Modern replacement for 075 tweeter...

[thinktubes]

Hello all - I'm running a pair of vintage JBL C36 Viscounts (d130, 075, 2400 crossover). I like these speakers a lot; however, sometimes the 075 tweeter is just too much. The speakers' impedance is 8 ohms.

I'm would like to try a replacement tweeter that is less "beamy" and less fatiguing. Someone suggested that I try these:

B&C DE 35 (http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=294-580)

Overall I would like something just a tad smoother, and less directional.
My system is all tube, and I mostly listen to vinyl.

Thanks

[Zilch]

The recommended crossover is a full octave higher than what you have, and it looks like it's just as beamy as the bullet above 10 kHz.

BMS 4540nd and JBL 2408 will play low like you need; you just have to find a suitable horn. Will this fit?

http://www.eighteensound.com/index.aspx?mainMenu=view_product&pid=179

See also:

http://www.electro-voice.com/products/164.html

Also available 60° x 40°

http://www.electro-voice.com/products/163.html

Check if you have room for 2404H-1 behind the grille. JBL crossed it at 3 kHz in some products....

[pos]

here is the one I am using with my 2407H:
Dayton H45E
http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=270-314

[pos]

and here is John W's approach to it (post #2):
http://audioheritage.org/vbulletin/showthread.php?t=17617#post177863

[GordonW]

T
Check if you have room for 2404H-1 behind the grille. JBL crossed it at 3 kHz in some products....

I could never figure out why they called the crossover point 3KHz on the 2404, on stuff like the 4612 and such. If you do the math on the high-pass network on one of those, it's more like 5KHz... again, too high of a point to work well with a N2400.

Regards,
Gordon.

[Zilch]

here is the one I am using with my 2407H:
Dayton H45E
http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=270-314Minimum recommended XO 3.5 kHz, alas.... :dont-know

[pos]

The HO7E goes down to 2.2khz, but it would require some baffle adjustement:
http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=270-316

there is also a round version:
http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=270-308

[thinktubes]

Man - you guys are light years ahead of me when it come to this stuff!

If I were to use a horn like the one from parts express, I would have to get a driver to attach to it. More than likely, I would have to modify the cross-over? Any suggestions for a suitable driver?

What are the options for some kind of drop in replacement? How would a standard, non-horn type of tweeter fair in this setup? I beginning to think I might be in over my head on this one.

I wish I had the time to become a speaker tweaker. I already have a huge pile of tube amp and turntable projects to tackle.

Thanks for the help.

[robertbartsch]

Yeh, I added a pair of slot 077 tweeters to a 15 inch two-way system that had a compression driver and horn in the late 1970s. I also purchased the recommended JBL x-over for this project.

I owned this system for >30 years until my wife religated them to the basement and then, after a few years, we (UHG) sold them... which was a HUGE mistake. Today's HT speakers cannot touch them.

Anyway, until you mentioned it, I had forgotten about the impact of the 077 tweeter modification I made.

I retorspect, the mod was a tad harsh sounding - a tad too bright. In other words, the system probably sounded better without the 077s.

I saw a pair of 077s on E-bay recently for >600 USD. They cost about $300 without the crossovers in the 1970s, which was big money back then.

I would hang on to them, however.

[Beowulf]

An old custom system I took apart recently had some L300-style (HL91?) lenses in front of the 075s. I never did hear this setup with properly-working 075s . . . but it seems like it might work nicely. I still have the lenses kicking around if you'd want to give them a try . . .

[robertbartsch]

...yeh, I was discussing with a sound engeneer some possible component combinations for a couple of systems I am building.

He suggested a specific 12 inch JBL woofer and a 077 compression driver for rear channels in a HT!

I said, what about a mid-range driver and he said the 077 is sufficent and I would not need one with the woffer and 077.

I thought that was strange, but I not a professional sound engeneer.

[johnaec]

I said, what about a mid-range driver and he said the 077 is sufficent and I would not need one with the woffer and 077.According to JBL, recommended crossover for the 077, (equal to 2405H in Pro), is 7K or higher: http://www.jblpro.com/pub/obsolete/2405.pdf

Methinks he was getting the 077 confused with the 075, (2402H in Pro): http://www.jblpro.com/pub/obsolete/2402.pdf , which recommends 2.5K or higher.

I can't think of a single 12" speaker that's effectively useable up to 7K...

John

[Beowulf57]

I picked up a pair of 2405Hs ($300) and a pair of 3106 crossovers ($200) recently and after adding bypass caps to the HF section, they sound great. Neither harsh, not too bright and I run them with no attenuation. Mind you, I am using excellent quality tube amplification...with lower quality transistor gear I would anticipate harshness/brightness as these drivers are extremely revealing of your source and amplification.

[thinktubes]

I picked up a pair of 2405Hs ($300) and a pair of 3106 crossovers ($200) recently and after adding bypass caps to the HF section, they sound great.

What type and value of by-pass caps did you use?

It would like to give it a try. I just need to take a little of the edge off.+

I'm using tube equipement for both the preamp and power amp.

[Beowulf57]

What type and value of by-pass caps did you use?

It would like to give it a try. I just need to take a little of the edge off.+

I'm using tube equipement for both the preamp and power amp.

.01uF MIT multicaps

[speakerdave]

Since poster likes the classic JBL system he might try the JBL upgrade path of the era, some N1200's and classic JBL 1" horn/driver assembly like the 175DLH. Keep the 075's and build some N7000's to add them in higher up.

David