Anomalous L80T?

[brutal]

I picked up a pair of nearly flawless L80T today for $150.

Noticing what seemed like an 035TiA (plastic face) on both, I was a bit perplexed and thought maybe the OE had replaced the 035TI drivers that should have been there per JBL's lit. After getting them home and digging into all the drivers, it seems JBL might have put together some late model L80T during the period they should have been shipping L80T3's. :dont-know

All the drivers except one 104H-2 have date stamps of Month 1989. I verified the x-over is the L80T design. Serials are 18090 and 18524

I've read about extending the port tube 2" to improve the LF response, wondering if picking up a set of L80T3 x-over is worth the trouble. These and a set of L20T I'm sprucing up may replace the SVA1600 and HLS610 sets doing HT duty in my BR. I haven't actually fired the L80T's up yet, so it will be interesting to see how they sound after reading some of the comments on them here.

Thoughts? Comments?

[SEAWOLF97]

I bought a nice pair about 2 mos. ago for $100. They are virtually the same driver load as 4410's , but I find them overly bright and could not run them alone (no pot controls) , just filling in as SR rears for the Walsh's.
The componets are worth more than the whole speakers....

[brutal]

I normally EQ everything so if they go into the BR, I might just have to drop some more gear in there...

Else, I do have a few LPADs laying around and could attenuate that little bugger like I've seen mention of.

[hjames]

I've got 4 L60Ts right now, all have the 035Tia tweeters, instead of the 035TI tweeters I had expected. So I had planned to improve the L20Ts but when I opened one of the L20T, I found it too had the improved tweeter ..
I didn't change any of them - maybe thats why Seawolf found them shrill - if they had the old crossover design but a hotter tweeter?

I picked up a pair of nearly flawless L80T today for $150.

Noticing what seemed like an 035TiA (plastic face) on both, I was a bit perplexed and thought maybe the OE had replaced the 035TI drivers that should have been there per JBL's lit. After getting them home and digging into all the drivers, it seems JBL might have put together some late model L80T during the period they should have been shipping L80T3's. :dont-know

All the drivers except one 104H-2 have date stamps of Month 1989. I verified the x-over is the L80T design. Serials are 18090 and 18524

I've read about extending the port tube 2" to improve the LF response, wondering if picking up a set of L80T3 x-over is worth the trouble. These and a set of L20T I'm sprucing up may replace the SVA1600 and HLS610 sets doing HT duty in my BR. I haven't actually fired the L80T's up yet, so it will be interesting to see how they sound after reading some of the comments on them here.

Thoughts? Comments?

[BMWCCA]

The tweets in my L20T's, while still plastic faced, are stamped 035TI, no "A". I pulled them just to check (and for another coat of Feed 'n Wax). Now the 4412A has a metal face on it's nearly identical 052TI's which would appear to be a much more expensive way to build them. For the sake of discovery, the serial number on one of my 035Ti-equipped (non-A) L20T is J001-10839 if anyone can turn that into a date-of-manufacture. Perhaps the tweeter had a date on it, but if it did I didn't record it. Interesting.

[SEAWOLF97]

OK , you made me look ...

mine are 035TI ....no "A"

[hjames]

biZARRE!!@

[brutal]

I've got 4 L60Ts right now, all have the 035Tia tweeters, instead of the 035TI tweeters I had expected. So I had planned to improve the L20Ts but when I opened one of the L20T, I found it too had the improved tweeter ..
I didn't change any of them - maybe thats why Seawolf found them shrill - if they had the old crossover design but a hotter tweeter?

I thought they spec'd out the same freq response-wise, but the metal framed version had a heavier magnet and tended to be smoother.

[BMWCCA]

OK , you made me look ...

mine are 035TI ....no "A"

Plastic, or metal?

[brutal]

The tweets in my L20T's, while still plastic faced, are stamped 035TI, no "A". I pulled them just to check (and for another coat of Feed 'n Wax). Now the 4412A has a metal face on it's nearly identical 052TI's which would appear to be a much more expensive way to build them. For the sake of discovery, the serial number on one of my 035Ti-equipped (non-A) L20T is J001-10839 if anyone can turn that into a date-of-manufacture. Perhaps the tweeter had a date on it, but if it did I didn't record it. Interesting.

...runs to check already pulled L20T drivers...

Hot damn, they're plastic faced 035TI. Date coded 11 4 85 and 1 23 86

Too bad someone painted them with glossy spray paint. WTF?

So was it only the 044Ti, 046Ti and 052Ti that were all metal Ti drivers?

I just checked the L80T vs L80T3 spec sheets and the freq resp is listed 35-32K and 40-27K respectively. How does that make the T3 network better? And what then is the real freq resp of the L80T if it has the 035Tia driver as opposed to the 035Ti driver listed in the specs? I realize it probably tones down the harshness a bit, but why the loss at the bottom end?

I've tried to find detailed specs here to compare all these drivers but I must be looking in the wrong place. There certainly still is a lot of conflicting info on our beloved JBL's. There's even a 1984 GT tech sheet listing the 250Ti as having an 033Ti driver... I thought that only went into the TBQ later in life?

[duaneage]

Far more knowledgeable people than me have stated here the 035Ti and the 035Tia are identical in performance, but different in lead position.

THe Txx3 networks changed the midrange response to be more "forward", whatever that translates to. You could sub out the parts on one network with the difference and decide for yourself which you prefer.

[BMWCCA]

So was it only the 044Ti, 046Ti and 052Ti that were all metal Ti drivers?

I just checked the L80T vs L80T3 spec sheets and the freq resp is listed 35-32K and 40-27K respectively. How does that make the T3 network better? And what then is the real freq resp of the L80T if it has the 035Tia driver as opposed to the 035Ti driver listed in the specs? I realize it probably tones down the harshness a bit, but why the loss at the bottom end?

Everything with the 035Ti is listed to 32k, the 035TiA to 27k, and the 052Ti to 30k. In my stuff, L20t shows 45-32k, L5 35-27k, and 4412A 30-30k. So even the tiny woofers on the L5 get lower than an L80t3 with the same tweets——according to the specs. That's odd. And that the tinier L20t gets that close, is remarkable. Oddly enough, the L20T3 also drops bottom end, being rated at 55-27k. Seems like somebody screwed up on the T3s, or did they change how they measured response? Seems like only the L1, L3, L5, and L7 kept the bottom end while using the 035tiA.

[duaneage]

I'd guess it was probably a difference in how they are measured. The same woofer in similar box with the same tuning would perform at the bottom end the same. The crossover would have little to do with LF cuttoff. The high end is also a testing matter. Considering human hearing falls off about 20K (15K for us old fogeys) I would not see a dimes worth of difference (although my dog might) and would focus on the differences in midrange performance, driver to driver phase transistions, and lobing from the HF and MR.

Crossovers can affect the dispersion a lot by changing the amount of overlap the drivers have, and at what frequency.

[johnaec]

The 052Ti is not metal - it's plastic. And both the 035Ti and 035TiA are plastic, and have the same size magnets. Some 035Ti's and 035TiA's even have the leads in the same place, (changeover period?): http://audioheritage.org/vbulletin/s...35&postcount=5

John

[brutal]

The 052Ti is not metal - it's plastic. And both the 035Ti and 035TiA are plastic, and have the same size magnets. Some 035Ti's and 035TiA's even have the leads in the same place, (changeover period?): http://audioheritage.org/vbulletin/s...35&postcount=5

John

Good info.

I also saw this http://audioheritage.csdco.com/vbull...7&postcount=12 measuring chart that would seem to indicate by the measured Q's why the 035TiA is considered "hot," although a read through of the full thread here: http://audioheritage.org/vbulletin/s...38844#poststop where Widget actually measured during a "tweeterfest" would seem to indicate that they measure nearly identical - although he didn't show the harmonics for the TiA.

I think I'll definitely be looking at running an LPAD between the XO and the 035TiA to tame them down a bit if needed - once I have a listen for myself.

Cheers!