JBL L88 new to me

The only "problem" with these speakers compared to the L100 is that the little LE20-1 paper-cone tweeter does a ridiculous amount of the work. In the L88 the LE20-1 Tweeter is crossed over with the 123A-1 Woofer at 2000Hz... With that in mind, consider that in the L100 model that uses this same LE20-1 tweeter, it is crossed over with the mid at 7500Hz, and the Mid is crossed over with the 123A-1 woofer at 2500Hz.

Kinda crazy that the LE20-1 tweeter in the L88 is crossed over with the 123A-1 woofer at a lower frequency than the midrange is crossed over with the 123A-1 woofer in the L100. With the tweeters being responsible for such a large frequency range, you will be asking a lot of them if you play your speakers loud.

Didn't the L100's use the LE25 tweeter? The LE20-1 is the next generation of the LE20 which JBL paired with the D123 and LE14A in several of their 2-way systems of the 1960's.
 
Ok ...so I have had these for some time now. I do like them ......but....I feel there is some mid-range missing. Is there anyway to get some more? (If I worded that rite) I don't want to "add" any holes for more speakers....is there a better tweeter and or crossover upgrade? I bounced them back and forth with some kg4a and I keep going back to the jbl. Maybe a small set of speakers next to them?
 
Turn them upside down and add the ewave waveguide and compression driver. Not a cheap upgrade but very effective (and easy to repurpose). That will move the crossover point to about 1500Hz.
 
I think I can figure out the upside down part...But do you have a link or part #s for the rest? I did google it but there seems to be a ton of variables out there...Is there a place or person that has kits? Any further help would be great...thanks.
 
Start with the "project summary" in the first post of the econowave thread. Don't get lost in the weeds of 16,500 posts.

You want to more or less stick with the original design (Selenium D220Ti compression driver https://www.parts-express.com/selenium-d220ti-1-titanium-horn-driver-8-ohm-1-3-8-18--264-270 the Dayton copy of the JBL waveguide https://www.parts-express.com/dayton-audio-h6512-6-1-2-x-12-waveguide-1-3-8--18-tpi--270-318) and the original crossover http://techtalk.parts-express.com/filedata/fetch?id=1171062&d=1452466360

Note - search the thread for L88, L100, or 123A-1 to see if anyone has a more specific recommendation for modifying the crossover (change L2 and/or C2) to better work with the frequency response of the woofer. The "generic" crossover is a good place to start but it can be improved on (and is miles ahead of the stock L88 tweeter).
 
20180723_225032.jpg So I take it the "block" that the tweeter is in comes out? Where would I put the breather hole?
 
You can move the port closer to the woofer, or even relocate it to the back panel, so long as you don’t plan to push the cabinets back against a wall.
 
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I have some 88s sans tweeters and am considering the Econowave versus using a Heil tweeter. I have access to some JBL 2426 compression drivers but cannot find a crossover that mates it to the horns/ waveguide Zilch recommended and the Lansing Forum site did not provide any good answers. The 123a woofer really needs a crossover and it should cut at 1500hz or less IMO...I guess one could use the low pass off the L 36 and use a robust modern tweeter on up from there.
 
One approach was recommended by Zilch, our not so recently departed JBL aficionado. He plugged the bass reflex port. I did this and felt (subjectively) that it improved the sound. Initially I used the plumbing plug for, I think , 2 " pipes. Measure your port; this plug is in the 2 - 3 dollar range at big box hardware stores.

The econowave project modification, also a Zilch lead collaborative project, is in the $150 range. I have an econowave speaker, as well.

Lots of fun to be had, here.
 
I have access to some JBL 2426 compression drivers but cannot find a crossover that mates it to the horns/ waveguide Zilch recommended and the Lansing Forum site did not provide any good answers.

Unfortunately I think the 2426 was out of production before the JBL Progressive Transition waveguide (part # 338800-001) was introduced so there are no JBL designs to work from. Maybe you could use the (really complicated) HF section from the 4430 or 4425 monitors as a place to start...though it may not be any better than the ewave crossover used with the 2426.
 
One approach was recommended by Zilch, our not so recently departed JBL aficionado. He plugged the bass reflex port. I did this and felt (subjectively) that it improved the sound. Initially I used the plumbing plug for, I think , 2 " pipes. Measure your port; this plug is in the 2 - 3 dollar range at big box hardware stores.

The econowave project modification, also a Zilch lead collaborative project, is in the $150 range. I have an econowave speaker, as well.

Lots of fun to be had, here.

I read in one of those threads that plugging the port decreases the output of the woofer and limits cone movement. Cranking the volume to compensate can potentially damage the voice coil if it can't move as it was designed to do. Can't recall who stated this, it may have been Zilch.
 
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