View Full Version : Okay! JBL L26 vs L36 comparison. The winner is.......??


sealy
08-06-2012, 11:24 PM
A friend has a pair of both models, so the other night, we decided to do a side-by-side comparison. We tried different combinations of amps, pre-amps and cd players, as well as various genres of music. We listened to both for a good half-hour, making sure that positioning of each pair was precisely the same, vis-a-vis the listening position and room placement. We were surprised by the results.

Bass response(a strength of both models) was about equal, with a very pleasant warmth that made for easy listening. Treble response was approximately equal, although we both agreed the treble was a bit more aggressive on the L36, this despite our efforts to tame it with the attenuator. The deciding factor was the mid range. For whatever reason, the mid performance of the L26 was much smoother and easier on the ears. The mids of the L36 have a "shouty" in-your-face quality that is hard to take. Again, much tinkering with the mid attenuator could not fully resolve the problem. We were in agreement that the mid driver in the L36 is the weak link. I wish that we were able to map the response characteristics of the L36 in order to validate our perceptions.

The L26 was the winner, in our opinion, with a more cohesive sound that was easier to listen to for the long-term.

As an interesting aside, we experimented with replacing the existing LE-25 tweeters in the L26s with some tweeters from the AR 93. The results were fascinating. With the AR 93 tweeters installed, clarity improved noticeably. The AR tweeters also proved a very good match in terms of efficiency.

I'd be glad to hear any comments or observations.

Zonker92
08-07-2012, 12:30 AM
I've owned both models and if memory serves, your observations are similar to mine. Troels Gravesend basically converted some L26s to L36s with fancy crossovers and bracing, and his testing showed a strong midrange peak on the LE5 midrange driver. He worked hard to tame it. The LE25 tweeter did quite well with a waveguide he made for it.

http://www.troelsgravesen.dk/JBL-L26.htm

http://www.troelsgravesen.dk/JBL-L26-3way.htm

Check out his crossover designs and cabinet work!

mech986
08-09-2012, 02:00 AM
Interesting observations. Many people feel JBL did nice work with smaller and medium size two way systems. The 4430 is one of the biggest two-way monitors they ever built.

Seems that Troels built a nice crossover for his custom system.

fisheric
08-11-2012, 12:58 AM
I've been parting out my L26s. For my taste the midrange was lacking.

Zonker92
08-11-2012, 01:02 AM
Ouch. Parting out vintage JBLs just hurts me, although I once did that to a clean pair of L100s. I still regret that.

I dig my L26s. Gotta recap them one of these days.

fisheric
08-11-2012, 01:57 AM
really. I dont know a whole lot about vintage hifi, but I was under the impression these speakers were not very desirable.

Zonker92
08-11-2012, 02:13 AM
The L26 is pretty low on the vintage JBL totem pole. The L36 is only a little higher. Neither is much sought after but I regard both fondly, as do some others around here. :shrug:

(I bought my L26s in minty condition on Craigslist for $100 after they'd been listed for a week or more. Not exactly in high demand.)

GordonW
08-11-2012, 09:17 AM
In the spirit of experimentation... one thing folks might want to try, is substituting the tweeters from a set of early Genesis Physics speakers (the EPI-like inverted domes, with the big square face plates) into an L26. It's virtually a drop-in fit (at most, you might have to file the corners of the tweeters, or clearance the hole in the cabinet for the corners of the Genesis tweeter magnet- but the screw holes even line up!).

That seemed to work VERY well with an L26, that we use for a video room center channel speaker for Anime Weekend Atlanta. We've had that speaker in use like that, for many years, now...

Regards,
Gordon.

fisheric
08-11-2012, 01:57 PM
In the spirit of experimentation... one thing folks might want to try, is substituting the tweeters from a set of early Genesis Physics speakers (the EPI-like inverted domes, with the big square face plates) into an L26. It's virtually a drop-in fit (at most, you might have to file the corners of the tweeters, or clearance the hole in the cabinet for the corners of the Genesis tweeter magnet- but the screw holes even line up!).

That seemed to work VERY well with an L26, that we use for a video room center channel speaker for Anime Weekend Atlanta. We've had that speaker in use like that, for many years, now...

Regards,
Gordon.

I may try those out. One of the reasons I parted them out is because I refinished the cabinets and wanted to do a DIY 2 or 3 way.

Chris Brown
08-11-2012, 02:25 PM
Without having seen a frequency response graph for either speaker, I'd guess that the L26 has more of a recessed mid-range compared to the L36 (due obviously to the removal of the mid-range driver).

This should have almost the same effect as if someone had adjusted the bass and treble knobs on their receiver up a bit - something many do anyway.

So in that situation, with both run flat, I can understand why most would prefer the L26. I just wonder if that might change when EQ is added to the equation. If you can use an EQ to get your desired result then that could make the comparison more about the capabilities of each speaker rather than their default sound signature. I just can't imagine that the LE5-6 wouldn't help the speaker come out ahead. They are functionally the same as the LE5-10 mids in my L150s, a much larger and more powerful speaker.

With that said I actually restored a pair of L36 speakers a few years back after acquiring a pair that had car subs in them and then finding a pair of original woofers. I really didn't care much for them in the end and sold them, so it's hard for me to argue much with others negative impressions. In my case however I felt it was the paper tweeter that was the week spot.

Zonker92
08-11-2012, 04:07 PM
The links I posted above contain a wealth of data on the frequency responses and driver performance.

http://www.troelsgravesen.dk/JBL-L26_files/L26_SPL_originalXO.jpg

The 125A driver has a major bump around 2 kHz as we shall investigate later. Blue graph above is with tweeter attenuated to give the flattest response and red is with inverted tweeter polarity. Blue is correct but the reduction of the bump at 2 kHz is really achieved by the tweeter out-phasing the bass driver. Not ideal at all. A deep suck-out just below 2 kHz Hz is the result, which can actually be difficult to hear. The overall sound is better than you would expect. Acoustic guitars sound great but vocals really do not.