AudioAficionado.org - JBL L220 Labor of Love

Good evening friends,
Most who know me here know that I am, and pretty much always have been, a JBL lover. I became hooked as a teenager when I heard a pair of Lancer 99’s at a friend’s house. From that moment, I just had to own JBL…but they were expensive for my young pocketbook. Then in 1977 I managed to snag a new pair of L100’s on sale at a local stereo shop. (what JBL lover here has not owned a pair of L100’s?). I loved the speakers, but of course I was always looking at other JBL offerings. A JBL catalog or other literature was never far from me. I moved to Florida in 1979, with my system in tow of course. In 1982 I spotted a two-page JBL ad in a magazine on the L220. The ad was well written, with a gorgeous photo of these beasts, inviting the reader to come celebrate the L220’s-because “there is no such thing as too much music”. There stood these two beauties featuring a 14” woofer with the signature white aquaplas cone, a 15” passive radiator, a 5” midrange mounted behind a very cool acoustic lens, and an elliptical ring radiator tweeter. The ad also explained that this driver arrangement, with the lens and horn tweeter, placed the drivers in acoustical alignment with each other, as well as in vertical alignment. I had actually seen this ad before-perhaps around 1979 before I moved south. But when I saw it again in 1982, I was mesmerized by it and I HAD to have a pair. The ad said the L220 was priced at $1,750 per pair, but as I checked around I learned that by this time they retailed at $1,000 each. In 1982, this was pretty good change for a pair of speakers. I wasn’t quite 24 years old, and I contemplated how I was going to be able to scrape up $2,000 plus tax for these beauties. I was working on contract as a design draftsman at the time. Lucky for me, work suddenly picked up and we went on pretty heavy overtime. Could I do it now? Then, I got even luckier. A local stereo shop announced a sale on much of the JBL L-series, up to and including the L220. While the newspaper ad described the smaller models as 10” 3-way, 12” 3 way tower (L150) and so on, it simply described the L220 as “massive towers”. The price: $550 each. (!!!). I got right on the phone with that store…the guy explained that they had two pairs of L220 demonstrators that they were selling, as new, for $550 each. He would do a 2-week layaway for me with a $100 deposit. I ran right up there and secured a pair, and then arranged to sell my L100’s to a co-worker. I sold him the L100’s, with stands, for $350. I was on top of the world when I realized I was actually getting these speakers. In two weeks I picked up my L220’s. That was a bit over 34 years ago. I believed then, as I do now, that this was one of the best purchases I ever made. I’ve taken good care of the speakers over the three decades, refoaming as needed, and in 2002 I had the LE14H woofers reconed, as I had done with the passive radiators a few years before that. (My speakers are actually the L220 “A” version, with the LE14H woofer having a heavier magnetic structure and the newer symmetrical field geometry coil gap design. The overall system power capacity was increased from 300 watts per channel to 400 watts per channel). I’ve always considered the design a brilliant one, for many reasons-the acoustical alignment of the drivers, the cabinet’s non-parallel sides, to name just a couple of reasons. Its tower design places the 076 elliptical horn tweeter at an ideal height for the listener. The system’s dimensions work well in my room (the highly revered L300 is too short and too wide to work for me). They sound like big speakers, they have great depth of image, and terrific sound staging. Also in 2002, I acquired a B460 subwoofer, which complements the L220 quite well with its 18” 2245H driver. All three systems are powered by McIntosh MC501 amplifiers.

In this post I’d like to share with you a series of upgrades I’ve performed on this pair of L220’s, over the last three years or so, with the last of the efforts completed last weekend. Firstly, both the PR15C passive radiators and the LE14H woofers have been refoamed (in January 2013 and March 2014, respectively). In March 2013, I upgraded the stock binding posts with WBT Nextgen WBT-0705-cu binding posts. Here’s a shot of the binding posts:

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But the really exciting upgrades have taken place over the last month. On the advice of quite a few JBL fans (including my good friend Dan aka jdandy here on AA), I finally took the step of rebuilding the aging dividing networks. I’ve been thinking of doing this for quite some time, but was a little reluctant for a few reasons. Would it really make a lot of difference? (They say it will…) What if I screw up the systems? What kind of parts should I buy? How much should I spend? There was another issue as well. One of the networks had a faulty L-pad, with a couple of dead spots. That should be an easy fix, but complicated by the fact that the knobs are pretty much impossible to remove (they are pressed on the spline shaft in such a way that you can’t get them off without damaging the back plate). So…I acquired a spare network on eBay, in the hope that this one will have two good L-pads in it. That gamble paid off, upon testing I found it to be good. Next, I settled on a parts plan and budget. I didn’t want to use cheap parts, as the L220 deserves premium parts. While the networks may not have used the best components back in the early 80’s, the design itself was very good, with each network having a compliment of 7 capacitors, 5 inductors, 9 power resistors and 2 L-pads. JBL described the network as having incorporated impedance-leveling and phase-correcting circuitry. I was actually a little skittish about attempting this project. Here is what one of the stock networks looks like:

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I opted to go with premium audio grade, metal film polypropylene capacitors from Audio Cap, Audyn Cap, and Solen. I also decided to replace all of the 10% tolerance power resistors with precision 1% tolerance, 10 and 12 watt resistors. My total cost of parts for the two network rebuilds came to just shy of $700. It could have spent a lot less, or a lot more. But I was least confident that I was going to be doing the L220 justice. I ended up with a total of 10 capacitors in each network, since in 3 cases I had to parallel caps to obtain the correct values. Here is what one of the rebuilt networks looks like:

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This was a marathon project of sorts, taking a total of about 12 hours to complete both networks. I had a sore back from standing too long! To be honest, when I was done, I was probably more concerned that the systems still worked properly (they did!) than I was with audible benefits. Did I hear any benefits? Well, yes I thought so…perhaps a little better bass, and a bit more air. But I wasn’t all THAT excited. But what happened next did, and still is, exciting me A LOT. I knew that these new parts would require some breaking in. People in the know told me 300 hours or more break in time to really hear the differences. I completed the rebuilds on October 29, it is now November 29. Over the last week or so, the systems have improved DRAMATICALLY. Suddenly, it’s like the speakers are in a different league altogether. The mid-bass is much warmer and clearer. The midrange and higher end has much more “air”. The overall sound has a much more palpable character, and the sound staging is fabulous. The already excellent L220 has moved up I don’t know how many notches….and it may continue to do so. I’m actually astonished. I can hear the difference immediately with any recording, or any source. I’m having a lot of trouble now tearing myself away from the system. I simply can’t be bothered with silly things like eating, sleeping etc….even writing this post is keeping me from my music!

And if all this isn’t fun enough, my latest effort puts the cosmetic icing on the delicious audio cake. When I bought the L220’s, the literature stated that an optional brown grille with a cutout for the midrange lens was available separately. There was this little tiny photo showing the version. I always thought this was a cool idea, very unique. But, I had never seen one, ever. Nor had anyone else, as far as I knew. These grilles were very rare, if in fact JBL ever actually produced them (aside from a prototype for the photo perhaps). Over the years I thought about making myself a pair of these grilles. (I used to chat with a guy on Lansing forums who was an L220 nut-he owned 3 pairs. He was making a set, but I never did see how they turned out). I snagged an extra set of grilles (from the same seller I acquired the spare network from), designed a center piece to support the grille around the lens, and had a machinist friend of mine make them up for me. Of course I purchased new fabric as well. Here’s a few photos of the project as it progressed:

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Checking the center frame fit:

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One of the challenges was dealing with the tapered outside corners of the grilles. In order to get this right, I had to develop some CAD flat patterns.

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Ready to start cutting fabric:

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I also removed the lenses for cleaning, and to clean and dress up the area in front of the sub-chamber where the midrange driver resides:

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Things are cleaned up so we can reinstall the lenses....

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And finally….the finished product:

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Between the elevated performance brought about by the rebuilding of the networks, and with the fresh and unique “new” appearance of the systems, I am absolutely thrilled. Once again, I can hardly stay away from the system…playing just one more, just one more, just one more….

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I can tell you one thing for sure. The right decision was made 34 years ago, and my L220’s aren’t going anywhere. Thanks for “listening” to my story….