Adding an 077 to a LE-85 driver

[tjm001]

Way back in the mid 1960’s I purchased pairs of JBL LE-85’s, LE 15A’s and L-91 lenses. The last I used these was in a built-in system on each side of a brick fireplace wall. I removed them when the house was sold and they have been gathering dust since. Something I have always wondered about is what would they sound like if I added either a 075 or 077 tweeter to them? I guess the basis for this is because when I originally bought them what I really wanted was the three way system with the 375 driver, 075 and LE-15A’s but could not afford them at the time.

Over the last 10 years or so I have also procured pairs of 075’s, 077’s, LX5’s and N8000’s to gather dust alongside the LE-85’s and LE-15A’s. Now that I finally have the time I’m thinking of building some boxes to hold a three-way using the LE-85’s, LE-15A’s and 077’s. So my question is, do you think putting a LE-85 in the middle instead of a 375 is worth the effort? Has anyone done this?

[grumpy]

JBL has done this in rough concept a number of times:
15", 1"exit mid, ring radiator.

I'd guess you have the shorter horns H91/2307, so this
would probably be most like an augmented S7 setup.
Running a ported box, rather than a passive radiator
seems more common now. If the yellowish lansalloy
le15a surround has hardened, you might want to have
them taken care of... and you could consider moving
closer to an L300 system with woofer/network/horn
updates, but I like your idea of using "period" components
together.

The one thing I'd have in mind right off is goosing up
the bass/mid crossover point, but you might find you
like it as-is... which would save a lot of work.

Nice component set. It will be fun to see where you take it :)

[tjm001]

Way back in the mid 1960’s I purchased pairs of JBL LE-85’s, LE 15A’s and L-91 lenses. The last I used these was in a built-in system on each side of a brick fireplace wall. I removed them when the house was sold and they have been gathering dust since. Something I have always wondered about is what would they sound like if I added either a 075 or 077 tweeter to them? I guess the basis for this is because when I originally bought them what I really wanted was the three way system with the 375 driver, 075 and LE-15A’s but could not afford them at the time.

Over the last 10 years or so I have also procured pairs of 075’s, 077’s, LX5’s and N8000’s to gather dust alongside the LE-85’s and LE-15A’s. Now that I finally have the time I’m thinking of building some boxes to hold a three-way using the LE-85’s, LE-15A’s and 077’s. So my question is, do you think putting a LE-85 in the middle instead of a 375 is worth the effort? Has anyone done this?

Thanks for the info. I appreciate it and am now inspired to start building some boxes. My only hesitation at this point is whether to use my existing H91 horns or to look for a couple of the longer H92’s. Am I correct in assuming that was the reason you mentioned the possibility of goosing up the bass/mid crossover point? Thanks.

[Mr. Widget]

Go for it with what you have... I would use the 077s. I would also suggest avoiding the JBL crossovers entirely, but if building your own networks isn't your thing then whip up some 5 cubic foot boxes tuned to 30 Hz and enjoy.


Widget

[grumpy]

I'd rather hear the bass driver up a bit higher and less of the horn down there, that's all. Personal preference.

For a turnkey set, use as-is. Should still sound great :) Futz with it later if you like.

[donsof]

I was fortunate to land these same components and used them this way.
Started with LE-15s and LE85s with LX5.
I reconed the LE-15 with 8 ohm cones.
Then learned the LX5 crossover is not right for this setup.
So I switched to 3110A crossovers, which spec out at 16 ohm HF and 8 ohm LF, crossover at 800Hz

I later learned all the good home HIFI, LF JBLs are the foam surround type.
The guys here will tell you the 2235 / 2231 woofers are as good as alinco LE-15s.
I would say this is true.

For me, I wanted the mid century looking, C36 or C35 cabinets.
I used my stuff as two way only in some C36 cabinets, with several horn setups.
Its not supposed to be right, to use this small of a box, which is appx 2.7 cubic feet.
However, It sounds pretty good this way.
I want the original C36 look, so I am currently with LE-85s and potato mashers.

I have looked at Widgets and Wardswebs custom builds, and like them alot.
But with a little looking, you can get some empty C36 boxes for under 400 online.
A set turn up every other month.
A set of C35s would be better suited for 3 way, as there is more room inside.
I suppose the tweeter could sit on top of the C36's

I have a hard time dedicating more than 22 inches of floor space width.
You can get some pretty good boxes already done, and pretty too.

these were good reads for me
http://www.audioheritage.org/vbulletin/showthread.php?7140-LE15A-375-075-Box-Design

http://www.audioheritage.org/vbulletin/showthread.php?5951-Wood-Horn-3-way&highlight=wood+horn+3-way

http://www.audioheritage.org/vbulletin/showthread.php?166-4333-S300-L300-equivalent-bandbass-circuit/page2&highlight=2231A+woofer

This setup is to die for... how are these working out for the lucky owner?
http://www.audioheritage.org/vbulletin/showthread.php?10692-quot-The-Widgets-quot-update&highlight=wardsweb


thanks to the forum for all the help! I took the easy way out.
Don

[audiomagnate]

Thanks for the info. I appreciate it and am now inspired to start building some boxes. My only hesitation at this point is whether to use my existing H91 horns or to look for a couple of the longer H92’s. Am I correct in assuming that was the reason you mentioned the possibility of goosing up the bass/mid crossover point? Thanks.

I think the longer 92 horn is a worthwhile upgrade. Why compromise? I don't know about "goosing up" anything, it just sounds better to my ears, and makes better use of the driver.

[Mr. Widget]

My very first pair of JBLs were S7s... I know them and their limitations well.

I guess my rationale is to just get them going and start enjoying them... yes you can upgrade here and there with numerous minor improvements along the way. I suggest you decide if you want to spend time enjoying building and tweaking speakers or spending your time enjoying listening to them.

I've done both and have taken great pleasure in messing about with DIY projects that seemed to take forever and also have left vintage speakers in their original state realizing their warts and enjoying them as is.


Widget

[tjm001]

Thanks to all for the additional info. Unless someone convinces me otherwise this is what I have decided to do. I will construct boxes with the general dimensions and shape of the L300 Summit boxes using the components I have. Then I can tinker with different crossovers, horns, etc. later. My only concern now is what material to use for the boxes. I really hate working with 1 inch MDF because of its weight. I realize this can be an acoustical advantage, but you will need a crane to move these things with 1 inch MDF. I was thinking of using ¾ inch cabinet grade walnut or cherry plywood with screwed and glued oak bracing strips on the inside of the panels. What do you think? Thanks.

[Mr. Widget]

I think your plan makes a lot of sense… I agree about the 1 inch MDF it is a serious pain. If possible use preveneered MDF core with a lot of bracing. I wouldn't use hardwood for the internal bracing unless you really want to. I find KD fir works quite well and is easier to work with.


Widget

[tjm001]

Thanks. The main reason I mentioned using oak as bracing is because I have a bunch of it left over in my shop. But my big question now is what are the dimensions of the L300? I keep finding this incomplete thread from this guy in the Netherlands (jdelange) in 2008 to a guy in Texas (mbottz), but no one seems to have followed up with the dimensions. Anybody know what they are? Thanks.

[tjm001]

This is the post I was referring to:


http://www.audioheritage.org/vbulletin/showthread.php?20230-Need-L300-dimensions

[Mr. Widget]

If no one chimes in with the information that you need, I would suggest starting a new thread titled: "L300 Information Needed" or something like that… There's a lot of interest in L300s you will probably get more eyes on it.

Good luck.

Widget

[Odd]

This is from a previous thread.

Something is missing, someone here with L300 add the missing measurement?

[highcut28]

to simplify construction u might consider the cuboid 4333 which is the studio version of the L300

[Doc Mark]

Good Morning, Odd,

Are you looking for porting info on the L300's? The ports on mine measure 4" long (from the baffle front), and 4.085" across. If you need something else measured, please let me know what you want, and I'll do my best to supply that information for you. Take care, and God Bless!

Every Good Wish,
Doc

[Odd]

Hi Doc

It is not for me, I try to help member tjm001

Attached Image in post 14 is a good start to collect all missing dimensions for L 300

[Doc Mark]

Morning, Odd,

Sorry, I got confused in my reply! Hope all is well with you, and God Bless!

Doc

[tjm001]

I guess I was not honored

[Doc Mark]

Hi, tjm001,

I sent an answer that I thought you are needing. If the porting info is not what you need, please let me know what dimension you are seeking, and I'll do my best to help. Take care, and God Bless!

Every Good Wish,
Doc