few people will be on the fence about them. Personally, I like them, but that could be due to the fact that most speakers I review end up being some variety of a black box and so I am far more receptive to something that breaks out of that mold. Were it not for the Quadrex foam grille, they would simply look like older speakers to an undiscerning eye and not particularly attractive or notable. The Quadrex grille gives them a style that some may find gaudy but I think it is fun and just a bit flamboyant. They are definitely a better fit in the more colorful interior decors of the ’70s than today’s dour modernist interiors. These are speakers with personality that belong in a home with personality rather than the mausoleums that pass for living rooms these days. The L100 Classic is available in a black Quadrex grille for a tamer look, but what’s the point of that for speakers like these which are supposed to be splashy?

One aspect that will draw attention is how the size and shape will determine placement. JBL calls these bookshelf speakers, but that laughably strains the label “bookshelf speaker” (However, in the day of the original L100, many bookshelf speakers were this size). No ordinary bookshelf could fit these speakers, nor would you want to place them in a bookshelf anyway since that is an acoustically compromised location. They are not quite tall enough to be floor-standing speakers unless you have a low seating position like the Maxwell ad guy, but they are awfully big for stand-mount speakers. JBL provides an angled stand for them at an extra cost, and JBL’s stands sort of split the difference between stand-mount and floor-standing. I think JBL’s stand is the best approach aesthetically, but a problem with it from a sound performance standpoint is that most speakers sound best when the tweeter is aimed at the listener’s ear level, and these stands make distance a factor in achieving the best listening position where it wouldn’t if the speakers were placed at a level angle.

The L100 Classics have a real wood walnut veneer for side-paneling, and a matte black front and back panel. Without the grille, the front baffle looks almost totally utilitarian, with a big white woofer mounted under a black midrange, a large port, and a tweeter with a silver dome. There is also a small panel with a couple of knobs for adjusting tonality. This functional appearance is a deliberate stylistic choice, and if you like vintage speaker design, it does have a fashionably old-school look. This look is a design pretension though, and speakers aren’t made like this anymore for several reasons, only one of which being that consumers started drifting toward smaller and narrower speakers over the years.

Design Analysis

We should start our analysis of the L100 Classic’s design by saying it only looks old-school. This is a retro loudspeaker in looks alone, and under the hood, it is all modern loudspeaker technology. Let’s start our analysis of them at the top with the tweeter. JBL uses a 1” titanium dome tweeter mounted in a shallow waveguide with an acoustic lens. The motor for the tweeter is quite substantial and uses a hefty 3 ⅛” diameter ferrite magnet instead of neodymium like so many other tweeters. While iron ferrite magnets need to be a lot more massive to equal neodymium’s magnetic flux, their advantage is that there the much greater volume and surface area gives them a greater ability to soak up and transfer heat, so the motor will be much less affected by thermal compression. The waveguide and acoustic lens should enable the tweeter to hold a more consistent dispersion pattern throughout its frequency band.

Moving down to the midrange driver, we have a 5.25” polymer-coated pulp cone. It has its own sealed compartment that was strongly adhered to the driver frame so I wasn’t able to get a look at the motor. The isolation from the internal air volume of the speaker is a good idea because pressure waves from the bass driver can interfere with the motion of the midrange cone otherwise and lead to distortion. The bass driver itself is a formidable piece with a 12” pure pulp cone held in place by a large cast-aluminum frame and a 3” diameter voice coil. The hefty magnet section consists of two rings adding up to a 1 ⅛” stack with a 7” diameter. This beefy bass driver weighs over 21 lbs., and in order to mount the speaker on my testing platform when I measured it, I removed the bass driver to lift the cabinet onto the platform since it would have been tortuously heavy to do otherwise. A driver like this is doubtlessly capable of some pretty high SPLs.

The JBL L100 Classic 12" Bass Driver with Cast Frame & Massive Motor Structure and Vented Pole Piece

The crossover network is a pretty serious piece, and I counted 15 components on the board with some very large electrolytic and poly film capacitors, resistors, air-core inductors, and an iron core inductor. The crossover frequencies are 450Hz and 3.5kHz using and use 2nd order filters except for the high-pass filter on the tweeter which uses a 3rd order slope. That is a relatively wide range for a midrange driver, and the advantage of that is there won’t be any crossover-related phase changes across this band that is critical for speech as well as most acoustic instruments. Adding further complexity to the circuit are the attenuators which allow the user to adjust the level of the tweeter or the midrange driver. The documentation doesn’t say how much the levels can be adjusted by, but we will see what they do in the measurements section. The L100 Classic does not provide bi-amping or bi-wiring capabilities, and that would probably be a sensible decision given the existing complexity with the attenuators.

The JBL L100 Classic Crossover Network Uses Premium Parts and Large Gauge Twisted Speaker Wire

The enclosure is a fairly sturdy construction with a 1” thick front baffle and ¾” thick side panels and brace. There is a ‘V’ shaped bracing at the midsection to give the enclosure rigidity where it is most needed. There is a thick layer of dacron-type damping material lining the interior sides of the enclosure, which should help to absorb internal pressure waves. JBL tells me it is thicker than normal polyfill/dacron and so has higher absorption. There are no feet attached to the cabinet. If the user wanted to add feet, I would recommend adhesive rubber dome feet so as not to alter or mar the cabinet itself. The grille frame is very solid, so these grilles won’t break easily if unattached, although they may contribute to some diffraction effects when placed on the speaker. While the foam of the grille is quite thick, it is still acoustically transparent, so it won’t interfere with the sound very much (we will take a closer look at the grille effects when we measure it). The grille is held on by some heavy-duty pegs for a ball-socket, so they won’t break off easily unlike so many cheap grille pegs. Low-bass is abetted by a front-mounted dual-flared port with a 3” diameter and a 5 ½” depth. A port with those kinds of dimensions should be pretty resistant to turbulence, but that is needed since the bass driver is certainly capable of moving a lot of air. 

The only really vintage part of the L100 Classic design that could affect performance is the wide cabinet shape, but that is pretty much necessitated as an homage to the original L100 design. There are many reasons why home audio speakers don’t use these types of wide baffles anymore, and one of them is baffle diffraction. Baffle diffraction is when sound waves emitted from the driver reflect off of the corners of the cabinet and interfere with the sound that arrives at the listener directly from the driver. There are a lot of factors that play a role in the severity of baffle diffraction as well as a number of ways to mitigate it even for a wide baffle, so I wouldn’t assume that it is a significant flaw in the L100 Classics. I am merely offering an explanation of the reason why a narrower loudspeaker cabinet with rounded corners is more advantageous than a wide baffle with a sharp angle. This effect wasn’t well understood in the day of the original L100 Century which is why most loudspeakers from that era had a wide baffle with square edges relative to modern speakers.

Looking at the L100 Classic design as a whole, it looks to be a high-sensitivity speaker that modernizes the original and especially capitalizes the ability to use a 12” bass driver. This could be a very good thing, so let’s find out by giving it a listen…

Listening Sessions

In my 24’ by 13’ (approximately) listening room, I set up the speakers with a few feet of stand-off distances between the back wall and sidewall, and equal distance between speakers and listening position. I angled the speakers to face ahead in parallel directions as prescribed by the L100 Classic user manual. The listening distance from the speakers was about 9 feet. Amplification and processing were handled by a Pioneer Elite SC-55. No room correction equalization was used. No subwoofers were used.

Music Listening

A great tool for evaluating a loudspeaker’s naturalness is a recording that has a clean and clear recording of a human vocal. For this purpose, I found a fun new album called ‘Not Your Muse’ by a British singer named Celeste. ‘Not Your Muse’ is primarily R&B but is heavily tinted by soul, pop, and, to a lesser extent, jazz. It is quite a bit more energetic than traditional R&B, and I think it will have broad appeal well outside of R&B. Celeste’s singing is reminiscent of Aretha Franklin, although her voice is a bit lower-pitched. Her singing style resemblance to Franklin is not surprising as she cites Franklin as one of her chief influences. She displays a remarkable range and control over her voice; she has a nicely mellifluous timbre which sounds great whether she is singing with a full-bodied force or whispering softly and everything in between. The production is first-rate and Celeste’s voice is accompanied by jazz bands as well as orchestral players and everything is beautifully recorded.  

‘Not Your Muse’ sounded well-balanced and full from the first track onward on the L100 Classics. Perhaps I was subconsciously expecting a bass-heavy tonality from the sight of those 12” cones, but that wasn’t the sound that I received. The soundstage was large and reached well outside of the positions of the speakers. The imaging wasn’t the most precise that I have heard from the most laser-like loudspeakers. However, it was still good, and Celeste’s voice had a strong position centered between the speakers. Celeste’s voice was reproduced with terrific detail but without being too forward or harsh. Her voice on the recording was so well articulated by the speakers that the aural rendering was nearly photographic; her performance was very easy to picture from this sound. Instrumental accompaniment also sounded nice with a lucid presentation and good imaging. There are many good tracks on this album, and many of them are strong enough to serve as singles. They all sounded great on the L100 Classics and deserve to be listened to on loudspeakers as good as these.  

Moving the human voice to a much wider palette, I listened to a 2019 recording of some of Bach’s cantatas that were performed by the Thomanerchor Leipzig (English: St. Thomas Choir of Leipzig) called ‘J.S. Bach: Cantatas, BWVV 33, 17, & 99’ from the Accentus label and streaming from Qobus in 96kHz/24-bit resolution. It is fitting to have these cantatas performed by the St. Thomas Choir and recorded at the Luther Church in Leipzig since Bach had originally written them to be performed by that group back when he was director of music at that church almost three centuries ago. I couldn’t say how this performance compares to those of Bach’s day, but I can say these are some lovely pieces of music and the St. Thomas Choir gave a gorgeous rendition of these cantatas. This recording nicely balanced the acoustics of the church space with the direct sound of the performers and makes for a great demonstration of classical choral music.

The first thing that struck me about this recording on the L100 Classics is the scale of the performance. It sounded big, although the venue isn’t huge nor are the performers a massive group. I would attribute it to the recording technique as well as the reverberation of the Luther Church. It was a delicate balance of location acoustics and performers, and the L100s were able to recreate these conditions with aplomb. Choral sections covered the width of the speakers giving the impression of front-row seating, and I am sure this was due to close proximity of the microphones to the performers. I also received this sense from the orchestral section which was performed by the Saxon Baroque Orchestra. Individual singers held a well-defined position in the soundstage when performing in solos, duets, and trios. Indeed, this recording would make for a great demonstration of how not to lose precise imaging in large reverberant space. Tonality sounded very good, and the instruments and vocalists all sounded natural and realistic. ‘Cantatas, BWVV 33, 17, & 99’ sounded gorgeous from beginning to end on the L100 Classics. The original L100s might have a reputation for being a rock’n’roll speaker, but on this album, the L100 Classics proved to be just as adept with a more complex and genteel music genre.   

With the announcement of the break-up of Daft Punk, I figured it would be a great moment to revisit a work of theirs that ended up being a classic soundtrack, which is, of course, their score for ‘Tron: Legacy.’ Even today, more than a decade after that film’s release, we still hear elements of that score echoing through modern film and television scores. It is a brilliant blend of electronic and orchestral music and greatly adds to the epic, futuristic tone of the movie. One nifty aspect of the music is that it pays homage to the 1982 movie ‘Tron’ with fat, vintage-sounding synths, so it does have a slight retro-future flavor going on, much like the movie to which it is attached. This music sounds ‘big,’ it is bass-heavy, and it demands to be played loud, so it is a perfect fit for the JBL L100 Classics. How well would the L100s tackle this colossal sound?

Not that I doubted that the L100 Classics could rock, but they killed it with ‘Tron: Legacy,’ and I mean that in a good way. They delivered just the monumental sound that I hoped for in an album like this. The sound was balanced and full-bodied. Daft Punk’s synths sounded great, but it occurred to me while listening to this album on the L100 Classics at a lively level that not enough credit has been given to the orchestral elements for its success. The orchestral sections, performed by the London Symphony Orchestra, were critical to the sound here, and without it, it would not have nearly as much of an epic feel or emotional gravity. Both the electronic and acoustic instruments produced tons of bass, and the L100s handled the low frequencies like a boss. Subwoofers were not missed at all. Indeed, the bass in ‘Tron: Legacy’ made the L100’s 12” woofers sing. The throbbing bass violins, electronic bass, and percussion could all induce that tactile ‘chest rumbling’ sensation that can even elude subwoofers since the L100’s bass drivers were punching at higher bass frequencies than subs are tasked with. The mid-bass headroom seemed to be beyond that of many tower speakers even though the L100s are classified as ‘bookshelf’ speakers (albeit ridiculously so). Hearing the soundtrack sounding this good made me want to watch the movie again. The L100’s dynamic range scaled with the ‘Tron: Legacy’ soundtrack magnificently, and they proved that they could do loud without losing their composure. If you want a speaker that looks like it can rock but actually can rock and do so with finesse, the L100 Classics are a terrific choice. 

For something a bit crazy and rambunctious that let the L100’s stretch their legs in a very different way, I queued up the album ‘Heavy Black Heart’ by the artist Death’s Dynamic Shroud. I always like to throw in something far out that serves as a counterbalance to the more conventional music; I have heard what the speakers sound like with natural, acoustic music, but what about something totally unnatural? ‘Heavy Black Heart’ is certainly that. Death’s Dynamic Shroud hails from the vaporwave genre, but they go beyond just adding distortion to sampled loops from 80’s advertisement music. The album is largely made from sampled pop music but fractured, contorted, and reassembled into something strange, new, and interesting. It is like a psychedelic, self-aware collage of pop music that takes conventional music and puts it through a blender for a hypnotic and fascinating new sound. Aside from the bizarre and wild soundscape it presents, I thought that ‘Heavy Black Heart’ would make for good demo music for the L100s because of the pervasive use of heavy bass throughout the album which should really wake up those 12” bass drivers.

Loading up ‘Heavy Black Heart,’ I had previously left the volume at a rather high level and didn’t realize that this album started with a very loud crash which had me diving for the volume control. This taught me not to underestimate the L100 Classics, and I was certain not to make that mistake again. ‘Heavy Black Heart’ is pure multi-track editing experimentation, and, as such, the soundstage presented is all over the place. It is a recording probably intended more for headphones, but on a capable set of hi-fi loudspeakers, it sounded positively manic. Sounds could image from nearly anywhere in the front hemisphere of my listening position, but it was more than barely-controlled chaos; there was a method to this madness. It was like musique concrete collided with the vapidest modern pop music, and the resulting wreckage sounded great on the L100 classics. They were able to recreate the gonzo soundstages and thump of the bass-heavy passages with a visceral wallop. This music could often have many layers of sound activity that on a lesser speaker might just blend together into anarchy, but the L100s kept everything clear and unambiguous. This was abstract music that you could still tap your toes to, and the L100s managed to convey ‘Heavy Black Heart’s rhythm and thump without losing the sheer weirdness of the sound. There probably aren’t a lot of people shopping for vintage-styled speakers with such avante-garde music listening in mind, but when the speakers and music sound this good, there ought to be.  

Movie Watching

One movie I had been interested in watching but just didn’t get around to was the Netflix release, ‘The Midnight Sky’ with George Clooney. It concerns the efforts of a scientist in the arctic circle who tries to warn a crew of astronauts not to return to Earth because of some global cataclysm that had rendered the planet mostly uninhabitable. It looked like science fiction of a more cerebral type, so probably talky but with some imaginative sound effects. I thought it would be a good opportunity to evaluate speech intelligibility for the L100 Classics as well as an opportunity to catch up on a movie that looked intriguing.

After having watched the film, there were a few more action and effects setpieces than I expected, and that did give the L100’s a chance to shine with something a bit more bombastic. Alaxandre Desplat’s orchestral score was surprisingly tender considering the morose plot, but it could supply some real energy during the movie’s crisis moments, and the L100’s were more than up to the challenge of recreating the physical dread of those sequences. Dialogue intelligibility was never a problem. The L100’s bass ability was made abundantly clear in scenes in arctic storms where the gusting wind made a continuous rumble, and the verve at which the L100’s reproduced those low-frequencies were very much on par with what a good subwoofer could do. While ‘The Midnight Sky’ has some scenes of questionable scientific accuracy, the emotional core of the story was strong enough to help me forgive those sins, and the terrific soundmix as heard on the L100 Classics also helped to make the movie that much more enjoyable.

Another film that I finally sat down to watch was ‘Harley Quinn: Birds of Prey.’ It looked like it would have a rowdy sound mix that would go great with the L100 Classics. The music score was a mixture of rock, punk, and hip-hop, and the sound mix promised lots of limbs snapping, baseball bat violence, and swearing. This is a colorful movie, and these are colorful speakers, so it should make for a great combination. Indeed, they did make a great pairing. ‘Birds of Prey’ had high-energy music from start to finish, and it was a blast to hear on the L100 Classics. One thing that surprised me was how well choreographed the action scenes were. The effect sounds as reproduced by the L100s were as brutal as the imagery. Thumps and thuds from kicking, punching, bat strikes, and hammer blows, gunshots, crashes, shattering glass, and explosions all had a weight and impact beyond that of normal home audio loudspeakers. Speech intelligibility was very good throughout, although sometimes the music drowned out the dialogue, but that was a problem stemming from the sound mix, not the audio system. For the most part, the sound mix was well-balanced and sounded terrific. It was a movie that demanded to be played loud, and the L100s satisfied those demands effortlessly. Even though I watched ‘Birds of Prey’ on a two-channel speaker system with no subwoofers, I didn’t feel as if I had missed anything. I don’t think a surround sound system would have provided much improvement beyond the sound that just a pair of L100 Classics could provide. They had a full, enveloping, vibrant sound, and made for a quite enjoyable time at the movies. 

JBL L100 Classic Bookshelf Loudspeaker Measurements & Conclusion

The JBL L100 Classics were measured in free-air at a height of 7.5 feet at a 2-meter distance from the microphone, and the measurements were gated at a 9-millisecond delay. In this time window, some resolution is lost below 250 Hz and accuracy is completely lost below 110 Hz. Measurements have been smoothed at a 1/12 octave resolution.

The above graph shows the direct-axis frequency response and other curves that describe the speakers’ amplitude response in a number of ways. For more information about the meaning of these curves, please refer to our article Understanding Loudspeaker Measurements Part 1. At a glance, the response is not as neutral as we have come to expect from other modern JBL products like the HDI-3800 which had a terrifically flat response. The major linear deviations occur with a dip at around 1kHz, and two resonances at around 2kHz and 5kHz. The peak at around 5kHz would stand a chance of being glaring - if these speakers were listened at an on-axis angle. However, that is not the way they are intended to be used, so the above graph is potentially misleading. We will discuss this a bit more below.

The above graphs depict the L100 Classic’s lateral responses out to 90 degrees in five-degree increments. More information about how to interpret these graphs can be read in this article: Understanding Loudspeaker Review Measurements Part II. In these graphs, we get a better look at what exactly is occurring at off-axis angles. One thing to note is that some of the resonances don’t quite hold across the front hemisphere of the speaker. There is nothing wildly uneven, however, there is a bit of waviness here and there, and it is angle-dependent. What that means is that this wouldn’t be an easy speaker to equalize with precision. Since the overall response holds to a relatively even baseline, you could do broad equalization with tone controls to control its sound. The front-mounted tone controls are somewhat capable of doing this, and we will show their results below.

The above polar map graphs show the same information that the preceding graphs do but depict it in a way that can offer new insight regarding these speakers’ behavior. Instead of using individual raised lines to illustrate amplitude, these polar maps use color to portray amplitude and this allows the use of a purely angle/frequency axis perspective. The advantage of these graphs is they can let us see broader trends of the speaker’s behavior more easily. For more information about the meaning of these graphs, we again refer the reader to Understanding Loudspeaker Review Measurements Part II. In this graph, one interesting aspect that leaps out is the asymmetry of the off-axis dispersion. We would expect this, naturally, given that the speaker itself is vertically asymmetrical, but it’s still interesting to see how that manifests itself. Much of the asymmetry happens from 600Hz to about 5kHz. Up to 16kHz, this dispersion pattern is actually quite broad. The waveguide on the tweeter is really doing its job in keeping the tweeter from beaming in high frequencies. That only works up to a point, naturally, but that point is so high up in frequency that it scarcely matters anymore.

The above graph compares the on-axis response to the response at 30-degrees which is typically where a listener would sit between the speakers when they are facing forward in a parallel direction. The user manual states that the speakers should be facing straight ahead instead of toed-in toward the listener, and in that case the direct response to the listening position is significantly more neutral than the on-axis response. This is how I listened to the speakers. I had listened to the speakers for quite a while before I had measured them, and I was surprised to see that resonance at 5kHz since I didn’t hear anything like that in my own listening. I am normally pretty sensitive to elevations in response in that area which makes the sound more sibilant. We do see a more peak at 2kHz at 30-degrees, but that may not be much of an offender since stereo crosstalk can often reduce the region around 2kHz from a comb-filtering effect (here is a paper that describes this phenomenon). While early-reflections will also play a big role in the spectral composition of perceived sound, the direct sound is still paramount, so I would encourage users to follow the user manual guidelines on speaker placement for the L100 Classics.

The above graph shows the L100 Classic speaker’s response behavior along its vertical axis where zero degrees is directly in front of the tweeter, negative degree values are below the tweeter, and positive degree values are above the tweeter.  It should be said here that the vertical response isn’t nearly as critical as the horizontal response, so an imperfect vertical dispersion is much less of a problem. This graph tells us that the most neutral response occurs on-axis, with the tweeter facing the listener. However, if you give or take ten degrees up or down from the tweeter, the sound should stay pretty steady. Outside of a +/-10 degree vertical angle, you do start to run into crossover cancellation nulls. What is surprising is how mild these dips are, in fact, many of the vertical angle responses are surprisingly stable for a three-way speaker of this type, especially one using 2nd-order crossover slopes. One possible explanation for this is that all of the drivers are mounted relatively close to each other on a vertical plane, since the drivers’ distance from each other is what exacerbates these nulls. The advantage of such good uniformity of vertical dispersion is that reflections will not differ much from the direct sound, so this is a speaker that will have more benign acoustic reflections from the floor and ceiling.

The above graphs show the L100 Classic speaker’s low-frequency responses that I captured using groundplane measurements (where the speaker and microphone are on the ground in a wide-open area). This is a very flat and well-controlled bass response. I would guess from this graph that the port tuning happens somewhere around 40Hz where the low-end slope becomes steeper. The roll-off looks to start at 80Hz but is quite gradual until 30Hz, so this speaker looks to be asking for just a little bit of help from low-frequency room gain which it will surely get. A flat response down to port-tuning would have potentially yielded a bloated bass-response in-room. Most users in a typical room should be able to count on solid bass down to at least 40Hz and likely a bit lower.

The above graphs show the electrical behavior of the L100 Classic speakers. As JBL states, these are 4-ohm speakers and consistently so out to 20kHz. I wouldn’t advise these to be driven by a budget amp, but then few people who do get a pair will contemplate doing that. We can see from the low-end saddle that the port-tuning frequency is around 35Hz. The much taller height of the first peak in the saddle shape indicates that the bass driver’s resonant frequency is much lower than that of the enclosure. Overall, this is not an especially tough load for a good amplifier, with the minima being just a hair under 4-ohms at just over 100Hz but with a somewhat steep phase angle. Whatever amp the user pairs this speaker with needs to be comfortable with 4-ohm loads, at least for loud listening. I measured sensitivity to be 90.2dB for 2.83v at 1 meter. That is very close to JBL’s spec of 90dB. That is relatively high sensitivity so they can get loud without a huge amount of amplification.

The above graph illustrates the difference that the grille makes in the on-axis response. It is not a completely transparent grille, but it doesn’t change the response that much. The difference is due more to the frame than the Quadrex foam cover. I included this for those who are curious about the effects of such an unusual grille. Common grille effects are discussed in this Audioholics article: Speaker Grilles On or Off: Which Way Sounds Better? 

 The above graphs exhibit the effect that the front-mounted tone control knobs make. Curiously, there is a lot more room to lower the response than raising it for both the mid and high-frequency knobs. The overall flattest response seems to occur with the knobs set to zero as would be expected.

Conclusion

The JBL L100 Classics prove that fun and high-fidelity can exist at the same time. Many other “fun” speakers crank the bass and treble for an exciting sound, but that kind of sound grows wearying fast, and it is no good for content that strives for realism. The JBL’s sense of fun comes from the dynamic range enabled by the design of the unit as well as its splashy retro look. Good sound doesn’t have to come from audio components that look so serious that they would be at home in the inner sanctum of a cathedral. The L100 Classics look like they are good rock’n’roll speakers, but the truth is they are just good speakers for whatever you throw at them.

Let’s now briefly go over the pluses and minuses of the L100 Classics, and, as always, we will start with the minuses. One potential minus of owning them is the somewhat awkward form factor; they are too short for floor-standing speakers but awfully big for stand-mount speakers. As was discussed before, JBL has stands for them that are pretty sensible considering their size and shape, but outside of those, you are going to want a heavy-duty but short speaker stand for them; they need fairly particular stand criteria to work well.

Another minus is that the response isn’t as neutral as other speakers from JBL that can be had. If you are interested in sheer accuracy, the HDI series or 7 Series Reference monitors are a better choice. This is not to say that the L100 Classics are badly inaccurate, but the response is a bit ragged compared to JBL’s designs that aren’t bound to a 50-year old form factor. The L100 Classics are a far more capable and higher-performing speaker than the originals, but some of the design cues that the L100 Classics are obliged to follow from the original L100s do constrain what JBL can do for a performance profile.

One potential minus is an obvious one: the aesthetics are a love-it-or-hate-it deal. Few people are going to see the L100 Classics and be on-the-fence about their appearance. I quite like them but they aren’t going to be an easy fit into homes that are going for an austere interior decor. 

With the minuses out of the way, let’s go over their highlights, the first of which is their sound. The L100 Classics may not measure perfectly, but they sound terrific nonetheless. A look at the basic on-axis response wouldn’t do justice to them, and a deeper look at their overall acoustic behavior gives a better indication of their sound. When used as recommended, they give a full, natural sound that is balanced and open. They have a wide dispersion that makes for a broad soundstage and spacious sound as well providing coverage over a wide area over their front hemisphere. Their dynamic range is on another level from most home audio loudspeakers, so if you want something that can get loud without compression or distortion -especially in the bass range where loudspeakers most commonly begin to exhibit dynamic range limitations- the L100 Classics are a great choice. They don’t need a tremendous amount of amplification to get loud either.

The L100 Classic’s low-frequency extension is very good, and if you enjoy bass-heavy music at loud levels, they will do nicely. The real star of the show here is that 12” woofer; there is not much it can’t do. With port-tuning at around 35Hz, there isn’t much music bass that it is going to miss, even for bass-heavy electronic genres. It is such a capable driver that a normal subwoofer would be more likely to degrade the bass than add, even if it had lower-frequency extension. The reason is that it would take a serious sub to match the dynamic range of the L100 Classic, and an average subwoofer would choke at the kind of mid-bass dynamics these speakers can do in that same frequency range. I would be looking at some of the better subs starting around the $1000 range that could actually make a positive contribution to a speaker like the L100 Classic if you wanted to extend the low-frequency response of the system. I should add that with all the praise of their bass ability, the sound wasn’t bass heavy but rather it could reproduce bass with remarkable authority.

The build quality is very good. The drivers are serious when you examine the motors and overall construction, and the capacitors and inductors in the crossover circuit are real chonkers. The cabinet might have used a couple more braces, but I’m not sure how much good that would have done, and the speaker was already very heavy at nearly 60 lbs (that’s around 27 kg for all you metric-system kids for whom easy division by ten is all the rage).  

The JBL L100 Classic is an eccentric speaker but one that is very easy to enjoy. Older audiophiles who grew up with the original L100 Century speakers are sure to enjoy this new iteration, and younger audiophiles with a taste for vintage styling are going to enjoy the powerful sound. As was said before, it is not a speaker for everyone, but if you have read this far into this review, you surely know where you fall on that divide. I, for one, had a great time with them, and everyone that I showed them too were quite enamored with the unique styling as well as the impressive sound. Since times have changed and so have tastes, I don’t think JBL will see the kind of sales with these that the original L100 had. However, I do think that if more people get exposed to the sight and sound of the L100 Classics, JBL will certainly have another hit on their hands.

The Score Card

The scoring below is based on each piece of equipment doing the duty it is designed for. The numbers are weighed heavily with respect to the individual cost of each unit, thus giving a rating roughly equal to:

Performance × Price Factor/Value = Rating

Audioholics.com note: The ratings indicated below are based on subjective listening and objective testing of the product in question. The rating scale is based on performance/value ratio. If you notice better performing products in future reviews that have lower numbers in certain areas, be aware that the value factor is most likely the culprit. Other Audioholics reviewers may rate products solely based on performance, and each reviewer has his/her own system for ratings.

Audioholics Rating Scale

• — Excellent
• — Very Good
• — Good
• — Fair
• — Poor

Metric	Rating
Build Quality
Appearance
Treble Extension
Midrange Accuracy
Bass Extension
Bass Accuracy
Imaging
Dynamic Range
Fit and Finish
Performance
Value