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Tuesday, June 25, 2013

JBL L26 Finished

The JBL L26 refresh project is complete.

These speakers turned out great, when they were first dropped off we hooked them up and had a hard time getting my thick speaker wire to attach to the original spring post. Also the L Pad pots were sounding pretty scratchy with sound coming out intermittently in one tweeter. These classics would have to wait to be properly auditioned.

After breaking down the speakers, one woofer surround needed to be reattached in one spot.

I started off with sanding the first speaker with 220 grit sandpaper and then using extra fine steal wool. This speaker had a water ring mark on it from a pot. I got most of the ring out but the ghost of it is there to stay. Once sanded the first coat of Minwax was applied.



While the one speaker was curing it was time to do the crossovers. I left the old cap in place and made up a 8.1uf out of 2 poly caps that had a +/-5% tolerance and soldered them in place. I replaced the lead wires with thicker copper replacements. Trying to get into the inductors with all that glue attached was not worth the effort. It is best to leave that sleeping dog lie. The original ALPS L pads are really good and got a thorough cleaning .

The top crossover is finished, the bottom one is original.



I added a gasket to the backside of the crossover to seal any airflow from around the L pad adjuster knob.


The left speaker has had two coats of Minwax and it was time to get started on the right speaker. This speaker had a bit of water damage to it that caused little ripples in the wood grain.



The left speaker has been sanded and is ready for Minwax.


Before reassembly I needed to install proper 5 way binding post.


Re assembled and ready to rock


In good company with other fine classics, Mission 770's and Energy 22's.


So how do they sound? Classic JBL, these are an amazing speaker for their vintage. The bass is full and warm, almost thunderous. JBL always prided their speakers on being loud and clear and these are no exception. They drove my family members out of the room listening to Van Halen's Jump at half volume.

There is a hump around the 2000hz which is clearly audible and brings the vocals forward. It has a resonance sound and it can be a bit brash on some tracks. This characteristic has been referenced on this JBL site. Below is a screen shot from Troels Gravesen site documenting the frequency response.


These speakers are classics in both finish and sound, I can understand the premium they command to today's vintage collector. I will miss their classic sound when they are gone, next JBL's on the list is sourcing a pair of L19's or L16's.


Saturday, June 22, 2013

JBL L26 Decade



 
The Gentlemen that bought my JBL L60T speakers from me dropped off this pair of JBL L26's for a restoration job.

The woofers have been re foamed once so I will leave them as is. Who ever did the foam job attached the foam to the up side of the woofer instead of the backside. It will not affect the sound but it is more of an aesthetic thing.

There are a few restoration sites out there for these classics speakers.
The work I am going to do is recap the crossovers, add 5 way binding posts, upgrade the internal wiring and refinish the veneer.

Here is a few links to other JBL L26 restoration jobs.

http://www.audiovintage.fr/leforum/viewtopic.php?t=14443

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



Tuesday, June 11, 2013

Genesis 22 speaker update

My Genesis 22 speaker modifications are now complete. In an attempt to extract more bass out of this speaker I removed the 8" passive radiator and wired in an EPI 100 woofer. I wired the woofer in directly off the terminal cap and let it run like an EPI 100 would.


The resulting bass response is deep yet punchy. A big improvement over the original set up.




Sunday, June 9, 2013

More bass from the Genesis 22 speakers

I am going to swap out the 8" passive radiator on the Genesis 22 speakers and install EPI 100 8' woofers to obtain more bass out of these gems.

I will bypass the crossover and hook them up directly to the terminal cup and let the upper end fall off like a pair of EPI 100's.

I will post how the results sound. Should be fun.





JBL L60t found a new home

The JBL L60t found a new home today. I will be on the lookout for another pair of "L" series JBL's. They are always welcome in my home.


Friday, May 24, 2013

Lab Series 3 found a new home

The Lab Series 3 found a new home this week, Mandi the Metal Queen will enjoy the double kick drums with 12" woofers.

I found that the bass on these speakers cleaned up a lot when elevated off the floor. The other thing that is great about 12" woofers is you feel the concussion of the base at high volume levels. I did not get fatigued with these speakers and the Philips domes really shined.




Thursday, April 25, 2013

EPI 70C

Before I re installed the Genesis woofers I wanted to run them in the EPI 70C's as the woofers in the 70C's are not original and do not do the speaker justice. The original EPI tweeters were donated to the Advent/EPI project.

The EPI 6.5 inch woofer is really well built and has a very long throw. The magnet structure is huge for such a small speaker.


Here is a picture of the EPI 70C's with the spare set of Epicure tweeters and original woofers. They sound fantastic for their size. I will have to keep my eye out for another pair of these woofers or maybe a pair of Dayton 6.5" woofer might work as well.