instead of re-foam, replace L-65 woofers with 128hs?

[bob wood]

Bought my L65s new in the mid-70s, and still love them. Woofers need to be re-foamed, but I'm thinking about switching to a set of 128hs that I see on eBay. Seems like a good idea, but anybody have any cautionary advice before I make the plunge? Thanks.

[evans224]

If you are thinking about the 128H-1's (black) on ebay-DON"T. The guy sells stuff way overpriced (check the L150A's for $1300), and these woofers are incorrectly re-foamed. I was looking for a spare set, and the pics he put up on ebay were suspicious looking, as in cut off on the edges. I had him send me more pics, and he still cut them off. Finally, he sent me some that I could see-he has the incorrect surround and there is glue everywhere.

[Triumph Don]

These don't look real good either.

http://pics.ebaystatic.com/aw/pics/s.gifhttp://pics.ebaystatic.com/aw/pics/s.gif128h jbl 12" woofers, cones are not as white as they should be, one has a metal label, the other doesnt. i done think it ever had one. in fine working condition
http://pics.ebaystatic.com/aw/pics/s.gifhttp://pics.ebaystatic.com/aw/pics/s.gifhttp://pics.ebaystatic.com/aw/pics/s.gifSelect a picture
http://i.ebayimg.com/22/!BQ2!BowB2k~$(KGrHgoH-CYEjlLl9odTBJ6-YneL3w~~_1.JPG

[Robh3606]

Bought my L65s new in the mid-70s, and still love them.

Than why monkey with them?? The L-65 went through 3 woofers the 126A, 122A and 129H. The 128H isn't on the list.

Rob:)

[bob wood]

Yep, I was looking at the white ones. The black ones seem way over-priced. The guy selling the white ones has 100% favorable ratings, and the price wasn't too high.

Do you guys know of a better (more reliable and affordable) source for the 128h's?

And, do you also think that the 129h's are worth pursuing, or should I just get mine re-foamed?

Appreciate your advice. Thanks.

[Triumph Don]

Than why monkey with them?? The L-65 went through 3 woofers the 126A, 122A and 129H. The 128H isn't on the list.

Rob:)

The 128 H1 is JBL's recomended replacement.

http://manuals.harman.com/JBL/HOM/Technical%20Sheet/L65%20Jubal%20ts.pdf

[Robh3606]

The 128 H1 is JBL's recomended replacement.

Yes but it is not an exact acoustic replacement. It says "No" That's why they reccomend you replace the pair.

The only time is "safe" to swap is when it says "Yes" there. Sure you can end up with a decent sounding speaker but it won't be the same.

You also need to check the other 2 techsheets for the other 2 versions. You don't know which L 65 he has unless you know which woofer it is.


Rob:)

[bob wood]

Thanks, Don, for providing the link to the JBL tech sheet. And, thanks, Robh for the cautionary remarks. Both helpful.

I've liked my L65's so much that I was simply curious if replacing the woofers with 128h-1's would be an improvement for the already quite good speakers. I've read some fairly glowing comments about the 128h-1's, and assume that I have 122's or 126's in my Jubals now.

I may have the current woofers refoamed AND find a pair of 128h-1's and do an audio test in my living room. That's probably the truest test, anyway.

So, do you guys know of a reliable and reasonable source for 128h-1's other than trying to find a pair on eBay?

Again, thanks for your help.

[Andyoz]

If you are thinking about the 128H-1's (black) on ebay-DON"T.

Just had a look at that guys photos and he certainly has an interesting "technique" there. Manages to only show about 25% of the cone clearly.....the rest is either in shadow or cropped. :blink:

[evans224]

eBay is your best bet. Be patient, because the 128h-1's (all black) aren't all that common. It looks like they are still available new at $397 apiece.....

[ROSSO]

Why don't you want to simply refoam the originals? Sounds like you were happy with them for many years in their original configuration. Simply changing to a different woofer may not produce a result you are happy with. Refoaming is easy to do with patience and not expensive, even reasonable if you pay someone to do it for you. Certainly cheaper than replacing the woofers.


Yep, I was looking at the white ones. The black ones seem way over-priced. The guy selling the white ones has 100% favorable ratings, and the price wasn't too high.

Do you guys know of a better (more reliable and affordable) source for the 128h's?

And, do you also think that the 129h's are worth pursuing, or should I just get mine re-foamed?

Appreciate your advice. Thanks.

[bob wood]

Rosso (is there a Ducati in Kentucky?): I'll go ahead and refoam what I think are 126A's in the speakers now. And, I'll find a pair of decent 128h-1's, too. Then, I'll sit down and listen to both permutations. I've heard the 128h-1's are a bit of an upgrade, so I'm curious.

I always enjoy improving good things. Cars, guitars, audio equipment. It's just fun.

Thanks for your comment, too. And, to you other guys, as well. This thread has been very helpful to me.

[Triumph Don]

Now that sounds like a plan! Please let us know your results.

[bob wood]

I don't know if anyone is interested, but I thought I would add some info that I just learned. I found a pair of used 128h-1s at a JBL service center, and am having them re-foam my 126s, install the 128h-1s, and go through the Jubals to check performance parameters. I'll do an A/B (126/128h-1) listening test in my room to hear the differences.

From what the guy said at the service center, the 128h-1s have a deeper spider that permits longer piston throw. The longer throw enables the speaker to reach lower notes and, potentially, provides a punchier bass slam. I found it interesting.

I'll update this thread after the listening test.

[Triumph Don]

I am very interested in your results/opinions!

[BROCKWOOD]

I am very interested in your results/opinions!

+1

[Doctor_Electron]

As long as the original crossovers' low-pass function is not totally off the map with the 128's, and you can reasonably readjust port tuning, why not?
I had Jubals, purchased new in 1976. Their bass was disapointing. I traded them for a pair of 4310WX and was more pleased with them.
Just about everything about driver selection and implementation on the 4310's was "wrong", but they sold well, so their sound wasn't so wrong.
Try everything (within reason) and hear how it works.

Just my $.02 :blah:

[duaneage]

I would run a simulation on the 128H woofers in WinISD and then do some testing with a meter and sig generator to see what the Fb and Vb are. The woofers are designed for vented applications but need to be properly tuned.

If they are more than 10% off you can adjust the tuning and box volume accordingly. Then the comparison will have more meaning. A 128H in an improper design will probably not sound as good as the other drivers properly loaded.