Super cool Altec JBL speaker find
- Thread starter musiqlovr
- Start date
musiqlovr
Well-Known Member
I'll put up some pics tomorrow. I did get the woofers installed, there are moments of pure excellence but...they definetly need some work. I am going to let the foam surround break in for a week or so of action. I suspect the N500e crossovers are the current weak link... previous owner says no updates and he never opened the crossovers. So we probably have 50 year old caps.
While breaking in the woofer, I am going to research crossover schematics. The N500e is 16 ohm, which I think means on an 8 ohm woofer and compression driver it is currently at 250hz! I may have the match wrong but I think I am correct. Since both drivers are 8 ohm, this crossover is not ideal. I think I'd like to be somewhere in the 500-700hz range for crossover frequency.
I must say, Miller Sound was incredible! The work is amazing, woofers look new! And the people at Miller Sound are wonderful to talk to...
While breaking in the woofer, I am going to research crossover schematics. The N500e is 16 ohm, which I think means on an 8 ohm woofer and compression driver it is currently at 250hz! I may have the match wrong but I think I am correct. Since both drivers are 8 ohm, this crossover is not ideal. I think I'd like to be somewhere in the 500-700hz range for crossover frequency.
I must say, Miller Sound was incredible! The work is amazing, woofers look new! And the people at Miller Sound are wonderful to talk to...
Looking forward to pics. Glad they turned out so nice! And yes, those caps certainly would benefit from a refresh.
musiqlovr
Well-Known Member
Ju
Just out of curiosity, what is not suitable about the 515?
bowtie427ss
Lunatic Member
515(with the exception of 515E) was optimized as a horn driver, and is best suited to a large bass horn like the 210/211 or similar. It's very powerful motor precludes it from making natural sounding low bass in a typical reflex box. The 416 is much better suited to such duty and will have better/smoother low frequency extension in a typical size bass reflex cabinet.
Very interesting, bowtie427ss. Thanks!
bowtie427ss
Lunatic Member
musiqlovr
Well-Known Member
Some pics and @BillWojo crossovers...
Sounds so much better with Bill’s crossovers vs the N500e crossovers.
Can anyone help adapt the model 19 type
Crossover that Bill built (in the pictures) to a lower crossover frequency? I know the inductors need to change but assuming the caps and resistors must change too?
Sounds so much better with Bill’s crossovers vs the N500e crossovers.
Can anyone help adapt the model 19 type
Crossover that Bill built (in the pictures) to a lower crossover frequency? I know the inductors need to change but assuming the caps and resistors must change too?
musiqlovr
Well-Known Member
Thanks, active I am not interested in. I want to keep the preamp/amp combo simple and use what I have...I love my Shindo separates...I've heard nothing better
musiqlovr
Well-Known Member
These aren’t my crossovers (Bill is letting me borrow them)....I think the issue is the other inductors are not correct? Meaning they are for a higher frequency (Model 19).
Do you happen to have a schematic that might work?
Nice to have Bill in the neighborhood, super cool and generous dude!
I looked around when I was building the Z19 crossover for my Votts and could not find any threads where anyone had adjusted the crossover for a lower hi-pass frequency optimized for 511b horns. I have my speakers setup using the 511b horns using the standard Z19 at the moment and they sound quite good. I also bought a minidsp to experiment with, but I haven't had much time to play with lower hi-pass frequencies.
I looked around when I was building the Z19 crossover for my Votts and could not find any threads where anyone had adjusted the crossover for a lower hi-pass frequency optimized for 511b horns. I have my speakers setup using the 511b horns using the standard Z19 at the moment and they sound quite good. I also bought a minidsp to experiment with, but I haven't had much time to play with lower hi-pass frequencies.
For a new point ( of say @ 800hz ) simply multiply the following cap & coil values of ( C1, C2, C3, L2, L3 ) by 1.5 .
Your new values ( rounded to somewhat available component values will be ( 12uF, 24uF, 32uF, 4mH, + 1.2mH ) .
These will get you in the ball park, after which you'll need to adjust to taste ( ie' some tweaking of values is required ).
Use something like REW to capture the frequency response to help find the problem areas to then give an idea of what values need adjusting.
- ( IOW, you'll need to do a lot of the leg work ).
Most of the greatest errors of your new network will be from the substitute woofer ( the JBL ) as well as from using the larger 511 horn
( which puts the "Z-axis" // Voice-coil offset, at a greater distance than between the 811/802 + the 416-8B ).
Without out some real data it's impossible predict how good or bad these values will work for you.
Eventually you'll likely want to add a tweeter to address the anemic HF response of the 807 driver ( above 7 -10K ) or get a pair of 802-8G's.
<> EarlK
BTW, Bills work on his custom 1201 is masterful !
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Have you looked for some inspiration from Luthers ( Wardwebs ) thread ?
- ( his custom speakers use a similar set of Altec + JBL components to yours )
See ( click the pic for the thread link ) ;
He looks to have used for his crossover values ( woofer + horn ) the basic values of Altec's N809-8a network .
He's used these passive values for over a decade now and is obviously quite happy with the result since I believe he used the same values when he upgraded to uber expensive parts ( which says quite a lot IMHO )
- you might consider asking him directly exactly what values he used.
- ( his custom speakers use a similar set of Altec + JBL components to yours )
See ( click the pic for the thread link ) ;
He looks to have used for his crossover values ( woofer + horn ) the basic values of Altec's N809-8a network .
He's used these passive values for over a decade now and is obviously quite happy with the result since I believe he used the same values when he upgraded to uber expensive parts ( which says quite a lot IMHO )
- you might consider asking him directly exactly what values he used.
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musiqlovr
Well-Known Member
For a new point ( of say @ 800hz ) simply multiply the following cap & coil values of ( C1, C2, C3, L2, L3 ) by 1.5 .
Your new values ( rounded to somewhat available component values will be ( 12uF, 24uF, 32uF, 4mH, + 1.2mH ) .
These will get you in the ball park, after which you'll need to adjust to taste ( ie' some tweaking of values is required ).
Use something like REW to capture the frequency response to help find the problem areas to then give an idea of what values need adjusting.
- ( IOW, you'll need to do a lot of the leg work ).
Most of the greatest errors of your new network will be from the substitute woofer ( the JBL ) as well as from using the larger 511 horn
( which puts the "Z-axis" // Voice-coil offset, at a greater distance than between the 811/802 + the 416-8B ).
Without out some real data it's impossible predict how good or bad these values will work for you.
Eventually you'll likely want to add a tweeter to address the anemic HF response of the 807 driver ( above 7 -10K ) or get a pair of 802-8G's.
<> EarlK
BTW, Bills work on his custom 1201 is masterful !
This is awesome! Thank you. Reading now...